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Forestt (and) PrimatesConservationn and ecology of theendemicc primates of Java andBorneo oVincentt NijmanTropenbos-Kalimantann Series 5

Forestt (and) PrimatesConservationn and ecology of theendemicc primates of Java and Borneo

ISBNN 90-5113-052-XISSNN 1566-6522©© Tropenbos InternationalThee opinions expressed in this publication are those of the author(s) and do not necessarily reflect theviewss of Tropenbos InternationalAlll rights reserved. No part of this publication, apart from bibliographic data or brief quotations incriticall reviews, may be reproduced, re-recorded or published in any form including print,photocopy,, microfilm, electronic or electromagnetic record without written permission.Coverr photo :Printedd byMale proboscis monkey Nasalis larvatus, a Bornean endemic, in degraded forestalongg the Mahakam River, East Kalimantan (photo: G.M. Frederiksson).Drukkerij Ponsen en Looijen B.V., Wageningen, the Netherlands

ForestForest (and) PrimatesConservationn and ecology of theendemicc primates of Java and BorneoAcademischh proefschriftterr verkrijging van de graad van doctoraann de Universiteit van Amsterdam,opp gezag van de Rector Magnificusprof.. dr. J.J.M. Fransetenn overstaan van een door het college van promoties ingesteldecommisiee in het openbaar te verdedigen in de Aula der Universiteitopp dinsdag 25 september 2001 te 10.00 uurdoor rVincentt Johannes Nijmangeborenn te Oudorp

Promotor::Overigee leden:Prof. dr. S.B.J. MenkenHoogleraarr EvolutiebiologieProf. dr. F. SchramProf.. dr. W. AdmiraalProf.. dr. H.H.T. PrinsDr.. H.H. AlbrechtDr.. H.D. RijksenDr.. T. GeissmannFaculteit: :Natuurwetenschappen,, Wiskunde en Informatica

Harapp tenang"I

TABLEE OF CONTENTSLISTT OF TABLES AND FIGURESACKNOWLEDGEMENTS SChapterr 1 Forest and primates, a general introduction to the conservation ofendemicc primates in the Sundaic region 1SECTIONNI. BACKGROUND AND SURVEY METHODOLOGYChapterr 2Chapterr 3Chapterr 4Chapterr 5Density and biomass estimates of gibbons (Hylobates muelleri) inBorneann rainforest: a comparison of techniques 13WithWith Steph B.J. MenkenEffects of behavioural changes due to habitat disturbance on densityestimationn of rain forest vertebrates, as illustrated by gibbons(Primates:: Hylobatidae) 33Pp.. 217-225 in: P.J.M. Hillegers and H.H. Iongh (eds.) (2001).TheThe balance between biodiversity conservation and sustainable useofof tropical rainforests. The Tropenbos Foundation, Wageningen,thee Netherlands.Calling behaviour of wild Javan gibbons Hylobates molochinn Java, Indonesia 43WithWith Thomas GeissmannGeographical variation in pelage characteristics in grizzled leafmonkeyy Presbytis comata (Desmarest 1822)(Mammalia:: Primates: Cercopithecidae) 61ZeitschriftZeitschrift für Sdugetierkunde 62: 257-264, 1997SECTIONN II: STUDIES ON ENDEMIC PRIMATES OF JAVAChapterr 6Chapterr 7Occurrence and distribution of grizzled leaf monkey Presbytis comata(Desmarestt 1822) (Mammalia: Primates: Cercopithecidae)onn Java, Indonesia 71ContributionsContributions to Zoology 66:247-256, 1997Geographical distribution of ebony leaf monkey Trachypithecusauratusauratus (Geoffroy Saint Hilaire 1812)(Mammalia:: Primates: Cercopithecidae) 83ContributionsContributions to Zoology 69: 157-177, 2000

Chapterr 8A faunal survey of the Dieng mountains, Central Java, Indonesia:statuss and distribution of endemic primate taxa 115WithWith S. (Bas) van Balen, Oryx 32: 145-156, 1998SECTIONN III: STUDIES ON ENDEMIC PRIMATES OF BORNEOChapterr 9Distribution and conservation of the proboscis monkeyNasalisNasalis larvatus in Kalimantan, Indonesia 129WithWith Erik Meijaard, Biological Conservation 92: 15-24, 2000Chapterr 10 The local extinction of the proboscis monkey Nasalis larvatus inPulauu Kaget Nature Reserve, Indonesia 145WithWith Erik Meijaard, Oryx 34: 66-70, 2000Chapterr 11 Patterns of primate diversity on Borneo and selection of priorityareass for conservation 153WithWith Erik MeijaardSECTIONN IV: SYNTHESISChapterr 12 Re-assessment of IUCN conservation status of the endemicprimatess of Java and Borneo 169Chapterr 13 General discussion 183Summary:: Forest (and) primates: conservation and ecology of endemicprimatess on Java and Borneo 197Ringkasan:: Hutan (dan) primata: ekologi dan pelestarian primata endemik diJawadann Kalimantan 199Samenvatting:: Bos (en) primaten: bescherming en ecologie van endemischeprimatenn op Java en Borneo 201Referencess 205Curriculumm vitae 231Listt of publications 233

LISTT OF TABLES AND FIGURESLISTT OF TABLESTablee 1.1 Endemic primates on Borneo and Java and their IUCN threat status 5Tablee 1.2 Selected study sites on Borneo and Java where long-term studiesonn endemic primates have been conducted 8Tablee 2.1 Density and biomass estimates for Bornean gibbonHylobatesHylobates muelleri for two areas in East Kalimantan, Indonesia 23Tablee 2.2 Two-way Analysis of Variance of density estimates inBorneann gibbon Hylobates muelleri 25Tablee 3.1 Behavioural responses of two gibbons species to an observerinn disturbed versus undisturbed habitats 37Tablee 3.2 Number of days Hylobates moloch groups were heard callingatt different times of the day 39Tablee 5.1 Pelage characteri sties of grizzled leaf monkey Presbytis comata 66Tablee 6.1 Study sites on the island of Java, Indonesia 76Tablee 6.2 Localities with records of grizzled leaf monkey Presbytis comata 77Tablee 8.1 Javan gibbon, grizzled leaf monkey and ebony leaf monkeyobservedd in the Dieng mountains 122Tablee 8.2 Estimates of the numbers of Javan gibbon present at thedifferentt vegetation zones on the Dieng mountains followingthee assumptions of Supriatna et al. (1994) 124Tablee 8.3 Estimates of the numbers of Javan gibbon present in thedifferentt vegetation zones on the Dieng mountains usingthee assumptions of Kappeler (1984) and Asquith et al. (1995) 125Tablee 8.4 Endemic and restricted range bird species recorded in theDiengg mountains 127Tablee 9.1 Priority areas for the protection of proboscis monkeysNasalisNasalis larvatus in Kalimantan, Indonesia 134Tablee 9.2 Proboscis monkey Nasalis larvatus habitat (km 2 ) in Kalimantan(afterr MacKinnon etal., 1996) 135Tablee 10.1 Summary of the numbers of proboscis monkeys involved in thePulauu Kaget translocation 150Tablee 11.1 Centers of endemism or species-richness in northern Borneo 155Tablee 11.2 Habitat and altitudinal limits of the primates of Borneo 157Tablee 11.3 List of large reserves that rank(ed) among the highest inprimatee species richness 164Tablee 12.1 Estimates of densities of grizzled leaf monkey Presbytis comatainn Java 172Tablee 12.2 Densities of white-fronted leaf monkey Presbytis frontatainn Borneo 174Tablee 12.3 Estimated number of Javan gibbons Hylobates moloch presentinn Java 179

LISTT OF FIGURESFiguree 2.1 Bornean gibbon Hylobates muelleri in Sungai Wain protection forest 15Figuree 2.2 Location of Kayan Mentarang National Park andSungaii Wain protection forest on Borneo 18Figuree 3.1 Percentage of canopy use by two gibbon species in disturbedandd undisturbed habitats 38Figuree 4.1 Map of Java showing the remaining forest areas inhabited bygibbonss showing Ujung Kulon and the Dieng mountains 46Figuree 4.2 Sonagrams of representative phrases of female songs, femalescreamm calls, communal group calls, and male phrases 49Figuree 4.3 Frequency distribution of the starting time of gibbon song boutsonn Java 53Figuree 4.4 Frequency distribution of the song bout duration during111 consecutive days in Linggo Asri 54Figuree 5.1 Geographical variation in pelage characteristics in grizzledleaff monkey Presbytis comata 65Figuree 6.1 Geographical distribution of grizzled leaf monkeyPresbytisPresbytis comata, on Java, Indonesia 78Figuree 7.1 Geographical distribution of ebony leaf monkeyTrachypithecusTrachypithecus auratus on Java, Bali, and Lombok, IndonesiaFiguree 7.2 Melanic pelage morph of ebony leaf monkeyTrachypithecusTrachypithecus auratus 1Figuree 7.3 Three individuals of the erythristic pelage morph of ebonyleaff monkey Trachypithecus auratus 111Figuree 7.4 Melanic and erythristic pelage morph of ebony leafmonkeyy Trachypithecus auratus 111Figuree 8.1 The Dieng mountains, Central Java, Indonesia 317Figuree 8.2 A view of the lowland forests near Linggo, Dieng mountains,Centrall Java, with on the foreground areas clearedforr wet rice fields 119Figuree 9.1 Area covered during the 1994- 1997 survey 131Figuree 9.2 The 153 recent records of proboscis monkey Nasalis larvatusonn Borneo 133Figuree 9.3 The land use planning in Central Kalimantan, Indonesia, basedonn forest use classification (TGHK) maps 137Figuree 10.1 The island of Borneo (insert) and the location of Pulau Kagetandd adjacent islands 146Figuree 10.2 Male proboscis monkey in illegal private captivity 147Figuree 10.3 Former prime proboscis monkey Nasalis larvatus habitat onPulauu Kaget 149Figuree 11.1 Geographical distribution of white-fronted leaf monkeyPresbytisPresbytis frontata 159Figuree 11.2 Geographical distribution of Bornean leaf monkeyPresbytisPresbytis hosei 160Figuree 11.3 Geographical distribution of Bornean gibbonHylobatesHylobates muelleri 161Figuree 11.4 Pattern of primate diversity on Borneo 162Figuree 11.5 Pattern of endemic primate diversity on Borneo 163Figuree 13.1 Relationship between island size and number of primate speciesinn the Sundaic region 189Figuree 13.2 Relationship between island size and number of endemicprimatee species in the Sundaic region 190

ACKNOWLEDGEMENTS SAss with any study that stretches over several years it will be hard to acknowledgealll those who helped me by word and deed. The only way I could think ofexpressingg my appreciation for all those who have helped and supported me withoutforgettingg anybody would be by a simple 'thank you all'. While running the risk offorgettingg those who deserve mentioning, in order to make these acknowledgementsslightlyy more personal, I will nevertheless make an attempt to thank peoplepersonally. .Firstt of all I would like to thank my promoter Professor Steph Menken fortakingg on this project, and for his support over the last few years; this extends to myformerr supervisors in Amsterdam, Dr Jan Wattel and Dr Peter van Bree. I also wishtoo thank my scientific counterparts in Indonesia for their help: Iwan Setiawan, AndiPrimaa Setiadi, and Dr Dewi M. Prawiradilaga.Thee Indonesian Institute of Sciences (LIPI), the Directorate General for ForestProtectionn and Conservation (PKA, formerly PHPA) and the Ministry of Forestryandd Estate Crops (MOFEC, formerly MoF) allowing me to carry out the surveysandd to conduct my research. In the field I was not rarely assisted and guided byPHPAA officers for which I express my gratitude.Althoughh I spent considerable time in the forest on my own, I greatlyappreciatee the times others joined me while climbing mountains and walkingthroughh the forests. I like to mention Bas van Balen, Gabriëlla Frederiksson,Thomass Geissmann, Asep Purnama, Andi Prima Setiadi, Iwan Setiawan and ResitSözer.. Gabriella is thanked for providing an excellent shelter in Sungai Wain, andforr good talks. Visits to Bas and Like in Bogor and Resit and Ana in Sukabumimadee the hectic life in the city more bearable.Inn Indonesia I received support from a large number of people and institutions.Myy thanks go to the directors and staff at Puslitbang Biologi and Museum ZoologiBogor:: Dr Soenartono Adisoemara, Dr Soetikno Wirjoatmodjo, Dr SampoernoKadarsan,, Drs M. Amir, Dr Dewi M. Prawiradilaga, Dr Arie Budiman, and DrsBoeadi;; at the division of Inter-institutional cooperation of LIPI: Dewi Soenarijadi,Krisbiwati,, Mangembang Tarihoran, Sophie Muzwar, and Ina Syarief; at FFI-Indonesia:: Dr Jito Sugarjito; at the BirdLife International Indonesia Programme inBogor:: Paul Jepson, Richard Grimmett, Colin Trainor, Ria Saryanthi, Rudyanto,Sujatnika,, Wara Hapsari, Iwan Setiawan, Yusup Cahyadin, and all the others; atWWF-Indonesia:WWF-Indonesia: Tim Jessup, Ron Lilly, Barita Manullang, and A. PurnomoMOFECC Tropenbos: Bas van Helvoort and Tinus de Kam.Workingg with various NGO's on Java was a pleasant way of getting morepeoplee involved in the conservation of forest and forest animals. I like to thank all atKutilangg IBC, Yogyakarta; KSBK, Malang; YPAL, Bandung; Konus, Bandung;NGO-movement,, Bogor; KIH, Semarang; CIBA, Cibodas; Mitra Dieng, Pekalonganandd Semarang, and I wish you all the best with your future work. Thanks to ResitSözer,, Bas van Balen and Ria Saryanthi for their help in preparing the Indonesiansummariess at short notice.Inn the Netherlands it was always a pleasure to work at number 61: Wouter Los,Tinekee Prins, Kees Roselaar, Jan Wattel, Peter van Bree, Wim Bergmans, ArneMooers,, Danielle Kreb, Martjan Lammertink, Willemijn Prast, Kees Hazevoet,

Resitt Sözer, Rutger Vos and all the others are thanked. Working at the Departmentoff Animal Behaviour has always been a delight. The support of Dr Helmut Albrechtass former head of the department and sharing his views on research, conservation,andd life in general are greatly appreciated. The other ethologist in Amsterdam, DrBoudewijnn Heuts introduced me to the hidden pleasures of statistics andexperimentall design for which my thanks. This extends to all the students whoparticipatedd in SP 240 Animal Behaviour and to those who chose to conduct theirfieldd work with the department; I probably learned as much from them as they fromme. .Myy sincere thanks go to the mammal curators of the Zoological MuseumAmsterdamm (Dr. P.J.H. van Bree), Zoological Museum Bogor (Drs Boeadi),Nationall Museum of Natural History, Leiden (Dr C. Smeenk), British Museum forNaturall History, London (Dr P. Jenkins), and the Zoological Reference Collection(Drr CM. Yang, Prof. dr. P. Ng) for allowing me to examine specimens in thecollectionss under their care, and for help of various sorts.Almostt half of the chapters included in this thesis are co-authored by others,viz.,, Steph Menken, Thomas Geissmann, Bas van Balen and Erik Meijaard. All fourdifferent,, I greatly appreciated working with you and I am sure our collaborationwilll continue. I want to thank you for your permission to include our mutual work inthiss thesis. Part of the data analysis for chapters five, six, and eight were done inpartiall fulfilment for passing the requirements for a degree in Behavioural Ecologyatt the Manchester Metropolitan University; my thanks to my supervisors Dr ChrisGoldspinkk and Dr Jan Chapman, and Sara Jayne Booth for their help in this. I thankProf.. dr. F. Schram, Prof. dr. W. Admiraal, Prof. dr. H.H.T. Prins, Dr. H.H.Albrecht,, Dr. H.D. Rijksen and Dr. T. Geissmann for participating in the thesisexaminingg committee.II also would like to thank the (anonymous) reviewers and editors of thejournalss in which most of the chapters in this thesis were published originally fortheirr time and effort in improving the papers offered to them. All those people whohelpedd with comments and suggestions on individual chapters are thanked in theacknowledgementt sections at the end of each chapter.Additionall financial support for the study came from the NetherlandsFoundationn for International Nature Protection (Van Tienhoven Stichting), Societyforr the Advancement of Research in the Tropics (Treub Maatschappij), Stichting hetKronendak,, H.H. van Urk Fund, and the Gibbon Foundation. Thanks due to Hans deIonghh and Jelle Maas of the Tropenbos Foundation in their help publishing thisthesiss in the Tropenbos Kalimantan Series, and to the University of Amsterdam fortheirr financial support.Finally,, as has become customary but therefore not less sincere, I would like tothankk my friends and family for their help and support as well as for reminding methatt there is more to life than science.Amsterdam,, May 2001

ForestForest and Primates, a General IntroductionCHAPTERR 1FORESTT AND PRIMATES, A GENERAL INTRODUCTION TOTHEE CONSERVATION OF ENDEMIC PRIMATES IN THESUNDAICC REGIONINTRODUCTION NThee Sundaic region, also known as Sundaland, Malesia, or the Indo-Malayan region,andd defined as Thai-Malay peninsula south of the isthmus of Kra, Sumatra, Borneo,Javaa and Bali, has been identified as one of the hottest biodiversity hotspots on earth(Meyerss et al., 2000). The area ranks second in number of endemic plants, fifth innumberr of endemic vertebrates (excluding fishes), tenth for endemic plants / arearatioratio and endemic vertebrate / area ratio, and ranks seventh in having the leastamountt of primary vegetation remaining as percentage of the original extent. Withthee Philippines and Madagascar, the Sundaic region is the only area to appear in thetopp ten of all the above listed factors (Meyers et al., 2000).Duringg interpluvial periods the region was originally covered by and large inrainn forest of different types, depending on, among other things, altitude and soiltypee (Park, 1994). Interpluvial periods correspond with the 'glacial' periods intemperatee regions and during such times so much of the northern and southernlatitudess was covered in ice that sea levels were reduced by as much as 100 m.Alongg the south eastern edge of the Sunda Shelf, i.e. eastern Java and parts of Bali,drierr forest types could be found including deciduous forest. Especially over the lastdecades,, but much earlier in the lowlands of Java, due to rapid deforestation, largeareas,, are now converted into agricultural land, plantations, and, increasingly'wastelands',, i.e. virtually unoccupied land covered in e.g., alang-alang Imperatagrasslandd and other depauperate vegetation types (e.g., Myers, 1989).Thee once large continuous areas of forest of the Sundaic region are home to alargee variety of non-human primate species (hereafter 'primates' 1 ). Depending on thetaxonomyy followed 26-28 species can be found in the region. This includes four ofthee eleven families commonly recognised (Corbet & Hill, 1992; Mittermeier &Konstant,, 1996/1997): Loridae (one species), Tarsidae (one species),Cercopithecidaee (17-18 species, including the bear macaque Macaca arctoideswhichh occurs marginal in northern part of the Thai-Malay peninsula), Hylobatidae(sixx species), Hominidae (one or two species depending on whether the two orangutanntaxa from Sumatra and Borneo are given the species rank, see below). From a11Biologically and taxonomically humans are included in the order primates, for practical reasonshowever,, in the present thesis, 'primates' unless specified otherwise normally denotes 'non-humanprimates'. .1 1

ForestForest (and) Primatesbroadd geographic perspective the region is important as it harbours adisproportionatelyy large number of primate species and primate endemics(Mittermeierr & Konstant, 1996/1997).Withh the exception of a few, most notably the long-tailed macaque M.fascicularis,fascicularis, most species are confined to natural forest. Some species are able tosurvivee in certain man-made habitats, most notably certain forest plantations, butmostt of them will not survive for any length of time in these habitats.Inn this thesis I will present data on the ecology and conservation of the endemicprimatess of Java and Borneo. Combined, these two islands, and their smallerneighbouringg islands, comprise more than half of the land surface of the Sundaicregion.. In this first chapter I will briefly introduce the islands of Java and Borneo(geology,, climate, vegetation, human population etc.), the endemic primate speciesoccurringg on them and their conservation status. The main causes of the decline ofthee populations of the endemic primates on Java and Borneo are presented, afterwhichh a brief overview of primate conservation studies that have been conducted onthee islands will be given. The chapter ends with a concise summary of the history ofthee present study, its aims, and an outline of the thesis.BACKGROUNDD ON THE STUDY ISLANDSJavaa is an island of about 130,000 km 2 and politically includes the island of Madura(5,6200 km 2 ) which lies just north of the east Javan province. It is administrativelydividedd in six areas, viz. West Java (at the end of 2000 this was split in two smallerprovincess Banten and West Java), DKI Jakarta (the nation's capital), Central Java,DII Yogyakarta, and East Java (which includes Madura). As Indonesia's political andindustriall centre, it is one of the most densely populated areas in the World. Theveryy fertile soils which lend themselves to terracing for irrigated rice, sustain about1155 million people, at an average population density of 862 people km" 2 (Whitten etal.,, 1996). Geologically Java is dominated by its backbone of (active) volcanoes,runningg over the central axis of the island. Eleven volcanoes reach over 3000 m andwithh 3676 m Mt Semeru is Java's tallest mountain. Rivers are relatively short andrunn mostly from the central axis of the island straight to either the Java Sea or theIndiann Ocean.Javaa is largely deforested and most of the remaining forest fragments cover(partss of) the numerous volcanoes; human pressure on the remaining forests is veryhigh.. Less than 10% of the original forest remains: 54% of the mountain forest, 19%off the hill forest, and only 2% of the lowland forest (Smiet 1992). The lastmentionedd forest type is now almost exclusively found scattered along the southerncoastt and in the easternmost part of the island. Once the island was probablycompletelyy covered by tropical forest (MacKinnon et al., 1982), but its destructionalreadyy commenced in the 15th century (Whitten et al., 1996). An estimated totalareaa of 10 million ha of natural forest was present in the 17th century. Some hundred2 2

ForestForest and Primates, a General Introductionyearss ago four million were left, which was reduced to about one million in the firsthalff of the 20th century. During the past 50 years no further significant change inforestt cover has taken place (Smiet, 1990). At present deforestation has sloweddown,, but fragmentation and forest degradation continues (Smiet, 1992). Forest hasbeenn replaced by cities and villages, agricultural land, estate crop plantations (coffeeCoffeaCoffea sp., quinine Cinchona calisaya, sugar cane Saccharum sp.), forest plantations(teakk Tectona grandis, pine Pinus sp., rubber Hevea brasiliensis), leaving the naturalforestt areas as habitat islands. Less than 25% of the remaining forest on Java isincludedd in the protected area network (RePPProTT, 1990).Thee climate on Java differs greatly from the west to the east. The eastern partoff Java and the north coast have a pronounced dry season, while in the western halfitt is weak and nowhere marked. In general, the wettest vegetation types (mixedlowlandd and hill rain forest and everwet montane forest) only occur in areas with atleastt 30 rainy days during the driest four consecutive months (van Steenis &Schippers-Lammertse,, 1965), and hence is mostly found in the west and central partoff Java. Rain forest is also found throughout the otherwise seasonally dry east in thewett 'islands' which arise as a result of stowage on the southern and south-easternslopess of the higher mountains (van Steenis, 1972). In the drier areas rain-forest isreplacedd by moist forest and deciduous forest.Thee island of Bali (5560 km 2 ), situated east of Java, is politically a separateentity,, but bio-geographically it is included in the Javan faunal province. Bali has apopulationn of some three million people at an average population density of 520 perkm 2 .. Most humans live in the fertile southern part of the island (Whitten et al.,1996).. Less than one fifth of the island remains under forest cover, most of which issituatedd in the central mountain range and in the northern part of the island(MacKinnonn et al., 1982). Large-scale deforestation on Bali is more recent than onJava,, and around the turn of the 20th century most of the northern half of the islandwass still covered with forest. The loss of forest during the 20th century has beenlargelyy due to the introduction of coffee, clove Syzygium aromaticum and coconutCocosCocos nucifera plantations, and use of fuel-wood (see maps in Whitten et al., 1996:335).. The climate of Bali is comparable to the eastern part of Java, with a long dryseasonn along the north coast and a negligible dry season on some of the highervolcanoess (RePPProT, 1990).Borneoo is much larger than Java, in fact with a size of 746,305 km 2 it is the thirdlargestt island in the world (after Greenland and New Guinea). Administratively it isdividedd into the four Indonesian provinces of West, Central, East and SouthKalimantan,, the two autonomous Malaysian states Sabah and Sarawak and theBruneii Sultanate. The Indonesian part of Borneo covers some three quarters of thetotall land area of Borneo. Borneo mainly consists of relatively low lying areas andoverr half of the island lies below 150 m a.s.1. In the centre of the island lies a chainoff higher hills and mountains, running from south-west to the north-east. Borneo'shighestt mountain is Mt. Kinabalu in Sabah, which is, with its 4101 m, the highestpeakk between the Himalayas and the mountains of New Guinea. Other than Java,3 3

ForestForest (and) PrimatesBorneoo is dissected by a large number of great rivers; the Kapuas river (1143 km inlength)) to the west, the Barito River (900 km) to the south, and the Mahakam River(7755 km) to the east. High levels of weathering and leaching are characteristic ofmanyy Bornean soils (Burnham, 1984), and the soils on Borneo are generally muchlesss fertile than the volcanic rich soils of Java.Borneoo has a much smaller human population than Java (some 12.5 million in1990:: MacKinnon et al., 1996), and an average population density of less than 17peoplee km" 2 . All major cities are located near the coast, and population densities inlargee part of Borneo's interior are less than one person per km 2 . Within large parts ofthee island the infrastructure is poorly developed and boats are the main mode oftransportation.. Settlements are also concentrated along waterways.Borneoo supports the largest expanse of lowland evergreen rain forest in theSundaicc region, with some 60% of the land surface still under natural forest(MacKinnonn et al., 1996; Collins 1991: this figure may be as low as 45% due todeforestationn over the last decades, E. Meijaard, in litt). The forests arecharacterisedd by a high diversity of dipterocarps, the most important timber speciesinn the region (Whitmore, 1984). Timber is a major source of revenue for theMalaysiann states and for Kalimantan; oil-rich Brunei has less need to exploit itsforestt for timber. Large scale exploitation of forest for timber began at the end of the1960s;; in 1967 all Indonesian forests were declared property of the state. Some 90%off all forest (excluding conservation areas) in Sarawak is under concession(MacKinnonn et al., 1996) whereas the total are of forest under concession inKalimantann is actually larger than the total area of remaining forest (Rijksen &Meijaard,, 1999). Besides for timber production, every year vast areas are cleared foragriculture,, plantations, human settlements and transmigration. Lowland forests inparticularr are directly threatened by these practises due to their accessibility andtheirr higher soil fertility than higher altitude forests. The last few decades forest fireshavee taken an immense toll on the remaining forest areas. During the 1982-1983firess an area of some 50,000 km 2 was affected (Goldammer et al, 1999), and,althoughh figures vary widely, the 1997 fires affected an area significantly larger thanthis.. Less than 10% of the forest on Borneo are formally protected as conservationforest,, and most of this is concentrated in the mountains (Sujatnika et al., 1995;MacKinnonn etal., 1996).Mostt parts of Borneo have few months with rainfall less than 100 mm. Most ofthee hilly inland areas receive between 2000 and 4000 mm per year. West and CentralBorneoo are the wettest parts of the island, whereas certain parts of east Borneo haveaa longer dry season with several months receiving less than 100 mm of rain.However,, nowhere is the dry season as pronounced as it is in eastern Java or Bali.THEE ENDEMIC PRIMATES OF JAVA AND BORNEOOnn Java and Borneo a large proportion of the non-human diurnal primates areendemic,, viz. three out of four and five out of 13 respectively. Six of these eight4 4

ForestForest and Primates, a General Introductionspeciess are leaf monkeys (Cercopithecidae, subfamily Colobinae), whereas the othertwoo are gibbons (Hylobatidae) (Oates et al., 1994; Geissmann, 1995) (see Table 1.1).Inn the other diurnal primate families present on Java and Borneo, viz. the macaques(Cercopithecidae,, subfamily Cercopithecinae) and orang-utan (Pongonidae),endemismm is absent (although consistent differences between the orang-utan fromBorneoo and Sumatra in mtDNA [e.g., Karesh et al., 1997], karyotype [Seuanez et al.,1979],, habitus [e.g., Markham 1980] and morphology [e.g., MacKinnon 1973]suggestt that the two are perhaps best treated as distinct species).Tablee 1.1Endemic primates on Borneo and Java and their IUCN threat statusSub(family) )Species sFamilyy Cercopithecidae, subfamily ColobinaeGrizzledd leaf monkey Presbytis comataBorneann leaf monkey Presbytis hosetWhite-frontedd leaf monkey Presbytis frontataRedd leaf monkey Presbytis rubicundaEbonyy leaf monkey Trachypithecus auratusProbosciss monkey Nasalis larvatusFamilyy HylobatidaeJavann gibbon Hylobates molochBorneann gibbon Hylobates muelleriIUCNN statusEndangered dLowerr RiskDataa DeficientLowerr RiskVulnerable eVulnerable eCriticallyy EndangeredLowerr RiskIslands sJava aBorneo oBorneo oBorneo oJava,, Bali, LombokBorneo oJava aBorneo oNotee that fuscous leaf monkey Presbytis fredehcae is not included in this listing, as it is consideredsynonymouss with P. comata (chapter 5). Based on Eudey, 1996/1997, Geissmann 1993, Oates & Davies,1994. .Withoutt exception, all of the endemic primates of Java and Borneo are found only inforestedd areas. For most species this originally consisted of everwet forest only(includingg riverine, swamp, and montane forest), apart from the ebony leaf monkeywhichh is also found in deciduous forest. A number of species, in particular some ofthee leaf monkeys, can also be found in forest plantations; but mostly only if morenaturall forest is present nearby. Since large areas on Java and Borneo are deforestedorr are under severe threat of being deforested in the near future, and because ofincreasingg human pressure on populations, most if not all endemic species arethreatenedd with extinction. Half of them are included in the IUCN (1996) list ofthreatenedd species (see also Chapter 13 for a more detailed assessment of IUCNthreatt criteria). Two species of leaf monkey, i.e. red leaf monkey Presbytisrubicundarubicunda and Bornean leaf monkey P. hosei are listed as Lower Risk (leastconcern),, whereas the Bornean gibbon is listed as Lower Risk (near threatened).White-frontedd leaf monkey P. frontata is listed as Data Deficient, i.e. there isinadequatee information to make a direct, or indirect, assessment of its risk ofextinctionn based on distribution and / or population status (Table 1.1).5 5

ForestForest (and) PrimatesMAINN CAUSES OF DECLINEOverr the last few decades the interest in non-human primates in the Sundaic regionhass increased substantially, and researchers from many disciplines and from variouscountriess have focused their attention on this diverse order. Ironically enough theseyearss have also seen serious declines in primate populations. For an increasingnumberr of species these declines threaten their survival. The major threats to wildpopulationss of primates in the Sundaic region fall into three broad categories: habitatdestructionn (including total loss and fragmentation), hunting, and capture for localtrade. .Itt is important to understand the threats an endangered species is subjected to inorderr to make recommendations that could positively influence its survival. This isalll the more important as the effects of different threats are cumulative.1.. Habitat destructionThee main threat to the endemic primates of the Sundaic region is habitat destruction(e.g.,, MacKinnon, 1987; Eudey, 1996/1997). This includes not only the total loss offorestt and its replacement by forest plantations, pasture, or other forms of cultivatedland,, but also the degradation of the forest. The continuous fragmentation of primaryforestss and the intensification of land use in the areas between the remaining forestpatchess result in isolation of the populations trapped in these forest remnants. Manyspeciess of primates are completely arboreal and will not cross open land of anywidth,, which makes them especially susceptible to the effects of forestfragmentation.. In the long run, gaps between populations may soon becomeunbridgeablee due to further habitat loss and fragmentation may result in loss ofvariabilityy due to genetic drift and inbreeding depression. In practise, however, smallpopulationn will often never reach this stage of the extinction vortex as they arewipedd out by hunters, are captured for the pet-trade, or further habitat destructionwilll results in the death of the last remaining individuals. Thus, in all likelihood, thereductionn and the fragmentation of the forests result in populations too small and toowidelyy separated to persist in the long term.Anotherr immediate threat to many of the endemic primates is encroachment byhumanss along the edges of the forested areas. As the infrastructure is beingimprovedd the accessibility is increasing and primate and man are getting more andmoree in conflict. This usually turns out to be unfavourable for the former species.2.. HuntingThee greater accessibility may also increase hunting activities. More on Borneo thanonn Java and Bali, primates are hunted for food and sport, as crop pest and formedicine.. Many rural people depend on wildlife meat for their protein and primatesaree frequently eaten. Hunting is deeply ingrained into almost all cultures on Borneo(Bennettt et al., 1994). With little traditional controls and the almost universalavailabilityy of shotguns and cartridges (more so in the Malaysian States than in6 6

ForestForest and Primates, a General IntroductionKalimantan),, the effect on primate populations is devastating. Although largelyprotectedd by law, in practise the only safeguard for most species is inaccessibility.Withh the spread of logging roads, and improved river transport no areas are anymoresafee (Bennett et al., 1994).Withh respect to the success of the conservation of primates, it is relevant tonotee that human attitudes towards primates differ greatly between religious groups,andd that the distribution of religious groups differs between Borneo and Java (andBali).. For Hindus primates are often considered sacred and in certain areas and atcertainn times offerings are brought to primates (Wheatly, 1999). Primates are notconsideredd sacred by Muslims, but religious restriction permits the consumption ofprimates.. This is in contrast to Christianity where few dietary restrictions prevail.Thee human population on Java is predominately Muslim and only a smallproportionn is Christian or of another religion. Concentrations of Hindus on Java areonlyy found in a few remote highland areas. Bali however, is predominately Hindu.Thee coastal regions of Borneo are mostly inhabited by people with a Malayan originwhoo have adopted Islam as their main religion. Most of Borneo's interior is inhabitedbyy people of the Dayak and Punan tribes, many of which have been converted toChristianity,, although animistic beliefs are still widespread (Cleary & Eaton, 1992).Overr the last hundred years there has been a heavy migration from the interiortowardss the coastal areas, generally as a result of better health facilities, bettereducationn and better living conditions (Sirait et al., 1994) bringing people fromdifferentt cultural and religious backgrounds in closer contact. At a different scaletransmigrationn (in the present context mostly involving people from Java, Sumatraandd Sulawesi migrating to (rural) Borneo) has done the same.Inn general, hunting of primates is rare or absent in most areas on Java and Bali(althoughh in certain areas long-tailed macaques are hunted as crop pest, andsometimess for sport), whereas it is widespread on Borneo, especially in the interior.Onn Borneo all primates that constitute more than a mouthful of meat (involving allspeciess with the exception of the nocturnal slow loris and the tarsier) are frequentlyeatenn (Caldecott, 1992).3.. TradeInn the Sundaic region, the human attitude towards keeping primates as pets differgreatlyy from those in the western world and seems to differ little between religiousgroups.. Capturing of primates for pets is widespread throughout western Indonesia,withh trade routes mostly running from the 'outer islands' (Sumatra, Borneo, andSulawesi)) to Java, and within Java, from east to west (Nursaid & Astuti, 1996;Nursaid,, 1998; R. Nursaid, pers. comm.). The trade in primates is a profitablebusinesss and although many species protected by law (both in Indonesia andMalaysia)) they are frequently offered for sale at bird markets. Few quantified dataaree available, but it must be feared that trade in primates has increased, especiallyafterr the economic depression of the late 1990's (R. Sözer, pers. comm.; R. Nursaid,pers.. comm.). Zoos and safari parks, just as some 'animal lovers', see primates, andpreferablyy the rarer ones, as status symbols and important assets for their collections.7 7

ForestForest (and) PrimatesItt is beyond doubt that zoos and birdparks play an important role in education aswelll as in conservation of many animal species, but prudence is called for keepingsomee of the rarest species.Tablee 1.2Selected study sites on Borneo and Java where long-term studies (> one year or severalshorterr studies) on endemic primates have been conducted.Country yState,, ProvinceMalaysia aSarawak kSabah hBrunei iIndonesia aWestt KalimantanCentrall KalimantanSouthh KalimantanEastt KalimantanWestt JavaCentrall JavaEastt JavaBali iLombok kStudyy siteSamunsam mDanumm valleySepilok kKinabatang g--Altitudinal lrange e0-50 0200-300 050-100 00-100 0-100Gnn Palung 0-100 0Tanjungg Puting 0-50 0Baritoo Ulu 150-350 0---Kutai i 100-300 0Dieng gCepu u~ ~Balii Barat--Studyy speciesN.N. larvatusP.P. hosei, H. muelleriP.P. rubtcundaN.N. larvatus--P.P. rubtcundaN.N. larvatus.H.H. muelleri x H.--H.H. muelleriUjungKulonn 0-100 H. molochTelagaa Patengan 1600-1800 P. comataPangandarann 0-50 T. auratus300-800 00-100 00-50 0Principall researchersEL.. Bennett,A.. SebastianA.D.. (Grieser)-JohnsAGG DaviesRR Boonratana--MM Leighton, N. SalafskiC.P.. Yeageragilis agilis D.. Chivers, R. Mather--D.. Leighton, J.C. Mitani,PS.. Rodman, A SuzukiM.. Kappeler, RinjaniY.. Ruhiyat, I.M. WedanaE.. Brotisworo, K. Kool,E.. Megantara,K.. WatanabeP.. comata, H. moloch, V. N ij manT.T. auratusT.T. auratusT,T, auratusDjuwantokoT.. VoghtAltitudinall ranges are approximate and refer to the main study areas; often higher parts are in the vicinityFIELDD STUDIES ON THE ENDEMIC PRIMATES OF BORNEO AND JAVAMostt long-term primatological studies in Indonesia, and indeed in most of SoutheasttAsia have been concentrated at a limited number of field stations. These stationsaree mostly situated in relatively pristine habitat, in areas with limited or no huntingpressure,, and almost without exception in the lowlands (Table 1.2). At these fieldstationss different aspects of the synecology of tropical rain forests and theirinhabitantss have been studied, including primates. Borneo seems to follow thispattern,, but on Java few long-term studies have been conducted and manyprimatologicall studies have been conducted in isolation. From a conservationperspectivee the data collected at field stations (habitat preferences, densities, group8 8

ForestForest and Primates, a General Introductionsizes,, and other population parameters) are often the only ones available. Examplesoff studies on the endemic primates of Borneo and Java are listed in Table 1.2.Off the endemics on Borneo the gibbons are relatively well-studied, with long-termstudiess conducted in Kutai National Park (e.g., Mitani 1984, 1985ab; Leighton,1987;; Rodman, 1978, 1988), Danum valley (Johns, 1992; Grieser-Johns, 1997), andBaritoo Uiu (Chivers, 1992, including studies on the hybrid zone between H. muelleriandd H. agilis: Mather, 1992). Of the colobines, only the proboscis monkey has beenstudiedd in detail at a number of localities throughout its range (e.g., Yeager, 1989,1990,, 1991, 1993; Bennett, 1988; Bennett & Sebastian, 1986; Boonrata, 2000). Redleaff monkey has been studied in detail in Sabah (Davies, 1987, 1991; Davies &Baillie,, 1988) and to a lesser extent Central Kalimantan (Supriatna et al., 1986).Dataa on the other colobines is scant and often collected during short studies. Hardlyanyy published studies are available on white-fronted leaf monkey (Blouch, 1997) orBorneann leaf monkey.Off the Javan endemics the Javan gibbon has been studied in detail in UjungKulonn only (Kappeler, 1981, 1984 abc; Rinaldi, 1999), although some base-linesurveyss have been conducted in other parts of the island (Kappeler, 1981, 1984c;Asquith,, 1995; Asquith et al., 1995; Nijman, 1995). The grizzled leaf monkey hasbeenn studied mostly in montane habitats (Ruhiyat, 1983, 1991; Sujatnika, 1992;Wedana,Wedana, 1993), whereas this species is probably more common at lower elevations(Nijman,, 1997b; chapter 6; Whitten et al., 1996). The ebony leaf monkey has awiderr niche breadth than the other endemics and occurs in a large variety of foresttypes.. This species has been studied mostly in the more open forest types, includingteakk plantations (Brotoisworo, 1983; Brotoisworo & Dirgayusa, 1991; Kool, 1993;Kooll & Croft, 1992; Djuwantoko, 1991) and deciduous forest (e.g., Kartikasari,1986;; T. Voght, pers. comm.). No long-term studies on this species have beenconductedd in the rain forest, although it can be found in all wet forest types on Java.Mostt studies are selectively conducted in those areas where the study speciesaree present at relatively high densities. This may introduce a bias for assessing theconservationn status of primates. For example for estimation of total population sizesoff primates often rely heavily on published density estimates and hence overestimationnof true population sizes is likely to occur. Only recently have studiesbegunn to evaluate the effects of habitat disturbance. However most factors ofdisturbancee (selective logging, hunting, and fire) have been studied in isolation (e.g.,Suzuki,, 1984; Caldecott, 1992; Johns, 1985, 1992). In reality disturbances do notoccurr in isolation but seem to be tightly linked. As an example, it is not uncommonforr a forest area to be selectively logged (during which the rules for proper forestmanagementmanagement may or may not be followed), during and after which it is frequentlyvisitedd by hunters. Parts of the concessions are subsequently invaded byopportunisticc farmers and settlers, who take out some additional timber and 'nontimberrproducts', including animals. During a extended dry season the forest is setalight,, after which the remaining large trees are felled, and the last animals huntedout.. Hence, for primates to persist in under the current management regime, it is9 9

ForestForest (and) Primatesnecessaryy to assess the conservation status of these primates based on data collectedoverr a variety of habitats in different stadia of re- and degeneration, facing differentthreatss (human pressure, encroachment, logging, hunting etc.).AIMSS OF THE STUDYTheree is a lack of base line knowledge concerning the ecology of most, if not all,endemicc primates in Indonesia. The precise geographical distribution of manyspeciess has not been documented. The types of habitats preferred and the densities atwhichh individual species occur in different land use types remains largely unknown.Thee likely impacts of current factors such as hunting, capturing, habitat alterationandd habitat fragmentation are unknown for many of the primates concerned. Theislandss of Java and Borneo are excellent locations to study the effects of humaninterferencee on the survival and conservation of primates. On both islands similarendemicc primates are found but the pressures facing these species are quite different.Javaa represents an area where little forest remains, where the pressure on theremainingg populations of primates dates back several centuries, and where manypeoplee are no longer dependent on the forest, whereas Borneo represents an area intransition.. Although still largely covered in forest, rapid changes in land-use andchangingg human attitudes will greatly alter the pressures that wildlife populationsaree facing. The history of deforestation on Java will most likely repeat itself on theotherr Sundaic islands, e.g., Sumatra and Borneo and possibly other parts of SoutheasttAsia. These areas have a much higher number of primate species. The findingsandd conclusions of the present study will therefore aim at presenting a frameworkforr the conservation of South-east Asian primates.Inn order to gain greater understanding in the conservation status of the endemicprimatess of Java and Borneo, this study set out to collect relevant ecological dataandd to document the pressures facing the different species. Specific aims of theresearchh are:(i)) To assess the geographical distribution of individual species on Java and(ii))Borneoo (Chapters 6, 7, 9 and 11).To develop, test and evaluate census methods by which primate populationscann be assessed and monitored (Chapters 2, 3 and 4).(iii)) To determine the type and magnitude of the threats facing the individualspeciess and habitats on the islands (Chapters 8, 9, 10 and 11).(iv)) Using data collected under (i), (ii) and (iii), to re-assess the conservation statusoff the endemic primates of Java and Borneo using the IUCN threat criteria(Chapterr 12), and subsequently(v))To identify key areas for conservation based on densities of particular primatespecies,, the co-existence of a disproportional large subset of primate speciesandd management feasibility (Chapters 8 and 11).(vi)) To discuss the results of the present study into greater perspective andformulatee further research priorities (Chapter 13).10 0

ForestForest and Primates, a General IntroductionSETTINGG OF THE PROJECTThee Zoological Museum of the University of Amsterdam has several decades ofpracticall experience with conservation related studies in the tropics, including theSundaicc and Wallacean regions. During the decades prior to Indonesia gainingindependencee most studies were focused on descriptive taxonomy, although part thestudiess of among others Prof. Dr L.F. de Beaufort, director of the museum during1922-1949,, would nowadays be classified as biodiversity conservation research.Laterr Prof. Dr. K.H. Voous, curator of birds from 1940-1964, worked on theornithologyy of the region and published some influential studies on the birds of Javaandd Sumatra (Voous, 1950; van Marie & Voous, 1988).Inn the years after Voous' superannuation the number of projects increased duetoo the activities of the former heads of the department of birds, Dr J. Wattel, andmammals,, Dr P.J.H. van Bree. For vertebrates studies include: seabirds (de Korte,1989,, 1991; de Korte & Silvius, 1994; Argeloo, 1993; Argeloo & Dekker, 1996),megapodess (Dekker, 1990ab; Argeloo, 1992; Jones et al., 1995), pheasants (Sözer,1997;; Sözer et al., 2000, in press; Nijman & Sözer, 1997), birds of prey (van Balenett al., 2000; Sözer et al., 1998), woodpeckers (Lammertink, 1998, 2001), bats(Bergmanss & Rozendaal, 1982, 1988; Bergmans & van Bree, 1986), and marinemammalss (de Iongh et al., 1997; Kreb, 1999).Thee present project was initiated in 1996 and stems from an agreementbetweenn the Zoological Museum Amsterdam and the Zoological Museum Bogorwithh ongoing projects concerning woodpeckers, birds of prey, pheasants, primatesandd dolphins.OUTLINEE OF THIS THESISAfterr the general introduction of primate conservation studies in the Sundaic region,inn the following twelve chapters the results of field studies on Javan and Borneanprimatess which were carried out between 1994 and 2001 will be described,interpreted,, and their implications discussed.Sectionn I (Chapter 2-5) presents some background information on surveymethodology,methodology, behaviour, and morphology. In Chapter 2 a comparison is madebetweenn three commonly used methods for estimating densities and biomass of rainforestt vertebrates. Chapter 3 deals with the effects that behavioural changes in rainforestt vertebrates due to habitat disturbance have on estimation of densities. Bothchapterss use data from the Bornean gibbon and Javan gibbon, but the results andconclusionss are likely to be applicable to other animal groups as well. Chapter 4dealss with the calling behaviour of Javan gibbons. It presents data on the frequencyoff calling in both sexes, and explores the use of bio-acoustics in conservationstudies.. Chapter 5 describes the geographical variation in pelage of grizzled leafmonkeys,, one of the three endemic primates of Java. Contrary to previous studies it11 1

ForestForest (and) Primatesarguess that a number of morphological and behavioural characteristics of individualsoff the western populations of this species are not diagnosably different from those inthee eastern part of the species' range. It is therefore argued that the grizzled leafmonkeyy on Java comprises only one species; for conservation purposes thepopulationss on Java should be treated as one single unit.Thee following two sections deal with the geographical distribution, conservationstatuss and conservation of the endemic primates of Java and Borneo; section II dealswithh the Javan species, whereas Section III deals with those from Borneo.Sectionn II (Chapter 6-9) begins with addressing the geographical distribution of thetwoo endemic colobines on Java. Chapter 6 deals with the grizzled leaf monkey andchapterr 7 deals with the ebony leaf monkey. Chapter 8 presents data on theconservationn status and distribution of the endemic primates in the Dieng mountains.Sectionn III begins with presenting data on the distribution and conservation ofprobosciss monkeys on Borneo (chapter 9), and chapter 10 tells the story of the localextinctionn of this species from the Pulau Kaget Nature Reserve. Both chaptersdemonstratee the in-effectiveness of species conservation on Kalimantan. Chapter 11attemptss to assess the patterns of primate diversity on Borneo, and the implicationsoff these patterns for the selection of priority sites for conservation.Sectionn IV starts with a re-assessment of the conservation status of the endemicprimatess of Java and Borneo based on the present IUCN threat criteria (Chapter 12),incorporatingg data from the previous three sections. Finally an overall discussionandd an integration of the different themes is presented (chapter 13). This chapter alsoprovidess some suggestions for further research on primates and their forest in Javaandd Borneo.Mostt chapters have been published in scientific journals, with a number of differentco-authors.. In order to increase readability as much as possible a single style isadopted.. Nomenclature and english names for the different species followsGeissmannn (1993) for the gibbons, and Oates & Davies (1994) for the colobines (seeTablee 1.1); these may differ from the ones used in the original publication.12 2

DensityDensity and Biomass Estimates of Gibbons in Bornean Rainforest: a Comparison of TechniquesCHAPTERR 2DENSITYY AND BIOMASS ESTIMATES OF GIBBONS(HYLOBATESMUELLERI)(HYLOBATESMUELLERI) IN BORNEAN RAICOMPARISONN OF TECHNIQUESwithwith Steph B.J. MenkenABSTRACT TCensusess were conducted of the Bornean gibbon in two forest areas (KayanMentarangg National Park [TNKM] and Sungai Wain Protection Forest [HLSW],Eastt Kalimantan, Borneo, in 1996 and 1999-2000, respectively) using three differenttechniques.. Gibbons live in stable and cohesive groups in permanent territories andsingg regularly, making it relatively easy to locate them. Firstly, range mapping 3.8km 22 (TNKM) and 5.0 km 2 (HLSW) was executed to locate all groups and to maptheirr ranges. Secondly, repeated line transects were run on permanent transects andalongg ridges. Encounter rates on ridges in both areas were higher than on thepermanentt transects, reflecting gibbons' preference for higher ground duringmorningg hours. Thirdly, fixed point counts were executed, which make use of thefrequentt calling of gibbons; the locations from where gibbons were vocalizing weremappedd during the early morning (06.00-09.00 hrs) from listening points at summitsandd ridges. Densities were calculated for two sets of data based on the distance (0.7andd 1.0 km) from where gibbons could be mapped. Overall, density estimates inbothh areas were relatively similar with between 2.1 and 2.9 groups km" 2 . The lowestdensityy estimate for TNKM, obtained by the fixed point counts using a radius of 1.0kmm 1 groups km" 2 or 2 individuals km' 2 , corresponding with a biomassoff 0 kg km" 2 ) was some 30% lower than the highest estimate which wasobtainedd by the line transect technique 2 groups km" 2 or 3 individualskm" 2 ,, corresponding with 0 kg km* 2 ). The lowest density estimate forHLSWW however, obtained by the line transect technique 4 groups km" 2 or88 individuals km' 2 , corresponding with a biomass of kg km" 2 ), wasupp to 17% lower than the highest estimate obtained by the fixed point countstechniquee using a radius of 0.7 km 1 groups km" 2 or 5 individuals km* 2 ,correspondingg with a biomass of 4 kg km" 2 ). The interaction between siteandd census technique explained a large proportion of the variation in density, largerthann census technique did alone. This data suggests that care must be taken wheninterpretingg density estimates from different areas obtained by different techniques.13 3

ForestForest (and) PrimatesRINGKASAN NPerkiraann Kepadatan Populasi serta Biomasa Kelawat (Hylobates muelleri) di HutanHujann Borneo: Suatu Perbandingan Metoda (bersama Steph B.J. Menken): Sensussensusstentang Kelawat telah dilaksanakan di dua kawasan hutan (Taman NasionalKayann Mentarang [TNKM] dan Hutan Lindung Sungai Wain [HLSW], KalimantanTimur,, Borneo, masing-masing pada 1996 dan 1999-2000) dengan menggunakantigaa metode yang berbeda. Owa hidup dalam rombongan yang tetap dan kohesifdalamm teritori yang per manen dan secara teratur menyanyi, yang mempermudahuntukk mencari mereka. Pertama, pemetaan rentang sejauh 3.8 km 2 (TNKM) dan 5.0kmm (HLSW) telah dilakukan untuk menemukan semua kelompok serta untukmemetakann masing-masing daerah jelajah. Kedua, metoda transek garis berulangulanggtelah dilaksanakan di transek-transek yang permanen dan di sepanjangpunggungann bukit. Frekwensi pertemuan di punggungan bukit di kedua daerahtersebutt lebih tinggi daripada di transek-transek yang permanen, mencerminkanpreferensii Kelawat terhadap dataran yang lebih tinggi selama waktu pagi. Ketiga,metodaa titik hitung yang tetap telah dilaksanakan, yang menggunakan frekuensibersuaraa dari Kelawat; lokasi-lokasi yang dipakai Kelawat untuk bersuara telahdipetakann selama waktu pagi (jam 06.00-jam 09.00) dari tempat-tempat dengarnyadii puncak-puncak dan punggungan-punggungan bukit. Kepadatan populasi telahdikalkulasikann untuk dua set data berdasarkan jarak maksimal (0.7 dan 1.0 km) yangdapatt dipakai untuk memetakan Kelawat. Rata-rata, kepadatan populasi di keduadaerahh tersebut adalah hampir sama dengan antara 2.1 dan 2.9 kelompok per km 2 .Perkiraann kepadatan populasi yang paling rendah untuk TNKM, yang didapatkandarii perhitungan titik-titik tetap dengan menggunakan radius 1.0 km (2.1 0.1kelompokk km" 2 atau 6.9 2.2 individu km" 2 , setara dengan biomasa 30.7 31.0 kgkm'' ) adalah 30% lebih rendah daripada perkiraan yang tertinggi yang didapatkandengann metode transek garis (2.9 0.2 kelompok km" 2 atau 9.9+3.3 individu km" 2 ,setaraa dengan 43.2 40.0 kg km" 2 ). Akan tetapi, perkiraan kepadatan populasiterendahh untuk HLSW, yang diperoleh dengan metoda transek garis 4kelompokk km" atau 8 individu per km" 2 , berhubungan dengan biomasa dari35,1+89,44 kg km" 2 ), yaitu hingga 17% lebih rendah daripada perkiraan kepadatanpopulasii tertinggi dengan metoda hitung titik tetap dengan radius 0,7 km 1kelompokk km" atau 5 individu km 2 , setara dengan biomasa 4 kgkm"" ). Hubungan antara lokasi dan metode sensus menerangkan bagian besar darivariasii kepadatan, daripada metoda sensus itu sendiri. Data ini memberi kesanbahwaa kehati-hatian harus diambil pada saat kita menginterpretasikan perkiraankepadatann dari berbagai daerah yang berbeda yang didapat dari metoda yangberbedaa pul a.14 4

DensityDensity and Biomass Estimates of Gibbons in Bornean Rainforest: a Comparison of TechniquesINTRODUCTION NGibbons,, or lesser apes (genus Hylobates), are widely distributed throughout theIndo-Chinesee and Sundaic regions, from Assam and Bangladesh in the north-west,acrosss southern China and Vietnam, through the Thai-Malay peninsula to Sumatra,Java,, and Borneo. Apart from the siamang Symphalangus syndactylus, which occurssympatricallyy with white-handed gibbon H. lar and agile gibbon H. agilis, in parts oftheirr range, gibbons are largely parapatric with varying degrees of hybridization andreproductivee isolation (Gittens & Raemaekers, 1980; Geissmann, 1995). On Borneotwoo species occur: the agile gibbon and the Bornean gibbon, H. muelleri (see Figure2.1).. The agile gibbon occurs in the southernmost part of Thailand, PeninsularMalaysia,Malaysia, central and south Sumatra, and in the south-western corner of Borneo,betweenn the Kapuas and Barito rivers. The Bornean gibbon is endemic to Borneoandd can be found in the remaining part of the island. In the contact zone at theheadwaterss of the Barito river, an apparently stable, hybrid population occurs(Mather,, 1992).Figuree 2.1Bornean gibbon Hylobates muelleri in Sungai Wain protection forest (photo G.M.Frederiksson). .15 5

ForestForest (and) PrimatesBorneann gibbons are completely arboreal and are confined to closed canopy forest inthee lowlands and hills up to c. 1500 m a.s.l. (Payne et a!., 1985; V. Nijman & E.Meijaard,, unpubl. data). The species is largely frugivorous, eating mostly ripe,sugar-rich,, juicy fruits (Rodman, 1978, 1988; Leighton, 1987). Bornean gibbons areterritoriall and live in monogamous family groups consisting typically of an adultpairr and up to four offspring. Pairs perform elaborate duet songs that are thought toformm and maintain the pair bond and to establish and maintain the territory(Raemaekerss & Raemaekers, 1985; Mitani 1984; Leighton, 1987). The populationmayy furthermore contain a number of floating (sub-adult) males and females, whocalll rarely.Borneann gibbon is classified as Lower Risk (near threatened) according toIUCNN threat criteria (Eudey 1996/1997), and the species is protected throughout itsrange.. Although the total area of forest on Borneo is still large compared to otherpartss of the distribution range of gibbon, every year vast areas are cleared for timberproduction,, transmigration or agriculture and are increasingly lost due to arson (e.g.,Rijksenn & Meijaard, 1999). Especially lowland forests are directly threatened bythesee practices due to their accessibility and higher soil fertility than higher altitudeforests.. Throughout Borneo, accessibility has greatly increased over the last fewdecades:: out-board motors and logging roads make all but the most remote areasaccessiblee for exploitation. Only a small proportion of the lowland forest on Borneoiss formally protected as conservation forest (MacKinnon et al., 1996), but especiallyinn the Indonesian part of the island, many conservation areas are protected on paperonlyy (Rijksen & Meijaard, 1999; Meijaard & Nijman, 2000). Numbers of Borneangibbonss are declining overall because of habitat disturbance or habitat alteration, andpopulationss in some areas have been greatly reduced or even eliminated by hunting.Locall gibbon populations are easily exterminated by hunting because of the species'loudd songs, which attract attention, monogamy, which easily disrupts breeding, andstrongg sedentary behavior which renders both evasion of hunters and rapid recolonizationnof depopulated areas more difficult (Bennett et al., 1987a).Rangee mapping of all known primate groups in a given area is generallyconsideredd to provide the most accurate approximation of true density for rain forestprimatess (see e.g., NRC, 1981; Skorupa, 1987). However, forest primates aredifficultt to census accurately. Because of the three-dimensional structure of theSouth-eastt Asian evergreen closed canopy forests, where trees can reach heights of600 m and more, arboreal primates are difficult to locate. Range mapping is,furthermore,, time consuming and labor intensive, and only applicable in relativesmalll accessible areas. The technique is furthermore not suitable for rugged ormountainouss terrain, where access can only be obtained via ridges.Althoughh range mapping is considered more accurate, the most commonlyusedd technique of estimating primate population density is the (repeated) linetransectt (NRC, 1981; Whitesides et al., 1988; Buckland et al., 1993). This techniquedependss on the detection of animals (or sometimes merely animal signs such asnests)) on one or both sides of a survey path. Ideally, transects should be placedrandomlyy or through a stratified random technique and should follow a straight line.16 6

DensityDensity and Biomass Estimates of Gibbons in Bornean Rainforest: a Comparison of TechniquesInn practice, however, transects often follow geographic features as crests, ridges andspurss (Blouch, 1997) or logging roads (Johns, 1985; Grieser-Johns, 1997). Thetechniquee has been employed for survey work (Davies & Payne, 1982; Bennett &Dahaban,, 1995; Nijman & van Balen, 1998), comparative studies (Glanz, 1982;Johnss & Skorupa, 1987; Yanuar et al, 1995; Johnson & Overdorff, 1999), and forestimationn of population parameters in areas where other methods (mark-recapture,completee counts, home range or territory mapping) are not feasible (Green, 1978).Althoughh line transects have been widely used for censusing gibbons (Marsh &Wilson,, 1981; Davies & Payne, 1982; Johns, 1985; Haimoff et al., 1986; Bennett &Dahaban,, 1995; Blouch 1997), Brockelman & Srikosamatara (1993) considered thetechniquee not particularly suitable for this taxon. Gibbons live in small familygroupss which makes them difficult to detect and they can behave unpredictably (e.g.,flee,, hide, approach) when detecting humans. Brockelman & Ali (1987) andBrockelmann & Srikosamatara (1993) discussed the possibilities of estimating gibbondensitiess by fixed point counts making use of gibbon's great calls. Fixed pointcountss have the advantage of allowing density estimation over relative large areas inaa short time span.AA number of studies have been conducted with the specific aim of comparingdifferentt census techniques (Green, 1978; Whitesides et al., 1988; Defler & Pintor1985;; Mitani et al., 2000; Fashings & Cords, 2000; Brugiere & Fleury 2000), butfeww studies were conducted in South-east Asian forest and none involving gibbonshavee been published. Here we compare three different techniques, namely rangemapping,, repeat line transects, and fixed point counts, to estimate densities ofBorneann gibbon at two lowland primary forest sites.METHODS SStudyy AreaDataa were collected in the Kayan Mentarang National Park (Taman Nasional KayanMentarangg [TNKM]) in Oct.-Dec. 1996 and Sungai Wain protection forest (HutanLindungg Sungai Wain [HLSW]) in Dec. 1999-Feb. 2000. Both field studies lastedtenn weeks. Figure 2.2 depicts the location of the study areas.Gazettedd in 1980 as a strict nature reserve (cagar alam), Kayan Mentarangbecamee a national park in 1997. With adjacent (proposed) reserves, TNKM totalssomee 20,000 km 2 . The study site proper was the Nggeng Bio river valley, in thesurroundingss of the Lalut Birai field station. The Nggeng Bio river is a tributary ofthee Bahau river which in this part of TNKM marks the eastern boundary of thereserve.. The study area consists of rather steep hills intersected by many smallstreams,, with the study conducted between c. 350 and 750 m a.s.1. The naturalvegetationn type in the area is lowland dipterocarp rain forest. Despite the existenceoff many rivers, true riverine terrace forest is rare or even absent. In many areas theriverbankss consist of steep, rocky gorges, with riverine forest only present in themoree gently sloping areas. The Nggeng Bio river valley has been a restricted forest17 7

ForestForest (and) Primates(tanaa ulen) of the nearby village of Long Alango for at least the last 75 years. Sincehunting,, fishing, cultivation, and collection of forest products have been mostlyprohibited,, the valley is still covered with mature, tall primary forest. Besidesgibbons,, other primates regularly recorded in the study area are Bornean leafmonkeyy Presbytis hosei, long-tailed macaque Macaca fascicularis, and pig-tailedmacaquee M. nemestrina (Nijman, 1997).Figuree 2.2Location of Kayan Mentarang National Park and Sungai Wain protection forest on the islandoff Borneo. The squares show the locations of the study sites.Partt of the Sungai Wain reserve was gazetted as a closed forest (hutan tutupan) in19344 by the Sultan of Kutai. Since 1947, the forest received protection as a watercatchmentt area for the oil industry in the Balikpapan region, and in 1983 it wasgazettedd as a protection forest (hutan lindung). As a research site for the Ministry ofForestry-Tropenboss program, HLSW became an orang-utan Pongo pygmeus,introductionn forest in 1992. In HLSW, the study site proper was in the Bugis rivervalley,, in the surroundings of the Camp Djamaludin field station. The area consistsoff undulating terrain with the study conducted between c. 50 and 127 m a.s.1. HLSWcoverss a variety of forest types, including fresh water swamp, riverine forest, moistlowlandd dipterocarp forest, and dry hill dipterocarp forest. In the east it is borderedbyy some unprotected mangrove forest. The study was conducted in the moist18 8

DensityDensity and Biomass Estimates of Gibbons in Bornean Rainforest: a Comparison of Techniqueslowlandd dipterocarp forest and dry hill dipterocarp forest, with small parts in riverineforest.. At present HLSW is the last remaining area covered with mature undisturbedprimaryy rain forest in the south-eastern coastal region of East Kalimantan. In 1998,forestt fires affected some half of the 100 km 2 large reserve, but the central coreremainedd untouched (Frederiksson & de Kam, 1999). Other primates regularlyrecordedd in the study area are red leaf monkey Presbytis rubicunda, white-frontedleaff monkey Presbytis frontata, and pig-tailed macaque M. nemestrina.Att the time of the study no zoological research had been conducted in TNKMotherr than a few short reconnaissance surveys (Yeager, 1991; Foead, 1995; vanBalen,, 1997) and no animals were habituated. In HLSW, some 20 introduced orangutansswere present (G.M. Frederiksson, pers. comm.), one of which wasoccasionallyy seen in the study area. No primatological studies have been conductedinn the study area and no animals were habituated. In summary, both study sites arecoveredd in tall mature forest, have been effectively protected since the beginning ofthee last century, no primatological studies have been conducted to date, and none ofthee primate species were habituated. This makes these areas one of the few inBorneoo suitable for the study of primates in undisturbed forests.DATAA ACQUISITION AND DATA ANALYSISRangee MappingInn TNKM a number of non-overlapping permanent transects were present; thesetransectss were originally laid out to monitor the phenology of the forest. In HLSW anetworkk of transects is present running north-south and east-west, and spaced some5000 m apart. In both areas, apart from the permanent transects a number of smalltrailss allows access to much of the entire area. All records of primates were plottedonn a map. In both study sites, apart from the first author, a number of researchers orfieldfield assistants were present, collecting additional data. In this way we collected dataonn the precise locations and group sizes of gibbons within an area of 3.8 km 2(TNKM;; excluding the field station itself and its direct surroundings) and 5.0 km 2(HLSW),, disregarding additional area due to slopes. Groups that were occasionallyseen,, but had more than an estimated three-fourths of their range outside the samplearea,, were omitted. Density estimates were obtained by dividing the total number ofgroupss or the total number of individuals found by the census areas.Linee TransectsAtt both study sites, three transects were selected, which were between two and threekilometerss in length. These transects were walked by V. Nijman; in TNKMoccasionallyy a second observer was included. Data were collected in both directions,butt always after a stop of at least 45 min, and always during periods of goodweather.. Since gibbons become less active in the afternoon (Leighton, 1987; V.Nijman,, pers. observ.) only censuses that were completed prior to noon wereincludedd for analysis. An average walking speed of c. 1.5 km h' 1 was maintained. A19 9

ForestForest (and) Primatestotall of 142.5 km (TNKM) and 172.8 km (HLSW) were thus covered before noon.Densitiess of gibbons were estimated using the effective distance method ofWhitesidess et al., (1988). The density of groups km' 2 is given by:D=n-A*'' = n-(L-2-(Ed+ 1/2 S))' 1 (equation 2.1)wheree D = density (groups km" 2 ), n = number of groups seen, A = census area (inkm 2 ),, L = length censused (km), Ed = Effective distance (km, estimated in m), and S== mean group spread (km, estimated in m).Thee effective distance is defined as the distance on each side of the transect at whichthee number of sightings at greater perpendicular distances equals the number'missed'' at nearer distances (Whitesides et al., 1988). It is determined by using ahistogramm of perpendicular distances and calculated as (N t / N f ) F d , where N t = totalnumberr of sightings, N f = the number of sightings below the fall-off distance, and F d== fall-off distance, defined as the maximum reliable distance beyond which thenumberr of sightings is reduced by 50% or more (Brugiere & Fleury, 2000). Thegroupp spread is the diameter of the circle of equivalent area to that occupied, onaverage,, by a group of primates. Group spread proved difficult to estimate and inorderr not to violate the underlying assumptions of the line transect method (such asdeviatingg from the transect line, remaining at one position for a longer period of timeandd walking backwards to obtain a better view: Buckland et al., 1993; Krebs 1989),itt was considered best to obtain group spread estimates from the range mappingtechnique.. The variance among the means of the three transects was used as ameasuree of error in order to estimate confidence limits. When the density is knowninn groups km" 2 , the density of individuals is then calculated using the mean groupsize,, as observed along the transect lines. For estimation of mean group size, only'completee counts' (counts that were made when there was confidence that allmemberss of the group had been actually observed) were included. Standard errors ofthee mean (s.e.) for individual densities were calculated following Raj (1968):s.e.(ID)) = GD 2 (s.e.GS) + GS 2 (s.e.GD) + (s.e.GS) (s.e.GD). (equation 2.2)Wheree ID = individual density (individuals km" 2 ), GD = group density (groups km" 2 )andd GS = mean group size.Brugieree & Fleury (2000) expressed the need to explore the influence of topographyonn bias in density estimation when using line transects. Therefore, in order to test forpossiblee biases of censusing along ridges, spurs, and crests only, data from eachtransectt line was converted into an encounter rate (average number of groupsencounteredd within a band of 50 m per km surveyed between 06.00 and 12.00 hrs),andd compared with encounter rate for one (HLSW) and two (TNKM) trailsfollowingg main ridges.20 0

DensityDensity and Biomass Estimates of Gibbons in Bornean Rainforest: a Comparison of TechniquesFixedd Point CountsThee density of gibbons was calculated by mapping localities from where gibbonsweree vocalizing from four (TNKM) and three (HLSW) listening posts mostlypositionedd at summits or ridges. These listening posts had a hearing angle of at least240°.. The bearing and distance of gibbons singing between 06.00 and 09.00 hrsweree plotted on a map (scale 1:25,000 [TNKM] and 1:17,000 [HLSW]). This timewindoww coincided with the time of greatest singing activity in Bornean gibbon inKutaii National Park as reported by Mitani (1984).Matedd female Bornean gibbons usually confine their singing behavior to duetsongg bouts only. The most prominent song contributions of female gibbons consistoff a loud stereotyped phrase, the 'great call'. This great call includes an accelerationtypee climax with fast bubbling notes. Great calls may be audible further than twokilometerss (V. Nijman, pers. observ.). Adult males do not produce great calls, butoftenn produce solo song bouts. During duetting the male and the female combinetheirr song contributions to produce complex but relatively stereotyped vocalinteractionss (Geissmann, 1995). For surveying, only songs that included a great callweree used and it is assumed that this indicates a family group (cf. Leighton, 1987).Duringg calling, gibbons move only limited distances. Songs that map morethann c. 500 m apart are considered to be given by separate groups (cf. Brockelman &AH,, 1987). Different groups calling simultaneously are distinguishable if one hasknowledgee of song organization; those singing at different times can bedistinguishedd with a combination of directional, distance information andoccasionallyy by individual characteristics.Sincee weather has been found to affect singing frequency in most if not allspeciess of gibbon studied (e.g., Brockelman & Ali, 1987; Brockelman &Srikosamatara,, 1993; this study), and since estimating distances is more difficultwhenn it is raining or windy (V. Nijman, pers. observ.), censuses were onlyconductedd during periods of suitable i.e., still and dry, weather.Inn a given population of gibbons on a given day there are also non-callinggroups.. The proportion of groups calling on an individual day (p) varies betweengibbonn species and between populations within gibbon species (Brockelman & Ali,1987).. For three (TNKM) and four (HLSW) groups, situated nearest to the fieldstations,, the proportion of them calling between 06.00 and 09.00 hrs ( p6 . 9 ) wasestimatedd by remaining within hearing distance of a focal group for a periodbetweenn five and 14 days. Only song bouts that included great calls produced by thefemalee were included.Thee fixed point count technique requires knowledge of song organization andiss probably suitable for experienced observers only (cf. Brockelman &Srikosamatara,, 1993). Therefore, in TNKM, prior to the fixed point counts, a threeweekk training period allowed improvement of distance estimation. In both studysites,, during the line transect surveys and during non-census walks, vocal bouts werenoted,, and their distance and bearing were estimated at different times. Usingtriangulationn from different locations along the transect and with the aid of21 1

ForestForest (and) Primatestopographicc maps it was possible to check the distance estimates and subsequentlytoo improve skills.Thee census area was obtained by plotting the locations of vocal bouts on amap.. From this it was concluded that, taking into account the topography of the area,gibbonn song bouts could accurately be recorded within a radius (r) of both 0.7 and1.00 km. A radius of 1.0 km covers and area twice that of 0.7 km.Thee density of gibbons was calculated byDD = n p 6 . 9 "' A" 1 = n p 6 . 9 "' ( n r 2 )" 1 (equation 2.3)wheree D = density (mated pairs km" 2 ), n = the average number of groups heardcallingg from the listening posts on a given day, p 6 . 9 = proportion of groups callingbetweenn 06.00 and 09.00 hrs, A = the census area, = the proportion of a circlefromm where gibbons could be heard (between 240° and 360°), and r = radius fromwheree gibbons could be mapped (either 0.7 or 1.0 km). The variance among themeansmeans from the listening stations allowed an estimate of confidence limits. Fixedpointt counts sensu stricto do not provide information on group sizes, and hence noestimatess on the density in number of individuals can be made using this technique.Dataa on group sizes were obtained by combining all accurate counts of gibbongroupss at other times during the study in the wide surroundings of the listeningpoints.. Standard errors of the mean for individual densities were calculatedfollowingg equation (2.2).Biomasss EstimatesGibbonn biomass was calculated based on group densities for each of the abovecensuss techniques. Geissmann (1993) tabulated weights of wild-shot animals ofdifferentt gibbon taxa on Borneo. Weights of animals from the north-eastern part ofBorneoo (//. m. funereus) do not differ significantly from those in the south-easternpartt (H.m. muelleri) (t-test, n.s.), and data are pooled in order to provide an averageweightt of Bornean gibbons in east Borneo. An adult female, on average, weighs 5.25kgg (s.e.=0.18, n=16) and an adult male 5.57 kg (s.e.=0.17, n=12); weights for twosub-adultt females were 3.29 kg and 4.20 kg, respectively (Geissmann 1993: 347).Neonatee weights of Bornean gibbons are some 0.40 kg (Geissmann & Orgeldinger,1995).. Few data are available on weights of the 'average' immature, but forcalculationn of biomass this was, arbitrarily, taken as halfway between birth weightandd mature weight, viz., 2.9! kg(cf. T. Geissmann, in litt).Groupss always contained an adult male and an adult female (with a combinedweightt set at 10.82 kg), and a varying number of immatures (between none to four).Sincee each group contains an adult pair variation in group sizes reflects the variationinn number of immatures in a group, and standard errors of group mass werecalculatedd using the variation in number of immatures multiplied by the averageweightt of an immature. Standard errors of total biomass were then calculated usingstandardd errors of both group mass and group density following equation (2.2).22 2

DensityDensity and Biomass Estimates of Gibbons in Bornean Rainforest; a Comparison of TechniquesStatisticall analysis were performed using Minitap 8.2, and throughout means arereportedd plus and minus one standard error of the mean ( s.e.). Significance wasassumedd when p

ForestForest (and) Primateskm"",, or 7.6 individuals km* 2 when the single male is included. Biomass wasestimatedd at some 35.8 kg km" 2 .HLSW:: within the 5.0 km 2 area, thirteen groups were present, totaling 45 or 46individualss (one group consisted of three or four individuals) (mean group size,, range 3-6). Of some seven groups small parts of their ranges might havebeenn outside the boundaries of the study area. Of some four other groups, small partsoff their ranges possibly fell inside the study area (subsequently these groups werenott included). The density was 2.6 groups km" 2 or 9.0-9.2 individuals km" 2 ,correspondingg with a biomass of 42.4 kg km" 2 .Linee TransectsTNKM:: Encounter rates varied between 0.14 and 0.21 groups km" 1 , and did notdifferr between directions within transect routes (paired t-test, t=2.0, df=2, p=0.18),norr when one or two observers performed the survey (unpaired t-test, t=0.59, df=29,p=0.56),, and thus data were subsequently pooled. Estimates of perpendiculardistancess did not differ significantly between transects (Kruskall-Wallis one wayanalysiss of variance, p>0.10) and data from all transects were used in order toestimatee the effective distance. This was estimated at 26.0 m, and using a meangroupp spread of 9.0 m (s.e.=0.9, n=14), following equation (2.1) a density of 2.9groupss km" - (s.e.=0.16, n=3) was reached. The mean group size of gibbons detectedalongg the transect lines from which accurate group counts could be made was 3.4individualss (s.e.=0.18, n=9). Encounter rates along two ridges in TNKM (0.25 and0.300 groups km' 1 ) were higher than along any of the transects, approachingsignificancee (mean encounter rate per 15 km: transects vs. ridges equals 27 vs. 41:binomiall test, p=0.06).HLSW;; Encounter rates varied between 0.08 and 0.20 groups km* 1 , and did notdifferr between directions within transect routes (paired t-test, t=3.46, df=2, p=0.07).Dataa from both directions were therefore pooled. Estimates of perpendiculardistancess did not differ significantly between transects (Kruskall-Wallis one wayanalysiss of variance, p>0.10) and data from all transects were used in order toestimatee the effective distance. Using an effective distance and a group spread of28.00 m and 11.0 m (s.e.= 1.0, n=20), respectively, this gives a density of 2.4 groupskm""" (s.e.=0.4, n=3). Mean group size detected along the transect line was 3.3(s.e.=0.2,, n=l5). The encounter rate along one ridge in HLSW (0.30 groups km" 1 )wass significantly higher than along any of the transects (mean encounter rate per 12km:: transects vs. ridges equals 19 vs. 36: binomial test, p

DensityDensity and Biomass Estimates of Gibbons in Bornean Rainforest: a Comparison of Techniquesthreee days per listening post. The census area for r=1.0 equals 9.7 km 2 . Followingequationn (3) the density estimates obtained from the four listening posts ranged from1.99 to 2.5 groups km" 2 , with an average of 2.1 groups km" 2 (s.e.=0.1, n=4). For r=0.7thee census area equaled 5.3 km" 2 . The corresponding density equaled 2.4 groups km"22 (s.e.=0.1, n=4). Combining all accurate counts of gibbons groups surrounding thestudyy area, the average group size for Bornean gibbon was estimated to be 3.3(s.e.=0.1,n=18). .HLSW:: More than in TNKM, gibbons in HLSW were frequently heardvocalizingg prior to dawn, often commencing at c. 04.00 hrs. The average proportionoff days that female gibbons were calling between 06.00 and 09.00 hrs was 0.70 (fourgroupss were monitored over seven days). Eleven days were spent at listening posts,att least three days per listening post. The areas surveyed for r=0.7 km and r=1.0 kmweree 4.1 km 2 and 8.4 km 2 , respectively. Following equation (3) the average densityforr r=0.7 equaled 2.7 groups km" 2 (s.e.=0.1, n=3, range 2.5-2.9) and for r=1.0 itequaledd 2.4 groups km' 2 (s.e.=0.3, n=3, range 1.8-2.7). Average group size ofgibbonss in thee the study site at large was 3.5 (s.e.=0.28, n=16).Comparisonss of techniquesForr comparisons between techniques and for calculation of technique-siteinteractions,,densities expressed in groups km" 2 were used, as all the other estimatesweree derived from these. For fixed point counts only the estimates with a radius of0.77 km were included, as these are probably more accurate (see discussion), andestimatess from fixed point counts with a radius of 0.7 km or 1.0 km are notindependent. .Tablee 2.2Two-way Analysis of Variance on density estimates in Bornean gibbon Hylobates muelleri,withh fixed point counts (r=0.7 km) and line transects as techniques and Kayan MantarangNationall Park and Hutan Lindung Sungai Wain as sites.Source eTechniquee (A)Site(B) )AxB BError rDegreess offreedom m1 11 11 19 9Sum m off Squares0.012 20.04 40.534 41.317 7F F0.083 30.273 33647 7P P0.78 80.61 10.09 9Inn a two-way Analysis of Variance neither method nor site explain a significantproportionn of variance in density, while their interaction is approaching significance(Tablee 2.2). At first sight the type of estimation procedure seems to make littledifferencee to the outcome of the density estimation. However, given that theinteractionn is approaching significance and because in comparisons sites are oftendifferent,, this suggests that prudence may be called for as the interaction is moreimportantt than methodology within sites. It is illustrative to compare densitiesobtainedd by the two techniques as a post-hoc test: for TNKM the difference between25 5

ForestForest (and) Primatestechniquess is larger than in HLSW (unpaired t-test, t=2.27, df=4 vs. t=0.87, df=2 forTNKMM and HLSW respectively). Hence, density estimates vary more in TNKMthann in HLSW. This may be related to the larger variation in micro-habitats inTNKM,, including a greater altitudinal range than in HLSW.DISCUSSION NDensityy and BiomassThee estimates of population parameters obtained in this study are comparable withthosee reported from various other studies on Bornean gibbons that have beenconductedd in undisturbed lowland sites (MacKinnon, 1974; Rodman, 1978;Leighton,, 1987; Mather, 1992; Bennett & Dahaban, 1995; Yanuar et al., 1995).Groupp sizes in Bornean gibbon seem to vary little with mean group sizes around 3.0-3.88 individuals (e.g., Leighton, 1987; Rodman, 1978), although habitatfragmentationn fragmentation, in the absence of hunting, may lead to larger groupsizess and locally larger densities, as offspring are unable to migrate out of their natalforestt fragments (Oka et al., 2000). However, there seem to be a few anomalousreportss of densities and/or group sizes in Bornean gibbon. First, Bennett (1994)reportss a density of 5.3 groups km" 2 at Belalong, Temburung district, east Brunei,andd comments on the unussual group structure: "normally monogamous, associatinginn groups of four to five, comprising of an adult male, an adult female and theiroffspring,, at Belalong a high proportion (42%) of the gibbon groups have more thanonee female". However, Bennett et al., (1987b), also working in Temburungcalculatedd 'normal' densities of 3.3 groups km" 2 , and did not mention an atypicalsociall structure. Second, Blouch (1997) estimated a density of no less than 10.20groupss km"" or 31.42 individuals km" 2 for south Lanjak Entimau, Sarawak, anestimatee at least two times that of any other undisturbed forest area. Similar reportscomee from the adjacent Betung-Kerihun National Park (J.K. Gurmaya pers. comm.1998).. These estimates may be somewhat biased by the use of ridges and spurs formanyy of the transects (due to the difficult accessibility of the terrain), but densities inLanjak-Entimauu seem to be really much higher than in other sites where gibbonshavee been studied to date (R.A. Blouch, in litt. 2000).Likee group density estimates, reported biomass estimates of Bornean gibbonseemm to vary little among (undisturbed lowland) forest sites (Mather 1992; Suzuki,1992;; Bennett et al., 1987; Rodman, 1988; Davies & Payne 1982). However,comparingg biomass estimates directly is complicated by the limited amount of datawee have on group mass. In the present study, average group mass ranged from 14.0too 15.2 kg, largely depending on the average number of immatures in the group.However,, Rodman (1988) estimated group mass at 12 kg (mean group size 4.0individuals;; Rodman, 1978), Suzuki (1992) at 14.5 kg (mean group size 3.6individuals),, and Davies & Payne (1982) and Bennett et al., (1987) at 16 kg (meangroupp size 4.0 individuals).26 6

DensityDensity and Biomass Estimates of Gibbons in Bornean Rainforest a Comparison of TechniquesRangee MappingRangee mapping is methodologically less demanding than either line transect walksorr fixed point counts. There are few underlying assumptions, it is possible to deviatefromfrom the route to check anything uncertain and it can be done at all times of the day.Gibbonss can be located by sight, hearing as well as smell. Range mapping isfacilitatedd by a number of social characteristics of gibbons: groups are relativelystablee and cohesive and live in permanent territories, groups are relatively easy torecognizee individually by their age and sex composition, and mated pairs singregularly.. Brockelman & AH (1987) stated that, under favorable weather conditions,ann experienced observer can crudely map the ranges of all gibbon groups within anareaa of 1-2 km 2 within a ten day period. Precision of range mapping increases withthee number of observers and the length of the study period. However, intensecensusingg may create too much disturbance and as a result some animals may moveoutt of the study area. We think that within the ten-week study periods all gibbongroupss present within the study area were identified at an accuracy sufficient for theaimss of the study, while disturbance levels were kept low.Inn small census areas, the ratio of edge to area increases, so that there is agreaterr chance of error per unit area in determining whether groups (or individuals)onn the edges of the census area are inside or outside the boundary (Sen, 1982; Krebs,1989).. For gibbon studies, Brockelman & Ali (1987) recommended the census areatoo be at least five times larger than the average home-range size in order to reducethee edge effect. Home-range sizes of Bornean gibbon average 36 ha (range 33-43ha)) (Leighton, 1987). In the present study the census areas were some ten (TNKM)andd 14 (HLSW) times larger than the average home range size and at least eighttimess larger than the largest home-range size reported. Although the study areasweree large enough to contain a fair number of groups and in part had sharpboundariess (TNKM: the Bahau river; HLSW: boundary between burned andunburnedd forest), it is anticipated that the edge effect introduces the largest probleminn establishing densities when range mapping. In both study areas groups that hadsmalll parts of their ranges outside the boundaries of the study area (and thus wereincluded)) were more numerous than those with small parts inside the boundaries(andd hence were excluded). This difference may reflect a preference for including agroupp rather than excluding it.Floatingg individuals, i.e., mostly sub-adults that have left their natal area, mayintroducee another problem during range mapping, as a subjective judgement has tobee made whether or not to include the animal(s). Floaters were rare in the presentstudy,, possibly reflecting difficulties in detecting single individuals that will behaveinconspicuouslyy as to avoid detection by resident pairs. However, floating animalsmayy be genuinely rare as successful dispersal is hampered for reasons related toterritorialityy and monogamy. Floating sub-adults receive severe aggression frommatedd territorial adults (Tenaza, 1975; Mitani 1988) and undisturbed forests aregenerallyy saturated with territories. Few vacancies occur due to the mated status andrelativelyy long life span of adults (Mitani, 1990). Although little is known about thefatess of floaters, given the shortage of suitable habitat in a socially hostile27 7

ForestForest (and) Primatesenvironment,, it is reasonable to assume that many floating sub-adults soon die afterleavingg their natal groups (cf. Mitani, 1990).Linee TransectsWhilee conducting line transect censuses, problems can arise when collecting data ongroupp size and group spread. Gibbons live in groups that are tightly clustered,dispersedd over rather small distances (a small group spread), and the chance ofdetectingg all individuals in a group is large. Problems with grouping, as elucidatedbyy Brockelman & AH (1987), are less apparent in gibbons than in most otherprimatess on Borneo. Their large size, their vocal behavior, and the accessibility ofthee permanent transects, allowed reasonably accurate counts and distance estimates.Inn species where groups either are dispersed over distances exceeding the limits ofvisibility,, and where only parts of the group can be observed, or split in sub-groupsforr example when foraging, sub-groups may be counted as two (or more)independentt groups. Gibbons do not split up in sub-groups, and hence the use ofmeann group size as obtained from 'complete counts', as opposed to party size (i.e.,thee number of animals ranging together in the forest at a certain moment: van Schaikett al., 1983), is unlikely to lead to over-estimation of true densities.Forr east African forest primates, Plumtre (2000) showed that group spreadvariess between different times of the day and between months, and recommendedthatt survey techniques that used group spread not to be used. Yet, Fashing & Cords(2000)) also working with east African forest primates, concluded that Whiteside etal.'ss (1988) method, which incorporates species-specific group spread for estimatingtransectt width (equation 2.1), provide the most accurate density estimates. We feelthatt variation in group spread in the present study introduced less of a problemcomparedd to Plumtre's (2000) study. Gibbons live in tightly clustered groups, thelinee transect censuses were conducted in the mornings only, and seasonal variationinn group spread in Bornean gibbons is expected to be generally small andunimportantt given the short duration of the present study.Itt has been suggested that for gibbons, since at least some groups escapeobservation,, line transects will tend to systematically under-estimate true densities(Marshh & Wilson, 1981). We are confident that relatively few groups were missedduringg transect walks as sighting angles >90° (reflecting groups that were initially'missed')) were uncommon (TNKM: 4% and HLSW: 6% of groups within theeffectivee sighting distance). Density estimates from line transects in TNKM werejustt higher than from the other two methods, whereas in HLSW it was in line withestimatess from the fixed point count. Hence, there is no indication that the linetransectt technique systematically under-estimates density.Estimationn of sighting distances and/or perpendicular distances inevitablyintroducess error in calculation of the census area. Mitani et al., (2000) found thatinter-observerr variability in estimating sighting distances may be high. Since in thepresentt study only one observer estimated perpendicular distances, inter-observervariabilityy is absent, although distances may have been systematically over- orunder-estimated.. Steep slopes may introduce another problem in estimation of28 8

DensityDensity and Biomass Estimates of Gibbons in Bornean Rainforest: a Comparison of Techniquesperpendicularr distances. Blouch (1997) estimated perpendicular distances assumingthatt the animals were on a plane with the observer's eye. In hilly terrain this will leadthee area censused to be larger than the effective strip width indicates, and will createann over-estimation of true densities. Inaccurate measurement of transect length,whichh will be more apparent in rugged terrain, and failure to strictly follow theproceduress at the beginning and end of the transect may introduce another source oferror,, albeit a minor one.Inn the present study a comparison was made between encounter rates atpermanentt line-transects and trails following ridges. In both areas, encounter ratesfromm the ridges were 25-60% higher than from the transect lines. In hilly areas,gibbonss use ridges disproportionately for singing and also spent incommensuratemoree time on ridges than in valleys (HLSW: V. Nijman, unpubl. data; Whitten,1982)) or along rivers (TNKM: Nijman, 1997). Preference for ridges is morepronouncedd in the morning than in the afternoon (Whitten, 1982), coinciding withthee period most researchers conduct their transect walks. Positioning of transectroutess along ridges is therefore not recommended as it introduces a bias and willleadd to an over-estimation of true densities.Fixedd Point CountsDensityy estimation by means of fixed point counts was the most time-efficienttechnique,, and covered the largest survey area. The largest source of error isestimationn of the distance between the observer and the location from where gibbonsaree calling. Accuracy decreases with increasing distance (Brockelman &Srikosamatara,, 1993) and the error introduced in estimating density increases withincreasingg distance (Burnham et al., 1993). In the forest, calls can carry as far a twotoo three kilometers and estimation of distance for calls given at the farther end of therangee are inevitably inaccurate (V. Nijman, unpubl. data). More distant groups,whenn calling simultaneously, can be recorded as one calling group. This may lead tounder-estimationn of true densities. Again the error arising increases with increasingdistance.. As air heats up in the morning it becomes harder to locate groups (D.J.Chiverss in Duckworth et al., 1995), and thus accuracy of density estimation isgreatestt in the early morning. Calls carry poorly through vegetation and can best beheardd from high vantage points, away from noisy rivers.Byy censusing in the early hours of the day and by taking the topography of theareaa into account bearings and distances can be estimated with more accuracy,whereass by limiting the analysis to the nearest calls only, inaccuracies in densityestimationn can be reduced. Although it is generally assumed that Bornean gibbonsbecomee active at dawn (Leighton 1987; Mitani 1984), especially in HLSW gibbonscommencedd calling often at 04.00 hrs when it was still dark. Estimation of distanceatt these times was obviously more difficult than during daytime, and like in TNKM,fixedd point counts were only conducted between 06.00-09.00 hrs, coinciding withthee time of greatest singing activity in gibbons. Censusing at times of low activitywilll lead to under-estimating densities (Burnham et al., 1993).29 9

ForestForest (and) PrimatesTheree are inherent difficulties in calculating the proportion of groups calling on aparticularr morning. This proportion varies with species, populations, and season(Brockelmann & Ali, 1987). Both study sites are situated near the equator andcomparedd to other parts of the gibbon's range, seasonal variation is relatively small.Thee studies were furthermore short in duration making it unlikely that seasonalvariationn in the proportion of groups calling on an individual morning introduced asourcee of error. Calling frequency can be altered under the influence of variouskindss of habitat disruption, such as sounds of chain saws, logging, or hunting (Johns,1985,, 1986; Nijman, 2001). Both HLSW and TNKM are relatively secure fromloggingg and hunting and it is unlikely that during the study periods levels ofdisturbancee increased or decreased.CONCLUSIONS STheree is considerable variation in density and biomass estimates among the threedifferentt census techniques. For group densities, the lowest estimate was 28%(TNKM)) and 11% (HLSW) lower than the highest, for individual densities thesefiguress were 30% and 17%, and for biomass 29% and 15%, respectively. Incomparingg temporal changes of gibbon populations or in comparing habitats withdifferentt degrees of disturbance, changes in the order of 10 to 30 % can be quitesignificant.. Methodology did not explain a statistical significant proportion of thevariancee in density estimation, nor did site. The interaction between site andtechniquee explained the greatest proportion of variation, albeit not significant.Likee in many other studies the 'true density' in TNKM and HLSW is notknown,, as for this all individuals in the area should be individually recognizable(mostt likely only to be achieved by habituation), or some other, probably moreintrusive,, method should be employed (e.g., collecting, tagging). The differentestimatess may reflect differences in methodologies, but may also reflect nonhomogeneoussdensities. Although the three techniques were employed in the samegenerall area, the actual area sampled did differ in size and partially in location. Forbothh study areas the smallest area was sampled by the line transects, and this areawass completely included in the range mapping area. The largest area was sampledduringg the fixed point counts. For this method hill tops and ridges were chosen, andsincee gibbons tend to have a preference for ridges (V. Nijman unpubl. data; Whitten1982)) this may introduce a bias. If gibbons are not distributed evenly, than estimatesatt different spatial scales are expected to differ. This will be in part related to thedifferencess that exist in crude density, i.e., the density in the study area as a whole,andd ecological density, i.e., density in the habitat types actually occupied. Thegreaterr variation in micro-habitats present in TNKM and its greater altitudinal rangethann HLSW may account for the larger variation in density estimates in TNKM.Thee results of this study indicate that the interaction between site and techniqueexplainss the greatest proportion of the recorded variation and that different censustechniquess employed by the same observer can explain some 10 to 30 per cent of the30 0

DensityDensity and Biomass Estimates of Gibbons in Bornean Rainforest: a Comparison of Techniquesvariationn in density and biomass estimates. This result seriously questions thevalidityy of directly comparing estimates obtained by different techniques fromdifferentt areas often collected by different observers. Yet, this is precisely howcomparisonss (between densities and any other parameter) are done, viz., relying ondataa collected by others by a range of techniques over a range of areas. The largeinter-observerr variability in estimation of sighting distances, as reported by Mitani etal.,, (2000), clearly adds and subscribes to our viewpoint.ACKNOWLEDGEMENTS SThankss are due to the Indonesian Institute for Sciences (LIPI), the DirectorateGenerall for Nature Conservation (PKA formerly PHP A), the Ministry of Forestryandd Crop Estates (MOFEC), and the provincial branch of the Forestry Department(SBKSDA)) for permission to conduct field work in Indonesia. For information andhelpp of various sort we are grateful to Ir A. Rachmat (SBKSDA, Samarinda), Dr T.Jessup,, Dr C. Eghenter and Mr. A. Purmono (WWF-Indonesia), Messrs. D. Lenjau,I.. Lawin, I. Njuk, and M. Sudana (WWF-Indonesia, Lalut Birai), Dr R.K. Puri (East-Westt Center, Hawaii), M. de Kam and S. van Helvoort (MOFEC Tropenbos,Samboja),, G.M. Frederiksson (Sungai Wain), Dr D.M. Prawiradilaga (LIPI), DrP.J.H.. van Bree (ZMA, Amsterdam), Dr T. Geissmann (Tierartzliche HochschuleHannover),, Dr R.A. Blouch (Kerinci Sebelat ICDP-project), Dr J.K. Gurmaya(Padjadjarann University Bandung), and Dr A.0. Mooers (Simon Fraser University,Burnaby).. Additional financial support was received from the Society for theAdvancementt of Research in the Tropics, the Netherlands Foundation forInternationall Nature Protection and Stichting Het Kronendak. Dr A.0. Mooers, DrT.. Geissmann, and Dr K. Nagelkerke (IBED, Amsterdam) commented on themanuscript t31 1

ForestForest (and) Primates32 2

EffectsEffects ofBavioural Changes on Density Estimation of Rain Forest VertebratesCHAPTERR 3EFFECTT OF BEHAVIOURAL CHANGES DUE TO HABITATDISTURBANCEE ON DENSITY ESTIMATION OF RAIN FORESTVERTEBRATES,, AS ILLUSTRATED BY GIBBONS (PRIMATES:HYLOBATIDAE) )PpPp 217-225 in: P.J.M. Hillegers and H.H. de Iongh (eds.J. (2001). "Thebalancebalance between biodiversity conservation and sustainable use of tropical rainforests.forests. " The Tropenbos Foundation, Wageningen, the Netherlands.ABSTRACT TMonitoringg programmes often rely on changes in densities of single species toindicatee an ecosystem's health. These densities are estimated by a range of censustechniques,, including line transects and fixed point counts. Using data from gibbons(Primates:: Hylobatidae) the present study demonstrates that habitat disturbance (e.g.,logging,, encroachment) induces changes in the behaviour of species in such a waythatt it affects density estimation. As a result of disturbance, gibbons alter theirresponsee to humans, change their time budgets, and use different canopy levels.Callingg rates are generally lowered in response to disturbance and relatively morecallss are given at later times of the day. These behavioural changes alter thedetectabilityy of gibbons, both positively and negatively. The different factorsinfluencingg population estimation act in concert and may be difficult to separate todeterminee their effect. It is argued that in order to improve the effectiveness ofmonitoringg and censussing, the link between behavioural biology and conservationbiologyy should be strengthened.RINGKASAN NDampakk perubahan perilaku yang disebabkan oleh gangguan habitat kepadaperkiraann kepadatan populasi vertebrata hutan hujan, dicontohkan dengan owa(Primates:: Hylobatidae) (pp 217-225 in: Hillegers P.J.M. & de Iongh H.H. (eds) Thebalancee between biodiversity conservation and sustainable use of tropical rainforests.. Tropenbos, Wageningen, 2001): Program-program monitoring seringkalibergantungg pada perubahan kepadatan spesies tunggal dalam mengindikasikan suatukesehatann ekosistem. Kepadatan-kepadatan ini diperkirakan dengan menggunakanmetoda-metodaa yang berbeda, termasuk metoda garis transek dan hitung titik tetap.Dengann menggunakan data owa (Primata: Hylobatidae) studi saat inimemperlihatkann bahwa gangguan habitat (seperti penebangan, perambahan)menyebabkann perubahan perilaku spesies sehingga mempengaruhi perkiraankepadatan.. Akibat gangguan, owa mengubah responnya terhadap manusia,33 3

ForestForest (and) Primatesmengubahh penggunaan waktunya, dan menggunakan ketinggian kanopi yangberbeda.. Rata-rata bersuara secara umum berkurang akibat gangguan dan relatiflebihh banyak bersuara lebih siang. Perubahan perilaku ini mempengaruhikemudahann pencarian owa, baik positif maupun negatif. Faktor-faktor yang berbedamempengaruhii perkiraan populasi secara bersama-sama dan mungkin sul it untukdipilahh untuk menentukan pengaruhnya. Sedang didiskusikan bahwa untukmengembangkann kefektifan monitoring dan penghitungan, hubungan antara biologitingkahh laku dan biologi konservasi harus diperkuat.INTRODUCTION NBehaviourall studies have been considered to be of limited value to conservationbecausee of the discordance in the level of focus between behavioural andconservationn biologists. Behavioural research focuses on the level of populationsandd individuals, whereas many conservation biologists claim that conservation isonlyy effective on higher levels of biological organisation (Clemmons & Buchholz,1997).. Hence, in order to be meaningful, conservation research should focus itselfonn these higher levels. It may, however, be argued that single species can play animportantt role in monitoring the health of ecosystems when used as indicators. Inorderr to be useful, indicator(s) should, amongst other things, be amenable, revealmeaningfull trends, cost effective to monitor, be consistent, and yield data that areprecisee and unambiguous in its interpretation (GEC, 1998). Primates may meet someoff these demands. They are present throughout the tropics over a large range ofhabitats,, occur often in relatively high densities, and fulfil important roles in theirrespectivee ecosystems (Smuts et al., 1987). Hence, primates have been usedfrequentlyy in monitoring programmes (Glanz, 1982; Brockelman & Ali, 1987; Johns&& Skuropa, 1987; Whitesides etal., 1988).Thee two most commonly used census techniques to estimate primate densitiesemployedd in monitoring programmes or studies to quantify the effects of habitatdisturbancee are based on line transects (Sen, 1982; Whitesides et al., 1988) and to alesserr extent fixed point counts (Brockelman & Ali, 1987; Brockelman &Srikosamatara,, 1993).Thee transect technique depends on the detection of animals (or sometimesmerelyy signs such as nests) on one or both sides of a survey path. It has beenemployedd for survey work, where rapid estimates of populations in inaccessibleterrainn or in widely different geographic areas are required (e.g., Payne & Davies,1982;; Nijman & van Balen, 1998). It is also used for detailed studies within alimitedd geographic area, including monitoring of temporal changes in density(Glanz,, 1982), for comparisons of habitats within the same general area (Johns &Skuropa,, 1987; Blouch, 1997; Johnson & Overdorff, 1999), and for estimation ofpopulationss in areas where other methods (mark-recapture, complete counts, homerangee or territory mapping etc.) are not feasible (Green, 1978; Blouch, 1997). When34 4

EffectsEffects of Bavioural Changes on Density Estimation of Rain Forest Vertebratesusingg the transect method the number of groups detected, the effective sightingdistancee (an estimate of the distance at which the number of sightings at greaterdistancess equals the number 'missed' at nearer distances) and the group spread(definedd as the diameter of a circle of equivalent area to that occupied, on average,byy a group of the species under consideration) are parameters needed for estimatingdensitiess (Whitesides et al., 1988). For the method to be meaningful, criticalassumptionss are (i) animals are not affected by the presence of the observer; (ii)groupss are always detected on the transect line itself; (iii) groups behaveindependently. .Censusess based on fixed point counts are widely used in ornithological studies(e.g.,, Reynolds et al., 1980; Bibby et al., 1992a) and are especially suitable inruggedd terrain. A similar method has been developed to estimate the density ofprimatess producing loud calls at predictable times of the day, e.g., Indri (Indridae),certainn colobines (Colobinae), and gibbons (Hylobatidae) (e.g., Kappeler, 1984;Brockelmann & Ali, 1987; Brockelman & Srikosamatara, 1993). This method isbasedd on the number of groups that can be heard calling over a given number ofdays.. The observer is situated at a vantage point and notes the number of groupscallingg within the census area. This method allows density estimation over relativelylargee areas in a short time span. In order to calculate densities using fixed pointcounts,, parameters needed include the number of groups calling on a given day, theproportionn of groups calling on a given day, and the radius of the area from withinsongss can be mapped (Brockelman & Srikosamatara, 1993). Critical assumptionsincludee (i) only paired groups call; (ii) groups behave independently; (iii) groups callatt least once during the study period.Johnss (1985ac; 1986) followed a primate community in Western Malaysiawhilee their habitat was selectively logged. In his study a number of behaviouralchangess following logging were observed in a number of species, including: (i) largibbonn Hylobates lar showed a tendency to increase their freezing behaviour andfleeingg noisily decreased; (ii) Activity patterns in H. lar and banded leaf monkeyPresbytisPresbytis melalophos changed with a significant increase in time spent resting and asignificantt decrease in time spent feeding and travelling; (iii) For the same twospeciess there was a significant shift from the upper to the middle canopy level for alltypess of behaviour combined; (iv) During heavy disturbance, gibbons often ceasedcallingg altogether, and calling rates may have remained depressed for several yearsafterr logging had ceased. Similar behavioural changes were found by J. Mitani (inBerenstainn et al., 1982) when comparing the singing behaviour of Bornean gibbonH,H, muelleri in forest prior and after the drought and fire associated with the 1982-19833 El Nifio Southern Oscillation Event. Population numbers remained unchanged,butt audible ranges of songs decreased, frequency of singing declined, and gibbonssangg from lower heights.Sincee these behavioural changes may be relevant to monitoring and censussing,thee present study considers two questions: 1. How and to what extent do primatesalterr their behaviour in response to human induced changes in their environment(e.g.,, logging, hunting, encroachment), and 2. Do these behavioural changes affect35 5

ForestForest (and) Primatespopulationn density estimates when using either the transect method or fixed pointcounts? ?Thee implications may be crucial when comparing the results of surveys inhabitatss differing in their degree of disturbance and in monitoring programmeswheree disturbance levels change over time. Whether behavioural changes do affectdensityy estimation will be illustrated with examples from studies on different gibbontaxaa from the Sundaic region, but the conclusions and recommendations are mostlikelyy to be valid for other regions and for other rain forest vertebrates as well,includingg other primates, mammals, and birds.Inn order to address the two questions, a comparison is made between thebehaviourr of gibbons in disturbed and undisturbed situations and the subsequentimplicationss for monitoring are assessed. The behavioural changes can both affectthee parameters needed for density estimation and violate the (critical) assumptionsoff the methods employed.MATERIALL AND METHODSGibbonss are territorial and live in monogamous family groups consisting of an adultpairr with none to four offspring, Gibbons are completely arboreal, and are largelyfrugivorous.. Paired groups give loud morning calls, which can be heard over severalkilometres,, whereas single individuals rarely call (Leighton, 1987; pers. observ).Thee present study concerns data collected on Bornean gibbon H. muelleri in EastKalimantann (Kayan Mentarang National Park and adjacent areas in 1996 [115°51E,2°50'N])) and Javan gibbon H. moloch on Java (Gede-Pangrango National Park andadjacentt areas in 1994-1999 [107°OO'E, 6°45'S], and Dieng mountains proposedNationall Park and adjacent areas in 1995-1999 [109°35'E, 7°06'S]).Undisturbedd and disturbed study sites were selected either in close proximityandd were similar in climate, original vegetation type, altitude and topography (Gede-Pangrangoo and Kayan Mentarang), or a forest area was sampled before (1995-1998)andd during logging (1999) during the same months of the year (Dieng). Given theclosee proximity and similarity of the forest areas, it is anticipated that the behaviouroff the gibbons prior to the commencement of disturbance did not differ significantly.Setss of disturbed and undisturbed areas had mean densities differing less then 10%,whichh was established by a number of techniques (line-transects, range mapping,fixedd point counts). For the present study, disturbance is taken in a rather broad termandd may include hunting, encroachment, small scale logging, commercially(selective)) logging, or a combination. Behavioural measurements were collectedalongg line transects, on vantage points during fixed point counts, and ad libitumwhilee surveying in the forest. Singing behaviour of at least eleven H. moloch groupswass monitored in Dieng for 35 days in Sept-Oct 1998 (pre-logging) and for 25 daysinn Sept-Oct 1999 (during logging). Some additional data on singing behaviour ofsiamangg Symphalangia syndactylus was collected in Way Kambas National Park,Sumatraa (1994 and 1999 [105°36'E, 4°50'S]).36 6

EffectsEffects of Bavioural Changes on Density Estimation of Rain Forest VertebratesForr all analyses non-parametric statistics were used (Siegel, 1956) and Yates'scorrectionn for continuity was applied in the x 2_ tests where appropriate.RESULTS SBehaviourall changes affecting line transect censusing/.. Responses to observersThee most common response of gibbons to the approach of a human is to flee. Thiscann be accompanied by branch shaking and vocalising. Alternative responsesincludee freezing, i.e., remaining immobile, and hiding, i.e., moving out of the fieldoff vision of the approacher. Vocalisations are normally uttered only when theprimatess detected humans at close proximity.Tablee 3.1Behavioural responses of two gibbons species to an observer in disturbed versus undisturbedhabitats.. Cases where the gibbons did not detect the observer are excluded.Speciess Fleeing Fleeing Freezing HidingStudyy site with vocalising without vocalisingHylobatesHylobates muelleriKayann Mentarang (1)undisturbed ddisturbed dHylobatesHylobates molochGede-Pangrangoo (2)undisturbed ddisturbed dMtss Dieng (3)undisturbed ddisturbed d20 012 212 25 560 037 71.. Undisturbed forest consisted of primary forest in the Nggeng Bio River valley, whereas disturbedforestt consisted of 45 year old secondary forest which was situated c. five km south-east in the BuaAlatt river valley, East Kalimantan.2.. Undisturbed situation consisted of relatively undisturbed forest in Gede-Pangrango National Park,whereass the disturbed situation consisted of adjacent (smaller) forest patches outside the parkboundaries. .3.. Undisturbed situation consisted of old secondary forest near Linggo, Central Java, in 1998, whereasthee disturbed situation consisted of the same forest area in 1999, when a small scale illegal loggingoperationn was in force10 09 95 532 224 4Inn response to the continued or the increased presence of humans, gibbons alter theirbehaviourr (Table 3.1). Freezing and hiding and silently moving away becomes morecommon,, though none of the differences are significant (x 2 , all p>0.05). In all threestudyy areas, and for both species, the response was in the same direction, i.e.gibbonss tended to behave in such a way as to reduce the likelihood of beingdetected.. Increase in freezing, hiding and silently moving away, makes it moredifficultt to locate or detect groups of primates and will lead to a decrease of groups37 7

ForestForest (and) Primatesdetected.. It is furthermore likely that group sizes will be under-estimated as itbecomess more difficult to detect all individuals in a group.2.2. Change in activity patternsPrimatess are most often detected when engaged in conspicuous activities such asvocalising,, travelling or feeding, either due to visual or auditory cues of the animalsthemselvess or their surroundings (moving of branches, falling fruit etc.). They arelesss easily detected when resting. Since time spent travelling and feeding is loweredinn disturbed forests, this means that fewer groups will be detected in disturbedhabitats.. This will also include groups at the transect line, violating one of thecriticall assumptions of the method. Considered in isolation, the observed change inactivityy patterns will lead to an under-estimation of true densities in disturbedhabitats. .Hylobatess larUndisturbeddDisturbedHylobatess molochUndisturbeddDisturbedEmergents sUpperr canopyMiddlee canopyLowerr canopyFiguree 3.1Percentage of canopy use by two gibbon species in disturbed and undisturbed habitats1.. undisturbed situation consists of hill forest in the Sungai Tekam, West Malaysia, whereas thedisturbedd situation consists of the same area after >50% of the trees were lost due to selective logging(afterr Johns, 1986)2.. see footnote 3, Table 3.1.3.3. Use of canopy levelsGibbonss prefer tall trees for certain activities. Emergent trees and the upper canopyaree disproportionately used (favored) for singing and travelling (cf. Kappeler, 1984;Johns,, 1986). In disturbed forests, due to the loss of many large trees, generallyactivitiess have shifted from the upper to the middle canopy (Figure 3.1: H. lar. % 2 =89.4,, df=3, p

EffectsEffects ofBavioural Changes on Density Estimation of Rain Forest Vertebratesobserverr and the animal, primates are more easily detected at lower canopy levels. Ingeneral,, the shift to lower forest strata will lead to an increase of groups detected.Behaviourall changes affecting fixed point counts censusing1.. Calling ratesThee frequency of calling in gibbons is dependent on, among other things, populationdensity,, weather (rain, wind), and seasonality of food production (e.g., Chivers &Raemaekers,, 1980; Brockelman & AH, 1987; V. Nijman, unpubl. data). Disturbanceinn the form of for instance logging will lead to an increase in ambient temperature inthee forest, greater differences in temperature between day and night, and an increaseinn windiness (e.g., Grieser-Johns, 1997). These changes in the (micro)-climate of theforestt can affect calling rates.Contraryy to one of the critical assumptions of the fixed point count method, groupsdoo not behave independently. In the present study it was found that songs werestimulatedd by neighbours (H. moloch and H. muelleri), and sometimes songs seemedtoo pass round the local population (H. moloch, H. muelleri, and S. syndactylies).Loweredd calling activity makes detection less likely, whereas estimation of theproportionn of groups calling on a given day becomes more prone to errors.2.. Timing of callsDuringg a study into an undisturbed population of H. moloch, Geissmann & Nijman(2000)) noted that some 85% of the female calls and all male calls were given withinfourr hours after sunrise. In disturbed situations, timing of calling changes, with moregroupss calling later during the day (Table 3.2). As air heats up during the daylocatingg groups becomes more difficult and the estimation of distance between theobserverr and gibbons becomes more error prone (cf. D.J. Chivers in Duckworth etal.,, 1995). Lowered precision in locating groups may result in two groups callingfromm the same general direction being recorded as one, whereas the estimation of theradiuss at which songs can be mapped becomes more difficult. This in effect caninfluencee density estimation in either a positive or negative direction.Tablee 3.2Number of days Hylobates moloch groups were heard calling at different times of the day(Mtss Dieng 1998-1999).Timee after sunrise (hrs)>6Habitatt

ForestForest (and) PrimatesDISCUSSION NThee data indicate that gibbons (and probably other primates as well) do responddifferentlyy to the presence of humans, including surveyors, in disturbed habitats thaninn undisturbed habitats (cf. Johns, 1985a; 1986). In the present study, hunting levelsweree generally low, but high hunting pressure can alter the behaviour of primates toann even greater extend (Kavanagh, 1980; Watanabe, 1981). When conducting linetransects,, fewer groups will be detected in disturbed habitats as gibbons show anincreasee in freezing, hiding, and silently moving away. A decrease in conspicuousactivitiess such as vocalising, travelling and eating, as reported by Johns (1985a;1986),, should lead to a decrease in number of groups observed, and may violate theassumptionn that all groups are detected on the transect line. Only if the decrease innumberr of groups is unequal for groups on the transect line and groups locatedfartherr away, in such a way that groups on the transect line are still always recorded,aa decrease in groups detected will not necessary result in a reduction of estimateddensityy (Skorupa, 1987). However, as there is no indication whatsoever that thenumberr of groups detected on the transect line itself will not have decreased, one ofthee critical assumption of the line transect method is violated. This will lead to anunder-estimationn of true densities. Under-estimation of true densities will be evenstrongerr when indeed actual group sizes are under-estimated owing to the increaseddifficultyy in counting individuals. However, not all behavioural changes by gibbonswilll lead to an under-estimation of true densities, since the marked increase in theusee of the lower to middle canopy over the upper canopy in disturbed habitats makesitt easier for an observer to detect gibbons.Callingg frequency in gibbons is dependent on a number of environmentalvariables,, including population density, weather, temperature in the forest, andseasonalityy of food production (Chivers, 1974; Kappeler, 1984; Brockelman &Srikosamataraa 1993; V. Nijman unpubl. data), which all might be affected by habitatdisturbance.. Logging will induce changes in the micro-climate of the forestincludingg an increase in ambient temperature, greater differences in temperaturebetweenn day and night, and an increase in windiness (e.g., Grieser-Johns, 1997).Habitatt disturbance may also alter the acoustical environment on which organismsrelyy for communication (Clemmons & Buchholz, 1997). Increase in windiness willleadd to a significant decrease in calling (H. pileatus: Brockelman & Srikosamatara,1993),, and changes in the ambient temperature may affect pre-dawn calling bymaless in two species (H. klossi and H. moloch), as pre-dawn calling in male Kloss'gibbonss is positively related to temperature (Whitten, 1982c).Contraryy to one of the critical assumptions of the fixed point count method,groupss do not behave independently. Songs were stimulated by neighbours (cf. H.lar,lar, Raemaekers & Raemaekers, 1985b), and songs seemed to pass round the localpopulationn as has been reported in other studies (Brockelman & Ali, 1987). Fixedpointt counts are furthermore affected by a depression of calling rates during the day,andd possibly by an increase in pre-dawn calling. Lower calling rates make detection40 0

EffectsEffects ofBavioural Changes on Density Estimation of Rain Forest Vertebrateslesss likely, and calls given later during the day makes distance estimation moredifficult. .Similarr to the studies conducted by Johns (1985ac; 1986) and J. Mitani (inBerenstainn et al., 1986), the present study compared the behaviour of primates inareass where the true density was either very similar or had remained virtually thesame.. Effects of a lowered (or increased) density were not taken into consideration.Habitatt disturbance often has an effect on density, due to a lowered carryingcapacityy of the forest, lowered fecundity, higher mortality (aggravated by anincreasee in hunting), and sometimes due to groups migrating out or into an area.Loweredd densities will introduce additional changes in the parameters needed fordensityy estimation, including smaller group spread for smaller groups, smallereffectivee sighting distance due to reduced group sizes (e.g., van Schaik et al., 1983;V.. Nijman unpubl. data), and a disproportionate reduction of calling rates (V.Nijman,, unpubl. data). Alternatively, locally habitat disturbance may lead to largergroupp sizes and higher densities. In degraded forest with a discontinues canopy theobligatee arboreal nature of many primates, and gibbons in particular, does not permitthemm to move from one remnant forest patch to another. This induces delayeddispersall of sub-adults, leading to larger group sizes and (temporarily) higherdensitiess (e.g., Brockelmann et al., 1998; Oka et al., 2000).Comparingg census data from habitats differing in degree of disturbance shouldbee viewed with caution and conclusions should be drawn with care. The mereobservationn that certain animals are more/less often recorded in these differenthabitatss in itself carries little information. Hence, comparisons of abundances ofvertebratess in disturbed and undisturbed situations based on encounter rates only, asdonee extensively for example by Grieser-Johns (1997) when reviewing theresponsess of vertebrates in relation to timber production and biodiversityconservationn in tropical rain forests, becomes in effect meaningless.CONCLUSION NHabitatt disturbance clearly alters the behaviour of gibbons, and probably many othervertebrates,, in such a way that it affects density estimation. Behavioural alterationsmayy be species specific, but may also be related to the types of disturbance, such asthee presence or absence of hunting/capturing. Different factors influencingpopulationn size estimation act in concert, and may be very difficult to separate todeterminee their net effect. When comparing census data from habitats differing intheirr degree of disturbance, the effect of behavioural alterations should berecognisedd and conclusions drawn with care. It is concluded that there is anincreasedd need for understanding the behavioural plasticity of indicator species, andbehaviourall studies should play a more prominent role in conservation.Strengtheningg the link between studies in behavioural biology and conservationbiologyy is needed for improved monitoring and censusing (cf. Beissinger, 1997;Clemmonss & Buchholz, 1997).41 1

ForestForest (and) PrimatesACKNOWLEDGEMENTS SII wish to thank the Indonesian Institute of Sciences (LIPI), the Directorate Generalforr Forest Protection and Conservation (PKA) and the Ministry of Forestry andEstatee Crops (MOFEC) for allowing me to conduct this research. In this, the help ofthee Museum Zoologi Bogor, and especially Dr D.M. Prawiradilaga is kindlyacknowledged.. Financial support for the study came from the NetherlandsFoundationn for International Nature Protection (Van Tienhoven Stichting), Societyforr the Advancement of Research in the Tropics (Treub Maatschappij), and Stichtinghethet Kronendak. Dr H. Albrecht (formerly Dept. of Animal Behaviour, University ofAmsterdam)) was instrumental in offering insight into the links between ethologyandd primate conservation. Dr P.J.H, van Bree (Zoological Museum Amsterdam) isthankedd for his help throughout the project. Prof. Dr S.B.J. Menken and Dr A.0Mooerss (ISP /ZMA, University of Amsterdam) gave valuable comments on a draftoff this paper.42 2

CallingCalling Behaviour ofWildJavan Gibbons in Java, IndonesiaCHAPTERR 4CALLINGG BEHAVIOUR OF WILD JAVAN GIBBONSHYLOBAHYLOBA TES MOLOCH IN JAVA, INDONESIAwithwith Thomas GeissmannABSTRACT TThee Javan gibbon Hylobates moloch is endemic to the island of Java, Indonesia. Ashardlyy any behavioural data are available for this endangered primate, we studied thesingingg behaviour of the easternmost population of this species in the Diengmountains,, Central Java, Indonesia in 1998-1999. The aim was to document thetimingg of singing, to quantify the amount of singing by the respective sexes and toexploree the role of bio-acoustics for density estimation. We recorded location andsexx of the singer, and starting and ending time of all song bouts we heard. We heardaa total of 122 song bouts of at least 12 groups. Most groups could be identified byindividual-specificc song characteristics. No duet songs were heard. Most of the songboutss (91.5%) were female solo song bouts or female scream bouts. Pure femalesoloo song bouts with one participant are significantly shorter in duration than femalesongg bouts with two participants of the same group (median duration of 6 and 9 min,respectively).. In contrast to earlier studies on the westernmost population of Javangibbon,, in which few if any male songs were heard, at least 8.5% of the song boutsinn our study were male solo song bouts. Male songs are significantly longer indurationn than female songs (median duration of 12 and 7 min, respectively). Allmalee song bouts uttered before dawn (05:20 hrs) were produced in a chorus fashion,withh at least three individuals participating. Choruses occur about once every 8.5dayss and all lasted longer than the longest female solo song bout (range 42 min - Ih477 min). Male choruses and female solo song bouts appear to be temporallysegregatedd events: Most male songs (60%) started between 03:55-04:40 hrs, when itwass still dark. All female songs, in contrast, started after 05:00 hrs and femalesingingg activity peaked around 06:00. Neither regular male singing, nor malechorusing,, nor regular pre-dawn singing, have previously been reported for Javangibbons.. Similarly separated periods of male and female solo songs and the absenceoff duetting are known from Kloss gibbons (H. klossiï) on the Mentawai Islands andmayy represent a synapomorphy shared by H. moloch and H. klossii. The individualspecificcsong characteristics of Javan gibbons allow accurate mapping of groups.Thee density of gibbons at our study site was established as such at 1.9-3.7 groupsperr km 2 corresponding with 6.7-13.1 individuals per km 2 . We reassess the suitabilityoff gibbon songs as a means for estimating density and size of gibbon populations.43 3

ForestForest (and) PrimatesRINGKASAN NPerilakuu bersuara Owa Jawa Hylobatus moloch liar di Jawa, Indonesia (bersamaThomass Geissmann): Owa Jawa Hylobatus moloch merupakan jenis endemik PulauJawa,, Indonesia. Berhubung sangat sedikitnya data tingkah laku primata terancamini,, kami mempelajari perilaku bemyanyi populasi bagian paling timur spesies ini diPegunungann Dieng, Jawa Tengah pada tahun 1998-1999. Kami bertujuan untukmendokumentasikann waktu bemyanyi, untuk mengetahui jumlah nyanyian olehmasing-masingg jenis kelamin dan untuk mengetahui peranan bio-akustik untukperkiraann kepadatan. Kami mencatat lokasi dan jenis kelamin yang bersuara, danawall dan akhir waktu bersuara yang kami dengar. Kami mendengar 122 suarapanggilann dari sektidaknya 12 kelompok. Kebanyakan kelompok dapat diidentifikasidarii karakteristik suara individu yang spesifik. Tidak ada suara duet yang terdengar.Kebanyakann suara panggilan (91,5%) yaitu suara panggilan betina atau suarateriakann betina. Suara panggilan betina yang murni tunggal dengan satu anggotamemillikii jangka waktu yang lebih pendek daripada suara panggilan betina denganduaa anggota di dalam kelompok yang sama (masing-masing rata-rata lama bersuara66 dan 9 menit).Berlawanan dengan studi-studi lebih awal pada Owa Jawa populasibagiann paling barat, di mana sangat sedikit suara jantan terdengar jikapun ada,setidaknyaa 8,5% panggilan di daerah penelitian kami adalah suara panggilan jantan.Suaraa panggilan jantan secara signifikan lebih panjang durasinya dibanding suarapanggilann betina (rata-rata masing-masing 12 dan 7 menit). Semua panggilan jantanyangg bersuara sebelum fajar (jam 05:20) dihasilkan dalam bentuk bersahutan(chorus),, dengan setidaknya tiga individu ikut terlibat. Sahutan terjadi kira-kirasekalii setiap 8,5 hari dan semua bertahan lebih lama daripada suara panggilantunggall betina terpanjang (rata-rata 42 menit- 1 jam 47 menit). Sahutan jantan dansuaraa panggilan betina tunggal secara temporal terjadi pada waktu terpisah: Suarajantann terbanyak (60%) dimulai antara jam 03:55-04:40, saat hari masih gelap.Sebaliknya,, semua nyanyian betina dimulai setelah jam 05:00 dan puncak aktivitasbersuaraa betina sekitar pukul 06:00. Tidak ada nyanyian jantan tetap, atau sahutanjantan,, atau nyanyian tetap sebelum fajar, yang telah dilaporkan sebelumnya untukOwaa Jawa. Periode bersuara tunggal antara jantan dan betina yang terpisah ini, sertatidakk adanya duet juga dikenal dari Siamang Kerdil (H. klosii) di KepulauanMentawaii dan mungkin mewakili synapomorfi antara H. moloch dan H. klosii.Karakteristikk suara individu khusus Owa Jawa memungkinkan pemetaan kelompokkelompokkyang akurat. Kepadatan owa-owa di tempat penelitian kami begituditetapkann sebesar 1,9-3,7 kelompok per km 2 setara dengan 6,7-13,1 individu perkm 2 .. Kami menetapkan kembali kesesuaian suara owa sebagai alat untukmemperkirakann kepadatan dan ukuran populasi owa.44 4

CallingCalling Behaviour ofWildJavan Gibbons in Java, IndonesiaINTRODUCTION NAlll gibbon species are known to produce loud, long and well patterned songs.Typically,, songs are produced early in the morning. In mated pairs, male and femalesongg contributions are sex-specific. In virtually all species, mated males spend atleastt as much time singing as mated females (e.g., Gittins, 1984ab; Haimoff, 1985;Raemaekerss et al., 1984; Whitten, 1984). The following song patterns occur amonggibbonn species (Geissmann, 1993, 1995, and unpublished data; nomenclature andclassificationn follow Geissmann, 1994, 1995, in press): (1.) Duet song bouts only(sixx species: all species of the genera Bunopithecus, Nomascus and Symphalangy);(2.)) duets and male solo songs (four species: Hylobates agilis t H. lar, H. muelleriandd H. pileatus); (3.) female solo songs and male solo songs (two species: H. klossiiandd H. moloch).Gibbonn songs probably have several functions. These may include spacingamongg groups, defence of resources (such as territories, food sources or mates),matee attraction, strengthening of the pair bond and / or advertisement of the pairbondd (Cowlishaw, 1992; Geissmann, 1999; Leighton, 1987; Mitani, 1984, 1985ab,1987;; Raemaekers & Raemaekers, 1985ab).Thee Javan gibbon is endemic to the western half of Java, Indonesia. Mostpopulationss can be found in the western province (Asquith et al., 1995; Kappeler,1984b),, but a few populations remain in the Central Javan province (Nijman, 1995).Thee most recent population estimates based on extrapolation of the availablehabitat,, range from 2,000 animals (Supriatna et al., 1994) to 3,000 animals (Asquithett al., 1995); however, both studies did not take into account the Central Javanpopulations.. The species has lost some 96-98% of its habitat (MacKinnon, 1984,1987)) and has merited the highest conservation priority rating for Asian primates(Eudey,, 1987ab). The Javan gibbon is included in the Critically Endangeredcategoryy according to the IUCN threat criteria (IUCN Species SurvivalCommission,, 1996; Eudey, 1997), is protected by Indonesian law, and is listed onAppendixx I of the CITES convention.Soo far the only comprehensive study on the behavioural ecology, includingcallingg behaviour, of wild Javan gibbons has been conducted by Kappeler in 1975-19766 and 1978 (Kappeler 1981, 1984abc). Because males of the resident groups inhiss study area, Ujung Kulon, West Java [6°45'S, 105°20'E, see Fig. 4.1], did notsing,, he concluded that territorial male gibbons do not sing. Two other short studiesconductedd in other parts of Ujung Kulon provide some data on calling behaviour butdoo not specify the sex of the calling animals (Gurmaya et al., 1995; Rinaldi, 1999).Consideringg the Javan gibbon's threatened status and the small amount ofdetailedd information available on its behavioural ecology, all of which was collectedonn the westernmost population in Ujung Kulon, we set out to collect data on thespecies'' calling behaviour in the opposite end of its distribution area, i.e. the Diengmountainss in Central Java (Fig. 8.1).45 5

ForestForest (and) PrimatesThee aim of the present study is threefold: (i) to provide an accurate description ofmalee and female singing behaviour, (ii) to document the timing of Javan gibbonsongs,, (iii) to quantify the amount of singing of the respective sexes and ofindividuall gibbons. In addition, (iv) we compare our results with those frompreviouss studies from Ujung Kulon, (v) we discuss our findings in relation tocurrentt knowledge on gibbon phylogeny and (vi) we explore the role of bioacousticsinn conservation monitoring studies of gibbons (in particular for density estimation).00 100 200Figuree 4 1Map of Java showing the remaining forest areas inhabited by gibbons. Ujung Kulon is thewesternmostt population and Dieng the easternmost, (gibbon distribution after Asquith et al.,1995;; Kappeler, 1984a; Nijman, 1995; and Nijman, unpubl. data).MATERIALL AND METHODSStudyy area and data acquisitionThee Dieng mountains harbour the largest population of Javan gibbons in CentralJava,, which is estimated at >500 individuals (Nijman & van Balen, 1998). DespiteCentrall Java being largely deforested, the Dieng mountains are still extensivelycoveredd with forest ranging from about 300 m a.s.1. in the area north of Linggo to25655 m a.s.1. at Mt. Prahu. The vegetation of the Dieng mountains is of the wettesttype,, and, roughly below 1,000 m, consists of mixed lowland and hill rain forest,and,, up to about 2,400 m, consists of montane everwet rain forest (for a morecompletee description of the study area see Nijman & van Balen, 1998, chapter 8).Thee study area proper was at the Linggo Asri resort [7°06'S, 109°35'E], nearthee village of Linggo in the western part of the Dieng mountains, Central Java. Theareaa is covered in a patchwork of old secondary forest mixed with more primaryforest,, and cultivated land. Its altitudinal range is between c. 450 and 650 m a.s.1.Thee climate is perhumid with daily maximum temperatures ranging between 27-46 6

CallingCalling Behaviour ofWildJavan Gibbons in Java, Indonesia31°CC and an annual rainfall of about 6,000-7,000 mm. Only during the months July-Sept,Sept, less rainfall is recorded, but the monthly average remains above 100 mm(climaticc data from the weather stations of Sumigih and Pagilaran, RePPProT,1990). .Wee monitored gibbon singing activity around Linggo Asri on a daily basisduringg 19 consecutive days from 23 Sept-11 Oct 1998. During the first 11 days,gibbonn singing activity was monitored from predawn to dusk, the remaining 8 dayscoveredd the predawn-dawn period only (i.e. from about 1.5 h prior to dawn to 0.5 hafterr dawn). Subsequently, male pre-dawn singing was monitored again for anadditionall 15 days over the period 31 July - 25 Aug 1999. Dawn was defined as thetimee that colour was first discernible in the forest canopy (Gittins, 1984a), andoccurredd around 05:20 hrs local time. Sunrise was determined by the time the sunwass first seen at the study site and occurred around 06:15 hrs. During eachobservationn period, we recorded location and sex of the singer, as well as startingandd ending time (to the next minute) of all song bouts heard.Thee density of gibbons was estimated by mapping of localities from wheregibbonss were vocalising, as detectable from one single listening post, as describedbyy Brockelman & Ali (1987). From this fixed point count, density estimates werecalculatedd using the following equation:DD = n / (p A) = n / (p (j) TIT 2 ), (equation 4.1)wheree D is density (mated pairs per square kilometre); n is the average number ofdifferentt groups heard calling per day, as determined over a ten day period; p is theestimatedd proportion of days on which gibbons sing, as established by monitoringthee complete song output of two individually recognisable groups (AS-9 and AS-2);(f>> is the section of a circle from which gibbons could be heard; r is the radius fromwithinn which gibbons could be heard.Wee made a calculation for a smaller area, within which all groups could beidentifiedd by their song (r = 1.0-1.4 km; ty is 135°), and for a larger area, which alsoincludedd unknown groups within hearing distance (r = 1.4-1.8 km; is 180°).Becausee more forest was intact in the larger area, the section of the circle fromwhichh gibbons could be heard is broader here.Inn addition to field work, songs of captive Javan gibbons were studied at thefollowingg zoos: Berlin Zoo and Munich Zoo (Germany); Jakarta Zoo and TamanSafari,, Cisarua (Indonesia); Howletts Zoo and Paington Zoo (United Kingdom). Themethodd of data collection was the same as that described above for wild Javangibbons. .Bioacousticc methods and definitions of bioacoustic termsAlll tape-recordings were made with a Sony TC-D5M tape-recorder equipped with aSennheiserr ME80 (+K3U) directional microphone or a Sony WM-D6C taperecorderrequipped with a JVC directional microphone.47 7

ForestForest (and) PrimatesSonagramss of song sequences were made with Canary 1,2.4 software (Charif et al.,1995)) on an Apple personal computer (PowerMacintosh). Recording parameters:111 kHz sampling rate, 16 bit sampling. Analysis parameters: FFT, Hamminganalysiss window; analysis resolution: 43.7 Hz filter bandwidth, 1024 points framelength;; grid resolution: 23.1 ms time, 75% overlap, 5.4 Hz frequency resolution,20488 points FFT size. Duration and frequency measurements of vocalisations werealsoo carried out using Canary 1.2.4 software.Thee acoustic terminology largely follows that proposed by Haimoff (1984). Asongg is what fulfils the criteria set forth by Thorpe (1961, p. 15): "What is usuallyunderstoodd by the term song is a series of notes, generally of more than one type,utteredd in succession and so related as to form a recognisable sequence or pattern intime",, or, a song is a succession of phrases with non-random succession probability("Strophenfolgenn mit nicht-zufalliger Folgewahrscheinlichkeit", Tembrock, 1977, p.33).. Song bouts are separated from each other by an arbitrarily defined interval of>55 min. A duet occurs when one individual coordinates its vocalisations in time ortypee of vocalisation with those of another individual (Seibt & Wickler, 1982;Wickler,, 1974), and a duet song is a song jointly uttered by two individuals andcoordinatedd in time or phrases.Gibbonn song bouts consist of phrases; phrases consist of notes. A phrase doesidentifyy a single vocal activity consisting of a succession of notes which areproducedd together in a characteristic manner, but which also may be producedindependently.. A note is any single continuous sound of any distinct frequency orfrequencyy modulation, which may be produced during either inhalation orexhalation.. Great calls are the most stereotyped and most easily identifiable phrasesoff gibbon song bouts and are produced by females of all gibbon species. Anothercharacteristicc phrase in many gibbon songs is the male's coda, a phrase which isproducedd at or near the end of the female's great call. A chorus is defined as thetemporall overlap of song bouts of several individuals during a continuous timeperiodd which normally exceeds the duration of any single participant's song bout(Tenaza,, 1976: p. 43).RESULTS SDescriptionn of female song boutsFemaless typically produce two types of vocalisations during their song bouts: (1)simplee wa notes or phrases of wa notes, and (2) great calls or aborted great calls. Afemalee song bout is usually introduced by a variable but simple series of notestermedd the introductory sequence. It consists of single wa notes uttered at irregularintervalss and series of wa notes. Thereafter, great calls are produced with an intervaloff about 1-2 min. Between great calls, females usually produce so-called interludesequences.. Similar to the introductory sequence, the interlude sequences consist ofsinglee wa notes uttered at irregular intervals and variable series of wa notes. Series48 8

CallingCalling Behaviour of Wild Javan Gibbons in Java, Indonesiawhichh are separated from other notes by an interval of at least 5 seconds are termed"femalee short phrases".11 H0 01 10=^ ^1 100 =1--00 =11 -00 =t t0=i i1 1mnnnir-r-^^JHitrrrrs, mnnncc Mnuiirr*~*Jjnmmtf Mnuiirr*~*JjIftfififfitrirr-fftIftfififfitrirr-fft unrrJ*0Vt»J*0Vt» J$ih,j, i&fiit.. m m AIFIFffftm & &VV f f f I / IF*«* , f f ffrh kWiii i0frh Ih, if Inrr £*&**J J> I , f f fQ-' Q-'ii 1 1 100 5 10 15sFiguree 4.2Sonagrams of representative phrases of female songs (a-c), female scream calls (d),communall group calls (e), and male phrases (f-i), tape-recorded from captive and wildJavann gibbons, (a) female wa notes and great call from Ujung Kulon, West Java; (b) femalewawa notes and great call from Pelabuhanratu, West Java; (c) female wa notes and great callfromm Linggo Asri, Central Java; (d) screams and wa notes of two neighbouring females atthee common territorial border in Linggo Asri, Central Java; (e) communal wa phrases offamilyy group (ad. pair and juvenile) at Berlin Zoo, Germany, (f) male phrases from GunungLawet,, Central Java; (g) male phrases "Omar" from Howletts Zoo (United Kingdom); (h)malee phrases "Hilo" from Howletts Zoo (United Kingdom); (i) male phrases ("Paul") fromMunichh Zoo, Germany.49 9

ForestForest (and) PrimatesFemalee great calls (Fig. 4.2a-c) are announced by a particularly regularly pacedseriess of wa's. The great call itself consists of 8-22 notes and often begins with aspeciall inflected note, followed by one or several long notes of slowly increasingfrequency.. Through a steady shortening of both note duration and intervals, thegreatt call develops into a series of accelerated wa notes building up to a trill-likeclimax,, after which the speed of note delivery becomes slower again at the end ofthee great call (Geissmann, 1993, 1995). As already noted by Kappeler (1981,1984c),, great calls are not only highly stereotypic, but often exhibit distinctindividuall characteristics. Among the females of our study site, one individual(AS1)) had a particularly short pretrill phase, another female (AS3) produced aparticularlyy long trill, and another one (AS9) produced the transition between note 2andd 3 at lowered intensity.Inn some groups, two animals can be heard to produce synchronised great calls.Becausee adult males are not known to sing great calls, it has been assumed thatsynchronisedd great calls are produced by sub-adult daughters singing along withtheirr mothers (Kappeler, 1981, 1984c). Observations on captive gibbons revealed,however,, that immature gibbons of either sex may accompany their mother duringgreatt calls (Geissmann, unpublished data).Femaless of neighbouring groups appeared to avoid singing at the same time.Ongoingg songs were often stopped as soon as a second group started to sing.Occasionally,, two neighbouring groups were heard singing at the same time (e.g.,AS11 and AS2), in which case the females produced their great calls in alternation.Femaless of Kappeler's study typically exhibited a locomotor display during theclimaxx of their great calls ("each great call is accompanied by a burst of locomotionwithinn the crown of the tree", Kappeler, 1984c: p. 381). This did not occur duringthee great calls we observed.Descriptionn of scream boutsScreamm bouts mainly consist of screams and wa notes (Fig. 4.2d). Scream notesbeginn like wa notes with rapidly increasing frequency, but have a more complexdrawn-outt ending of less steeply increasing frequency ("wa-ee") or of several shortfrequencyy modulations. Scream bouts tend to last longer than female song bouts.Wee heard one female which, at variable intervals ranging from 1-12 min, producedscreamscream bursts and wa notes during 41 min, but no great calls. Like female songbouts,, scream bouts may occasionally be interrupted by great call phrases, but theseappearr to occur in longer and less regular intervals than in female song bouts. Onescreamscream bout had a duration of 18 min, but no great calls occurred during the first 12minn and only 3 great calls were produced during the whole bout. Another screamboutt with a duration of 11 min included only one great call after 9 min. In some, butnott all scream bouts, several group members were heard participating in the screambursts.. They became silent when a female sang her great call.Screamm bouts appear to be common during group encounters and oftenincludedd several groups vocalising near each other. A particularly spectacular oneoccurredd during a meeting between groups AS1, AS2 and AS9, which resulted in a50 0

CallingCalling Behaviour ofWildJavan Gibbons in Java, Indonesiacontinuedd exchange of scream bouts during 69 min. No individual was callingcontinuouslyy during the entire exchange period, and each group resumed calling atleastt twice.Screamm bouts, as described in the present study, appear to correspond to whathass previously been described as "border conflicts between groups" (Kappeler,1984c).. According to Kappeler, all group members participate in producing theburstss of screams. Although males may have participated in some scream boutsseverall scream bouts that included only a single individual (the adult female) wererecorded,, suggesting that a participation of the male in scream bouts may not be therule. .AA third category of loud calls was described by Kappeler (1984c) as "harassingcalll bouts" emitted as a response to potential ground predators. According toKappeler'ss description, "harassing call bouts" consist of "loud screams emitted byalll group members mixed with bursts of agitated movement." Although we did notobservee anything fitting this description during our short study, we were not alwaysclosee enough to the calling gibbons to tell whether agitated movement occurredduringg screaming or not. Therefore, our scream bouts may also include some"harassingg call bouts".Whilee the structure of scream bouts often differs from that of female songbouts,, any attempt to exclude these from the following analysis would be subjective.AA female song bout may become a scream bout if the females are upset during thecoursee of the bout, and likewise a scream bout may normalise to a female song boutass the gibbons calm down. A similar observation has previously been made byRaemaekerss et al. (1984: p. 179) on the distinction between normal duet song boutsandd disturbed call bouts in white-handed gibbons (H. lar).Theree may be additional categories of call bouts produced by Javan gibbons. Aboutt consisting of communal bursts of wa notes produced by all group members(Fig.. 4.2e) was heard once in captivity and once in Dieng. The reasons for theoccurrencee of this type of calling is unknown. These call bouts also included greatcallss at more or less regular intervals. The other group members immediatelybecamee silent each time the female sang a great call. After having tape-recordedsuchh an unusual call bout from a family group of three individuals at the Berlin Zoo(Germany),, it was played back to the same group on the following morning. Thewholee group immediately responded by inserting bursts of wa notes in synchronywithh those on the tape. Each burst on the tape immediately triggered an identicalonee from the group, until the recorded song ended.Descriptionn of male song boutsMalee phrases consist of simple hoots ("wa") and various more complex hoots.Amongg the latter, longer hoots with one or two frequency inflections ("wa-oo'\ "waoo-wa")oo-wa")are particularly prominent for this species (Fig. 4.2f-i). Some malesregularlyy produce bi-phasic hoots (i.e. a wa note followed by an inhalation note, butsofterr than those of H. agilis). Only few males were heard to include short trills intheirr phrases.51 1

ForestForest (and) PrimatesMalee phrases are extremely variable. Even simple hoots in males phrases are rarelysimplee repetitions of identical notes, but often show a broad variability in frequencyrangee and speed in frequency change. Whereas males in many gibbon speciesproducee well patterned phrases (for instance H. klossii and all species of the genusNomascus,Nomascus, pers. observation TG), male Javan gibbons were often heard singingwithh highly variable phrase patterns and sometimes would sing for minutes withoutdistinctt pauses which would have been helpful to recognise the beginning of a newphrases. .Likee males of other gibbon species (Geissmann, 1993, 1995), Javan gibbonmaless gradually build up their phrases, beginning with single, simple notes, utteredwithh long intervals. As less simple notes are introduced, these notes are combined toincreasinglyy complex phrases, reaching the fully developed form only after severalminutess of singing. Male solo song bouts of Javan gibbons usually start with shortandd soft hoots which resemble the "disturbance hoots" which are occasionallyutteredd upon detecting the observer. Although disturbance hoots need not developintoo a male song, at least one male song during our study was produced after we metupp with a group and after several minutes of disturbance hooting by the group'smale. .Thee excerpts of male solo songs shown in Figure 4.2f-i show distinctdifferencess among each other. These appear to result from individual-specific songcharacteristics.. Because each male was heard only few times, however, it is difficulttoo determine whether context-specific differences (i.e. different types of male song)alsoo exist. It was our impression that male songs were less loud (and probablycarriedd less far) than female songs.Timingg of male and female songsDuringg 11 consecutive days in Sept-Oct 1998, we heard a total of 122 song boutsandd scream bouts of at least 12 groups. Most groups could be identified byindividual-specificc song characteristics. Most of the song bouts (n=107) werefemalee solo songs, but we also heard at least 10 male solo song bouts. Only 5 songsweree to short or too far away too be reliably sexed. No duet songs were heard.Maless phrases were heard neither as a response (coda) to female great call phrases,norr between female great calls nor during other female short phrases (see above).Individuall females sang on most days and mostly once. Occasionally they sangtwicee a day and rarely three times or not at all. The average number of songs perdayy for the two closely monitored groups AS9 and AS2 was 1.2 (s.d. = 0.83; n = 9)andd 1.2 (s.d. = 0.63; n = 10), respectively.Alll female songs in the Dieng mountains started after 05:00 hrs, and femalesingingg activity peaked around 06:00 hrs (Fig. 4.3). Compared to Ujung Kulon,femaless in the Dieng mountains appear to sing slightly earlier (peak singing activityatt c. 06:00 hrs vs. c. 06:30 hrs), and calling is spread out more equally over themorning.. Starting times of all gibbon songs in Ujung Kulon differs between studies,withh those of Gurmaya et al. (1995), having mean starting times peaking as late as c.09:000 hrs.52 2

CallingCalling Behaviour of Wild Javan Gibbons in Java, Indonesia33 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19600 -J I ' ,' I I I I -I I I I 1 1 1 1 Laa 40-o>> 20-o-Lpi—pi—111 ,'—|-i—|—[J—i- 1 —i i i—i i i i i—r33 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19Timee of day. hoursFiguree 4.3Frequency distribution of the starting time of gibbon song bouts on Java, (a) females inUjungg ICulon (n = 392 song bouts, Kappeler, 1984c); (b) gibbons of unspecified sex inUjungg Kulon (n = 114, Gurmaya et al., 1995); (c) gibbons of unspecified sex in UjungKulonn (n = 49, Rinaldi, 1999); (d) females in Linggo Asri (n = 107, this study); (e) males inLinggoo Asri (n = 20, this study). Dotted line: dawn (not available for Ujung Kulon), dashedline:: sunrise. Sunrise in Linggo was determined by the time the sun was first seen at thestudyy site, and hence time of sunrise may differ between mountainous areas and flat plainsevenn if situated at the same longitude Kappeler (1981, 1984c) provides the time of sunriseforr his study site and determined it like we did (Kappeler, pers. comm. to TG). Gurmaya etal.. (1995) and Rinaldi (1999) do not explicitly mention time of sunrise, but we infer it to besimilarr to that reported by Kappeler.53 3

ForestForest (and) PrimatesMostt male songs (60%) in the Dieng mountains started between 03:55-04:40 hrs,whenn it was still dark. We heard at least 10 male songs during 11 consecutive daysoff predawn-to-dusk observations. Considering that female songs of at least 12individuall gibbon groups could be heard from our listening post, the averagenumberr of male songs per day per group can be estimated as 0.08. It should benotedd that this is a very conservative estimate: It includes one all male chorus forwhichh only a minimum number of participants is available. In addition, male songsappearedd to be less loud than female songs and could more easily go undetectedthann female songs.Apartt from one solitary song bout which began at 05:12 hrs, all male songsboutss uttered before dawn were produced in a chorus fashion, with overlappingsongss of at least 3 individuals. These pre-dawn male choruses were recorded fourtimess during the whole study, i.e. twice during 19 consecutive days in Sep-Oct, andtwicee during 15 days in Jul-Aug. This corresponds to a chorus occurrence of aboutoncee every 8.5 days. Estimating the number of males involved during a chorus wasdifficultt because of the distance between the chorusing gibbons and the observers;thee median minimum number of males involved during a single chorus bout was>3.55 (n = 4 choruses, with a range of >3 to >5 males).Inn three instances, females started singing right after the male chorus hadstopped,, whereas once the last male (of an initial five males), stopped calling withinonee minute after the first female started her song. No male choruses and only fourmalee solo song bouts in eleven days were heard after dawn. Male choruses andfemalee solo song bouts appear to be temporally segregated events.T T200 30Songg duration, minutesFiguree 4.4Frequency distribution of the song bout duration during 11 consecutive days in Linggo Asri(females:: median 7 min, range 3-18 min, n = 39 song bouts: males: median 11 min, range 8-422 min, n = 5 song bouts)54 4

CallingCalling Behaviour of Wild Javan Gibbons in Java, IndonesiaSongg durationMediann durations of female song bouts and scream bouts are about 7 min (n = 39,rangee 3-18 min). Pure female solo song bouts with one participant have a mediandurationduration of 6 min (n = 17, range 3-18 min), female song bouts with two participantsoff the same group (presumably including an offspring of the main singer) have alongerr duration (median 9 minutes, n= 13, range 6-15 min). The difference issignificantt (Mann-Whitney t/test, p = 0.004).Malee solo song bouts produced outside of male dawn choruses have a mediandurationn of 11 min (n = 4, range 8-25 min). These male songs bouts are notsignificantlyy longer than female solo song bouts (Mann-Whitney U test, p = 0.056),butt this may be due to the small sample size.Exactt individual song bout durations during predawn choruses could not bedeterminedd because of the large distance between the observers and the singingmales.. At least one male was heard singing continuously for 42 min during onechorus,, but this is a minimum estimate, because the chorus had started prior todetection.. If this song is included in the comparison, median duration of male songboutss is 12 min, and male songs are significantly longer than female songs (Mann-Whitneyy Utest, p = 0.016).TwoTwo completely monitored pre-dawn male choruses had durations oflhh 43 min and lh47min, respectively, and two choruses which were alreadyunderwayy when detected by us had a minimum duration of 42 min and 45 min,respectively.. All lasted much longer than the longest female solo song bout(188 min).Densityy estimation by use of song boutsThee proportion of days that females were calling was 8 out of 9 days for group AS-9,, and 9 out of 10 days for group AS-2. The fixed point count of identifiable groupsinn the smaller area, revealed that the average number of females calling on a givendayy was 3.5 (s.d. = 1.3; n = 10). A corresponding density of 1.9-3.7 groups per km 2wass reached at. For the larger area, the average number of females calling on agivenn day was 6.7 (s.d. = 2.7; n = 10) and the density estimate is 1.5-2.4 groups perkm 2 .. The average group size near Linggo (i.e. at an altitude of 400-650 m) is 3.5(s.d.. = 1.2, n = 15 groups, range 2-6). This corresponds to a density of 6.7-13.1 and5.3-8.55 individuals per km 2 for the smaller and the larger area, respectively.DISCUSSION NFrequencyy of male and female singingInn virtually all gibbon species, mated males spend at least as much time singing asmatedd females. In Javan gibbon, however, Kappeler (1981, 1984c) heard only asinglee male song during 130 full days of listening in Ujung Kulon. This song wasproducedd by an unmated "floating" male. Another single male song was heardoutsidee of the study area (Kappeler, 1984c). Because no song was heard by any of55 5

ForestForest (and) Primatesthee resident males in his main study area Ujung Kulon, Kappeler (1981, 1984c)concludedd that in Javan gibbons territorial males do not appear to sing. Kappelerdoess not indicate how many songs he heard during his whole study, but indicatesthatt he heard 392 female song bouts in his study area during 89 days scattered overthee whole year (Kappeler, 1984; p. 384). Because he heard only one male song boutwithinn his study area, one can estimate that less than 0.3% of all song bouts he heardweree male songs. In contrast, we heard at least 10 male song bouts during 11consecutivee days of predawn-to-dusk observations, and several more during 23additionall pre-dawn surveys. Hence, male song bouts in Dieng mountains constituteatt least 8.5% of the total number of song bouts produced, and 50% of male songsheardd during predawn-to-dusk observations were produced in all-male predawnchoruses. .Neitherr regular male singing, nor male chorusing, nor regular pre-dawnsingingg have previously been reported for Javan gibbons. Whether this is due to alackk of focused research at the appropriate time, or if pre-dawn calling is restrictedtoo certain populations only is unclear. In our study area, male pre-dawn chorusesoccurredd only about once per week (once every 8.5 days). It is possible that inpreviouss studies, many male solo song bouts and all choruses were missed becauseoff their pre-dawn occurrence. Because all previous data on singing behaviour ofJavann gibbons was collected in the westernmost population of the species (UjungKulon),, it is also possible that male calling and pre-dawn chorusing are morecommonn in Central Java (or at least in the eastern part of the gibbons distributionrange). .Densityy estimation by use of song boutsGibbonn songs proved to be an appropriate mean to estimate gibbon density in theDiengg mountains. Data from the fixed point count suggest that densities in thesurroundingss of Linggo are in the order of 1.9-3.7 groups per km 2 based on a smallareaa (

CallingCalling Behaviour ofWildJavan Gibbons in Java. Indonesiapredictablee times of the day, like gibbons, fixed point counts are a frequently usedalternativee (e.g., Haimoff et al., 1986; Brockelman & Ali, 1987; Brockelman &Srikosamatara,, 1993). Fixed point counts have been used previously in the study ofJavann gibbons (Kappeler, 1981, 1984a; Kool, 1992; Nijman & van Balen, 1998;Nijman,, 2000). Because Kappeler's (1981, 1984c) study suggested that only matedfemalee Javan gibbons sing, it has been assumed that every vocalising individualrepresentss a family group (e.g., Nijman & van Balen, 1998). Densities are estimatedbyy multiplying the average group size with the number of groups per area unit. Ourfindingss indicate that at least 8.5% of gibbon calls heard in Central Java are malesongs.. We have little information concerning male calling in other parts of Java, butGurmayaa et al. (1995) and Rinaldi (1999) report that gibbon songs are occasionallyheardd well before dawn in Ujung Kulon (see Fig. 4.3). These calls may well havebeenn produced by males. If in other areas, as in Linggo, some 8.5% of the songsheardd are in fact male songs, it may imply that densities in the past may have beenover-estimatedd considerably. In order to accurately estimate densities a (sitespecific))correction factor has to be taken into account, or, better still, male andfemalee calls have to be separated during data collection.Withh practice, Javan gibbons can be recognised individually by their song(Kappelerr 1984c; Dallmann & Geissmann, 2001). Individual groups can thus bestudiedd more easily without many of the difficulties involved in observing primatesinn tall tropical rain forest, without intruding into their habitat, without habituatinggroups,, and without disturbing groups. As such, vocal recognition might be a moresuitablee tool for studying this critically endangered primate than some traditionalmethods.. Vocal recognition furthermore facilitates for longitudinal studies (Baptista&& Gaunt, 1997) which otherwise often require intrusive methods.Songg comparisons in a phylogenetic contextWhereass many gibbon species sing duet song bouts only (i.e. in all species of thegeneraa Bunopithecus, Nomascus and Symphalangus), male solo song bouts occurtogetherr with duet song bouts in most species of the genus Hylobates. In the Javangibbon,, however duet song bouts do not occur. Instead, both males and femalesproducee solo song bouts. The absence of duetting and the occurrence of female solosongg bouts are characteristics which the Javan gibbon (Kappeler, 1981, 1984c; andthiss study) shares only with KIoss's gibbon from the Mentawai Islands (Tenaza,1976;; Whitten, 1980, 1982; see also Geissmann, 1993, for a discussion of theevidencee for absence or presence of duetting in H. klossii). The absence of duettingandd the occurrence of female solo song bouts appear to represent a synapomorphysharedd by H. moloch and H. klossii, (Geissmann, 1993).Inn addition, male and female tend to sing at different times of the day: Mostmalee song bouts occurred before dawn, most female song bouts after dawn. In someotherr species of the genus Hylobates (such as H. agilis and H. lar), males also tendtoo produce their solo songs before or at dawn, but they resume singing again later inthee days when they participate in the duet songs with their mates (Geissmann, inprep.).. In the Javan gibbon, however, no male choruses were heard after dawn.57 7

ForestForest (and) PrimatesSimilarlyy separated periods of male and female solo songs were also observed inKloss'ss gibbons (Tenaza, 1976; Whitten, 1980, 1982). In this species, too, malespreferentiallyy sing solo song bouts before dawn, and females preferentially sing solosongg bouts after dawn. This may represent another derived characteristic shared byH.H. moloch and H. klossii. Only the Javan gibbon, however, appears to have goneonee step further. As pointed out by Geissmann (2000), gibbon songs probablyevolvedd from male loud calls similar to those which are common in most recent OldWorldd primates. In most Old World primates, females are not known to produceloudd calls or utter only incomplete versions (e.g., Gautier, 1988; Herzog &Hohmann,, 1984; Marler & Hobbett, 1975; Mitani, 1985c; Oates & Trocco, 1983;Steenbeekk & Assink, 1998; Tenaza, 1989). Although male singing appears to occurconsiderablyy more frequently in our study than in Kappeler's study, the rate of malesingingg is still very low if compared with other gibbon species. In most gibbonspeciess males participate in 0.18-1.90 song bouts per day (Gittins, 1984b: p. 422f),whichh in many species include both male solo and duet song bouts. Kloss's gibbonmaless (ƒƒ. klossii) produce about 0.59 solo song bouts per day (calculated after datapresentedd in Whitten, 1982, 1984). The lowest values were recorded in siamangpopulations.. Although mated siamangs are not known to produce solo songs, 0.18-0.311 duet song bouts per day were recorded (Chivers, 1974: p. 263; Gittins, 1984: p.422f),, which is still more than 2-3 times higher than our estimated male singing rateforr Javan gibbons of about 0.08 song bouts per day. In the Javan gibbons, the lowratee of male singing, combined with a high rate of female singing (about 1.2 songboutss per day) appears to represent a complete reversal of the hypothetical ancestralsituation. .CONCLUSIONS SJavann gibbons are unusual among gibbons in that duet songs do not occur and mostsongg bouts are female solo songs or scream songs (91.5%). Individual femalesproducedd about 1.2 song bouts per day.Inn contrast to an earlier study in West Java, males in Central Java alsoproducedd songs, albeit less frequently than females (10 vs. 107 song bouts in 11consecutivee days). Individual males are estimated to produce about 0.08 song boutsperr day (minimum estimate).Maless prefer to begin their song bouts before dawn (before 05:20 hrs), whereasfemaless sing later in the morning.Similarlyy separated periods of male and female solo songs were also observedinn Kloss's gibbons (//. klossii) on the Mentawai Islands. This may represent aderivedd characteristic shared by H. moloch and H. klossii.Thee rarity of male singing in the Javan gibbon appears to be unique amonggibbons.. The extremely pronounced dominance of female singing over male singingappearss to represent a complete reversal of the ancestral state.58 8

CallingCalling Behaviour ofWild Javan Gibbons in Java, IndonesiaJavann gibbons can be accurately censussed by means of their vocalisation, but it isadvisedd to separate male and female songs. The high degree of vocal recognitionallowss the species to be studied in detail in an non-intrusive manner.ACKNOWLEDGEMENTS SThee Indonesian Institute of Sciences (LIPI), the Directorate General for ForestProtectionn and Conservation (PKA) and the Ministry of Forestry and Estate Crops(MOFEC)) is thanked for granting permission to conduct research on Java. Financialsupportt for the study came from the Netherlands Foundation for InternationalNaturee Protection, Society for the Advancement of Research in the Tropics, andStichtingg het Kronendak (to VN). We wish to thank the officials and staff membersoff the numerous zoos for permission to study the animals in their care and for usefulinformationn about the animals' previous history. Additional tape-recordings of Javangibbonss used in the present study were kindly made available by Dr. MarkusKappeler.. We are particularly grateful to Robert Dallmann and Sylke Eyring fordigitisingg parts of our tape-recordings. Robert Dallmann, Prof. dr. Steph B.J.Menken,, and Prof. dr. Elke Zimmermann commented on an earlier version of thismanuscript. .59 9

ForestForest (and) Primates60 0

GeographicalGeographical Variation in Pelage Characteristics in Grizzled Leaf MonkeyCHAPTERR 5GEOGRAPHICALL VARIATION IN PELAGECHARACTERISTICSS IN GRIZZLED LEAF MONKEYPRESBYTISPRESBYTIS COMATA (DESMAREST, 1822) (MAMMALIAPRIMATES,, CERCOPITHECIDAE)ModifiedModified and expanded version ofZeitschriftfürSaugetierkunde 62: 257-264, 1997ABSTRACT TTwoo subspecies of grizzled leaf monkey Presbytis comata have been identified onthee island of Java, Indonesia. The nominate form is found in West Java whereas P.c.c. fredericae occurs in Central Java. Geographical variation in P. comata has beenstudiedd both in museum specimens and in the field. Some alleged differencesbetweenn the two described forms were found not to be diagnostic, while someintraspecificc variation was of a clinal nature, with intermediate populations existinginn the eastern part of West Java. It is concluded that a separation of P. comata intodifferentt subspecies let alone species is not warranted. None of the forest areas inCentrall Java are included in the protected area network. In order to preserve intraspecificcvariation it is timely that both the grizzled leaf monkeys and their the forestareass in Central Java are more actively protected.RINGKASAN NVariasii geografis dalam karakteristik bulu pada Surili Presbytis comata (Desmarest,1822)) (Mammalia, Primata, Cercopithecidae). (Versi yang telah dimodifikasi dandikembangkann dari paper yang dipublikasikan di Zeitschrift fur Saugetierkunde 62:257-264,, 1997): Dua subspesies Surili Presbytis comata telah diidentifikasi di PulauJawa,, Indonesia. Subspesies yang nominat ditemukan di Jawa Barat sedangkan P. c.fredericaefredericae terdapat di Jawa Tengah. Variasi geografis dalam P. comata telah ditelitibaikk di museum maupun di lapangan. Beberapa perbedaan dugaan antara keduasubspesiess tersebut tidak terbukti, sementara beberapa variasi intraspesifikmerupakann perubahan perlahan-lahan [sifat 'klinal'], dengan populasi peralihanterdapatt di bagian timur Jawa Barat. Disimpulkan bahwa pemisahan P. comatamenjadii subspesies apalagi spesies berbeda tidak dapat dibenarkan. Tidak adasatupunn kawasan hutan di Jawa Tengah yang masuk dalam jaringan kawasankonservasi.. Untuk melestarikan variasi intra-spesifik maka saatnya sekarang untukmelindungii baik Surili maupun kawasan hutan di Jawa Tengah di mana merekahidup,, secara lebih aktif.61 1

ForestForest (and) PrimatesINTRODUCTION NOnn the island of Java, Indonesia, two single island endemic primate species can befound,, both classified as endangered according to IUCN threat criteria (Eudey,1987):: the Javan gibbon Hylobates moloch and the Grizzled leaf monkey Presbytiscomatacomata (formerly P. aygula, see Weitzel & Groves, 1985). Grizzled leaf monkey isconfinedd to the rainforests of the western half of the island while some remnantpopulationss are found as far east as Mt Lawu, on the border of East Java (Nijman,1997,, chapter 6). Fossil finds, found in Middle Pleistocene deposits, indicate that thespecies'' former distribution might have extended eastwards to Mts Wilis-Liman(Nijman,, 1997; Theunissen, 1985).TwoTwo subspecies are traditionally recognised: P. comata comata (Desmarest,1822),, restricted by Sody (1930b) to West Java and P. comata fredericae (Sody,1930),, from Central Java. Eudey (1987) states that P. c. fredericae is known withcertaintyy only from Mt Slamet, although Bartels (1937) reported the occurrence ofthee species on Mts Dieng and some specimens have been collected on Mts Diengandd Mt Lawu. During the last few years it has become apparent that P. comata stillprevailss in those areas in Central Java from which it was historically known (Seitre&& Seitre, 1990; Nijman & Sözer, 1995; Nijman, 1997 chapter 6; M. Linsley, pers.comm.,, 1994). Recently, P. c. fredericae has been proposed as a separate species P.fredericaefredericae by IUCN (1994) and Brandon-Jones (1995, 1996a). The pelage colour ofadultss is the most striking difference between the two types: fredericae differs fromthee nominate race in having black upperparts instead of grey, and the underparts areblackk apart from the lower abdomen, innerside of the legs, which are white, and theupperpartt of the chest, which is whitish or light grey. The vent in the nominate isentirelyy white. Hence the proposed English names of Javan grizzled leaf monkey forP.P. comata and Javan fuscous leaf monkey for P. fredericae (IUCN, 1994). If P. c.fredericaefredericae is considered to be a separate species it undoubtedly can be rankedamongg the rarest and most endangered primate species in the world, making it a toppriorityy for primate conservation (cf. Brandon-Jones, 1995). It would be restricted tofourr isolated forest areas, viz., Mt Slamet, Mt Cupu-Simembut, Mts Dieng and MtLawuu (Nijman, 1997, chapter 6), in a province with one of the highest humanpopulationn densities of Indonesia. None of the forests are adequately protected andtwoo of them, the first and the last of the localities mentioned above, are situated onann active volcano.Thee aim of this study is to describe the geographical variation in pelagecharacteristicss among populations of grizzled leaf monkeys. Data collected over theentiree range of the species and data obtained from the study of museum specimensformm the basis of these descriptions.62 2

GeographicalGeographical Variation in Pelage Characteristics in Grizzled Leaf MonkeyMATERIALL AND METHODSAA total of 59 specimens in the National Museum of Natural History, Leiden(RMNH),, the Zoological Museum, Bogor (MZB), the British Museum of NaturalHistoryy (BMNH), London, and the Zoological Reference Collection (ZRC) of theNationall University of Singapore were examined, viz. 36 from the western provinceandd ten from the central Javan province. For another 13 specimens studied nolocalityy was given.Duringg field surveys from 1994 to 2000 descriptions of external appearanceandd pattern of coloration of grizzled leaf monkey were made. Survey areas includedthee western half of Java, east to Mt Lawu on the border with the East Javanprovince.. Mt Lawu is the easternmost locality where the species has been recorded(Nijman,, 1997 and chapter 6). Special attention was paid to the populations in thecentrall part of the species' range, i.e. the eastern part of West Java and the easternpartt of Central Java, as it is here where the expected boundary between the twodescribedd subspecies is to be found. The number of animals and number of neonatesoff which a clear view was obtained per forest area was estimated by summation ofthee maximum number of individuals observed at different localities throughout themountainn complex. When a group was observed at a locality where it had been seenpreviouslyy or when there was doubt whether a particular animal had previously beenencounteredd or was in fact a different individual, a description was made, but it wasnott included in the total estimate of numbers. When grizzled leaf monkey wereobservedd at the same locality in different years, only data from one year (the yearwithh the highest number of observations) is included in the analysis. In the course ofthee study numerous bird markets were visited. If grizzled leaf monkeys wereencounteredd at these markets, if possible, a description of its pelage was made.Thesee descriptions provide additional information on the variation in pelagecoloration,, but since often there was no certainty about the origin of the animal,thesee descriptions were not included in the analysis. No specimens were collectedandd hence the descriptions are exclusively based on field observations and museumspecimens. .RESULTS SGrizzledd leaf monkey was observed in ten forest areas. These areas (with estimatednumberr of individuals plus neonates of which a clear view was obtained given inparenthesis)) are: Mt Aseupan (5+0), Mt Halimun (5+1), Mt Salak (15+2), Mt Pancar(5),, Mt Gede-Pangrango (32+5), Situ Patengang (16+1), Mt Sawal (3+1), Mt Slamet(16+3),, Mts Dieng (61+12), Mt Lawu (0).AA typical grizzled leaf monkey {'comata 1 ) from the western part of West Java(e.g.,, Mt Pancar [106°54'E, 6°35'S], Mt Gede-Pangrango [107°00'E, 6°45'S]) has aratherr dark grey dorsum with the hair on the back being longer than on the tail, legsandd arms. The tail is dark grey to blackish, and arms and legs are dark grey, often63 3

ForestForest (and) Primatesdarkerr than the back. The venter, innerside of arms and legs, and innerside of the tailaree whitish. The species has a blackish prominent crest. In some individuals the haironn the back is rather short while in others it is longer. In individuals with longer hairthee uppercoat is formed by longer dark grey or blackish hair while the undercoatconsistss of short dark grey hair. In individuals from the central part of West Java,i.e.. the forest surrounding Situ Patengang, the sides of the venter near the flanks isintermingledd with grey hairs; This same pattern is found in museum specimens e.g.,RMNHH 26820 from Mt Tilu [107°30'E, 7°09'S]\ Observations in the wild andstudyy of museum specimens suggests that this is less so in animals from the westernpartt of West Java (e.g., Mt Aseupan [105°50'E, 6°10'S], Mt Salak [106°45'E,6°45'S]:: RMNH 34335, -36, -38, 51891).Grizzledd leaf monkeys from Mt. Sawal [108°I6'E, 7°12'S] in the eastern partoff West Java, are somewhat different in coloration from those in areas to the westandd to the east. The dorsum is not different from animals to the west, although in theanimalss studied it is rather dark. The arms are very dark grey, almost black. Theventerr consists of a whitish or light grey throat, edged on the upper side of the breastbyy a broad grey band. This band originates from the flanks and is narrower in thecentre,, with a thin whitish cross band. The lower abdomen, innerside of arm, legsandd tail are whitish. The same pattern of coloration, but less pronounced, was foundinn a skin labelled P. aygula aygula and collected at Ceringin-Cisaga [108°30'E,7°27'S]] near Banjar, West Java, near the border with Central Java (RMNH 34296)(Fig.. 5.1). This individual has rather dark arms, though at Mt Sawal the animals hadevenn darker arms.Inn typical grizzled leaf monkey ('fredericae') from Mt Slamet [109°13'E,7°19'S]] or Mt Prahu [109°55'E, 7°20'S] (e.g., MZB 2993, -94, -95, RMNH 14612)thee dorsum is black, the throat and upper chest are white or light grey, the lowerabdomen,, innerside of the legs, arms and tail are white, while the remainder is blackwithh a thin nearly white cross band. In other parts of the Dieng mountains some ofthee animals are less dark in colour. The pattern of coloration is as in the typicalform,, but the dorsum is (very) dark grey, not black, and resembles those of the MtSawall animals. For an overview of pelage characteristics based on fieldobservations,, see Table 5.1.Grizzledd leaf monkey has been observed in both primary and secondary forest,inn ecotones and in the forest interior. The species is present in lowland forests, inforestss on steep slopes and hills, and in montane and upper montane forests. There isnoo differentiation in habitat or altitudinal preferences between populations in theeastt or west. In behavioural terms all forms are indistinguishable from one another.Inn April 2000, Roland Wirth showed me a photograph of a single grizzled leaf monkey currently heldinn Howlett's Zoo, England, UK, which was obtained from Bandung Zoo. This individual is dark greyandd shows a ventral pattern intermediate to those from western Java and the area between west andcentrall Java. Although the exact origins of this individual are not known, it is likely that it originatesfromm the area near Bandung,64 4

GeographicalGeographical Variation in Pelage Characteristics in Grizzled Leaf Monkeyöö sopp „II s"aa *11 1ann J2~~ c"«'So oIs sOO H ^65 5

ForestForest (and) PrimatesTablee 5.1Pelage characteristics of grizzled leaf monkey Presbytis comata based on field observationsonn nine mountain complexes on Java, listed from west to east. The number of individuals ofwhichh a clear view was obtained is given in parenthesis.Locality yMtt AseupanMtt HalimunMtt SalakMt.. PancarMt.. Gede-PangrangoSituu PatenganMt.. SawalMtt SlametMtss DiengVenter rWhitee (3)Whitee (5)Whitee (12)Whitee (4)whitee (32)white,, greyish on the flanks(6) )whitee with dark grey band onbreast,, narrow in centre (3)whitee with black band onbreastt (16)whitee with dark grey band onbreastt (24); white with blackbandd on breast (30)Dorsum mgreyy (5)greyy (5)(dark)) grey (15)(dark)) grey (5)(dark)) grey (28)darkk grey (16)darkk grey (3)blackk (16)darkk grey (24);blackk (37)Arms sgreyy (5)greyy (5)(dark)) grey (15)darkk grey (5)(dark)) grey (28)darkk grey (16)blackishh (3)blackk (16)darkk grey (24);blackk (37)Dorsum mneonate e--lightt grey (1)greyy (2)--greyy (5)grey(l) )darkk grey (1)blackk (3)darkk grey (4),blackk (8)Mostt notably the vocalisations, in particular the alarm call, of animals on MtHalimun,, Mt Salak, Mt Gede-Pangrango, Mt Sawal, Mt Slamet, Mts Dieng and MtLawuu are qualitatively similar (cf. Battels, 1937). In other Presbytis species, e.g.,thosee on Sumatra and Borneo, the different species are readily distinguished by theirspecificc vocalisations (e.g., Wilson & Wilson, 1977; Aimi & Bakar, 1992; 1996;pers.. observ.).Sodyy (1930b) noted that inhabitants of the Mt Slamet region, where heobtainedd the specimens described as fredericae, were not familiar with the Javannativee name surili, nor did they made a linguistic distinction between grizzled leafmonkeyy and the sympatric ebony leaf monkey Trachypithecus auratus; both speciesweree named lulling (Sody, 1930a). Lutung is the local name used for the morecommonn and more widespread ebony leaf monkey in West and Central Java, andBali,, while this species is named budeng in East Java. Battels (1937) reported thatgrizzledd leaf monkey was known as rekrekan in the Mts Dieng region. In the presentstudy,, it was found that grizzled leaf monkey is locally known as surili throughoutwestt Java, east to Mt Sawal (inclusive). From Mt Slamet to Mts Dieng it is knownass (lutung) rekrakan or (lutung) rekrekan. In certain areas, e.g., on Mts Dieng andMtt Lawu, some informants were aware of the presence of two types of leafmonkeys,, but both of them were called lutung or budeng (confirm the findings in MtCupu-Simembutt by Linsley & Nawimar, 1994; also Brandon-Jones, 1995). Thelinguisticc separation between fredericae and comata in rekrakan and surili,respectively,, is accounted for by the two different languages, Javanese andSundanese,, spoken in different parts of the island (the boundary between the twolanguagess runs almost parallel to the provincial boundary) and is most likely not ofbiologicall significance.66 6

GeographicalGeographical Variation in Pelage Characteristics in Grizzled Leaf MonkeyDISCUSSION NIntraspecificc variation, in particular the coloration and pattern on the venter, inPresbytisPresbytis comata is not geographically disjunct but seems to be of a clinal naturewithh intermediate populations existing in areas between those from where the twosubspeciess have been described. Whether or not more populations of the speciesremainn in these intermediate areas remains unclear. As nowadays large areas of Javahavee been deforested, populations of grizzled leaf monkeys are found scatteredthroughoutt West and Central Java. However, there seems to be no major gap in thespeciess distribution between West Java and Central Java, nor does there seem to beaa geographical or ecological barrier in the intermediate area that can explain apossiblee separation between populations east or west of the provincial boundary.Onee of the morphological characters on which the separation between comataandd fredericae has been based, namely the dorsal coloration, shows, at least in thepopulationss on the Dieng mountains, considerable variation and cannot be used as adiagnosticc character. Vocalisations of populations in the western part of its range donott seem to differ from those in the eastern part.Onn the basis of the data presented above, it can be concluded that theseparationn of western and eastern populations of grizzled leaf monkey into twodifferentt species is not warranted. Neither form can be recognised as a diagnosablydistinctt taxon and therefore the appropriate name for the species (sensu lato)remainss Presbytis comata (Desmarest, 1822). For those who do not wish to abandonthee use of trinomials, it should be understood that these can only be used to identifypopulationss within a continuum of geographical variation. The geographical limitsoff these populations will, however, remain arbitrary.Iff the central Javan population were to recognised as a different species, it wouldrankk among the most endangered primates in the world. In the most recent IUCNlistingg (IUCN, 1996) it is classed as Data Deficient, i.e., more information isrequiredd on the exact nature of its population status and future prospects, but it islikelyy that it belongs in one of the threat categories (critically endangered,endangered,, vulnerable). Recent field surveys (Nijman, 1997; Nijman & van Balen,1997;; chapter 6) found the species to be present in all forest areas from where it wasknownn historically. The species is to be rather common in certain forest areas (MtsDiengg and Mt Slamet), but rare in others (Mt Lawu). Like many of the westernpopulations,, those in the east are isolated from each other by large areas ofunsuitablee habitat and seem to be in need of active conservation efforts. None of theforestt areas in the eastern part of West Java or Central Java are included in theprotectedd area network, although most of them have been proposed as such for alongg time (MacKinnon et al., 1982). The present study indicates that the easternpopulationss of grizzled leaf monkey are not diagnosably distinct from those in thewestt and as such should not be treated as separate species. Yet, it is timely that boththee grizzled leaf monkeys and their the forest areas in Central Java are more activelyprotectedd in order to preserve intra-specific variation.67 7

ForestForest (and) PrimatesThee tripartite distribution of the grey leaf monkeys of the genus Presbytis in theSundaicc region, currently known as comata (western Java), thomasi (northernSumatra),, and hosei (north-eastern Borneo), has been a protrackted issue of debate.Pocockk (1934) considered these taxa as constituting four different species, includingtwoo on Borneo (sabana and hosei on Borneo some populations show adult sexualdimorphismm in crest shape and extent of white on the brow while others aremonomorphic,, resulting in the description of a number of (sub)species: seeBrandon-Jones,, 1997). Chasen (1940) subsequently considered them to be races of asinglee species, P. comata, as did some authors afterwards, e.g., Hooijer (1962). Thismadee P. comata a polytypic species, with a distribution following the periphery ofSundaland.. The three zones were regarded as areas of convergent evolution byMedd way (1970) and in his more cautious interpretation the three forms {comata,thomasi,thomasi, and hosei) were considered to be separate species, a view supported byGrovess (1970) and most subsequent workers (Napier, 1985; Weitzel et al., 1988;Corbett & Hill, 1992; IUCN, 1994). In contrast, Brandon-Jones (1978, 1984, 1993,1996a),, while ignoring the diagnostic differences in vocalisation that exists betweenthee three taxa ('...for reasons of consistency, geographic variation in vocalisationmustt remain subordinate in taxonomie status to geographic variation in pelagecolour...'' Brandon-Jones, 1996b: p 72) regarded them as relicts of a singlepopulation,, differentiated at the subspecific level. The grey-backed taxon isperceivedd as a relict in its present disjunctive distribution, representing an earliercoloniserr of the Sundaic region. Brandon-Jones (1993) postulated that thephylogenyy of the genus involves unidirectional integumental colour degradation,comparablee with Hershkovitz' (1968) theory of metachromism. In this view thepelagee colour of the pre-glacial relict species in the genus Presbytis ispredominantlyy black (Brandon-Jones, 1978, 1993), after which bleaching occurs viathee eumelanin pathway from (brown to) grey to white (Hershkovitz, 1968). Thus,thosee mammal species that are characterised by a very dark/black coloration can,generally,, be regarded as progenitors of all living members of their group. If wefolloww the Brandon-Jones (1987, 1993) model and accept the predominant glossyblackk P. potenziani from the Mentawai islands of the west coast of Sumatra, as thesolee representative of the genus during a Pleistocene period of climaticdeterioration,, after which it evolved (or 'degenerated' as preferred by Brandon-Jones,, 1993) into the grey P. comata (sensu lato), then the present occurrence ofmelanisticc individuals in that taxon warrants further explanation.Thee present finding of populations intermediate in coat coloration and pattern andthee presence of greyish individuals in the easternmost populations of P. comata,showw that the species is more variable in its pelage coloration than previouslyassumed.. If P. comata from Java is considered conspecific with P. thomasi and P.hosei,hosei, intraspecific variation in pattern and coloration below the head (which isgenerallyy more conservative then the pelage colour itself: Wilson, 1978; Wilson &Wilson,, 1977) in the Javan populations would be larger then variation betweencomata,comata, and extralimital thomasi and hosei. In conclusion, grizzled leaf monkey P.68 8

GeographicalGeographical Variation in Pelage Characteristics in Grizzled Leaf Monkeycomatacomata on Java can not be separated into two different subspecies or even species asneitherr form can be recognised as a diagnosably distinct taxon. Moreover the largevariationn in pelage characteristics within the Javan populations makes it increasinglymoree difficult to consider them conspecific with the other grey-backed leaf monkeys--P.--P. thomasi and P. hosei-- from north Sumatra and north-eastern Borneo,respectively. .ACKNOWLEDGEMENTS SII wish to thank Mr Boeadi (Zoological Museum Bogor), Dr C. Smeenk (NationalMuseumm of Natural History, Leiden), Dr P. Jenkins (British Museum for NaturalHistory,, London) and Dr CM. Yang (Zoological Reference Collection, Singapore)forr allowing me to examine specimens in the collections under their care, S.J.Booth,, Dr P.J.H. van Bree, Dr C.J. Hazevoet and an anonymous reviewer forconstructivee comments on the manuscript. Research on Java was made possible duetoo the co-operation of the Indonesian Institute for Science (LIPI) and the DirectorateGenerall of Forest Protection and Nature Conservation (PHPA). Dr P.J.H. van Breeiss thanked for his help and support throughout the study.69 9

ForestForest (and) Primates70 0

OccurrenceOccurrence and Distribution ofGrizded Leaf MonkeCHAPTERR 6OCCURRENCEE AND DISTRIBUTION OF GRIZZLED LEAFMONKEYY PRESBYTIS COMMA (DESMAREST, 1822)(MAMMALIA:: PRIMATES: CERCOPITHECIDAE) IN JAVA,INDONESIA AContributionsContributions to Zoology 66: 247-256, 1997ABSTRACT TThee grizzled leaf monkey Presbytis comata is confined to the rain forests of Westandd Central Java, Indonesia. In order to determine its distribution, a review of theliterature,, evidence from the study of museum specimens, and the results of recentsurveyss are presented. Recent surveys in the central parts of the island indicate thatP.P. comata is still present on four volcanic mountain complexes, viz. Mt. Sawal, Mt.Slamet,, Mts. Dieng, and Mt. Lawu. The present paper gives the results of thesurveyss combined with a review of its distribution. Altitudinal and habitatpreferences,, and the conservation status of the species are discussed.RINGKASAN NKeberadaann dan distribusi Surili (Presbytis comata Desmarest, 1822) (Mammalia:Primata:: Cercopithecidae) di Jawa, Indonesia (Contributions to Zoology 66: 247-256,, 1997): Keberadaan Surili Presbytis comata tergantung kepada hutan hujanJawaa Barat dan Tengah, Indonesia. Untuk menentukan distribusinya, suatu reviewliteratur,, bukti dari studi spesimen museum, dan hasil-hasil survey terbarudipaparkan.. Survey terbaru di bagian tengah Pulau Jawa memperlihatkan bahwa P.comatacomata masih terdapat di empat komplek gunung berapi, yaitu Gn Sawal, Gn.Slamet,, Pegunungan Dieng dan Gn. Lawu. Paper ini memaparkan hasil-hasil surveydengann review distribusinya. Preferensi ketinggian dan habitat, serta statuskonservasii dari spesies ini juga didiskusikan.INTRODUCTION NIndonesiaa supports a relatively high number of colobine monkeys belonging to thegenuss Presbytis sensu stricto and, due to the partial isolation of Asia and theintermittentt connection between islands, the country includes numerous endemictaxa.. One of these is the grizzled leaf monkey Presbytis comata (Desmarest, 1822)[formerlyy P. aygula, see Weitzel & Groves, 1985], endemic to the island of Java,71 1

ForestForest (and) Primatesviz.. the West and Central Javan provinces. Animals of this species live in singlemalee groups containing three to over thirteen individuals. During the day the troopsfrequentlyy visit the middle and lower layer of the forest, whilst resting at night in theupperr layer (Ruhiyat, 1983). The species is stricktly arboreal and is restricted to rainforestt areas with a continuous forest canopy. Grizzled leaf monkeys plays animportantt ecological role as one of the principal arboreal shoot- and leaf-eatingmammalss of the Javan rain forest (Medway, 1970), although fruit may also be eatenwhenn available (Sujatnika, 1992). Little is known about the ecology of the species,andd particularly knowledge about its distribution at the individual and populationlevell is limited (Supriatna et al., 1994).Javaa is Indonesia's most cultivated large island and has a long history of forestconversionn and degradation. Nowadays less then 10% of the original forest remainsinn Java and especially West and Central Java have suffered from deforestation. Inthesee two provinces 48% of the montane forest, 14% of the hill forest and less then2%% of the lowland forest remains (MacKinnon et al., 1982). For the latest update onlandd use and ecological issues concerning the island of Java (and Bali), see Whittenetal.. (1996).Becausee of its small, fragmented populations and its severely reduced habitatthee grizzled leaf monkey is considered to be among the most endangered primatespeciess in the world (Eudey, 1987). P. comata - together with another Javanendemic,, the Javan gibbon Hylobates moloch (Audebert, 1799) - have sufferedmoree than any other Malaysian primate from deforestation (MacKinnon, 1987).Populationn size estimates have been theoretically calculated and range from 8040(MacKinnon,, 1987) to 2285 (Supriatna et al., 1994).Sodyy (1930a) described the subspecies P. c. fredericae based on specimenscollectedd on the southern slopes of Mt. Slamet, Central Java. This subspecies differsfromm the grizzled nominate from West Java in having a dark collar on the upper sideoff the chest and a dark belly region, and by the occurrence of melanistic individuals.AA more elaborate discussion on geographical variation in pelage characteristics inthee grizzled leaf monkey is discussed elsewhere (Nijman, 1997b, chapter 5).Otherwisee very little has been written about the occurrence of grizzled leaf monkeysinn Central Java. If mentioned at all, the species was most frequently reported tooccurr on or to the east of Mt. Slamet (Chasen, 1940; Hooijer, 1962; Medway, 1970;MacKinnon,, 1987; Weitzel et al., 1988; Ruhiyat, 1991; Corbet & Hill, 1992). Apartfromm Kappeler (1984a), who conducted a gibbon survey in 1978 and visited somesitess in Central Java and M. Linsley (pers. comm, 1994) few people have extendedorr concentrated their (biological) surveys into Central Java (see e.g., Appendices IIandd III in Whitten et al., 1996). Eudey (1987) states that P. c. fredericae is knownwithh certainty only from Mt. Slamet. However, Bartels (1937) reported theoccurrencee of the species on the northwestern slopes of the Dieng mountains, andmoreoverr some specimens have been collected on the Dieng mountains and Mt.Lawu,, on the border between Central and East Java (National Museum of NaturalHistoryy (hereafter RMNH), Leiden, coll. Bartels, no. 14612, 14613, and 14614).72 2

OccurrenceOccurrence and Distribution of Grizzled Leaf MonkeyThee only other record from the eastern half of the island comes from Eugene Duboiswhoo collected a fragment of the right palate with P3-M2 in situ of a Presbytis sensustrictoo from a Middle Pleistocene deposit in Sumber Kepuh [112°5' E, 7°30' S], EastJavaa (RMNH, coll. Dubois, no. 3780). The sediments in which the fossils werefoundd are of volcanic origin and Dubois inferred that the animals in the deposits diedduee to a volcanic eruption. Based on the structure of the sediments he concluded thatmostt likely this had been an eruption of Mt. Wilis (cf. Theunissen, 1985).Thee aim of the present paper is to synthesize the main results from studiespublishedd in various journals and unpublished reports, not all of which are easilyaccessible,, and to integrate this with new data on the distribution and conservationstatuss of central Javan populations of the grizzled leaf monkey collected during twofieldd surveys in 1994 and 1995. An overview of the historic and present distributionoff grizzled leaf monkey is given, after which new data on the species gathered in thecentrall parts of Java are presented. Finally, altitudinal and habitat preferences arediscussed,, and some recommendations for conservation are given.METHODS SStudyy sitesInn order to assess the current distribution of grizzled leaf monkey in the central partsoff Java, data were gathered over an eight months (March-Sept.) period during 1994,withh an additional two months (June-July) survey in 1995. Surveys were conductedinn almost all forest areas larger than 5000 ha, between from the east of Mt.Papandayann and Mts. Wilis-Liman. The forest areas visited included Mt. Sawal, Mt.Segara,, Mt. Slamet, Mts. Dieng, Mt. Sundoro, Mt. Sumbing, Mt. Merapi, Mt. Muria,Mt.. Lawu and Mts. Wilis-Liman (see Table 6.1). Together the forests on thesemountainss comprise more than 90% of the remaining natural forest in the centralpartt of the island. In the same period additional data on the distribution of thespeciess were collected on Mt. Pancar and Mt. Gede-Pangrango, both in West Java.Surveyy methodsThee area was surveyed by scanning the forest area from vantage points over thecanopyy and by surveys inside the forest along available trails. Data were collectedonn habitat type and order of disturbance, and when the species was detected, notesonn group size, age-class composition, habitat utilization, altitude, and behaviourweree taken. Additional data on the presence or absence of grizzled leaf monkeys wasgatheredd by semi-structured interviews with local people living in the vicinity of theforestss and with officers of nature conservation and forestry departments.Comprehensivee information on the distribution of the species was obtainedfromm the study of specimens in the Museum Zoologi (Bogor, MZB), the BritishMuseumm of Natural History (London, BMNH) and the National Museum of NaturalHistoryy (Leiden, RMNH), from the literature, and from unpublished data obtainedbyy correspondents.73 3

ForestForest (and) PrimatesTablee 6.1Study sites on the island of Java, IndonesiaLocality yMt.. PancarMt.. Gede-PangrangoMt.. SawalMt.. SegaraMt.. SlametMts.. DiengMt.. SundoroMt.. SumbingMt.. MerapiMt.. MuriaMt.. LawuMt.. Wilis-LimanStatus 1 1unp. .NP Pwr r[nr]/unp. .[nr] ][wr]/unp. .Pf f[nr] ][rf] ][nr] ][nr] ][wr] ]Coordinatess E-S106°54'' 6°35'107°00'' 6°45'108°16'7 o 12' '108°48'' 7°07'109°15'7°15' '109 o 37'7 o 05' '110°00'' 7° 17'110°O4'' 7°22'110°26'' 7°32'110°52'' 6°37'111°11'' 7°40'111°46'7 D 48' 'Forestt type 2wett hillwett hill-montanewett hill-montanewett lowland-submontanewett hill-montanewett lowland-montanewett montanewett lowland-montanewett montanemoistt hill-submontanewett submontane-montanemoist-wett hill-montaneAlt.. Range'700-1000 0800-3019 9700-1764 4300-1812 2700-3000 0250-2565 52000-3135 5500-3371 1900 a -2911 1600-1620 01000-3000 0600-2563 3NPP = national park (Taman Nasional), nr = nature reserve (cagar alam). pf = protection forest (hutanlindung),, rf = recreation forest (hutan wisata), unp. = unprotected, wr = wildlife reserve (suakamargasatwa),, [ ]=proposed.Afterr MacKinnon et al., 1982.Numberss in italic represent approximate lower and upper limits of forest;Beforee the eruption on 22-11-1994: present state of forest unknown but lower limit has gone upconsiderablyy and only the eastern slopes are left covered with natural forest (Rudiyanto, pers. comm.,1996). .RESULTS SGeographicc distributionFiguree 6.1 and Table 6.2 show the localities where grizzled leaf monkeys have beenrecorded,, both in historic and recent times. The species' distribution encompassesthee area from the westernmost tip of the island at Ujung Kulon to Mt. Lawu on theborderr between Central and East Java. It has been recorded in 33 forest patches,mostt of which are located in the West Javan province and a few records originatefromm the Central Javan province. The only records from East Java are those fromMt.. Lawu and the Middle Pleistocene fossil excavated at Sumber Kepuh.Distributionn in the central parts of JavaInn this section, information gathered in the central parts of the island are discussed inaa west to east sequence.Mt.. Sawal. The characteristic vocalizations of the grizzled leaf monkey wererecordedd in a secondary forest patch, on the southern slopes at 1025 m a.s.1. Thedensee cover prevented sightings of the animals although the group was very close athand.. Three other individuals and a juvenile were seen later resting in an emergenttreee in the primary forest at an altitude of 935 m a.s.1.74 4

OccurrenceOccurrence and Distribution of Grizzled Leaf MonkeyTablee 6.2Localities with records, and altitude when available, of grizzled leaf monkey PresbMiscomata,comata, forest type with its approximate present altiludinal range, and climate type.No. ** . Locality1 1> >3. .4. .5. .6. .7. .8. .9. .10. .11. .12. .13. .14. .15. .16. .17. .18. .19. .20. .21. .22 223. .24. .25. .26. .27. .28. .29. .30. .31. .32. .33. .34. .Ujungg KulonCerita aRuncaa DanauHaurbentes-Jasinga aCikepuh/Cibanteng gHulimun nPelabuhann RaluMt.. SalakJampang gMl.. PancarMi.. Gede-PangrangoCiwangi iSanggabuana aMt.. MagesitKamojang gMt.. SimpangMt.. TiluBurangrang gCibee ureumMt.. KencanaMll PapandayanPatenggang gCikajang gMl.. LimbungMagesitt KareumbiMt.. SawalMt.. CiremayCiringin nMt.. SlametMl.. Cupu/SimembutMt.. LumpingMtt PrahuMtt LawuSumbcrr KepuhCoordinates sE-S S105 o 20'-6°45' '105 o 50'-6°10' 'i06°00'-6°10' '106°27'-6°31' '106 o 25 - -7°12' '106°30'-6°40' '106 o 32 , -6 o 59' '106°45'-6°45' '106°47'-7°15 --106°54'-6°35--IO7°0O'-6°45' '107°02'-7°04' '107°I5'-6°35 --107°20'-7°05' '107°22'-7°10' '107°25--7°15--107 Q 30"-7 C 09' '107°33-6 Q 46' '107°33'-7 Q 10' '107=35- - 7^18--107°45'-7 D 20' '107°46'-7°08' '107 o 47 - -7 o 22' '107°50"-7 C 25" "107 c 54'-6°54--108 C I6'-7°12' 'I08 : 25'-77 00'108 3 30'-7°27' '1099 15 -7 15'109°26'-7 = I4--109 G 38'-7 J 07' '10955-77 10111 11 1-7 40"11 1205-7 30Forest ttype** *L LL LL LP PL LH/SM/M MAlt.. rangeforest tClimate etypeTt t2-3 32 23 33 3*> *>3 30-623 3100 10090-744 4200-470 00-235 5500-1929 9L L 100 100 2 2SM/M M 1700-2211700-2211 3 3 1-- -- 2-3 3H H 700-1000 700-1000 3 3H/SM/M M SOO-3019 9 3 3-- -- 3 3L/H H Z50-1219 9 2 2SM/M M 1000-201% 1000-201% 3 3M M 1400-2250 1400-2250 3 3H/SM M 600-1600 0 3 3SM/M M 7200-2177 73 3SM/M M 1000-2000 1000-2000 2-3 3-- 3 3H/SM/M M 600-2182 2 3 3SM/M M 1000-2622 2 3 3M M 1600-1775 1600-1775 3 3-- 3 3L/H/SM M 300-\%\5 300-\%\5 3 3H/SM M2-3 3H/SM M 700-1764 4 3 3SM/M M 1000-3078 83 3-- 3 3H/SM/M M 700-3000 700-3000 3 3L/H H 350-350-10003 1000 3L/H/SM M 250-1327 7 3 3M M /600-2565 5 3 3SM/M M 1000-3000 1000-3000 2 2II (Mt Wilis 2-3)) (i)Alt.. record. (reference)TTT0-200(1-2) )(3) )(3-4) )200-4700 (5)(6) )(4)) 700-1075 (7), 900-1200 (6)30(8) )600(a) )(b) )785-8500 (9)900-1400(9),, 1000-2600(5)1200(8) )(6) )(10) )1390-1625(11) )(10) )(4-10-11) )(6) )(c) )(10) )(11) )1600-1775(11) )900(d) )(10) )(6) )915-1025(9) )(12) )(e) )1000(f)) 1400(g) 1500(13)700-2350(9)350-100(14) )300-1300(9) )1300-14000 (15), 2500-2565 (9)1500-16000 (h) 1880 (9) 1900 (3)** Cf. Figure 6.1*** L = lowland forest (0-500 m): H = hill forest (500-1000 m): SM = submontane foi est (1000-1500m):: M = montane forest (1500 m and above) P = forest plantation.tt Italic numbers represent approximate altitudes (after MacKinnon et al . 1982; Kappeler. 1984; ownobs.). .TTT Climate types based on the number of rainy days during the four driest consecutive months of theyearr (abbreviated as RDFDCM). 1 = areas with 0-10 RDFDCM: 2 = areas with 10-30 RDFDCM;33 = areas with more than 30 RDFDCM (aftervan Steenis, 1965).TT 1 ** Key: (1) Hoogerwerf. 1970; (2) Gurmaya et al.. 1992; (3) S. van Balen, pers comm., 1995; (4) vanderr Zon. 1979; (S)Sujatnika, 1992; (6) Supriatna el al.. 1994; (7) Kool, 1992; (8) Napier, 1985; (9)presentt study: (10) MacKinnon et al., 1982; (II) Ruhiyat, 1991: (12) Weitzel et al., 1988; (13)Seitree & Seitre. 1990: (14) Linsley & Nawimar (1994) in Brandon-Jones, 1995; (15) Bartels, 1937.(a)) RMNH 34302/34336/34337/34338: (b) MZB 3817; (c) RMNH 26822; (d) MZB 6646; (e) RMNH34296:: (f) RMNH 34318: (g) MZB 167; (h) RMNH 14614; (i) Middle Pleistocene fossil, coll.Duboiss no 3780. RMNH75 5

ForestForest (and) Primates=? ?<

OccurrenceOccurrence and Distribution of Grizzled Leaf MonkeyAccordingg to local villagers and staff from the forestry department, grizzled leafmonkeyss are also present in the higher parts on the northern slopes, although thespeciess was not recorded there.Mt.. Slamet. Both in 1994 and 1995, groups of grizzled leaf monkeys were recordedonn several occasions on the southern slopes near the hotwater springs near 'Pancurantujuh',, north of the village of Baturaden. Group sizes ranged from 4-5 to 10individualss and records were established at altitudes between 700 and 910 m a.s.1.Onn 30 June 1995, the vocalizations of the grizzled leaf monkey were heardcomingg from the edge of the forest at 1985 m, on the eastern slopes of Mt. Slamet.Thee same day two other groups were observed. The first group consisted of morethann three individuals and was seen descending to a lower part of the mountain fromann altitude of 2150 m a.s.1. A few moments later a group of ebony leaf monkeysTrachypithecusTrachypithecus auratus (E. Geoffroy, 1812), were seen heading in the samdirection.. It is not clear whether the two species formed one group or were dividedintoo two separate groups. A mixed group of both species was observed later that day:aa group of nine leaf monkeys — three to four of which were grizzled leaf monkeys —weree seen moving in the upper layer of the canopy, in oak-laurel forest at an altitudeoff 2350 m a.s.1.Mts.. Dieng. Grizzled leaf monkeys were found in different parts of this c. 255 km 2largee forest block, ranging from lowland to upper-montane. The species was firstseenn on 5 June 1994, near the summit (2565 m) of Mt. Prahu in the easternmost part.TwoTwo individuals were moving through the upper strata of the forest, and one couldbee observed for up to half an hour (Nijman & Sozer, 1995). Near this observationpoint,, in June 1995, a group of leaf monkeys was observed but it was not clearwhetherr or not grizzled leaf monkeys were involved.Inn the lower parts near the village of Linggo, seven times a group was seenrangingg from three to 13 individuals and two groups were detected by means of theirvocalizationss only. Records were established at altitudes of 1300 m a.s.1. on Mt.Lumpingg to 650 m near Linggo, but the species was also reported to occur at thelowerr parts to c. 300 m a.s.1.Mt.. Lawu. The species was recorded once during five days of surveying, in themontanee forests (1880 m) between Cemoro Sewu and the waterfall of Mojoseminearr Sarangan, East Java. On 12 July 1995, the characteristic diagnostic vocalizationoff the grizzled leaf monkey was heard and a few minutes later a group of at leastsevenn leaf monkeys was observed. Although the light conditions were far fromoptimall due to the incoming darkness, the shape of the monkeys and the clearpresencee of a pale belly and underside of tail left no doubt that grizzled leaf monkeywass involved. Groups of ebony leaf monkeys were also observed in the area.Accordingg to local informants, two types of budeng (East Javan name forebonyy leaf monkey) were present. I have not spoken with anybody who was familiarwithh the name (lutung) rekrakan (Javanese name for grizzled leaf monkey), nor have77 7

ForestForest (and) PrimatesII heard of anyone who had a local word to describe the species other than budeng orlutunglutung (the latter name is used in West and Central Java and Bali to indicate ebonyleaff monkeys).Onn 8 October 1988, S. van Balen (pers. comm., 1995) recorded a group ofgrizzledd leaf monkeys consisting of 10-15 individuals, at c. 1900 m a.s.1. in theforestss above Cemoro Sewu.Mt.. Wilis. Nowadays only the southeastern slopes of Mt. Wilis are left covered withrainn forests and might provide a suitable habitat for the grizzled leaf monkey. Theremainderr of this mountain complex consists of disturbed secondary forest, bushlandandd some patches of primary forest. The species was not recorded to be present.InIn May 1994, Linsley and Nawimar {in Brandon-Jones, 1995b) observed grizzledleaff monkeys on Mt. Cupu-Mt. Simembut in a fragment of natural forest apparentlytotallyy surrounded by pine plantations or open ground. In none of the other forestareass of Central Java have grizzled leaf monkeys been recorded, nor did we receiveinformationn that could indicate its presence.DISCUSSION NDistribution nThee present study shows that the distribution of the grizzled leaf monkey shows averyy scattered pattern with records originating from 33 forest areas. In some of theseareass the species is only known with certainty from historic observations andwhetherr or not the species is still present in these localities remains to be solved.Grizzledd leaf monkey is a stricktly arboreal species and even relative small areaswithoutt forest will not be crossed. The populations in most of the forest areas arethuss isolated from one another. Furthermore within the forested areas the forest itselfiss often not continuous resulting in the fragmentation into sub-populations ofgrizzledd leaf monkeys with a limited or unknown possibility of migration. Surveysinn the central parts of Java revealed that the grizzled leaf monkey is still present inalll three localities where it has been reported formerly. The independentobservationss of the species on Mt. Lawu by two observers might be significant, asBrandon-Joness (1995b) questions the validity of Mt. Lawu as the site of collectionforr the skin collected by Bartels (RMNH 14614). The Bartels did collect on Mt.Lawu,, and whether or not this skin was indeed collected on Mt. Lawu or on the Mts.Dieng,, as suggested by Brandon-Jones (1995b), might be of historic interest only.Att present it is unlikely that, apart from the Mts. Pembarisan-Mt. Segara andperhapss some small isolated forest patches, the species will be present at any otherlocality.. Mts. Pembarisan is an area of lowland and hill forest probably over 200kmm of which c. 130 km are proposed as conservation forest (MacKinnon, 1987)wheree both Javan gibbon and ebony leaf monkey were observed (Nijman & Sözer,78 8

OccurrenceOccurrence and Distribution of Grizzled Leaf Monkey1995).. Most of the forests in Central Java are severely diminished, and almost allremainingg forest areas were visited for several days.Inn some areas, for instance Mt. Sundoro and Mt. Sumbing, the absence of P.comatacomata may simply be explained by the total lack of suitable habitat, i.e., the totalabsencee of closed canopy forest. In other areas the absence is more difficult toexplain.. Some areas seemed, at least from the human observer's eye, to containsuitablee habitat. Most of the forests on the central Javan mountains are ratherdisturbed,, either as a result of human influences and/or of natural causes. Thoseareass that seem suitable at present may consist of regrowth, while isolation did notalloww them to be colonized.Itt was not until 1990, when Seitre & Seitre (1990) observed grizzled leafmonkeyss on Mt. Slamet, that there was any certainty about the continued existenceoff the species in Central Java. Grizzled leaf monkeys were also reported to occur onMt.. Slamet by M. Linsley (pers. co mm., 1994). The present study shows that thescantyy information we have on the eastern half of the species' distribution is equallylikelyy due to the limited amount of focussed research done in the area as well as tothee rarety of the species. However, it must be stressed that the species is present atfeww localities only and the nature of the species evades easy observation.Furthermore,, for unexperienced observers melanistic individuals are easily confusedwithh the more common Ebony leaf monkey.Withh the observations of grizzled leaf monkeys at Mt. Sawal, the (historic)presencee on Mt. Ciremay and at Cisaga, and the present observations at Mt. Slamet,Mts.. Dieng and Mt. Lawu, it becomes clear that the species shows a more or lesscontinuous,, though very scattered, distribution from Ujung Kulon in the west to Mt.Lawuu in the east.Altitudinall distributionSomee confusion exists in literature about the altitudinal distribution of the grizzledleaff monkey. Older researchers (e.g., Hoogerwerf, 1970; Med way, 1970) considerthee species to be restricted to the lowlands and not to high mountainous regions, andalsoo MacKinnon (1987) restricts the species to the lowland and hill forest up to 1500mm altitude. According to Whitten et al. (1996) the species' altitudinal limit isprobablyy about 1250 m a.s.1., although it is sometimes found higher than this,particularlyy where lowland forests have diminished in area. The given altitudes atwhichh museum specimens were collected range from sea level to 1600 m a.s.1.Recentt workers (e.g., Ruhiyat, 1983, 1991; Supriatna et al., 1994) however,considerr the species to be confined to higher elevations between 1200 and 1800 ma.s.1.,, and according to Supriatna et al. (1994), individuals have rarely been notedbeloww 1200 m a.s.1.Inn Table 6.2 the approximate present-day altitudinal range of the forest on thedifferentt localities is given, as well as altitudes at which individuals have beenreported,, in present or historic times. From these data it becomes clear that thespeciess covers the whole range between lowland and mountains from sea level up toabovee 2500 m a.s.1. As in West and Central Java more than twice as much forest79 9

ForestForest (and) Primatesremainss above the 1000 m line than below (MacKinnon et al., 1982), it is possiblethatt the species nowadays is more easily observed in montane areas than in lowlandandd hill forests.Inn some forest areas densities may be very low and the lack of sightingspreventss any density estimates from being made (e.g., Ujung Kulon: Hoogerwerf,1970;; Gurmaya et al., 1992; Halimun: Kool, 1992). Calculated densities range from288 individuals per km 2 at altitudes between 650-850 m on Mts. Dieng (Nijman &vann Balen, 1997, chapter 7), 4-5 per km 2 between 900-1200 m in Halimun (Maitar inSupriatnaa et al., 1994), 25 per km 2 at 1300-1500 m on Mt. Gede (Sujatnika, 1992;Sujatnika,, pers. comm., 1995) and 11 per km 2 at 1400-1600 m at Kamojang to 35perr km 2 at elevations between 1600-1800 m in Patenggang (Ruhiyat, 1983). As theprimaryy production of the forest decreases with increasing altitude, and the forestcompositionn changes as well, densities at higher altitudes may be lower whencomparedd with lower altitudes. All dietary studies on the species (Ruhiyat, 1983;Sujatnika,, 1992, Harjanti, 1996, Nurdiana, pers. comm.) have been conducted inmontanee forests above between 900 and 2100 m a.s.1. Sujatnika (1992) and Ruhiyat(1983,, 1991), respectively, found that only 8% and 14% of the species' dietconsistedd of fruit and seeds. Harjanti (1996), in contrast, found that some 58% of itsdiett comprised of fruit and seeds, whereas also Nurdiana (pers. comm.) reported thatsomee 30% of the species diet consisted of fruits. A review of the diet of differentPresbytisPresbytis species found that a proportion of 45-65% of fruit and seeds is typical(Bennettt & Davies, 1994). However, these other species were invariably studied inlowlandd forests. Whether the findings by Sujatnika (1992) and Ruhiyat (1983, 1991)aree indicative for living in a sub-optimal habitat and whether or not the species is'forced'' to live in mountain forests, due to the ongoing deforestation and disturbanceinn the lowlands, remains to be solved.Habitatt preferencesRecentlyy grizzled leaf monkeys have been recorded in both primary and secondaryforest,, as well as in some plantations (Seitre & Seitre, 1990; Sujatnika, 1992).Accordingg to Supriatna et al. (1994) the species might prefer younger rather thanmaturee forest stands, though the present study indicates that the species is present inbothh primary and secondary forest habitats. Most likely the optimal habitat for thespeciess will be rather undisturbed primary forest; the incidental observations ofgrizzledd leaf monkeys in degradated forests or even plantations may not lead to theconclusionn that the species can survive in these habitats for a long period of time.Thee plantation where Seitre & Seitre (1990) observed the species was situatedadjacentt to relatively undisturbed natural forest (pers. obs.), while the population inHaurbentes-Jasingaa studied by Sujatnika (1992) most likely has been 'trapped'insidee the plantation forest, unable to move out as there is no adjacent forest left(Sujatnika,, pers. comm. 1995).Thee original forest cover in Java consisted of two types; rain forest in the Westandd monsoon forest in the East (Van Steenis, 1965), Central Java forming thetransitionn zone between the two. The wettest forest types, viz. the mixed lowland80 0

OccurrenceOccurrence and Distribution of Grizzled Leaf Monkeyandd hill rain forest and the montane everwet forest occur only in those areas with atleastt 30 rainy days during the four driest consecutive months of the year (VanSteenis,, 1972). On the southern and southwestern slopes of some of the highermountainss in the otherwise seasonally dry East Java, some patches of everwet rainforestt exist. Condensation at higher altitudes causes rain to be given off by theotherwisee dry South-East trade winds, resulting in 'wet islands' (Van Steenis, 1972).Thee distribution pattern of mixed lowland and hill rain forest and the montaneeverwett forest corresponds roughly with the distribution of the grizzled leaf monkey,withh the vast majority of records originating from the wettest areas (see Table 6.2).Thee forests on Mt. Lawu lie far inside the drought area and the population ofgrizzledd leaf monkeys on this mountain is postulated to be a relic of a formerlylargerr distribution.Conservationn statusAlthoughh the range of the grizzled leaf monkey appears to be more extensive thanformerlyy suggested, the species should still be considered as among the world's mostendangeredd primate species. As discussed above, the species distribution is severelyfragmentedd and it is likely that many populations in the smaller areas contain toofeww animals to be viable. In the western part of its range at least some of the largerpopulationss occur in relatively safe nature reserves or national parks, most notablyUjungg Kulon, Halimun, and Gede-Pangrango. Although populations in these areasaree not totally safeguarded from loss of habitat, or occasional poaching or killing, atleastt there is a chance that these populations may survive in the long term.Thiss is in contrast with the larger populations in the eastern part of the species'range,, all of which are found in unprotected forest, protected forest in watercatchmentt areas, or production forest. None of the forest areas on Mt. Slamet, Mts.Dieng,, and Mt. Lawu are protected as conservation forests, although all three areashavee been recommended as such (MacKinnon et al., 1982; RePPProT, 1990).Althoughh more data on the status of the grizzled leaf monkey is needed,especiallyy for those populations in the central part of the island, somerecommendationss for its preservation can be given.Inn order to get a better insight in the population status of the grizzled leafmonkeyy it is suggested to perform a comprehensive survey on the distribution of thespecies.. As little is known about the ecology of the species (cf. Supriatna et al.,1994),, more detailed studies could be focussed on the species' habitat preferencesandd its ability to adapt to various degrees of disturbance over the widest possiblerangee of habitats, in different stadia of re- and degeneration. A dietary study in alowlandd forest area, e.g., Mts. Dieng, can explain whether the difference between thereportedd diets of grizzled leaf monkeys and other members of the genus areintraspecificc or due to the fact that grizzled leaf monkeys have been studied inmountainn areas and the others in lowland forests.Ass conversion of natural forest, forest fragmentation and encroachment are anongoingg process, raising the status of one or preferably more of the above-mentionedCentrall Javan forest areas to a higher conservation status, e.g., wildlife reserve,81 1

ForestForest (and) Primatesnaturee reserve, or even national park, seems of prime importance for the survival ofthee eastern populations of the grizzled leaf monkey. On the basis of the extent offorestt and the number of endemic (bird) species present, the two most importantforestt areas for conservation are considered to be those on Mt. Slamet and Mts.Diengg (Nijman & Sözer, 1996; see also chapter 8). As Java is one of the world'smostt active volcanic areas and Mt. Slamet is an active volcano, for the long-termpreservationn of the grizzled leaf monkey, protection of the population on Mts. Diengseemss most feasible. By following the recommendations of MacKinnon et al.(1982),, with the extension into the lowland zone as proposed by Nijman & Sózer(1996),, not only the grizzled leaf monkey would benefit from such an action but alsoseverall equally unique and endangered wildlife species, most notably the Javangibbonn and the Javan hawk-eagle Spizaetus bartels'x Stresemann 1924.ACKNOWLEDGEMENTS SII would like to thank the Indonesian Institute for Science (LIPI) for their sponsorshipandd the Directorate General of Forest Protection (PHPA) for allowing me to conductthee fieldwork. Mr. Boeadi (Museum Zoologi, Bogor), Miss P. Jenkins (BritishMuseumm of Natural History, London) and Dr. C. Smeenk (National Museum ofNaturall History, Leiden) are acknowledged for access to specimens under their care,andd Dr. J. de Vos (National Museum of Natural History, Leiden) for providinginformationn on the Middle Pleistocene fossil. Resit Sózer and Bas van Balen arethankedd for their work during surveys. Constructive comments were made by Dr.P.J.H.. van Bree, Dr. J. Chapman, Dr. C.J. Hazevoet, S. Cooper, and Dr. H. Albrechtwhenn reviewing earlier versions of the manuscript and also two reviewers madehelpfull comments.82 2

GeographicalGeographical Distribution of Ebony Leaf MonkeyCHAPTERR 7GEOGRAPHICC DISTRIBUTION OF EBONY LEAF MONKEYTRACHYPITHECUSTRACHYPITHECUS AURATUS (E. GEOFFROHILAIRE,, 1812) (MAMMALIA: PRIMATES:CERCOPITHECIDAE) )ContributionsContributions to Zoology 69: 157-177 (2000), with additional data.ABSTRACT TAss one of the fundamental units of ecology and biogeography, the geographicdistributionn of the endemic and threatened ebony leaf monkey Trachypithecusauratusauratus (E. Geoffroy Saint-Hilaire, 1812) on the islands of Java, Bali, and Lombok(Indonesia)) has been assessed. All localities where the species has been collected arelisted,, and forty-two areas (each in itself consisting of numerous smaller sites) wherethee species has been recorded are discussed. The species occurs in a large variety offorestt types, including mangrove, beach, and freshwater swamp forest; everwetlowlandd and hill forest; dry decidious forest; montane forest up to 3,000 - 3,500 ma.s.1.;; and in some forest plantations (teak Tectona grandis, rasamala Altingiaexcelsa,excelsa, acacia Acacia spp). In East Java, certain populations are dimorphic,containing,, besides the more common melanic individuals, also erythristicindividuals.. This erythristic pelage morph only occurs in the easternmost part ofJavaa of which the line between Mt. Penanggunang and the surroundings ofMojokertoo running south-wards, via Wonosalam and Blitar, to Mts Kidul roughlyformss the western boundary. Localities where individuals of the erythristic pelagemorphh have been collected or observed are given.RINGKASAN NDistribusii geografis Lutung Trachypithecus auratus (E. Geoffroy Saint-Hilaire,1812)) (Mammalia: Primata: Cercopithecidae) (Contributions to Zoology 69: 157-177,, 2000, dengan tambahan data): Sebagai salah satu bagian ekologi danbiogeografii yang mendasar, distribusi geografis Lutung Trachypithecus auratus (E.Geoffroyy Saint-Hilaire, 1812) yang endemik dan terancam punah di Jawa, Bali danLombokk (Indonesia) telah ditentukan. Seluruh lokasi dimana spesies pernahdikoleksii didaftarkan, dan empat puluh dua daerah (pada setiap daerah tersebut didalamnyaa termasuk beberapa tempat-tempat yang lebih kecil) dimana spesies pernahtercatat,, didiskusikan di sini. Spesies ini terdapat di banyak tipe hutan, yaitu di hutanmangrove,, hutan pesisir, hutan rawa air tawar; hutan dataran rendah dan pebukitanyangg selalu basah; hutan kerangas; hutan pegunungan sampai ketinggian 3000-350083 3

ForestForest (and) Primatesmm dpi; dan di beberapa hutan tanaman (Jati Tectona grandis, Rasamala Altingiaexcelsa,excelsa, Akasia Acacia spp). Di Jawa Timur, populasi-populasi tertentu bersifatdimorfis,, di samping individu-individu hitam [melanic] yang lebih umum, jugaterdapatt individu-individu kuning [erythristic]. Tipe bulu 'erythristic' ini hanyaterdapatt di bagian paling timur Jawa, dengan batas barat kira-kira garisnya antaraGn.. Penanggungan dan sekitar Mqjokerto ke arah selatan, melalui Wonosalam danBlitar,, menuju Pegunungan Kidul. Lokasi-lokasi dimana individu-individu dengantipee bulu 'erythristic' telah dikoleksi atau diamati dipaparkan di sini.INTRODUCTION NBeingg located in the extreme east of the Sundaic subregion, Java and Bali are themostt isolated of the remaining land masses and also furthest from the Asianmainland.. Java harbours a slightly impoverished non-human primate faunacomparedd to the other Sundaic islands. There are 5 species, including one nocturnalprosimian,, the slow loris Nycticebus coucang (Boddaert 1785) compared to 13speciess on Borneo and 12-13 species on mainland Sumatra; the exact speciesnumberr depends on the taxonomy followed. However, a relative high proportion ofthemm are endemic, viz. 60% {compared to 38-43% on Borneo, and 8-17% onmainlandd Sumatra). The endemics comprise one species of Hylobatidae, the Javan orsilveryy gibbon Hylobates moloch (Audebert, 1799) and two species of Colobinae,thee grizzled leaf monkey Presbytis comata (Desmarest, 1822) and the ebony leafmonkey 11 Trachypithecus auratus (E. Geoffroy Saint-Hilaire, 1812). The Javangibbonn and the grizzled leaf monkey are confined to the wettest forest types, whicharee more common to the western part of the island, and can be found as far east asMtss Dieng and Mt. Lawu, respectively (Nijman and Sözer, 1995; Nijman, 1995,1997b).. The ebony leaf monkey's range encompasses a larger area, and the speciescann be found in other forest types as well, on Java, Bali and Lombok. 2 Despite itsdistributionn encompassing a larger area than the other Javan endemics, its range isstilll restricted, and its habitat has largely dissappeared. Ebony leaf monkey are listedass Vulnerable according to the IUCN threat criteria (Eudey, 1987; IUCN, 1996). Thespeciess is protected by Indonesian law and is listed on Appendix II of the CITESconvention. .Ebonyy leaf monkey is also known as ebony or moor langur, Javan leaf monkey / langur, silver(ed)leaff monkey / langur, amongst others. Some of these names, however, are also used for the grizzledleaff monkey Presbytis comata and silvered leaf monkey Trachypithecus cristatus. Locally ebonyleaff monkeys are known as either lutung (both melanic and erythristic individuals) and in parts ofEastt Java budeng (usually only the melanic individuals)Basedd on a single skin, probably originating from the northwestern part of Vietnam, Brandon-Jones(1984,, 1995) described subspecies Semnopithecus (Trachypitecus) auratus ebenus. As it is of littlerelevancee to the present paper, and pending more information on this taxon and its distribution, it isnott discussed further.84 4

GeographicalGeographical Distribution of Ebony Leaf MonkeyThee ebony leaf monkey has for a long-time been regarded as conspecific with thesilveredd leaf monkey, T. cristatus (Raffles 1821) (e.g., Pocock, 1935; Napier, 1985;Wolfheim,, 1983), but it was given its specific status by Weitzel and Groves (1987).Thee species specific status of T. auratus is now generally accepted (e.g., Weitzel etal.,, 1988; IUCN, 1994; Brandon-Jones, 1984, 1995a; Corbet and Hill, 1992; Oates etal.,, 1994; Maryanto et al., 1997) although Rosenblum et al. (1997) found a highdiversityy in mtDNA between and among populations of T. auratus and T. cristatus,withoutt however, a clear distinction between populations of Pensinsular Malaysia,Sumatraa or Java. T. cristatus and T. auratus occur allopatrically with the formerhavingg a disjunct distribution with populations from southern Burma, southernThailand,, Cambodia and southern Laos and Vietnam, and from the western coast ofWestt Malaysia, Sumatra and Borneo (Corbet and Hill, 1992), while the latter, asstatedd before, ranges from Java eastwards to Lombok. Both species can bedistinguishedd by skull and dental characters (Weitzel and Groves, 1987; Maryanto etal.,, 1997). Furthermore, T. cristatus is brown, brownish-grey or blackish brown,whilee the Javan species is more blackish tingled with brown and grey. In bothspeciess some populations are polymorphic in pelage coloration, with melanic andusuallyy a small proportion of erythristic individuals occurring together. Thisproportionn may vary between areas. In the ebony leaf monkey, these populations arerestrictedd to the easternmost part of Java (see Discussion), while in the silvered leafmonkeyy these populations hitherto only have been recorded from Abai at the mouthoff the Kinabatangan River in eastern Sabah, Borneo (Davis, 1962; Payne et al.,1985).. Weitzel and Groves (1987) concluded that the type specimen of T. auratus,ann erythristic female, must have originated from the easternmost part of Java (seealsoo Brandon-Jones, 1995a).Littlee is known about the ecology of the species in natural forest areas, sinceonlyy a limited number of studies have been conducted so far. Most of thecomprehensivee studies, i.e., those of Brotoisworo and Dirgayusa (Brotoisworo,1983;; Brotoisworo and Dirgayusa, 1991), Kool (1993; Kool and Croft, 1992), and toaa lesser extend Megantara (1994) have been conducted in the Pangandaran naturereserve.. Pangandaran is a small c. 500 ha. uplifted limestone peninsula at thesoutheasternn corner of West Java. Parts of the area are covered with teak, Tectonagrandisgrandis and mahogany, Swietenia spp., stands, while the remainder consists ofratherr dry evergreen forest (Whitten et al., 1996). Data presented by Brotoisworo(1983)) suggest densities of c. 185 to 195 individuals km" 2 . Typical densities in areaswheree the species has been studied, which are often selected because the species isrelativelyy common, range in the order of 20 to 75 individuals km" 2 (Kartikasari,1986;; Supriatna et al., 1988; Bismark and Wiryosoeparto, 1980 in Supriatna et al.,1988;; Nijman and van Balen, 1998), with probably the more typical density leaningtowardss the lower figure (unpubl. data). Pangandaran receives more visitors than anyotherr conservation area in Indonesia, possibly 500,000 annually (Whitten et al.,1996).. Densities of the other primate in the reserve, the long-tailed macaque Macacafascicularisfascicularis (Raffles 1821) are very high (pers. observ.), quite likely resulting fromthee visitors feeding them. The large numbers of visitors and the high density of85 5

ForestForest (and) Primatesmacaquess most likely has its effect on the socio-ecology and structure of the ebonyleaff monkey population. Hence, findings and conclusions arising from studiesconductedd on the species in Pangandaran are probably not representative and cannotunhesitatinglyy be extrapolated to other areas.Ass many other species within the genus Trachypithecus, the ebony leafmonkeyy lives in groups with one adult male and a number of immature males,females,, and young (see reviews by Bennett and Davies, 1994; Newton and Dunbar,1994).. These group sizes range from three to over 30 individuals (pers. observ.;Supriatnaa et al., 1988; Brotoisworo, 1983). Group sizes on Java seem to differbetweenn areas with different climatic conditions; median group sizes in areas with amoree pronounced dry season, which are mainly found in the eastern half of Java aswelll as along the island's northern coast, tend to be larger than those found in areaswithh a perhumid climate (unpubl. data). Extra-group males either live as solitaries orcann team up with other bachelor males in bands or small groups (pers. observ.;Bennettt and Davies, 1994; Brotoisworo, 1983).AA number of studies have been performed on the species' feeding behaviour(Kartikasari,, 1986; Supriatna et al., 1988; Brotoisworo and Dirgayusa, 1991; Kool,1993;; Djuwantoko et al., 1994) often partially in teak plantations. Like all colobines,ebonyy leaf monkeys possesses a fore-stomach digestive system, which allows themtoo break down cellulose (Bauchop and Martucci, 1968; Kay and Davies, 1994). Thismakess the species able to cope with a substantial amount of foliage, a relativeunnutriciouss food source, in their diet (for an overview of food selection incolobiness see e.g., Waterman and Kool, 1992). Indeed, although depending onhabitatt type and seasonality, a large part of their diet consists of leaves and flowers(55%% and 67% Kool, 1993; 56% Kartikasari, 1986; 59% Supriatna et al., 1988; 90%Brotoisworoo and Dirgayusa, 1991; 94% Djuwantoko et al., 1994). As in mostcolobines,, ripe fruits is not a favoured food source, and often only the seeds areconsumed.. When fruit is eaten, e.g., figs Ficus spp, mahogany Swieteniamacrophylla,macrophylla, and acacia Acacia leucophloea, it is mostly not ripe (Kool, 199Kartikasari,, 1986).Thee geographic distribution of a species is perhaps the fundamental unit ofecologyy and biogeography. It affects probability of extinction (Jablonski, 1987) anddifferentt range sizes of species ultimately determine the number of species in agivenn area. The distribution of a species is determined by its geographical range andbyy the evenness or patchiness of occurrence within its range. Ecological analysis ofspeciess distribution patterns depends on the accuracy of the distributional data onwhichh it is based: if a distributional pattern has been incorrectly described anyinterpretationn of that pattern will be erroneous (cf. Wiens, 1992). Brockelman & Ali(1987)) stress the importance of publishing reliable and detailed data on thedistributionn of primates. The need for accurate mapping of species' ranges, theirrelevancee to biogeographic processes and the structure of local species assemblages,andd the potential sources of error in estimating species-range-size distributions haverecentlyy been discussed by Jones (1998) and Gaston (1996). Furthermore, for theproperr assessement of a species' conservation status and in order to monitor changes86 6

GeographicalGeographical Distribution of Ebony Leaf Monkeyinn abundance, range, and status an accurate description of its range of occurrence isessential.. Therefore, as part of an ongoing study on the ecology and conservationstatuss of ebony leaf monkey, the present paper attempts to thoroughly assess thegeographicall distribution of ebony leaf monkeys on Java, Bali and Lombok.METHODS SThee data originate from surveys conducted by the author over a period of 16 monthsinn March-September 1994, June-July 1995, August-September 1997, September1998-Januaryy 1999, June 1999-February 2000, June-September 2000 on Java, Bali,Lombok,, Madura, and Kangean. The presence or absence of ebony leaf monkeyswass assessed by surveying inside the forest and by scanning over the forest fromvantagee points (hill tops or forest edge). While in the forest areas additionalinformationn on the presence of ebony leaf monkeys was gathered by interviewinglocall inhabitants in Bahasa Indonesia.Thesee findings were supplemented with data derived from the literature,informationn from collected specimens stored in various museums, and from personalcorrespondencee with other observers. All records listed are those of the author,unlesss stated otherwise. Areas in which ebony leaf monkeys were observed are listedbyy province and in a west to east sequence. For each area the county names in whichitt is situated is given, a short description of the type of habitat is presented, the statusandd records of ebony leaf monkeys in that area are listed, as are the specimens, ifany,, which have been collected. Specimens collected were either collected in thedescribedd area itself or the described area nearest to the site of collection.Abbreviationss employed for the institutions at which the specimens are storedare:: ZMA: Zoological Museum Amsterdam, the Netherlands; RMNH: NaturalMuseumm of Natural History, Leiden, the Netherlands (many skins have only acollector'ss number and no access number); MZB: Museum Zoologicum Bogoriense,Bogor,, Indonesia; BMNH: Natural History Museum, London, UK; ZRC: ZoologicalReferencee Collection, Singapore.Notee that some areas discussed in fact constitute of numerous isolated patchesoff forest, and that ebony leaf monkeys are not by definition present throughout theentiree area. Furthermore, within forest areas ebony leaf monkeys may prefer certainpartss above others.Localitiess from where information was received about the presence ofindividualss of the erythristic pelage morph, either from direct observations, fromhearsayy evidence or from other biologists working in the area, as well as localitiesfromm where erythristic specimens have been collected, are indicated.RESULTS SForr the geographic location of of the areas discussed in this section, see Figure 7.1.Alll localities are discussed in a west to east sequence, and are classed by province.87 7

—ForestForest (and) PrimatesSS '«« .—— K.'C C/ ^ ^^ J*>(--11 ^si O\\l'' 7 "1rV.3 3.... APCOO S -~ ~CO O^ ^ QJ QJc cO O fi fiqj j,—, ,1—1 1—— ^

GeographicalGeographical Distribution of Ebony Leaf MonkeyProvincee of West Java (including DKI Jakarta)1.. Ujung KulonCounty:: Pandeglang.Habitat:: Ujung Kulon is a more than 750 km 2 area of old secondary lowland forest,withh primary forest in the higher parts. The peninsula is relatively secure fromloggingg and encroachment, but the mainland part is threatened by surroundingcultivation. .Status:: The species is present mainly in the coastal zone and along the rivers, butalsoo in the interior (July 2000; Hoogerwerf, 1970). Hoogerwerf observed ebony leafmonkeyy mainly in the peninsular part of the reserve, but the species is also presentonn the mainland on Mt. Honje (Gurmaya et al., 1992; Ruhiyat, 1991). The species isnott present on Peucang or Panaitan island (Hoogerwerf, 1970).Specimenss collected: Niur: MZB 6694.2.. Ranca Danau, Mt. Karang and Mt. AseupanCounties:: Pandeglang, Serang.Habitat:: Fragmented patches of forest with the last remaining substantial area offreshh water swamp forest in Ranca Danau totalling c. 250 km , while another 170km 22 is present in two patches in the adjacent Gunung Tukung Gede Nature Reserve.Severall thousands of hectares of disturbed lowland forest remain on Mt. Aseupan,whilee c. 100 ha of lowland forest is protected as recreation forest near the CurugGendangg waterfalls, Carita. On Mt. Karang c. 30 km 2 of montane forest remainsrangingg from c. 1000-1778 m.Status:: A small number of groups were observed near the waterfalls, as well as nearthee guard post at the entrance of the recreation forest at Carita (Sept. 1997; July2000);; one group was observed to foray into the adjacent Rasamala Altingia excelsaplantation.. S. van Balen (in litt., 1998) recorded the species on the 1346 m tall Mt.Pulosari,, c. 6 km south-east of Mt. Aseupan (Oct. 1995). The species is present inthee swamp forests of Ranca Danau and hill forest of Mt. Tekung Gede (Melish andDirgayusa,, 1996), as well as in the montane forests of Mt. Karang (April 1995: S.vann Balen in litt. 1998).Specimenss collected: Ujungtebu: ZRC 4382.3.. Dungus Iwul and YanlapaCounty:: Bogor.Habitat:: Dungus Iwul is a small relict patch of primary forest (9 ha) surrounded byrubberr Hevea brasiliensis plantation (MacKinnon et al., 1982). Despite its size the89 9

ForestForest (and) Primatesreservee is significant as one of the few remnants of low altitude lowland tropical rainforestt left on Java (Whitten et al., 1996). Yanlapa is a slightly larger (32 ha) naturereserve,, consisting of lowland rainforest on red clay soil, relatively well protectedandd used for scientific study (MacKinnon et al., 1982).Status:: Dungus Iwul is inhabited by a single group of ebony leaf monkeys, whichoccasionallyy foray into the surrounding rubber plantation (S. van Balen in litt. 1998;Whittenn et al., 1996). In Yanlapa, not only ebony leaf monkeys are present, but alsogrizzledd leaf monkeys (S. van Balen, in litt., 1998).4.. Ml. Halimun and Mt. SalakCounties:: Sukabumi, Bogor, Banten.Habitat:: The Halimun National Park covers lowland and hill forest from 500 to 1929mm (MacKinnon et al., 1982). The park proper totals 400 km 2 , with some additionallowlandd forest being situated outside the park boundaries. The Mt. Salak is a 2211 mtalll volcano, well vegetated above the 1000-1200 m line. Encroachment fromsurroundingg agriculture and large tea estate enclaves, hunting and illegal goldminingg form major threats to the area.Status:: The ebony leaf monkey is a well known inhabitant of the Halimun NationalParkk (e.g., Ruhiyat, 1991), and by virtue of its size the area probably harbours asignificantt population of the species. Observed frequently near the Cikaniki researchstationn (Aug. 2000). Kool (1992) reported of the sighting of four, most likelydifferentt groups in the western part of the Halimun reserve; one group in Aug. 1989(S.. van Balen in litt. 1998). Mt. Salak: regularly observed by S. van Balen (in litt.,1998);; a group of seven individuals was observed lower montane rain forest feedinginn river valley on the southeastern slopes (Aug. 1997) and one group was heard nearKawaa Ratu (Sept. 1998).Specimenss collected: Jasinga: MZB 6694, 3188; Leuwilang: MZB 2344,-5; Mt.Salak:: ZMA 5327, RMNH; Cisalak: MZB 558; Bolang: MZB 1876, 560.5.. Jampang KulonCounty:: Sukabumi.Habitat:: The forests in this rugged and sparsely populated area have partially thestatuss of protection forest, and is scattered into several smaller, and one larger forestblock.. The altitudinal range lies between sea level and c. 700 m a.s.1. The CibantengNaturee Reserve in the northern part of this area and the Cikepuh Game Reserve(togetherr more than 8500 ha) were established in 1925 and 1973 respectively(MacKinnonn et al., 1982). Cibanteng is a coastal lowland forest, and is adjacent tolargerr Cikepuh Game Reserve. The habitat is mostly secondary forest with patchesoff primary forest and grassland.90 0

GeographicalGeographical Distribution of Ebony Leaf MonkeyStatus:: Ladjar and Simanjuntak (1994) studied populations of the species in theCikepuhh Game Reserve and found them present from Citirem to Cibuaya. S. vanBalenn (in litt., 1998) recorded ebony leaf monkeys in Feb. 1987 in the forests ofCiogongg near the village of Sindabarang on the southern coast. Ebony leaf monkeysaree probably present in a large number of forest areas within this rugged andsparselyy populated area. Furthermore, ebony leaf monkeys may survive in a numberoff forest areas along the West Javan southern coast possibly from Cikepuhintermittedlyy to Leuwang Sancang [11].Specimenss collected: Teluk Pelabuan Ratu: ZRC 4380; Ciwangi: BMNH1909.1.5.14,-15,-16,-17. .6.. Mt. Gede-Pangrango, Puncak, Megamendung, Mt. PancarCounties:: Bogor, Sukabumi, Cianjur.Habitat:: The Mt. Gede-Pangrango are two well-known volcanoes, south of Bogor. Apasss runs through the Puncak area, with the Gede-Pangrango to the south and TelagaWarnaa Nature Reserve and Megamendung to the northeast. Although virtually theentiree area is enclosed in the 15,000 ha Gede/Pangrango National Park, ranging from500-30199 m a.s.1., encroachment from surrounding agriculture, hunting, and otheractivitiess impose continuous threats. The Telaga Warna area forms a 350 ha naturereserve,, but the remaining part of the area is much threatened by holiday resorts andencroachmentt of tea estates. Mt. Pancar is a somewhat isolated hill of 800 m withmoderatelyy disturbed forest on its summit.Status:: Ebony leaf monkeys have been observed in a number of localities, i.e., PasirPogorr (June 1994), above Selabintana (Sept. 1997), Cibodas (June 1995; Sept. 1999;Junee 2000), the forests near Taman Safari Cisarua (Aug. 1994), Telaga Warna (Sept.1997),, near Cibulau (Aug. 1997), and an isolated population survives on Mt. Pancar(Julyy 1995). The species is most likely to be present throughout the entire forestarea. .Specimenss collected: Mt. Pancar: BMNH 1907.6.18.1; Cikaso: MZB 8008; Mt.Pangrango:: RMNH; Cikujang: MZB 6693; Cibodas: BMNH 1949.423, 1954.62,MZB;; Sindanglaja: collected by Robinson and Kloss (1919).7.. Muara Gembong, Muara Angke-Kapuk, Tanjung SedariCounties:: Bekasi, DKI Jakarta.Habitat:: Muara Gembong is a mangrove area at the mouth of the Citarum River, c.600 km east of Jakarta. In 1981 at least 1000 ha of mangrove forest was left, by 1984somee areas had been converted into rice fields, settlements and fish ponds, and by19877 the forest were almost completely destroyed (Supriatna et al., 1989). TheMuaraa Angke-Kapuk is a small nature reserve totalling 15.4 ha, west of Jakarta. The91 1

ForestForest (and) Primatesareaa is covered with mangrove forest in a river delta (MacKinnon et al., 1984).Tanjungg Sedari is a 8200 ha large proposed nature reserve, wich is presently largelydevoidd of its mangrove forest (Rombang & Rudyanto, 1999).Status:: In the Muara Gembong, the ebony leaf monkey lived in groups of up to 30individuals,, at a density of 20 individuals km" 2 , but currently there is hardly forestleftt (Supriatna et al., 1989). The Muara Angke supports small populations of ebonyleaff monkeys and long-tailed macaques Macaca fascicularis (MacKinnon et al.,1984).. Silvius et al. (1987) report of the presence of ebony leaf monkey in TanjungSedari.. The conversion of mangroves into fish and shrimp ponds and theintensificationn of shrimp ponds especially along the north coast of Java, increaseddramaticallyy during the last decades. Most tall trees dissapeared and it is very hard tofindd any piece of forest that might be suitable for ebony leaf monkeys. Mauk,anotherr (proposed) nature reserve, that was known for its mangrove and swampforestt (MacKinnon et al., 1982) appeared to be completely devoid of closed forestand/orr tall trees (van Balen et al., 1993). If the north coast of West Java still holdsadditionall populations of ebony leaf monkey, regretably these will be small andisolatedd from one another, making them especially vulnerable to extinction.8.. SanggabuanaCounties:: PurwakartaHabitat:: The forests of Sanggabuana or Jati Lahur comprise of c. 5000 ha,approximatelyy 2500 ha of which have been proposed as a recreation forest(MacKinnonn et al., 1982). The area is covered with mostly disturbed lowland forestrangingg from c. 150 to 1291, and is centered around the artificial lake of Jati Lahur.Despitee being somewhat disturbed, the area is important for the conservation ofprimatess as all three Javan endemics do occur in the area.Status:: The species is reported to be present by B.O. Manullang (pers. comm. 1997);smalll number of individuals observed in Oct. 1986 (S. van Balen in litt. 1998).9.. North ParahyanganCounties:: Bandung, Sumedang, Purwakarta.Habitat:: The highlands around Bandung are collectively known as the Parahyangan(fromm para: many, and hyang: Gods). The northern part includes a number of tallvolcanoess of which the Tangkuban Perahu is the most well known. The areafurthermoree includes some interesting (proposed) reserves, including the Mt.Tapomass Hunting Reserve (1250 ha), and Burangrang Nature Reserve (2700 ha).Status:: The species is has been reported to be present in Burangrang and Mt.Tapomass (MacKinnon et al., 1982). Wiltjes-Hissink (1953) observed ebony leafmonkeyss on the southern slopes of Tangkuban Perahu above Lembang at 1700 m92 2

GeographicalGeographical Distribution of Ebony Leaf Monkeya.s.1.,, whereas Rombang & Rudyanto (1999) report the presence of the species onMt.. Manglayang.Specimenss collected: Subang: ZRC 4374,-5.10.. South ParahyanganCounties:: Bandung, Garut, and Cianjur.Habitat:: The extensive mountain forests south of Bandung form a more or lesscontinuouss block, locally intersected plantations and roads. Generally forest in theareaa is forest is extant above c. 1200 m a.s.1. A number of nature reserves areestablishedd in the area, of which the most important ones are Mt. Tilu (8,000 ha),Mt.. Simpang (15,000 ha) and Kawah Kamojang (8,000 ha), six others being lessimportantt because of small sizes; more importantly, four new reserves have beenproposedd across the area, totalling a coverage of almost 70,000 ha, ranging from 300too 2182 m a.s.1. (MacKinnon et al., 1982).Status:: Observed near Situ Patengan, Mt. Patuha (July 2000). Ruhiyat (1991)reportedd ebony leaf monkeys to be present at an additional number of sitesthroughoutt the South Parahyangan, i.e. Mt. Halu, Mt. Tilu, Mt. Papandayan, andKawahh Kamojang. Most if not all observations were made in areas at 1200 m a.s.1.andd above. MacKinnon et al. (1982) reported the species to be present also on Mt.Simpang.. Probably, ebony leaf monkey is present throughout the entire area innumerouss isolated populations.Specimenss collected: Pengalengan: RMNH; Tirtasari: RMNH; Cibeureum: RMNH.11.. Leuweung SancangCounty:: Garut.Habitat:: The Leuweung Sancang area contains a 2157 ha nature reserve rangingfromm sea level to 180 m a.s.1. The area is covered with sand dunes, mangroves,beachh forest and primary rain forest on limestone. The outer parts of the reserve areheavilyy damaged by illegal tree cutting (MacKinnon et al., 1982).Status:: Ruhiyat (1991) and A.R. Purnawa (pers. comm. 2000) reported the species tobee present in the area. Further information is not yet available.12.. Mt. CeremaiCounties:: Majalengka.Habitat:: Mt. Ciremai is a 3078 m tall volcano south of Ceremai; c. 12,000 ha offorestt have been proposed as recreation forest (MacKinnon et al., 1982)93 3

ForestForest (and) PrimatesStatus:: There have been no reports on the presence of ebony leaf monkeys, butNapierr (1985) reports the presence of twelve skulls from Cirebon, which may haveoriginatedd from this mountain,Specimenss collected: Cirebon: RCS(OM) S70.43(A)(G) (Napier 1985).13.. Mt. SawalCounties:: Ciamis.Habitat:: The forests on Mt. Sawal comprise of an isolated patch of forest of c. 5400ha,, which have been designated as a wildlife reserve. Ranging from 600-1704 ma.s.1.. the area contains tree species as Altingia excelsa and Podocarpus imbriacataandd may be a valuable area for both flora and fauna (MacKinnon et al., 1982).Ceringrinn is situated in the lowlands below 200 m a.s.1, whether or not forestremainss is not known.Status:: The species was recorded in a secondary forest patch, on the southern slopesoff Mt. Sawal at c. 1100 m a.s.1 and in a patch of Acacia trees (July 1995). Thespeciess was not recorded on the northern slopes, but according to local officers ofthee forestry departement the species is present troughout the reserve.Specimenss collected: Ceringrin: RMNH.14.. Pangandarang-KarangniniCounties:: Tasikmalaya, Ciamis.Habitat:: Pangandaran is a small c. 500 ha uplifted limestone peninsula at thesoutheasternn corner of West Java. The area consists of a 38 ha tourist park, adjacenttoo a 457 ha large nature reserve (MacKinnon et al., 1982). Parts of the area arecoveredd with Teak and Magogany stands, while the remainder consists of rather dryevergreenn forest (Whitten et al., 1996). Karangnini consist largely of beach forestandd teak forest. The latter is intersected by the Cikabuyatan river, the valley ofwhichh is covered with mixed forest.Status:: Pangandaran has been the location where a number of researchers havecolllectedd data on ebony leaf monkey (e.g., Brotoisworo, 1983; Brotoisworo andDirgayusa,, 1991; Kool, 1993; Kool and Croft, 1992; Megantara, 1994). The speciesiss very common and in the tourist park and adjacent nature reserve at least 5differentt groups observed were fully habituated to the presence of humans (Sept.1997).. Group sizes are relative large in comparison to other West Javan localities. InKarangninii three groups were observed at the mouth of the Cikabuyatan River (Sept.1997). .94 4

GeographicalGeographical Distribution of Ebony Leaf MonkeySpecimenss collected: Pangandaran: BMNH 1909.1.5.4,-5,-6(a),-7; Kalipucang:BMNHH 1909.1.5.18.Provincee of Central Java (including DI Yogyakarta)15.. Segara Anakan-Nusa KambanganCounties:: Cilacap.Habitat:: Sagara Anakan is the shallow bay on the southern coast of Java into whichthee Citanduy, Cibereum, and other rivers flow. The area consists of a complex ofmangrovee and tidal swamp forests. South of the area lies the 300 km 2 island of NusaKambangan.. The island largely is under control of the Prison Service of the Minsitryoff Justice, as three highly secured prisons are situated on the island. On the island c.80000 ha of largely undisturbed lowland forest remains.Status:: Erftemeijer et al. (1988) reported ebony leaf monkeys to be present in groupsoff up to 10 individuals in the 'better' forest areas, i.e., further inland in SegaraAnakan.. Near Kabujatan, three groups were observed retreating on a small hill afterhavingg spent the day in the mangrove forests (Sept. 1997). On Nusa Kambangan(Sept.. 1997) no ebony leaf monkeys observed, but the species was known to mostof,, if not all, of the villagers of Klacis. Apparently the species occurs all over theisland. .Specimenss collected: Jumblang: MZB 2094; Cilacap: BMNH 1909.1.5.8,-9,-11,-12,-13;; Karangbolong: ZRC 4.377.16.. Mts PembarisanCounties:: Brebes.Habitat:: In this severly under-explored lowland and hill rainforest area on nonvolcaniccsoils, c. 13.000 ha is proposed as a nature reserve (MacKinnon et al., 1982);too the south the area is bordered by extensive Pine plantations, to the east by Teakforest.. The area was regarded as one of the most valuable remaing forest in CentralJavaa (MacKinnon et al., 1982).Status:: One group of c. 8 individuals was observed on Mt. Segara, in the eastern partoff the Pembarisan mountains (July 1994). No further information is available.17.. Mt. SlametCounties:: Banyumas, Brebes, Tegal, Pemalang, Purbolinggo.Habitat:: The 3418 m Mt. Slamet is Java's second tallest mountain. On the wettersouthernn slopes extensive forest remains down to 700 m a.s.1. On the eastern slopeforestt disappeared below 1900 m a.s.1. Currently the forest above 1000 m a.s.1. onMt.. Slamet are a proposed nature reserve of 15,000 ha (MacKinnon et al., 1982),95 5

ForestForest (and) Primateswhilee proposals to include the forests at lower elevations have been made (Nijmanandd Sözer, 1996).Status:: Ebony leaf monkeys have been observed on the southern slopes aboveBaturadenn at c. 700-800 m a.s.1. (April-Aug. 1994; June 1995). The species was alsopresentt in oak-laurel forests on the upper eastern slopes above Blambangan, wherethreee groups were observed between altitudes of 2,200-2,800 m a.s.1. (June 1995).Specimenss collected: Kaligua: MZB 6690,-91,-92; Kalikidang: RMNH; Curugilang:RMNH. .18.. Mt. Cupu-SimembutCounty:: Banjarnegara.Habitat:: On these mountains small fragments of natural forest, surrounded by eitheropenn ground or pine plantations, remain. The altitudinal range of the forests in thisareaa lies from c. 350-1000 m a.s.1.Status:: Linsley and Nawimar (1994 in Brandon-Jones, 1995) reported the species tobee present in a forest block on a slope of the Tambra river, south of the Argusconfluence. .19.. Mts DiengCounties:: Pekalongan, Batang, Tenaggung, Wonosobo, Banjarnegara.Habitat:: The mountains north and northwest of the Dieng plateau are still coveredwithh an extensive block of natural forest covering the total range from lowland toupperr montane. On the northern foothills of Mt. Lumping above Linggo, the forest(partlyy a former coffee Coffea spp. plantation abandoned in the 1930s) are forestedabovee c. 300 m, while on the eastern slopes of Mt. Prahu, in the east, only above15000 m. The forest totals 25,500 ha, of which the area above 1000 m is a proposedgamee reserve (MacKinnon et al., 1982). Currently the area below 1000 m a.s.1. isunprotectedd forest managed by the Ministry of Forestry (Perum Perhutani), butproposalss to protect the lowland forests in the western part of the area have been putforwardd (Nijman and Sözer, 1996). Main threats to the area are planned logging ofthee lowland forest near Linggo and the conversion into rubber, pine Pinus merkusii,orr damar/4uracaria spp. plantations.Status:: A number of groups were observed throughout the lowland and lowermontanee forest in the westernpart of the Dieng mountains, and in the montane forestinn the central, western and eastern parts (Sept. 1994; June-July 1995; Sept. 1998-Jan.1999;; July 1999-Feb. 2000; July-Aug. 2000). The species was reported to be presentinn the upper montane forests of Mt. Prahu as well. Bartels (1937) reported on theoccurrencee of mixed groups of P. comata and T. auratus in the Pagilaran plantation96 6

GeographicalGeographical Distribution of Ebony Leaf Monkeyatt c. 1300-1500 m a.s.1. Densities at the lowland forests near Linggo are in the orderoff 20 individuals km" 2 (Nijman and van Balen, 1998).Specimenss collected: Pagilaran: RMNH.20.. Ceruk SewuCounty:: Temanggung.Habitat:: A small patch of isolated secondary forest on a cliff near a waterfall. Theareaa is used as a tourist resort.Status:: One group of ebony leaf monkeys was observed, most likely only a fewotherr groups might present. The group was observed feeding near the waterfall andseemedd partially habituated to the presence of humans (May 1994).Specimenss collected: Candi Roto: RMNH.21.. Mt. UngaranCounties:: Salatiga.Habitat:: This small isolated volcano near Semarang is covered with forest above15000 m, and a c. 5,500 ha area is proposed as nature reserve (MacKinnon et al.,1982). .Status:: What was most likely this species has been recorded in Oct. 1998 on Mt.Ungaran'ss western slopes (F. Arga Narata and Sugihartono, pers. comm. 1998), andebonyy leaf monkey have been collected nearby, in Gendangan.Specimenss collected: Gendangan: MZB 6695.22.. Mt. Merapi and Mt. MerbabuCounties:: Slemen (DI Yogyakarta), Magelang, Blora, Sukoharjo.Habitat:: The twin volcanoes Merapi and Merbabu c. 15,000 ha are proposed as arecreationn forest (MacKinnon et al., 1982). The southern slopes of Mt. Merbabuseemm to have little remaining natural forest, a situation similar to the northern side ofMt.. Merapi. In November 1994 an eruption devastated part of the forest on thesouthernn slopes, but spared most of the forest to the east. The northern slopes havebeenn deforested since long whereas the western slopes are devastated by apermanentt outflow of lava. Mt. Merapi is situated north of one of Java's largercities,, Yogyakarta, and is very attractive for recreational purposes.Status:: Ebony leaf monkeys have been observed on the southern slopes aboveKaliurangg in 1994, a few months prior to the eruption (June 1994). In the following97 7

ForestForest (and) Primatesyearr (July 1995) ebony leaf monkeys were said to be present in small patches offorestt on the northwestern slopes of Merapi at c. 1500 m a.s.1. The species isprobablyy present throughout the area (F. Arga Narata and Sugihartono, pers. comm.1998). .23.. Mt. MurioCounties:: Jepara, Kudus, Pati.Habitat:: The peaks of this dormant volcano on Java's northern coast are coveredwithh mostly secondary forest from c. 600-1602 m a.s.1. The lower, central parts ofthee complex are cultivated. The forests on Mt. Murio are a proposed nature reserve(MacKinnonn et al., 1982).Status:: H.V.J. Sody collected two females at Pangonan at an altitude of 550 m a.s.1.Duringg two surveys (Aug. 1994; July 1995) in the forest above Colo, no ebony leafmonkeyss were observed, although the forest were seemingly still suitable.Accordingg to local inhabitants ebony leaf monkeys used to occur here, but nowadaysonlyy long-tailed macaques were present. On 3 July 1995 while in the forests near theJalongg coffee plantation on the eastern slopes of Mt. Murio we received informationthatt the ebony leaf monkey is still present in these forests, but the species was notobservedd by me.Specimenss collected: Pangonan: RMNH.24.. CepuCounty:: Blora.Habitat:: The region is known for its vast extend of teak forests, which often alternatewithh small patches of alang-alang Imperata cylindrica grass and secondaryvegetation. .Status:: Djuwantoko and collegues (1992; Djuwantoko et al., 1994) studied thefeedingg and ranging behaviour of ebony leaf monkeys in the forests plantations nearCepu.. Rappard (1941), residing in the village of Cepu, reported on ebony leafmonkeyss in the teak forests nearby. The status remains to be solved, but the speciesiss likely to be present in a number of (isolated) forest areas.25.. Mt. LawuCounties:: Karanganyar.Habitat:: Mt. Lawu is situated on the border between Central and East Java. Theupperr slopes of the mountain remain forested. The volcano is a popular touristattraction.. A c. 21,000 ha large nature reserve has been proposed (MacKinnon et al.,1982). .98 8

GeographicalGeographical Distribution of Ebony Leaf MonkeyStatus:: Ebony leaf monkey were observed on the southern and southeasten slopes ataltitudess between 1800-2400 m a.s.1. (Aug. 1994; June-July 1995)Specimenss collected: Mt. Lawu: RMNH.Provincee of East Java26.. Mt. Liman-WilisCounties:: Madiun, Nganjuk, Kediri, Tuban, Trenggalek, Ponorogo.Habitat:: The mountain complex comprises four summits of which the Liman is thetallestt (2563 m a.s.1.). Forest fires occur regularly and large parts of the area arecoveredd with shrubs and small trees and sparse Casuarina forest on the upper slopes.Thee lower southeastern slopes of Mt. Wilis are still well forested, while in the otherpartss scattered patches of forest remain amidst secondary forest, regrowth, bushes,andd plantations. The forests on Mt. Wilis are a proposed 45,000 ha large gamereserve,, while two small areas, Mt. Sigogor (190 ha) and Picis (28 ha), are long-timeregisteredd nature reserves (MacKinnon et al., 1982).Status:: A number of groups of ebony leaf monkeys were observed mainly in theeasternn and northern part of the area between altitudes of 1,300-1,600 m a.s.1 (July1995).. The species was observed in the primary forests of both nature reserves, aswelll as in planted pine and acacia stands.Specimenss collected: Madiun: BMNH 1938.11.30.9.27.. Mt. Penanggunang-Mt. ArjunoCounties:: Modjokerjo, Malang, Pasuruan.Habitat:: The Mt. Kawi and Mt. Arjuno area is presently a mozaic of partlyregeneratingg former coffee plantations, partly degrading lowland, hill and montaneforestt in varying degrees of disturbance (Smiet, 1992). Only small parts of the areahavee protection in three existing nature reserves, of which the almost 5,000 ha ofArjunoo Lalijiwo is by far the largest. Mt. Pananggunang is situated north of Arjuno,andd remains largely covered in forest from c. 600 to the summit at 1653 m a.s.1.Status:: On Mt. Pananggunang a fair number of groups were observed near the PPLHCentree for Environmental Education, and near the Hindu temples of CandiColotundoo (Aug. 1997). This is probably the locality with the highest percentage ofgroupss containing one or more red individuals. On Mt. Arjuno groups were observedinn the lowland forests near the village of Tretes, between 1250 m a.s.1. and thesaddlee at 2250 m a.s.1. at the northern slopes (Aug. 1997), between 1300-1700 ma.s.1.. near the hot water springs of Cangar, and at 1500 m a.s.1. near the BatuOndo(k)) waterfalls, on the southern and southeastern slopes (Sept. 1997, Nov.99 9

ForestForest (and) Prinwtes1998).. Individuals of the erythristic pelage colour morph have been recorded in thearea. .Specimenss collected: Kawarasan: RMNH; Rembang: BMNH 1938.3.14.2, 1954.57;Arjuno:: MZB 1731, -2, ZRC 4378, -9; Mojokerto: BMNH 1938.11.30.12; Pugeran:MZBB 3620.28.. Mf. Kawi-KeludCounties:: Malang, Blitar, Kediri.Habitat:: Some 50,000 ha of continuous forest between the volcanoes of Mt. Kawiandd Mt. Kelud ranging from 300 to 2806 m a.s.1. is a proposed nature reserve(MacKinnonn et al., 1982). For a description of the area see Smiet (1992). The areasufferss heavily from forest fires.Status:: Three groups observed at altitudes between 1200 and 1700 m a.s.1. near thewaterfallss of Cuban Rondo, Mt. Kawi (Sept. 1997). Kohlbrugge (1896) reported onspecimenss from Lawang. The species has been collected throughout the area.Individualss of the erythristic pelage colour morph have been reported from in thearea. .Specimenss collected: Blitar: MZB 3372; Batu: RMNH.29.. Mts Kidul and P. SempuCounties:: Malang.Habitat:: The Kidul mountains on the southern coast of Malang are covered withsomee large stands of largely undisturbed lowland rain forest. The Lebakharjo andBanturr forests, respectively covering 13,000 and 5,000 ha, constitute two of the mostimportantt areas of lowland forest on Java, and have been proposed as reserves(Whittenn et al., 1996; Bekkering and Kucera, 1990). Only a few hundred hectaresnearr Balekambang, receive protection as a recreation forest. Wood cutting andhuntingg form major threats (MacKinnon et al., 1982). The area is connected throughplantations,, secondary forest area and separated by a road from the 57,000 ha Mt.Bromoo Tengger Semeru National Park. The island of Sempu is situated a fewhundredd meters of the coast of the Lebakharjo and Bantur forests, and has beendesignatedd as a nature reserve.Status:: Observed in Oct. 1989 near the village of Pujiharjo in Lebakhardjo (S. vanBalenn in lift., 1998). Three groups of ebony leaf monkey observed nearBalekambang,, both in the beach forest as in the rain forest adjacent to it (Aug.1997),, and the species seems to be present throughout the entire area. Individuals ofthee erythristic pelage colour morph have been reported to be present by local100 0

GeographicalGeographical Distribution of Ebony Leaf Monkeywardenss in Balekambang and Nursahid et al. (1996) reported on the occurrence oferythristicc individuals on P. Sempu.Specimenss collected: Wonokoio: RMNH.30.. Mt. Bromo-Tengger-Mt. SemeruCounties:: Probolinggo, Malang, Pasuruan, Lumajang.Habitat:: The Bromo-Tengger National Park is best known for its spectacular 10 kmwidee Tengger Caldera, its sand sea with squats the active volcano Mt. Bromo. TheMt.. Semeru is Java's tallest mountain rising 3,676 m a.s.1. Its slopes are coveredwithh some undisturbed lower and upper montane forests as well as Casuarina forests.Status:: Van Bemmel-Lenneman and van Bemmel (1940) reported on the occurrenceoff ebony leaf monkeys in the Tengger mountains, and noted that the species occursrelativelyy high up, in the surroundings of the Smeroehoeve at 2100 m a.s.1., and evenhigherr up near the summit of the Semeru. Also van der Veen (1940) recorded anumberr of ebony leaf monkeys that had died at Semeru's summit. Individuals of theerytristicc pelage morphs apparantly were more abundant than the melanic morph(vann Bemmel-Lenneman and van Bemmel, 1940). Kohlbrugge (1896) reported onspecimenss from Puspo. Beudels & Hardi (1980) list the species for the national parkandd R. Nursahid (pers. comm. 1998) reported the species to be common onSemeru'ss western slopes.Specimenss collected: Tosari: RMNH.31.. Nusa BarungCounty:: Jember.Habitat:: Nusa Barung is an island c. 6,000 ha in size, 10 km of the southern coast ofthee eastern part of Java. It is covered in deciduous forest and has been a reservesincee 1920 (MacKinnon et al., 1982). Timber theft posses a significant threat to theislandd and most marketable timber has been removed (Whitten et al., 1996)Status:: Whitten et al. (1996) and MacKinnon et al. (1982) reports the presence ofebonyy leaf monkeys on the island.32.. Daerah Tinggi YangCounties:: Probolinggo, Bondowoso, Jember.Habitat:: The Yang highlands comprise of an undulating plateau between 1,700 and2,4000 m a.s.1. The vegetation of the plateau mainly consist of Casuarina forests andgrassyy meadows. The forests are partially enclosed in a 14,500 ha wildlife reserve.101 1

ForestForest (and) PrimatesThreatss to the area include poaching, burning of the grasslands, and use of the areaforr military exercises (MacKinnon et al., 1982).Status:: MacKinnon et al. (1982) report ebony leaf monkey to be present on the YangPlateau.. The species was reported to be present on Mt. Lamongan, west of theplateauu (Aug. 1997). Individuals of the erythristic pelage colour morph have beenrecordedd in the area.Specimenss collected: Jember-Puger RMNH; Jember: MZB 6698; PegununganYang:: MZB 1927; Besuki: RMNH.33.. Pasir Putih, Mt. Ringgit and Mt. BeserCounties:: Bondowoso, Panarukan.Habitat:: Pasir Putih is a popular tourist beach on the northern coast of East Java. Justoutsidee the village some fringes of mangrove forest still can be found. These forestaree connected with the deciduous forests on Mt. Ringgit and Mt. Beser by a c. onekmm wide strech of teak forest. The forest on Mt. Ringgit and Mt. Beser are amongthee few remaining areas of deciduous forest left on Java. On Mt. Ringgit c. 2000 hahass been proposed as nature reserve, while on Mt. Beser c. 4000 ha has beenproposedd as wildlife reserve, both areas should be managed together (MacKinnon etal.,, 1982).Status:: Ebony leaf monkeys have been observed in the mangrove forests near PasirPutih,, and in the teak forests between Pasir Putih and Mt. Ringgit (Aug. 1997, I.Setiawan,, pers. comm. 1997). The species is very common on Mt. Ringgit (Aug.1997);; over 6 groups, observed in teak forest, in dense shrubs, and in dry deciduousforest.. The erythristic pelage colour morph is present (I. Setiawan and A. PrimaSetiadi,, pers. comm. 1996), which was confirmed by local inhabitants.34.. Meru BeteriCounties:: Jember, Banyuwangi.Habitat:: This 50,000 ha lowland forest ranging from sea level to 1223 m a.s.I. hasthee status of national park; it is the last area where the presence of Javan tigers hasbeenn confirmed (MacKinnon et al., 1982). The former coffee plantation enclave ispresentlyy being abandoned, but encroachment from the outer sides keep threateningthee integrity of this important area. The national park is separated by a relativelynarroww area of plantations, secondary forest and a road from the Ijen Mountains.Status:: Ebony leaf monkeys are most likely to be present throughout the greater partoff the National Park. Hoogerwerf (1972) reported ebony leaf monkeys to becommon,, especially in the surroundings of Bandi Alat and Sukamade. Bismark andWiryosoepartoo (1980 in Supriatna et al., 1988) studied the species in Meru Beteri,102 2

GeographicalGeographical Distribution of Ebony Leaf Monkeyandd reported densities of 20 individuals km" 2 . Seidensticker and Suryono (1980 inWhittenn et al., 1996) illustrated the unevenness of ebony leaf monkey in the MeruBetirii National Park, indicating a preference for beach and hill forest.35.. Mts IjenCounties:: Banyuwangi, Bondowoso, Ampera, Jember.Habitat:: The area is only partly protected by the 2,560 ha nature reserve of KawahIjenn Merapi Ungup-ungup, and three tiny reserves. More important reserves areproposedd for Mt. Raung (60,000 ha) in the southwest to Meru Betiri and Maelang(70,0000 ha) in the northeast to Baluran National Park (MacKinnon et al., 1982).Status:: Frequently observed along the road from Lijen to Kawah ungup-ungup (Aug.2000).. A number of specimens have been collected both at (Kawah) ungup-ungup,ass some adjacent sites. Individuals of the erythristic pelage colour morph have beenrecordedd in the area.Specimenss collected: Kendeng III: MZB 705,-6; Ungup-ungup: BMNH 1954.56,MZBB 704, ZRC 4372; Sodong Jerok: BMNH 1954.57,-8,-9; Tamansari: BMNH1954.60,, ZRC 4376.36.. BaluranCounties:: Besuki.Habitat:: The Baluran National Park totalling 25,000 ha with savannah and monsoonforestt centered on the dormant volcano of Mt. Baluran (1250 m). There is a smallmoistt forest inside the volcano crater, and the extensive coastline is covered withbeachh forest and mangroves.Status:: A fair number of groups observed in the beach forests near Bama, along theroadd from Wonorejo to Bekol, and in the savannah near Bekol. Groups up to 25individualss were not uncommon (Aug. 1997). The species occurs throughout thepark,, including Mt. Baluran, but is perhaps most easily observed in the beach forestnearr Bama. The erythristic pelage colour morph occurs in the Park (S. Hedges andM.. Tyson, pers. comm., 1998).Specimenss collected: Bajulmati: BMNH 1954.61; Kosambikamp: MZB 6696,-7,-9,6700. .37.. Alas PunvoCounties:: Besuki.Habitat:: Alas Purwo (or Blambangan, or Banyuwangi Selatan) is a 62,000 halowlandd forest reserve ranging from sea level to 360 m a.s.1. in the driest part of103 3

ForestForest (and) PrimatesJava.. Presently the area is a nature reserve (MacKinnon et al., 1982). Wood cuttingformss the major threat to the habitat.Status:: Appelman (1939) recorded ebony leaf monkeys in small numbers. Likewise,Hoogerwerff (1972) reported the presence of the species near Pantjur on the westerncoast,, but noted that the species was rather rare. Observed in Nov. 1989 and May19900 at Gucur near Pasar Any ar, both in natural and teak forest, and nearTrianggulasii (May 1990) (S. van Balen, in litt., 1998). The erythristic pelage colourmorphh occurs in the Park (S. Hedges and M. Tyson, pers. comm., 1998).Islandd of Bali38.. Bali BaratCounties:: Jembrana, Buleleng.Habitat:: The Bali Barat National Park consists of a large variety of forest types,includingg (disturbed) savannah, mangroves, and mixed monsoon forest, as well assomee sub-montane forests. The national park proper covers an area of just 19,000ha,, but inclusion of the proposed extension to the east would increase it to an area of77,0000 ha.Status:: Observed near the summit of Gn Klatakan and along S. Teluk Teluk (Aug.2000).. The species was recorded throughout the year, especially on the PrapatAgungg Peninsula (S. van Balen, in litt. 1989). According to Wheatley et al. (1993)thee Bali Barat National Park may have the last viable population of ebony leafmonkeyss on the island. It is not clear whether their statement refered to the nationalparkk proper or that it included the park's eastern extension.Specimenss collected: Sendang: RMNH E 9, 27,35,38,39,77.39.. Mt. BatukauCounties:: Buleleng, Tabanan.Habitat:: Relative undisturbed moist hill, sub-montane and montane forest on recentvolcanicc soils. The existing three nature reserve are centered around volcanic lakesandd totals 1762 ha. An extension as to include the three reserves to one large areacoveringg the whole Batukau complex (c. 20,000 ha) have been proposed(MacKinnonn et al., 1982).Status:: Pocock (1935) described subspecies stresemanni based on specimenscollectedd by E. Stresemann, from this locality. No further details available. Wheatleyett al. (1993) furthermore reported on the possible presence of ebony leaf monkeysnearr the dry forest on the mountains near Amlapura, on the eastern part of Bali.Hence,, the species might be present in other parts of the mountanous interior of Bali.Specimenss collected: DanauBratan: BMNH 13.3.6.1.104 4

GeographicalGeographical Distribution of Ebony Leaf MonkeyIslandd of Lombok40.. Mts MangsitCounties:: Lombok BaratHabitat:: Small patch of lowland forest on the western coast of Lombok.Status:: No information available, but the species had been collected in June 1896(Napier,, 1985).Specimenss collected: Mangsit: BMNH 1939.1143.41.. Mt. RinjaniCounties:: Lombok Tengah and TimorHabitat:: The Gunung Rinjani National Park covers an area of 40,000 ha, of largelymontanee forest. Despite its excistence since 1941, the park has failed to preserve theoncee very dense primary forest cover, at least on the northern and northeastern part.Nevertheless,, the national park is the only extensive forest complex covering themountainouss northern part of Lombok (MacKinnon and Artha, 1982).Status:: Eight different groups observed near the waterfalls of Senaru and on thenorthernn slopes of Gn Rinjani between 650 and 1500 m a.s.1. (Aug. 2000). Horst(1935)) recorded ebony leaf monkeys in the forests on the southern slopes of Mt.Rinjani,, between Sewala and Pusuk up to 1400 m a.s.1. In May 1990, the specieswass found at 600 m a.s.1. south of Bayan (S. van Balen in lift. 1998). Kitchener et al.(1990)) reported ebony leaf monkeys to be common on Lombok, and observedgroupss of one or two individuals on Mt. Rinjani.Specimenss collected: Sembalun: MZB 6688; Sapit: MZB 6689.42.. Suranadi and PucukCounties:: Lombok BaratHabitat:: Suranadi is a small (52 ha) recreation park c. 25 km east of the capital cityMataram.. The area comprises of mixed moist forest in a small patch around a watersourcee and is important for local water protection (MacKinnon and Artha, 1982).Thee forest west of the Pucuk Pass, north of Mataram, are isolated from those on GnRinjani;; the status of these forests is unknown.Status:: A single group (three individuals) observed from the Pucuk Pass (Aug.2000).. In Surandi, seen in groups of one or two, with the largest group consisting offivee individuals (Kitchener et al., 1990). Ebony leaf monkeys on Lombok seem tooccurr in smaller groups than in similar habitats on Bali or Java.105 5

ForestForest (and) PrimatesDISCUSSION NHabitatt and RangeFiguree 7.1. shows the natural forest cover on the islands of Java, Bali and Lombok(afterr RePPProT 1990). Note that many smaller forest areas, including coastalfringess of mangrove forest, do not show at the scale used. The map also indicates theforty-twoo areas from where the species has been recorded. Undoubtedly, the speciesmightt be present in other areas not yet surveyed, but the present listing probablygivess a fairly accurate account of the species' distribution. Furthermore, it clearlyillustratess the severe degree of fragmentation of populations of ebony leaf monkey,possiblyy having its effect on the survival of the species.Oatess et al. (1994) erroneously restrict the range of the genus Trachypithecusass far east as the Greater Sundas, excluding Lombok, but include this island, as wellass Bali, in the range of the genus Presbytis. P. comata ranges on Java as far east asMt.. Lawu, on the border of Central and East Java (Nijman, 1997; chapter 6), butdoess not occur on Bali or Lombok.Thee islands of Java and Bali are situated on the Sunda Shelf, while Lombokformss part of Wallacea, the transition zone between the Oriental and Australianfaunall regions. Although not providing a total barrier, the deep water of the LombokStraitt has restricted contact with the Lesser Sunda Islands. In Malesia, primates arelargelyy restricted to the Sundaic region, with only tarsiers Tarsier spp. havingreachedd Sulawesi, and macaques Macaca spp. reaching into Sulawesi and the LesserSundas.. Ebony leaf monkey is the only colobine that ranges into Wallacea. It hasbeenn suggested, firstly by A. Everrett (Hartert, 1896), that the species was almostcertainlyy introduced by Balinese Rajahs on Lombok. Alternatively, the possibilitythatt the species might have been a recent colonizer has been considered (e.g., Eudey,1987). .Dee Iongh et al. (1982) observed black monkeys on the Kangean Islands, andreportedd the possible presence of ebony leaf monkeys on the islands. The KangeanIslandss are a group of rather isolated islands situated on the eastern edge of theSundaa Shelf, c. 125 km east of Madura and c. 125 km north of Bali. Bergmans andvann Bree (1988), referring to the above mentioned observations, reported thepossiblee presence of the species on Kangean and speculated about the introductionoff a number of mammals on the islands by humans.Inn an attempt to clearify the distribution of ebony leaf monkeys on the Kangeanisland,, I visited Kangean for five consecutive days in August 1997. Throughout theislandd long-tailed macaques were numerous (cf. de long et al., 1982), but no ebonyleaff monkey was seen or heard. The pelage of long-tailed macaques on KangeanIslandd is darker than those from mainland Java, and was described as dark grey(ratherr than brown with a reddish or greyish gloss), often looking blackish underfieldd conditions. For long-tailed macaques to be darker pigmented is a knownphenomenonn on small islands on the Sunda Shelf (e.g., Simuelue: van Schaik andvann Noordwijk, 1985; Nias: Miller, 1903; Karimunjawa and Bawean: Sody, 1949).Locall inhabitants and officers of the forestry departement on the island, some of106 6

GeographicalGeographical Distribution of Ebony Leaf Monkeywhichh were familiar with ebony leaf monkeys from mainland Java or Bali, claimedthatt the species was not present on the island. Both S. van Helvoort (pers. coram.1997)) and Dr H.H. de Iongh (in litt. 1999) do not recall having seen ebony leafmonkeyss on the Kangean Islands. In conclusion, ebony leaf monkeys are most likelynott present on the Kangean Islands nor are there any indications that they werepresentt in the distant past. The reports of 'black monkeys possibly or likely ebonyleaff monkeys' (de Iongh et al., 1982; Bergmans and van Bree, 1988), most likelyreferr to long-tailed macaques, which can have a rather dark pelage coloration on theisland. .Ebonyy leaf monkeys are most likely absent from the island of Madura as well.Thee island is very arid and virtually all forest has long disappeared (Whitten et al.,1996).. During three days of surveying on the island in August 1997 no suitable areaoff forest was found on the island, and no information indicating the presence ofebonyy leaf monkeys was received. Few remnants of mangrove forest found on thesouthernn coast between Nipah and Jrengik were to small and the trees too stunted toofferr suitable habitat.Ebonyy leaf monkey, however, do occur on the islands of Sempu, severalhundredss of meters off the coast near the Lebakhardjo and Bantur forests [29 in theareaa account and in Figure 7.1], and Nusa Barung [31], which is situated 10 km ofthee southern coast of the eastern part of Java. At least three scenarios can account forthee presence of the species on these islands, none of which is mutually exclusive.Firstly,, the ebony leaf monkeys on Sempu and Nusa Barung can be considered relictpopulationss from a time when the sea level was lower as to provide a 'land bridge'too the islands. As Nusa Barung is separated from mainland Java by a relative deepstrait,, this relict population must have become isolated somewhere at the end of thelastt glacial period, at least 8-10,000 YBP, while for Sempu the separation may bedatedd somewhat later. Secondly, the species might have been introduced by man.Shipss might have transported the animals to the islands, where it was, accidentally ordeliberately,, set free. Thirdly, the species has been able to (re)colonize suitableislandss without the help of man, anytime from the time the islands became separatedupp to the present day. For long-tailed macaques Wallace (1869) already noted that"this"this species is very frequent on the banks of rivers, and may have been conveyedfromfrom island to island on trees carried down by floods.'''' Similarly, ebony leafmonkeyss might have spread naturally east to Lombok. Since the last ice-age therehass been more than sufficient time to colonize an island with a similar climate andvegetation,, and on which no other (competiting) colobine could exclude it. Giventhee species ability to occupy mangrove and beach forests, and the relativenarrownesss of the straits (although the Lombok Strait is broader that the Bali Strait),thiss possibility cannot be ruled out a priori.Vann der Zon (1978) reported the species to be present in mangrove, swamp,andd lowland rainforest up to 1500 m a.s.1., often near human settlements. Medway(1970)) considered its habitat to be inland forest from the lowlands up to almost2,0000 m a.s.1. Bennett and Davies (1994), in contrast, claim that the species isrestrictedd to coastal and riverine habitats. In fact, the species occurs over a wide107 7

ForestForest (and) Primatesrangee of habitats, from beach forests and swamp forests to dry deciduous forests,andd from mangrove, riverine, and lowland rain forest to upper montane forests up to3,5000 m a.s.1.Probablyy the species' ability to cope with considerable amounts of leaves in itsdiett allows them to live in a large variety of forest types. Ebony leaf monkeyoccur(red)) in the small remnants of mangrove forests on the northern coast of WestJavaa and East Java [7, 33], as well as in the larger mangrove and swamp area ofSegaraa Anakan [15], on the south coast of Central Java. It occurs in forests alongriverss and waterways and in the fresh water swamp forests [2]. In the western half ofthee island, it is widely distributed in the pockets of rain forest ranging from sealevel[1,, 2, 5, 10] to the upper montane forests at 2,500 m a.s.1. and above [6, 17, 19]. Inthee eastern part of its range, it occurs both in the pockets of rain forest both at sealevell [34] and on the eastern and southeastern slopes of the higher volcanoes [27, 28,30,, 41], in the fire resistant Cemara Casuarina junghuhni forests [26, 27, 32], aswelll as in the dry deciduous forests [33, 36, 38]. In the rain forest environmentebonyy leaf monkeys seem to be (almost) strictly arboreal, while in the more openforestt types, e.g., dry decidious forest and upper montane forest, it seems to be moreterrestrial. .Thee species is able to cope with a certain degree of habitat disturbance. Itseemss to survive in secondary forest types as well as some man-made forests such asdamarr Auracaria spp, pine Pinus merkusii, acacia Acacia spp, rasamala Altingiaexcelsa,excelsa, rubber Hevea brasiliensis and teak plantations [2, 3, 13, 14, 17, 24, 26, 33].Often,, however, these plantations are situated adjacent to other more natural forestareass [e.g., 2, 13, 24, 33], while others are intersected e.g., by (river) valleys with amoree diverse forest type [14, 17]. Typically, ebony leaf monkeys are found in ornearr these natural forest remnants. Alternatively some populations can be found'trapped'' in small fragments of (natural) forest, unable to move out as there is noadjacentt forest left [e.g., 3, 20]. Although the species has been observed in a widerangee of forest areas, generally it can be assumed that ebony leaf monkeys aredependentt on natural forest in one form or another, and that large stands ofmonoculturess offer little if any suitable habitat for the species.Distributionn of the erythristic pelage morphThee erythristic pelage colour morph, besides the more common melanic pelagecolourr morph, hitherto has only been recorded in East Java. Pfeffer (1965)erroneouslyy reported erythristic individuals to be common in West Java and absentfromm East Java. Whitten et al. (1996) states that the erythristic occurs in Central andEastt Java, albeit more common in East Java. Hoogerwerf s (1972) statement that "InCentrall and East Java another subspecies occurs [ ], among which adult reddishcoloreddindividuals were regularly noted...", may also have given the impression thatthee erythristic pelage morph also occurs in the central parts of Java.108 8

GeographicalGeographical Distribution of Ebony Leaf MonkeyFiguree 7.2 Melanic pelage morph of ebony leafmonkeyy Trachypithecus auratus (E. GeoffroySaint-Hilaire,, 1812), Taman Safari Zoo, Cisarua,Westt Java 1999.Figuree 7.3 Three individuals of the erythristicpelagee morph of ebony leaf monkeyTrachypithecusTrachypithecus auratus (E. Geoffroy Saint-Hilaire,, 1812), Taman Safari Zoo, Cisarua, WestJavaa 1999.Figuree 7.4 Melanic (foreground in cage) anderythristicc pelage morph of ebony leaf monkeyTrachypithecusTrachypithecus auratus (E. Geoffroy Saint-Hilaire,, 1812), Taman Topi, Bogor, West Java1999.. In Indonesia, many species of primates,includingg formaly protected species such as theebonyy leaf monkey, are openly offered for sale, inthiss particular case in front of the police station.Notee that the illegal primate trade includestransportss over considerable distances as thenearestt site where the erythristic pelage morphoccurss [Mt. Penanggunang-Mt Arjuno] is morethann 1000 km by road from Bogor.109 9

ForestForest (and) PrimatesInIn fact, they have been reported only from the easternmost part of East Java, i.e., theareaa bordered roughly in the northwest by Mt. Penanggunang [27] and thesurroundingss of Modjokerto south, via Wonosalam and Blitar [28] to Mts Kidul nearBalekambangg [29], east to the southeastern tip of the island at Alas Purwo [37], andnorthh to Baluran [36], and back along the northern coast via Pasir Putih and Mt.Ringgitt [33] to Rembang [27] and Mt. Penanggunang (See Figure 1). Although theerythristicc pelage morph may be rare in certain areas, it was generally known toinhabitantss living in the area. The morph is present in fairly large numbers in thecollectionss of the various museums visited, indicating a collector's bias towards therarerr type. Various surveys to Mt. Wilis-Liman [26] and Mt. Lawu [25] failed to finderythristicc individuals, nor were they known to inhabitants or officers of the forestrydepartments.. Hence, the western boundary of the distribution range of the erythristicpelagee morph in all likelihood runs east of Mt. Wilis-Liman. Currently, noerythristicc individuals have been recorded in the large teak stands east of Cepu [24],butt the area is under-explored. If present, the northern boundary would be extendedconsiderably. .Erytristicc individuals have not been recorded from either Bali or Lombok, anditt is not known whether they occur on the island of Nusa Barung [31]. They havebeenn recorded on the island of Sempu, south of Mts Kidul [29]. In certainpopulations,, e.g., those in Balekambang, probably only a small proportion of theindividualss is of the erythristic pelage colour morph, while in others, e.g., thosefoundd in the surroundings of the temples of Candi Colotundo, near Trawas on Mt.Penanggunang,, up to 15-20% of the individuals are. Van Bemmel-Lenneman andvann Bemmel (1940) reported the erythristic pelage colour morph to be morecommonn than the melanic pelage morph on Mt. Semeru [30].ACKNOWLEDGEMENTS SThee surveys could not have taken place without the cooperation of the IndonesianInstitutee for Sciences (LIPI), the Directorate General for Nature Conservation andForestt Protection (PKA), the Ministry of Forestry and Estates Crops (MOFEC) andthee regional forestry departements, to all of whom I would like to express mygratitude.. Drs Boeadi (Museum Zoologi, Bogor), Dr P.J.H. van Bree (ZoologicalMuseum,, Amsterdam), Dr P. Jenkins (Natural History Museum, London), and Dr C.Smeenkk (National Museum of Natural History, Leiden) are acknowledged for accesstoo specimens under their care. For sharing records of Trachypithecus auratus, forprovidingg other information, or help of various sort I am grateful to: F. Arga Narataandd Sugihartono (Kutilang IBC, Yogyakarta), Dr S. van Balen (AgriculturalUniversityy Wageningen), D. Cornelissen, Dr. T. Geissmann (Institute für Zoölogie,Tierartzlichee Hochschule Hannover), S. Hedges (University of Southhampton), DrB.A.. Manullang (formerly WWF-IP), R. Nursahid (KSBK, Malang), A.V.Reijngoud,, A.P. Setiadi (YPAL, Bandung), R. Sözer (ISP/ZMA), I. Setiawan andSujatnikaSujatnika (BirdLife International Indonesia Programme) and M. Tyson (Manchester110 0

GeographicalGeographical Distribution of Ebony Leaf MonkeyMetropolitann University). Dr. H.H. de Iongh and S. van Helvoort are thanked forprovidingg information on the black monkeys of the Kangean Islands. Dr. H.Albrechtt (Dept. Animal Behaviour, University of Amsterdam), Dr C.J. Hazevoet(Museuu de História Natural, Lisboa), R. Sözer and an anonymous reviewer madeconstructivee comments on previous versions of the manuscript. Additional financialsupportt was received from the Society for the Advancement of Research in theTropicss (Treub-maatschappij), the Netherlands Foundation for International NatureProtectionn (Van Tienhoven Stichting), and Stichting Het Kronendak. Dr P.J.H, vanBreee is thanked for his help throughout the project.Ill l

ForestForest (and) Primates112 2

AA Faunal Survey of the Dieng Mountains, Central JavaCHAPTERR 8AA FAUNAL SURVEY OF THE DIENG MOUNTAINS,CENTRALL JAVA, INDONESIA: DISTRIBUTION ANDCONSERVATIONN OF ENDEMIC PRIMATE TAXAwithwith S. (Bas) van Balen, Oryx 32: 145-156, 1998ABSTRACT TAA faunal survey was conducted in May-September 1994 and June-July 1995 in theDiengg mountains, one of the last remaining larger patches of forest in the CentralJavaa province, Indonesia. All three primate species endemic to the Javan faunalregionn -Javan gibbon Hylobates moloch, grizzled leaf monkey Presbytis comata andebonyy leaf monkey Trachypithecus auratus- were found to be present. Javan gibbononlyy occurs in the lowland and hill forests in the western part of the study area,whilee the latter two species were found to be present throughout the area fromlowlandd to montane forests. Although more research needs to be done on habitatpreferencess and densities at which the primates occur, the available data suggest thatthee Dieng mountains may harbour the second largest population of both Javangibbonn and grizzled leaf monkey in the same location. In order to safeguard thesetwoo endangered primates it is suggested that the reserve system in Java be expandedtoo include the Dieng mountains.RINGKASAN NSuatuu survey fauna Pegunungan Dieng, Jawa Tengah, Indonesia: penyebaran dankonservasii taxa primata endemik (bersama S. (Bas) van Balen, Oryx 32: 145-156,1998):: Suatu survey fauna telah dilakukan pada bulan Mei-September 1994 danJuni-Julii 1995 di Peg. Dieng, salah satu blok hutan cukup besar terakhir yang tersisadii Propinsi Jawa Tengah, Indonesia. Semua tiga spesies primata yang endemikRegioo Fauna Jawa -Owa Jawa Hylobates moloch, Surili Presbytis comata danLutungg Trachypithecus auratus- telah ditemukan kehadirannya di sini. Owa hanyaterdapatt di hutan dataran rendah dan hutan pebukitan di bagian barat dari lokasipenelitian,, sementara kedua jenis lainnya ditemukan berada di seluruh lokasipenelitiann dari mulai hutan dataran rendah sampai dengan hutan pegunungan.Meskipunn dibutuhkan penelitian lebih mendalam mengenai preferensi habitat dankepadatann spesies-spesies tersebut, data yang ada menunjukkan bahwa Peg. Diengbarangkalii mengandung populasi terbesar yang kedua, baik untuk owa maupunlutung,, di tempat yang sama. Untuk melindungi kedua jenis primata terancam punahinii disarankan bahwa sistem kawasan lindung di Jawa diperluaskan sehinggamencakupp Peg. Dieng.113 3

ForestForest (and) PrimatesINTRODUCTION NDespitee Central Java being one of the most densely populated and most deforestedareass in Indonesia, several patches of natural forest remain throughout the province.Thiss natural vegetation is restricted almost exclusively to hydrological forestreservess capping summits and ridges. A few of these forests descend into the hill orevenn lowland zone, but more often they only cover the upper part of the mountainabovee 1500-2000 m. Few of these patches are adequately protected and fewer stillhavee received recent attention of the conservation community. It has long beenknownn that several 'West Javan' species with high conservation priorities reach theeasternmostt limit of their distribution in Central Java but most conservation effortsorr even general survey work seem to be restricted to West Java (see e.g., AppendixIII and III in Whitten et al., 1996).Givenn the lack of knowledge on the current distribution and status of severalanimall species in Central Java, we present results of a faunal survey in the largestremainingg area of natural forest in Central Java, the Dieng mountains (also known asMt.. Prahu or Mt. Perahu, named after its highest peak: Figure 8.1).Betweenn May 1994 and July 1995 six visits were paid to the forests of theDiengg mountains. The aim of the visits was to obtain data on the bird and mammalfaunaa of the region in order to make recommendations for the conservation of thearea. .Thee subject of the present paper is to discuss three primate taxa found in thearea:: Javan or silvery gibbon Hyiobates moloch, grizzled leaf monkey Presbytiscomatacomata and ebony leaf monkey Trachypithecus auratus.Thee Javan gibbon is endemic to the western half of Java. Most populations canbee found in the western province (Kappeler, 1984), but a few remain in Central Java(Nijman,, 1995; Nijman & Sözer, 1995). The most recent population estimates, basedonn extrapolation of the available habitat, range from 2000 animals (Supriatna et al.,1994)) to 3000 animals (Asquith et al., 1995). The species is accorded the highestconservationn priority rating for Asian primates (Eudey, 1987), and has recently beenlistedd as Critically Endangered by IUCN (1996).Thee grizzled leaf monkey is also endemic to the western half of the island ofJava,, as far as Mt. Lawu on the border with East Java (Nijman, 1997b). The centralJavann populations have been proposed a seperate species Presbytis fredericae (e.g.,Brandon-Jones,, 1995), but Nijman (1997a) showed some of the alleged differencesnott to be diagnostic, while some intraspecific variation was of a clinal nature. Likethee Javan gibbon the species is severely threatened mainly due to habitat destruction(Eudey,, 1987; MacKinnon, 1987; Supriatna et al., 1994). Population sizes have beencalculatedd and range from 8040 animals (MacKinnon, 1987) to 2285 animals(Supriatnaa et al., 1994). Grizzled leaf monkeys have been classified as Endangeredaccordingg to IUCN (1996).114 4

AA Faunal Survey of the Dieng Mountains, Central Java115 5

ForestForest (and) PrimatesThee ebony leaf monkey is more widespread than the former species and is restrictedtoo Java and the smaller islands of Bali and Lombok to the east (Weitzel & Groves,1985).. The species is listed as Vulnerable (IUCN, 1996)METHODS SStudyy siteThee Dieng mountains are situated in the middle part of Central Java between c.109°32'-109°56'EE and 7°04'-7°13'S. Administratively they lie largely in thecountiess (kabupaten) of Pekalongan and Batang, with small areas in Banjarnegara,Wonosobo,, Temanggung and Kendal. The area is made up of a number of largelydormantt volcanoes that are more or less contiguous, surrounded by their foothillsandd adjoining plains. In the western part most peaks are less then 2000 m high (e.g.,Mt.. Langit, 1628 m; Mt. Besar, 1579 m), while to the east the mountains becomehigher.. Mt. Prahu, in the easternmost part, at 2565 m the highest. On the northwesternnand north-eastern part of these mountains a block of forest extends fromlowlandd to upper montane: in the west the forest descends to c. 300 m and on theeasternn slopes of Mt. Prahu to c. 1500 m. The forests total roughly 255 km 2(RePPProT,, 1990), disregarding the additional area due to slopes. Thearchaeologicall well known Dieng plateau situated at an altitude of c. 2000 m,borderss the area in the south-east and contains some interesting lakes, which aregazettedd as nature reserves: Telogo Warna (40 ha), Telogo Dringo (26 ha) andTelogoo Sumurup (20 ha) (MacKinnon et al., 1982).Rainfalll is plentiful throughout the year with average of 4000-7000 mm; onlybetweenn June and September there is little less rainfall. In most of the study areamoree than 40 rainy days are recorded during the four driest consecutive months ofthee year (van Steenis, 1965). In the lowlands the average daily temperature is 22-34°CC with an average of 26°C. Temperature decreases with altitude; at 2000 m it hasbecomee 14°C (van Steenis, 1972). At the Dieng plateau, and other areas above 2000m,, frost can occur at night, especially in the dry season.Thee vegetation of the Dieng mountains are of the wettest type: mixed lowland andhilll rainforest, below c. 1000 m, and montane ever-wet rainforest to c. 2400 m (vanSteenis,, 1972). As a result of human disturbance and/or natural conditions meadowswithh few trees cover the upper parts of Mt. Prahu. Throughout the area some largepatchess of undisturbed primary forest remain, but most of the area is somewhatdisturbed.. The forests near the village of Linggo partly consist of a former coffeeplantationn which, according to local inhabitants, has been abandoned in the 1930's.Halfwayy between Linggo and Mt. Lumping small patches of bamboo indicate aformerr settlement. Regrowth has resulted in a secondary forest, with emergent oldertreess distributed throughout. In the central part of the area, along the road fromKroyakann to the Dieng plateau, and in the north-west, wet rice fields are present (seeFiguree 8.2).116 6

AA Faunal Survey of the Dieng Mountains, Central JavaThee forests on the Dieng mountains are not yet protected as conservation forest. Thepartss above 1000 m are formally protected as hutan lindung (protection forest).Forestss protected in this category are state-owned and serve as water catchment, tomaintainn soil fertility and to prevent erosion and land slides (Anonymous, 1996).Alsoo a small part of the lowland forests near Kroyakan receive some form ofprotectionn as hutan negara (an unclassified state owned forest category); herecollectionn of fire wood and forest products is prohibited. The lowland forest nearLinggoo are managed as hutan produksi (production forest) and in 1995 were stillplannedd converted it into rubber and/or pine plantations. The forests on Mt. Prahuabovee the 1000 m line, i.e. roughly the eastern half of the Dieng mountains, havebeenn proposed a suaka margasatwa (wildlife sanctuary) (MacKinnon et al., 1982).Thee study area is largely surrounded by tea plantations in the north and south,byy pine plantations in the east and west, by rubber plantations in the north-west, andbyy agricultural land in the south-east. It is crossed by at least three roads runningfromm north to south: from Kayen via Linggo to Peninggaran, from Kroyakan toBaturr and the Dieng plateau and from Bawang to Dieng. The latter two are usedonlyy for local traffic.Figuree 8.2A view of the lowland forests near Linggo, Dieng mountains, Central Java, with on theforegroundd areas cleared for wet rice fields.117 7

ForestForest (and) PrimatesDataa acquisition and survey methodsWee surveyed the Dieng mountains on six occasions totalling 16 days of observation:(i)) on 5 May 1994 VN and Resit Sözer (RS), visited the northern part of Mt. Prahufromm the village of Bawang; (ii) on 4-6 July 1994 VN and RS visited the Diengplateauu and the southern slopes of Mt. Prahu; (iii) VN, RS, Iwan Setiawan and AndiPrimaa Setiadi, surveyed the eastern slopes of Mt Prahu from Tretep and the forestsnearr Linggo on 27 August 1994; (iv) on 25 September 1994 VN surveyed the forestsnearr Linggo; (v) on 9-11 June 1995 VN and SvB visited the Dieng plateau and thesouthernn slopes of Mt. Prahu; and on 11-16 June 1995 the surroundings of Linggo,includingg a two days visit to Mt. Lumping; and (vi) on 29 July 1995 VN travelledalongg the road from near Batur to Kroyakan, with short surveys inside the forest onthee north side of Mt. Rogojembangan and near Kroyakan. The survey coveredalmostt the total altitudinal range from 300-2565 m, with only a small gap at 1800-20000 m. We spent almost equivalent amounts of time in the lowland and hill forestbeloww 1000 m as in the montane and upper montane forests above 1000 m.Thee primate surveys were as much as possible concentrated in the interior ofthee forest areas and was targeted to the three endemic primate taxa: Hylobatesmoloch,moloch, Presbytis comata and Trachypithecus auratus. According to localinformantss the long-tailed macaque Macaca fascicularis was also present as mightbee the slow loris Nycticebus coucang, but these two species were not recordedduringg the survey.Thee area was surveyed from vantage points over the canopy and by walkinginsidee the forest along available trails. The presence of gibbons was establishedmainlyy by their calls. Gibbon density in the forests between Linggo and Mt.Lumping,, covering an area of c. 11 km 2 between altitudes of c. 300-1300 m, wasestimatedd by plotting the locations of gibbon song bouts heard from fixed points andwhilee surveying on a map. In the same area a transect of 3.8 km in length, partiallyalongg an existing trail, was walked using a fixed strip width of 100 m, and wasrepeatedd four times. This allowed density estimates to be made for the two leafmonkeys.. Whenever a primate or a group of primates was encountered observationsweree made ad libitum (Altmann, 1974), and data on the habitat were collected. Adlibitumlibitum sampling is not to be recommended for long-term comprehensive studies butcann be useful during preliminary observations (Martin & Bateson, 1993). Ad libitumsamplingg was used by default because there were no established trail systems in thearea,, the study covered a relative short time span, the study animals were nothabituated,, and the observation conditions were relatively difficult.Additionall information on the presence or absence of primate species wasgatheredd by interviewing local inhabitants, collectors of forest products (e.g., coffeeandd rattan) and officers of the forestry department.118 8

AA Faunal Survey of the Dieng Mountains, Central JavaBRIEFF HISTORICAL ACCOUNT OF FORMER FAUNAL EXPLORATIONRelativelyy little faunal exploration has been done in the study area other than on theDiengg Plateau itself. Some botanists like S.H. Koorders (October, 1891), C.A.Backerr (January, 1917; see Biinnemeyer, 1918) and C.G.G.J. van Steenis (August,1930)) have collected on the Dieng Plateau and Mt. Prahu (van Steenis-Kruzeman,1950).. The naturalist Junghuhn (1854) visited the Dieng Plateau and Mt. Prahu(March-Aprill 1840, October-November 1845). The interior and the western parts ofthee study area have always been somewhat neglected. The only zoologist whocontributedd considerably to our knowledge of the area is Thomas Horsfield whocollectedd in October 1816. He made some collections of birds and mammals in thearea,, some of which are type specimens (Horsfield, 1824; Mees, 1989).Bartelss (1937) reported on a series of Presbytis comata skins collected at analtitudee of c. 1300-1500 m, which he received from Mr Landberg, owner of aplantationn on the north-western slopes of the Dieng mountains. Apart from Kappeler(1984),, who visited Mt. Prahu in 1978 during a gibbon survey, other primatologists,suchh as Asquith et al. (1995), Martarinza (pers. comm. 1994) and M. Linsley (pers.comm.. 1994), did not survey the Dieng mountains. Kappeler did not find forestbeloww 2100 m on Mt. Prahu, and did not find any gibbons.Ass a result of the insufficient coverage by naturalists the forest on the Diengmountainss was for a long time considered to be of only minor significance for thepreservationn of Javan biological diversity. The area was accorded the lowest overallpriorityy ranking in MacKinnon et al. (1982), although the area was stated to be 'animportantt water catchment and of some botanical and faunal interest'.RESULTS SPrimatePrimate distribution and habitat preferencesJavann gibbon were found to be present between altitudes of c. 300 and 1300 m. fromLinggoo and Mt. Lumping in the west to Mt. Rogojembangan in the south-east (Table8.1).. Gibbon habitat consisted of secondary forest with a rather dense and closecanopy,, and undisturbed primary forest. The detected gibbons all appeared to preferthee taller trees for resting, foraging and locomotion. Gibbons were seen on threeoccasions:: a single adult, two adults and a group of seven. On the basis ofsimultaneouss or alternating vocalisations and sightings, a total of 10-12 groups couldbee recognised in an area of c. 11 km 2 between Linggo and Mt. Lumping. Assumingann average group size of 3.3 individuals (cf. Kappeler, 1984) the density of gibbonswass estimated to be 3.0-3.6 individuals km" 2 . Two additional groups were found atthee northern slopes of Mt. Rogojembangan and near Kroyakan, respectively.Grizzledd leaf monkey were found to be present in the western part of the studyareaa and on the higher parts of Mt. Prahu (Table 8.1). In July 1994 two individualsweree observed near the summit of Mt. Prahu (Nijman & Sözer, 1995) and on 11Junee 1995 a troop of monkeys were detected near this former observation point.119 9

ForestForest (and) PrimatesHoweverr because of the dense cover and the angle of observation it was not clearwhetherr these individuals were grizzled leaf monkeys or ebony leaf monkeys.Tablee 81Groups or individuals of Javan gibbon Hylobates moloch, grizzled leaf monkey Presbytiscomatacomata and ebony leaf monkey Trachypithecus auratus observed in the Dieng mountains,withh altitude at which the observations were made.Species sH.H. moloch 27/08/'94 4P.P. comataDate e25/09/'94 411-14,, 16/06/'9512/06/'95 513/06/'95 514/06/'95 514-15/06/'95 529/06/'95 505/07/'94 411/06/'95 513/06/'95 514/06/'95 515/06/'95 5T.T. auratus 25/09/'94 412/06/'95 514/06/'95 515/06/'95 516/06/'95 5No.. groupsheard d2 22 21 13-4 41 11 12 25-6 61 11 11 11 11 11 11 11 1No. . ndividuals sseen n1 12 27 72 2111 (+2 neonates)9(+ + 11 neonate)2 2>1 1>4 4>2 27 7>3 3>4 47(+ + 11 neonate)3 3155 (+4 neonates)10-122 (+1 neonate)1 18-10 0>5 5Altitude ec.. 400-600600 0c.. 400-600c.. 750c.. 300-700765 5880 0885 5c.. 850-900c.. 1000-1300c.. 1200c.. 7002565 52500 0780 0820 0820 0650 0925 51085 51150 0820 0775 5750-800 0750-800 0850 0765 5780 0815 51300 0865 5800 0570 0600 0500 0Locality yLinggo oLinggo oLinggo oLinggoo (centr.) 'Linggo oLinggo oLinggoo (centr.)Linggoo (centr.)Linggoo (centr.)Mt.. LumpingMt.. RogojembanganKroyakan nMt.. PrahuMt.. Prahu 2Linggo oLinggo oLinggo oLinggo oLinggoo (centr.)Mt.. LumpingMt.. LumpingLinggo oLinggo oLinggo oLinggo oLinggoo (centr.)Linggo oLinggo oLinggo oMt.. LumpingLinggoo (centr.)Linggoo (centr.)Linggoo (north) 1Linggoo (north)Kroyakan n1.. Linggo (centr ) refers to the area between Linggo and Mt. Lumping, Linggo (north) refers to thelowlandd forests north of Linggo. See figure 8.1,22 unconfirmed, see text.Moree direct observations were made in the western part of the study area. Groups of2-133 individuals were seen on seven occasions. The smaller group sizes wereprobablyy a reflection of the difficulties in observing the complete group rather than120 0

AA Faunal Survey of the Dieng Mountains, Central Javathee size of the group itself. On three occasions we had the impression that we couldobservee the whole troop, with group sizes of at least seven individuals, nine plusonee neonate, and eleven plus two neonates. Two groups were detected by means oftheirr characteristic vocalisations. In total at least six different groups inhabited thestudyy area.Onn six occasions we observed a group of grizzled leaf monkeys within 50 mfromm the transect line. Assuming an average group size of seven individuals (cf.Supriatnaa et al., 1994) the population density was estimated at 28 individuals km" 2 .Wee observed the species between altitudes of 650 and 2565 m. Local inhabitantsandd officers of the forestry department reported it to be present north of Linggo(forestss descends to c. 300 m) and also in the forests above Kroyakan (altitude c.4000 m). Grizzled leaf monkeys were recorded in primary forest and in secondaryforest,, both in edges and the interior. They were found in lowland forests, in forestsonn steep slopes and on hills and in upper montane forests.Thee ebony leaf monkey was the species observed most frequently. It wasreportedd to be rather common on both on Mt. Prahu and the central part of the studyarea.. In the western part we sighted groups on nine occasions and twice located a agroupp or individual by their characteristic vocalisation. In the forests aboveKroyakann a group was also identified by means of vocalisation. Records come fromthee north-western part north of Linggo, to Mt. Lumping in the south and Kroyakaninn the north-east, between altitudes of 500 and 1300 m (Table 8.1). At least eightgroupss of 3-19 individuals of ebony leaf monkey are present in the study area. Alongthee transect line groups were observed five times. Assuming an average group sizeoff seven individuals (V. Nijman, unp. data) the density may be 23 individuals km" 2 .Thee habitat in which ebony leaf monkeys were observed included primary andsecondaryy forest, both on the edges and in the interior.Populationn estimatesAlthoughh preliminary, we present some information of the number of individuals ofthee two most endangered primate species --the Javan gibbon and the grizzled leafmonkey-- possibly present within the area. The Javan gibbon was observed betweenaltitudess between c. 300 and 1300 m. It is likely to be distributed throughout thewesternn half of the study area up to altitudes of c. 1600 m. This is considered to bethee species' upper limit (Kappeler, 1984a) although it has been reported from higheraltitudess (e.g., 2400 m on Mt. Pangrango: Doctors van Leeuwen, 1926; 1900 m onMt.. Tangkuban Perahu: R. Sözer, pers. comm. 1992). The most widely used methodforr estimating population sizes of Javan gibbons is by extrapolation based on theforestt area inhabited by gibbons and their population density (e.g., Kappeler, 1984a,Kool,, 1992; Supriatna et al., 1994; Asquith et al., 1996). Population densities varywithh altitude (Kappeler, 1984a, Supriatna et al., 1994) and we followed theassumptionss of Supriatna et al. (1994) which are comparable with those of Kappeler(1984a)) and Asquith et al. (1996). The assumptions of Supriatna et al. (1994) arebasedd on data derived from studies of the white handed (H. lar) and pileated gibbon(H.(H. pileatus). They considered the edge effect (defined as the size of habitat on the121 1

ForestForest (and) Primatesforestt periphery not occupied by gibbons) for Javan gibbons to be one km. Thus,suitablee habitat for gibbons was calculated by subtracting the first kilometre ofhabitatt from the available habitat. This area was multiplied by the gibbon populationdensityy for that altitudinal vegetation zone (Table 8.2). A population of over 500individualss may be present in the area.Lesss is known about densities and altitudinal distribution of grizzled leafmonkeyss than for the Javan gibbon. Reported densities vary from 4-5 individualskm" 22 in Halimun National Park (Maitar in Supriatna et al., 1994) to 35 individualskm" 22 in Patenggang (Ruhiyat, 1983). Our density estimate of 28 individuals km" 2 issimilarr to the 25 individuals km' 2 found by Sujatnika (1992; Sujatnika, pers. comm.)inn Mts. Gede Pangrango National Park. According to Supriatna et al. (1994) grizzledleaff monkey do not inhabit the core of a forested area. Although tentative, if we, forreasonn of comparison only, follow the assumptions of Supriatna et al. (1994), i.e.grizzledd leaf monkeys range in a band of 2 km around the perimeter of the area withaa density of five individuals km" 2 , the available habitat totals c. 140-155 km 2 and thetotall number of grizzled leaf monkeys present in the Dieng mountains may be c.700-8000 animals.Tablee 8.2Estimates of the numbers of Javan gibbon present at the different vegetation zones on theDiengg mountains and total number of gibbons present in the area, calculated following theassumptionss of Supriatna etal. (1994).Altitudinall vegetation zone (m)Sizet t(inn km 2 )Edge e(inn km 2 )Core e(inn km 2 )Densityy TT(ind.. km 2 )Estimated dnumber rLowlandd (0-500m)Hilll (500-1000m)Lowerr montane (1000-1500m)Total l13-15 590-100 017-20 06-7 720-23 36-8 87-8 870-77 711-12 21-3 37 72 27-24 4490-539 922-24 4519-577 7TT Size of natural forest area after RePPProT (1990), scale 1; 250,000: edge is defined as the firstkilometree of habitat on the forest periphery not occupied by gibbons, while core is calculated bysubtractionn of the area of the edge from the forest size (after Supriatna et al., 1994).TTT Densities after Supriatna et al. (1994).DISCUSSION NEvenn though we realise that some of our data are rather limited and based on fewobservations,, we think that they allow comparison with other studies. Supriatna etal.. (1994) concluded that there was an inconsistent and incomplete dataset availabletoo estimate the sizes of wild gibbon and leaf monkey populations. In our attempts toestimatee the number of Javan gibbon and grizzled leaf monkey present in the Diengmountains,, we largely followed the assumptions of Supriatna et al. (1994). Some ofthesee assumptions however, are considered not to be valid in our study area, e.g.,gibbonss were heard frequently less than 100 m from the main road from Kayen to122 2

AA Faunal Survey of the Dieng Mountains, Central JavaPeninggaran,, and they were reported to be present in the lowland forest south-westoff the road from Kroyakan to Doro, questioning the assumption that gibbons do notinhabitt the first kilometre of the forest periphery. If we use the assumptions anddensitiess estimated by Kappeler (1984a) and Asquith et al. (1995) to estimate thenumberr of gibbons in the Dieng mountains, the results are similar to our own: 249-9555 and 523-577, respectively (see Table 8.3).Tablee 8.3Estimates of the numbers of Javan gibbon present in the different vegetation zones on theDiengg mountains using the assumptions of Kappeler (1984) and Asquith et al. (1995).Altitudinall vegetation zone (m)Afterr Kappeler (1984)Lowlandd (0-500m)Hilll (500-1000m)Lowerr montane (1000- 1500m)Total lSizet t(inn km 2 )13-15 590-100 017-20 0120-135 5Densityy TT(ind.. km 2 )1-13 32-7 71-3 3Estimatedd number52*195 5180-700 017-60 0249-955 5Afterr Asquith et al. (1984)Lowlandd (0-1000m)Montanee (1000-2000m; western part only)Total l77-85 511-12 288-97 76.5 52 2501-553 322-24 4523-577 7TT Size of natural forest area after RePPProT (1990), scale 1: 250,000.Ttt Note that Asquith et al. (1994) took the edge effect into acount but that Kappeler (1984) did not.Furthermore,, we do not agree with the assumption of Supriatna et al. (1994) thatgrizzledd leaf monkeys are not found in the core of a forested area, and a density of 5individualss km" seems rather conservative because our own estimate and thosereportedd from other studies (e.g., Ruhiyat, 1983; Sujatnika, 1992) are considerablyhigherr (see chapter 12). However, pending further research on the population densityandd habitat preferences of grizzled leaf monkeys, any further adjustment seemsunwarranted. .Despitee the number of limitations and perhaps low level of accuracy we havepresentedd our population estimates as it is believed that (i) even these roughestimatess are useful in order to get some idea on population sizes and (ii) theestimatess allow comparison with other areas and other studies which have beenconductedd so far.Thee only area, other than the Dieng mountains, where both grizzled leafmonkeyy and Javan gibbon are present in greater or similar numbers is HalimunNationall Park in West Java (360 km 2 of forest between 500 and 1929 m, of which 80perr cent is above 1200 m; Kool, 1992). Most patches of strict lowland forest inHalimunn National Park are discontinuous and are often situated outside the reserveboundariess (Whitten et al., 1996), so the area's protected status might create theillusionn that populations of Javan gibbons and grizzled leaf monkeys are relativelysecure,, this is not necessarily the case. Population estimates of Javan gibbon for this123 3

ForestForest (and) Primatesareaa range from 852-1320 animals (Kool, 1992), 870 animals (Asquith et al., 1995)too 908 animals (Supriatna et al., 1994). Up to 720 grizzled leaf monkeys may bepresentt (Supriatna et al., 1994), although Maitar (in Supriatna et al., 1994) reportsveryy low densities of this species in the area and Kool (1992) was not able to obtainaa density estimate because of the low number of sightings.Duringg our surveys in the Dieng mountains we were repeatedly confrontedwithh the fact that no one had recognised the high biological value of this area before.Therefore,, and as our surveys were limited in time and did not cover the area as awhole,, we highly recommend the area for those interested in studying Javan faunaandd flora in more detail. In our survey for instance we observed or found traces ofspeciess like large flying fox Pteropus vampyrus, binturong Arctictus binturong,leopardd Panthera parous, pigs Sus scrofa and/or S. verrucosus, barking deerMuntiacusMuntiacus muntjak, and black giant squirrel Ratufa bicolor. The is still much to bdiscoveredd (see for a more complete listing of the mammals of the Dieng mountainsNijmann & Setiawan, 2001). Scientific research would not only provide newinformationn and better insight, it would also serve as a constant reminder of theconservationn importance of the Dieng mountains.Contraryy to MacKinnon (1987), we strongly believe that there is room for afurtherr expansion of the reserve system on Java. In Central Java, currently scarselyanyy large terrestrial area has an adequate protected status, although several havebeenn proposed as nature reserves or wildlife sanctuaries (MacKinnon et al., 1982).Ass conversion of the last remaining natural forest areas on Java is an ongoingprocess,, resulting in an ever increasing fragmentation, it is of utmost importance toraisee one or preferable more areas in the central part of the island to a higherconservationn status.Thee Dieng mountains support relatively high numbers of two of Indonesia'smostt threatened primate species, the Javan gibbon and the grizzled leaf monkey,makingg it a top priority area for primate conservation. The area is amongst the mostdiversee left on Java, notably it is one of the few unprotected forests that covers thewholee range from lowland to upper montane. It harbours 67 per cent of all birdspeciess endemic to Java and Bali (20 of 30 species), and 70 per cent of the JavanRestrictedd Range forest birds (23 of 33 species; see Box 8.1). The creation of areservee in the Dieng mountains would be of international importance for globalbiodiversityy conservation. The area is probably sufficiently large to ensure themaintenancee of viable populations of unique flora and fauna.Followingg Nijman & Sözer (1996) we suggest that the proposed wildlifesanctuaryy (MacKinnon et al., 1982) be extended to the north-west so as to includethee lowland and lower montane forest of Linggo. In the central area, the boundaryshouldd follow the line between the summits of Mt. Rogojembangan and Mt.Kendalisodo.. From Mt. Kendalisodo the boundary should run westwards -excludingthee village of Petungkriyana- up to the Sengkarang River. From there the boundaryshouldd follow the eastern and southern slopes of Mt. Lumping. We recommendedthatt the provincial or national authorities eassessed the feasibility of creating anaturee reserve or national park in the Dieng mountains. If the reserve is to become a124 4

AA Faunal Survey of the Dieng Mountains, Central Javanationall park consideration should be given whether or not to include the Diengplateau,, with the three established lake nature reserves.Thee results of the present survey, and the proposals to extend the proposed wildlifesanctuaryy into the lowland zone, have been well received by the Directorate Generaloff Forest Protection and Nature Conservation (PHPA), and currently gazettment isbeingg processed.Tablee 8.4 Endemic and Restricted Range (R.R.) bird species recorded in the Dieng mountains.Endemismm is defined as being restricted to the Javan faunal region i.e. the islands of Java andBali,, while a Restricted Range species is a species which has a breeding range fewer then50,0000 km 2 (Bibby et al., 1992; Sujatnika et al., 1995). Nomenclature and sequence followAndreww (1992).Englishh nameJavann Hawk-eagleChestnut-belliedd PatridgePink-headedd Fruit-doveYellow-throatedd Hanging-parrotJavann KingfisherBrown-throatedd BarbetBlack-bandedd BarbetOrange-frontedd BarbetSundaa MinivetOrange-spottedd BulbulSundaa Streaked BulbulSundaa Blue RobinWhite-breastedd BabblerWhite-bibbedd BabblerCrescent-chestedd BabblerGrey-cheekedd Tit-babblerJavann FulvettaJavann TesiaWhite-rumpedd WarblerRufous-tailedd Fan tailWhite-belliedd FantailPygmyy TitWhite-flankedd SunbirdViolet-tailedd SunbirdGrey-throatedd DarkeyeSundaa SerinScientificc name Endemic R R. .SpimetusSpimetus bartelsiArboArbo rophila ja vanica•PtilinopusPtilinopus porphyreusLoriculusLoriculus pusillusHalcyonHalcyon cyanoventris•MegalaimaMegalaima corvinaMegalaimaMegalaima javensisMegalaimaMegalaima armillarisPericrocotusPericrocotus miniatusPycnonotusPycnonotus bimaculatusHypsipetesHypsipetes viriscensCinclidiumCinclidium dianaStachyrisStachyris grammicepsStachyrisStachyris thoracica••••StachyrisStachyris melanothorax *MacronousMacronous flavicollis •AlcippeAlcippe pyrrhoptera • *TesiaTesia superciliaris • *SeicercusSeicercus grammiceps

ForestForest (and) Primatesthankedd for his work during parts of the 1994 surveys, as are I wan Setiawan andAndii Prima Setiadi. Drs Boeadi (Museum Zoologi Bogor) helped with identificationoff prey remains. Dr H. Albrecht, Dr P.J.H. van Bree, Dr J. Chapman and threereviewerss commented on earlier drafts.126 6

DistributionDistribution and Conservation of the Proboscis MonkeyCHAPTERR 9DISTRIBUTIONN AND CONSERVATION OF THE PROBOSCISMONKEYY NASALIS LARVATUS IN KALIMANTAN, INDONESIA.withwith Erik Meijaard, Biological Conservation 92: 15-24, 2000ABSTRACT TThee proboscis monkey Nasalis larvatus is endemic to the island of Borneo. Arevieww of the species' distribution reveals that it occurs throughout Kalimantan, theIndonesiann part of Borneo, from the coastal areas to the headwaters of probably allmajorr rivers. Proboscis monkeys are more widely distributed than has been thoughtpreviously,, and were never confined to the coastal and downstream areas of riversonn the island of Borneo (including what is now Sabah, Sarawak, Brunei andKalimantan)) as has been assumed in some primate literature. Proboscis monkeyhabitat,, i.e. riverine and coastal forest, is the most threatened of all vegetation typesinn Borneo, owing to conversion into agricultural land and logging. Another threat totheirr survival is hunting. The combination of these threats has reduced populationsoff N. larvatus in Sabah, Sarawak and East Kalimantan, and based on this it isexpectedd that other populations elsewhere in Borneo are likewise threatened. Ourstudyy shows the present low efficiency of conservation programmes in Kalimantan,whichh adds to the problem of protecting N. larvatus. For the survival of the speciesthee populations in Kalimantan are still of great significance, as they are considerablylargerr than those in Sabah, Sarawak, and Brunei. We therefore recommend theprotectionn of some of the largest populations in order to ensure the long-termsurvivall of the species.RINGKASAN NPenyebarann dan konservasi Bekantan Nasalis larvatus di Kalimantan, Indonesia(bersamaa Erik Meijaard, Biological Conservation 92: 15-24, 2000): BekantanNasalisNasalis larvatus merupakan spesies endemik Pulau Borneo. Tinjauan ulang terhadapdistribusii spesies ini menunjukkan bahwa spesies ini terdapat di seluruh Kalimantan,Borneoo bagian Indonesia, dari daerah pesisir sampai hulu sungainya darikemungkinann besar semua sungai-sungai besar. Bekantan ternyata tersebar lebihluass dibanding dengan yang diperkirakan sebelumnya, dan tidak hanya terbatas dipesisirr dan kawasan hilir sungai-sungai di Pulau Borneo (termasuk Sabah, Sarawak,Bruneii dan Kalimantan) seperti diperkirakan di beberapa literatur primata. Habitatbekantan,, yaitu hutan di sepanjang aliran sungai dan pantai, merupakan tipe vegetasiyangg paling terancam di Borneo, karena peralihan menjadi lahan pertanian danpenebangann kayu. Ancaman lainnya adalah perburuan. Gabungan ancaman-ancaman127 7

ForestForest (and) Primatesinii telah menurunkan populasi N. larvalis di Sabah, Sarawak dan Kalimantan Timur,dann berdasarkan hal tersebut diperkirakan bahwa populasi-populasi lainnya diBorneoo juga terancam. Penelitian kami memperlihatkan rendahnya efisiensiprogram-programm konservasi di Kalimantan, yang menambah permasalahan dalamperlindungann Bekantan. Untuk keberlangsungan hidup spesies ini populasi-populasidii Kalimantan masihlah penting sekali, di mana populasi-populasi itu sangat lebihbesarr dibandingkan dengan di Sabah, Sarawak, dan Brunei. Karena itu kamimerekomendasikann perlindungan beberapa populasi yang terbesar untuk menjaminkeberlangsungann hidup spesies ini.INTRODUCTION NThee proboscis monkey Nasalis larvatus (van Wurmb, 1787) is a large, sexuallydimorphicc Colobine, endemic to the island of Borneo. It is closely associated withwaterways,, returning to the water's edge in the evening, and rarely ranging far fromrivers,, generally 250,000,, with c. 25,000 protected inside reserves. Yeager & Blondal (1992)consideredd this last figure too high and made an adjustment to < 5,000 animalsinsidee protected reserves. N. larvatus is protected by law throughout its range, and islistedd on Appendix I of the CITES convention.Thee aim of this paper is twofold: (1) to provide information on the distributionoff N. larvatus throughout Kalimantan in historic and present times, and (2) toprovidee information on threats facing the species.128 8

DistributionDistribution and Conservation of the Proboscis MonkeyMETHODS SInformationn was obtained by direct observation and by interviewing local people onthee status of N. larvatus: by the author EM from 1994-1997 in the course of aKalimantan-widee orang-utan Pongo pygmaeus survey, and by VN in the frameworkoff a WWF-Indonesia survey in 1996, which concentrated on Colobine monkeys. Forthee orang-utan survey a total of 78 field-checks involving 208 field days were madeinn Kalimantan. In addition 69 days were spent in towns and villages for officialvisitss and interviews. During that period a total of almost 35,000 km were travelledbyy various means of transportation, including transects on foot. The surveys coveredalll major river systems of West, Central, and East Kalimantan, all main towns inKalimantan,, and mountainous areas in Central and East Kalimantan. The WWFsurveyy was conducted between September and December 1996, totalling 78 fielddays,, and covered the north-eastern part of East Kalimantan. Because of the limitedmeansmeans of transportation in Kalimantan, survey routes were mostly dictated by thecoursee of rivers and roads and were not randomly chosen. Additionally, 32 daysweree spent in Sabah, Sarawak, and Brunei. Figure 9.1 shows the survey routes.Centrall Kalimantan loo o 100 200 KilometersFiguree 9.1Area covered during the 1994 - 1997 survey. Thick lines indicate the survey routes.129 9

ForestForest (and) PrimatesInterviewss were conducted in a semi-structured fashion. Questions were asked inIndonesian,, which is also understood in the Malaysian states and Brunei. Interviewsalwayss started as an informal conversation, and if the informant knew about generalwildlifee subjects, the interviews became more specific. As the orang-utan was themainn focus of the larger part of the survey, questions initially addressed thatparticularr species, after which information about other wildlife species wascollected,, including proboscis monkeys. Questions mostly concerned absence orpresencee of the species and threats to its survival. The anecdotal information used inthiss survey provides only subjective data, and information on absence of proboscismonkeyss was not recorded. We only include locations from where the species wasreportedd by at least two independent sources (c.f. Salter & MacKenzie, 1985).Additionall information was obtained from literature, and from biologists andconservationistss working in Kalimantan. The Environmental Impact Assessmentreportss of Kalimantan's logging concessions also provided information on thepresentt distribution of N. larvatus. A total of 115 reports were consulted.Alll N. larvatus records were given a latitude/longitude coordinate and enteredinn a computerized Geographic Information System (GIS), using PC Arclnfo and PCArcVieww software. Other data layers contain information on the 1993 forest cover(Worldd Conservation Monitoring Centre (WCMC) data base), and topography.Habitatt was classified according to personal observation, data from literature, andviaa personal communication. The distance from the N. larvatus locations to the coastwass calculated by proximity analysis in the spatial query builder of PC ArcView.Forr analysis we only included recent data. This was arbitrarily taken as records(published)) after 1980. We have listed all information on the occurrence of N.larvatus,larvatus, regardless of the numbers in which they may occur. For the 15 of what areprobablyy the largest populations we give an indication of population sizes based onpersonall observation, personal communication, and information in the literature,takingg into account the approximate extend of suitable habitat. Population sizes areclassifiedclassified as: 1: < 100; 2: 100-1000; and 3: >1000.RESULTS SDistribution nGroupss of N. larvatus were observed at 30 locations during the survey, and anadditionall 123 records were derived from literature and interviews (Fig. 9.2,Appendixx 9.1). The species is scattered throughout Borneo from the mangroves andsmalll islands in the coastal deltas, along virtually all major rivers to numerous inlandsites.. Eight percent (12/153) of the presence reports were > 200 km directly inlandfromm the coast; 18 % (n = 28) between 100 and 200 km; 16 % (n = 25) between 50andd 100 km; and 58 % (n = 88) < 50 km from the coast. Distances to the coastfollowingg the course of the rivers are even larger, often > 300 km, and sometimes asmuchh as 750 km. Our data suggest that N. larvatus does not occur at high altitudes.Overr 90 % (n = 138) of the presence records were from altitudes < 200 m a.s.1., and130 0

DistributionDistribution and Conservation of the Proboscis Monkeythee highest reports are from c. 350 m a.s.1. The occurrence of inland groups havesometimess been thought to consist of wandering males only (C. Yeager, pers.comm.).. It is therefore important to note that our inland sightings included groups ofN.N. larvatus comprising juveniles and females with dependent young.Figuree 9.2The 153 recent records of proboscis monkey Nasalis larvatus on Borneo as mentioned in thetext.. The numbers 1-16 refer to priority areas for N. larvatus mentioned in the text and Table9.1.. Protected areas in Borneo are cross-hatched.Withinn Kalimantan large populations have been reported from Danau SentarumWildlifee Reserve (No. 3 in Fig. 9.2 and Table 9.1; c. 600, Sebastian, 1994), and fromGunungg Palung National Park (No. 1; "several hundreds", Yeager & Blondal, 1992),Tanjungg Puting National Park (No. 5; c. 2000, Yeager & Blondal, 1992), and theMahakamm delta (No. 16; 600 - 900, Alikodra et al., 1992). Our data indicate thatwithinn Kalimantan a number of other areas remain where there are relatively largepopulationss of N. larvatus. Notably, this includes the delta of the Sungai Sesayap131 1

ForestForest (and) Primates(Sungaii = River, hereafter abbreviated as 'S'), S. Sembakung and S. Sebuku (No.15),, the Mahakam lakes area (No. 10), the fresh water and peat swamp forest areasoff Centra] Kalimantan (No. 6), and the Kendawangan area (No. 2).Tablee 9.1Priorityy areas for the protection of proboscis monkeys Nasalis larvatus in Kalimantan,Indonesia. .No" " Priorityy Area bStatus' 'Numbers' 1 1Habitatt *Mainn threatsReference' '1 12 23 34 45 56 67 78 89 910 011 112 213 314 415 516 6G.. PalungKendawangan nDanauu SentarumSambass PalohTanjungg PuttingNP PNR RWR RUNP PNP P2 22-3 32-3 32 23 3Centrall KalimantanNR/UNP 2-3 3Rivers sLowerr S. BaritoP.Laut tBalikpapann BayS.. Mahakam andUNP PUNP PUNP PUNP P2 2? ?1-2 22 2Lakes sS.. Kedang Kepala NR/UNP P 1-2 2Kutai iS.. KayanSangkulirang gS.. Sesayap, S.Sebuku,, S.Sembakung gMahakamm deltaNP PUNP PUNP PUNP PUNP P1 11 11-2 23 32 2F,, P, Ri. LoD Illegall loggingF,, PIllegall loggingF,, P, Ri Fire,, hunting, loggingNi,, Ma, LoD, P Logging gF,, P, LoD Goldmining,, logging,hunting gF,, P, Ri Swampp reclamationRi iRi,, LoD, FRi,, Ma, FRi,, F, PRi,, F, PRi,, F, P, LoDRi,, F, Ma, NiRi,, F, Ma, NiRi,, F, Ma, NiMa,, NiLogging gLogging gLogging gLogging,, disturbance,hunting gLogging,, fireLogging,, fireLogging,, huntingLogging gShrimpp farming,logging gShrimpp farming,logging g2,3 34,5 51,6,15 51,7,8 81,3 31 11 19 91 11,5,, 8, 141 11,, 10, 11, 121,8 81,, 131,5,, 1617 7(a)) cf. Figure 9.2.(b)(b) G.= Gunung (Mountain); P. = Pulau (Island); S. = Sungai (River).(c)) NP = National Park; NR = Nature reserve; WR = Wildlife Reserve; UNP = Unprotected.(d)(d) Indication of population sizes: 11000 individuals. Seetextt for details.(e)) Mangrove forest (M), Freshwater swamp (F), Peat swamp (P), Riverine (Ri), Lowland Dipterocarp(LoD),, and Nipah palm (Ni).(f)) 1 personal observation; 2 MacKinnon & Warsito, 1982; 3 Yeager & Blondal, 1992; 4 Noor &Hanafia,, 1994; 5. K.Jeanes, pers. com.; 6 Sebastian, 1994; 7 McCarthy, 1997; 8 Silvius et al.,1987;; W. Smits, pers. comm.; 10 Suzuki, 1984; 11 MacKinnon et al., 1994; 12 Rodman, 1978; 13Wibowoo pers. comm.; 14 R. Sózer, pers. comm.; 15 R. Dennis pers. comm.; 16 Momberg et al.,1998;; 17 Ahkodraetal., 1992.Threats sThee only direct threat to the survival of N. larvatus recorded during this study washunting.. Hunting was reported at six locations during the three year surveys. In thenorthernn Mahakam lakes, in East Kalimantan, N. larvatus is increasingly hunted toservee as bait for monitor lizards Varanus salvator, whose skins are highly valued.132 2

DistributionDistribution and Conservation of the Proboscis MonkeyFurtherr inland the species is hunted for food (R. Sözer, pers. comm). In the DanauSentarumm Wildlife Reserve, West Kalimantan, at least two proboscis monkeys wereshott by army or police hunters in late 1996 (R. Dennis, pers. comm.). Iban peoplefromm the area north of the Reserve will opportunistically shoot the monkeys whileonn turtle hunting expeditions during the dry season, much to the annoyance of localMuslimm fishermen (pers. obs.). Three instances of hunting along the S. Kayan and S.Pangeann (where the species is rare) were reported by two Dayak hunters in 1996.Finally,, it was reported by inhabitants of Tanjung Selor and its surroundings, EastKalimantan,, that since the early 1990s the population of proboscis monkeys haddeclinedd dramatically due to hunting by non-Muslim Dayaks.Anotherr threat to N. larvatus' survival is habitat destruction. Table 9.1 showsthatt in the 16 priority areas for protection, the main factors contributing to habitatdestructionn are logging (both legal and illegal), forest fire, gold mining, swampreclamationn and shrimp farming. Unfortunately, the proboscis monkeyis specialisedhabitatt coincides with the areas on Borneo that are the first to be colonised, farmed,industrialised,, and least protected by man. Table 9.2 shows that of the mostimportantt N. larvatus habitat types, only c. 39% has survived, of which 15% isprotected.. Hereby we need to note that the data in Table 9.2 are based onMacKinnonn & Artha's 1981 study, as no more recent data are publicly available.Afterr almost two decades of a continuous logging regime (for reviews see Sunderlin&& Resosudarmo 1996, and Rijksen & Meijaard 1999) considerably less habitatremains. .Tablee 9.2Proboscis monkey Nasalis larvatus habitat (km 2 ) in Kalimantan (after MacKinnon et al.,1996) )Vegetationn typeFreshwaterr swampsPeatt swampsMangrovee forestWett lowland forest (alluvium)Moistt lowland (alluvium)Dryy lowland forest (alluvium)Original larea a38,950 044,030 015,600 022,010 0870 0210 0Totall remaining (

ForestForest (and) PrimatesDISCUSSION NDistribution nEarlyy work on this species suggested that N. larvatus was dependent on mangroveforestss for food and cover (e.g., Kawabe & Mano, 1972; Davies, 1962; Kern, 1962).Bennettt & Gombek's (1993) map showed the species to be largely restricted tocoastall and nearby swamp forest, while Oates et al. (1994), Chivers & Burton (1988)andd Bodmer et al. (1991) all considered it to be an essentially coastal species withraree individuals inland. However, it was certainly not just a coastal species in thepast.. The most detailed accounts of TV. larvatus' historic distribution are given byZondagg (1931) who includes all downstream parts of essentially all major rivers inwhatt is now East, Central and South Kalimantan, but also several upstream areas:middlee and upper S. Kahayan; middle and upper S. Kapuas (Central Kalimantan);middlee S. Barito; middle S. Kayan; upper S. Sesayap. Upstream areas were alsogivenn by Westermann (1938), Gyldenstolpe (1920) and Pfeffer (1958): S. KedangKepala,, upper Barito, S. Murung (the same S. Murung as in Chivers & Burton, 1987andd Bodmer et al., 1991), middle Mahakam, Tumbang Maruwe on the upper S.Barito,, S. Liang, and S. Nggang. Other earlier upstream records were by Van der Aa(1884)) and Jentink (1897).Ourr own records show that proboscis monkey populations are still present inthee upstream parts of Borneofs rivers. Because of the small numbers observedinland,, it appears that proboscis monkeys are most frequent in coastal areas, with thepossiblee exception of the inland swamps surrounding the Danau Sentarum andMahakamm lakes. Owing to the nature of our study we cannot provide estimates of (achangee in) population numbers.Threats sInn the interior of Borneo hunting appears to be an important supplement to ruralpeoplefss diet and all primates including N. larvatus are hunted when the opportunityarisess (Van der Aa 1884, and Pfeffer 1958). Additionally, N. larvatus is sometimeshuntedd for the highly valued bezoar stones which are sometimes found in theintestiness of this and other Colobine species, and used in traditional Chinesemedicinee (Banks, 1931; Westermann, 1938). Jeffrey (1982), working in EastKalimantan,, found that hunting and farming had eliminated proboscis monkeys fromlargee areas of river and coast. Likewise, in Sarawak, Bennett (1988) reports huntingtoo be a major threat to N. larvatus. Davies & Payne (1982) mention an increase inhuntingg throughout the mangroves of Sabah's west coast, and in several localities thespeciess is now rare or absent in places where they were once common. The decreaseinn abundance occurred markedly within the past 10 to 35 years, coinciding with gunsandd outboard motors becoming available to local people (Davies & Payne, 1982).Thee results of our survey indicate that N. larvatus is hunted both inland and incoastall areas. There is a possibility that hunting in the coastal areas is mainly limitedtoo Dayak people and sport hunters, because for the Muslims, who predominate alongthee coast, consumption of monkeys is forbidden (Cleary & Eaton, 1992). Jentink134 4

DistributionDistribution and Conservation of the Proboscis Monkey(1897)) already noted this along the S. Kapuas. There are indications (mainlyinformationn from interviewees) that hunting by indigenous people (especially sincethee availability of guns and outboard motors) has had a significant impact onpopulationss of N. larvatus. Not only the larger rivers, but now also most smallerriverss have become easily accessible because of an extensive network of loggingroads. .Thee occurrence of N. larvatus close to waterways and its lower densities ininlandd areas have been explained by limited food availability, shortage of essentialresources,, and competition with other primates (e.g., Bennett & Sebastian, 1988).However,, our data suggest that hunting might be a factor largely overlooked.Huntingg has been, at least until recently, restricted to Borneo's interior, and mayhavee reduced population densities and caused local extinctions. In those areas inKalimantan'ss interior where hunting is traditionally forbidden for the local Muslimfishermen,, e.g., Danau Sentarum and surroundings and the Mahakam lake area, thespeciess thrives. Therefore it is worth noting that a hunting-related distributionpatternn has also been found for the orang-utan, another lowland specialist primate onBorneoo (Rijksen & Meijaard, 2000).Landd use planningConservationn aiBB Protection ForestHH Conversion Forest|| j ] Production Forestflililll Limned Production ForestFiguree 9.3The land use planning in Central Kalimantan, Indonesia, based on forest use classification(TGHK)) maps.Thee major cause for the recent decline of N. larvatus has undoubtedly been habitatdestructionn (MacKinnon, 1987; Wilson & Wilson, 1975; Salter & MacKenzie,1985),, since this primate frequents some of the riverine habitats most favoured bypeoplee for logging, cultivation, and village settlement. As an illustration (Figure 9.3)wee show the planned land use in the province of Central Kalimantan. This indicatesthatt almost all of the most suitable habitat, i.e. riverine forest is scheduled for135 5

ForestForest (and) Primatesconversion.. Watershed protection forest and protected areas (with the exception ofTanjungg Putting National Park) are situated in upland areas. Within the remaininghabitatt populations are being fragmented (Yeager & Blondal, 1992; Sebastian,1994).. The main factors limiting migration along and across rivers are the extensiveusee of waterways and river banks by humans and the severe degradation andconversionn of the forest along the rivers. Furthermore, the species' association withthee riverine forest combined with the preference for low altitudes may limitmigrationn between river systems.Finally,, forest fires appear to be an increasingly serious threat to JV. larvatushabitat.. Fuller & Fulk (1998) report that fire hot spots during the 1997-1998 forestfiress were more likely to occur near rivers. Yeager & Frederiksson (1998) state thatprobosciss monkey probably has the greatest proportion of its remaining habitatdestroyedd by fire of any primate in Kalimantan.Failingg conservation in Kalimantan.Outt of the 16 priority areas for conservation described in Table 9.1, seven are(partially)) included in the protected area network system of Kalimantan. In at leastfourr of these areas conservation measures seem to be completely inadequate for thelong-termm protection of the proboscis monkey populations.1.. Pulau Kaget (included in no 7 in Table 9.1), a 0,85 km 2 reserve was gazetted onthiss island in 1985, mainly for the preservation of a relatively large population ofN.N. larvatus. When visited by E.M. in 1996 only c. 10 % of the reserve wascoveredd with forest, 90 % was agricultural land. Many of the remaining trees hadbeenn ring-barked or poisoned and were dying. At that time, an estimated 300probosciss monkeys remained (Purwasuka, pers. comm.). In 1999 it was reportedthatt proboscis monkeys were dying due to lack of food and loss of habitat. Theconservationn authorities concluded that all monkeys had to be evacuated tonearbyy unprotected islands. So far 130 animals have been translocated and c. 60havee been brought to Surabaya Zoo on Java (Anonymous, 1999; Meijaard &Nijmann 2000, chapter 10).2.. Tanjung Puting (no 5; 3,000 km ): This area contains the largest protectedpopulationn of N. larvatus. Nevertheless it has been badly affected by illegallogging,, gold mining, and forest fires. Logging inside the park has left behindlargee patches of poorly regenerating fern wilderness on sand. Due to gold miningoperations,, north of the park, the original tea coloured waters of the black-waterriverr of the park have permanently turned into thin mud solution containing >200timess the toxic level of mercury (Rijksen & Meijaard, 1999). River traffic hasincreasedd from c. 10-15 boats month" 1 during 1984-1985 to an average of 27.5boatss day" 1 in 1989, making it difficult for proboscis monkeys to cross the river(Yeagerr & Blondal, 1992). Burned freshwater forest in Tanjung Puting lost c.75%% of its tree stands in 1997 and almost all vegetation had been reduced tocharcoall (Yeager, 1998).136 6

DistributionDistribution and Conservation of the Proboscis Monkey3.. Kutai National Park (no. 12; 1,980 km 2 ): This reserve was established in the1930s.. In the late 1960s however, a large sector of the reserve was given out as atimberr concession, and the coastal lowlands were soon occupied by illegalsettlers.. In the 1970s two large industrial complexes were established in thereservee and a third of the area was degazetted (MacKinnon et al., 1994; Rijksen&& Meijaard, 1999). Major forest fires occurred in this park in 1982-1983, 1987,andd 1998, and an estimated 5% remains forested. For proboscis monkeys theareaa has lost its value.4.. Kendawangan Nature Reserve (no. 2; 650 km 2 ): Although gazetted in 1981,strengthenedd in 1982, and demarcated in 1992, the Kendawangan NatureReservee does no longer appear on the official map of conservation areas inIndonesia.. In 1997, conservation officials recommended that conservation effortsinn the area should be halted as the reserve was too isolated and illegal loggingwass rampant.Thee above mentioned examples demonstrate that in-situ conservation of proboscismonkeyss on Kalimantan has been problematic. Conservation authorities seem to befailingg at different fronts. Even though the species is legally protected, lawenforcementt is weak. During the survey, only once active law enforcement withreferencee to proboscis monkey was observed, when an animal trader wasapprehended,, although many illegal activities (including hunting, illegal logging,disturbancee and capturing) were encountered and reported to the authorities. Withinreservess the situation seems to differ little from areas outside the protected areanetwork.. It is important to note that law enforcement seems to be equally laxindependentt of the status of the area (National Parks, nature reserves or wildlifereserves),, its remoteness, its size, and the time since its gazettement.Forr ex-situ conservation the odds do not seem to be any better. The speciesrequiress a specialised diet and is difficult to maintain in captivity (Collins &Roberts,, 1978). Relatively few proboscis monkeys have been kept in internationalzoos,, and in general these animals did not seem to thrive (Kern 1964). No Europeanzooss hold the species at the moment, while in North America two males and afemalee remain in the Bronx Zoo, New York (K. Brouwer, in litt. Nov. 1997). Anumberr of Indonesian zoos do have c. 70 animals on display (R. Sözer pers. comm.,1998;; Anonymous, 1999). Neither the European nor the North American zoos haveincludedd the species in their Regional Collection Plans for primates. Considering theabove,, and, more importantly, in view of the lack of release sites (without a residentpopulation),, ex-situ conservation will contribute little to the survival of the species.Wee have demonstrated that N. larvatus has declined in parts of EastKalimantan,, Sabah and Sarawak. For the other parts of the species range hard dataaree not yet available, but we expect the trend to be similar. Of the species potentiallysuitablee habitat c. 39% remained in 1981, and possibly much less now. This studyindicatess that the distribution range was larger than previously assumed, andsubsequentlyy the reduction in population numbers must have been more drastic.137 7

ForestForest (and) PrimatesEvidencee is lacking, but, based on our study, the conservation authorities shouldseriouslyy question whether the species can persist under the present conservationregimee or that it is facing a nose dive to extinction.CONCLUSIONS SItt is beyond the scope of the present study to address the underlying causes of thefailuree of the Indonesian conservation authorities (and conservation NGOs) tosafeguardd either the proboscis monkeys or their habitat. What is clear however, isthatt if sufficiently large areas of habitat can be protected and persistent lawenforcementtcan be ensured, N. larvatus could survive. Because of their spectacularappearancee and ease of observation in the wild the species is an excellent touristattraction.. If eco-tourism is well-guided and disturbance levels can be kept low, thespeciess may serve as a flagship for many protected wetland sites.Severall unprotected areas may still provide enough habitat for viablepopulationss of N. larvatus. The improved protection of the following areas (see Fig.9.2)) would significantly increase the survival of this primate: (1) The extensive andlargelyy pristine mangroves and peat swamp forests of the S. Sebuku, S. Sesayap andS.. Sembakung delta; (2) The 80,000 ha area of little disturbed swamp forest to thenorthh of the Mahakam Lakes and west of the Muara Kaman Nature Reserve; (3)Kendawangann Nature Reserve; (4) Danau Sentarum Wildlife Reserve; (5) TanjungPutingg National Park, and (6) Gunung Palung National ParkACKNOWLEDGEMENTS SWee thank the Indonesian Institute for Science (LIPI) for sponsoring our research andthee Directorate General of Forest Protection and Nature Conservation (PHPA) fortheirr cooperation. The help of Ir A. Rachmat (KSDA, Samarinda) is kindlyacknowledged.. WWF-Indonesia, and in particular Mr A. Purmono, Dr T.C. Jessup,Drr C. Eghenter, are thanked for their cooperation. Financial support was receivedfromm the Society for the Advancement of Research in the Tropics (VN), theNetherlandss Foundation for International Nature Protection (VN, EM), the WorldSocietyy for the Protection of Animals, World Wide Fund for Nature Netherlands, theBalikpapann Orang Utan Society and the Lucie Burgers Foundation for BehaviourStudiess (EM).Wee want to thank all people who generously shared their proboscis monkeydataa with us, or otherwise provided information, amongst which Dr. W.T.M. Smits(Tropenbos-Kalimantann Programme), Dr R. Puri (East West Centre, Hawaii), G.Limbergg (formerly WWF-IP), R. Sözer (ISP/ZMA, University of Amsterdam), D.Krebb (ISP/ZMA), R. Dennis (formerly ODA - Wetlands International), A. Erman(ODAA - Wetlands International), G. Frederiksson (ISP/ZMA-Wanariset), S. vanBalenn (Wageningen Agricultural University); K. Jeanes (formerly ODA - Wetlands138 8

DistributionDistribution and Conservation of the Proboscis MonkeyInternational),, P. Jepson (formerly Birdlife International), Wibowo (WetlandsInternational),, and K. Brouwer (European Association of Zoos and Aquariums).Finally,, comments on earlier drafts were received from Dr H. Albrecht (Dept.Animall Behaviour, University of Amsterdam), Dr D. Kitchener (WWF IndonesiaProgramme),, and S. van Balen. Dr B.N.K. Davis and two anonymous reviewersmadee constructive comments on the manuscript.139 9

ForestForest (and) PrimatesAPPENDIXX 9.1Localitiess (records published after 1980) where proboscis monkeys Nasalis larvatushavee been recorded in Kalimantan, Indonesia, the Malaysian states of Sarawak andSabah,, and Brunei. (D = Danau = Lake; G. = Gunung = Mountain; S. = Sungai =River;; P. = Pulau = Island; PT = Perseroan Terbatas = Inc. or Ltd.)Westt KalimantanBenuaa Martinus [112°25/r07N]; Danau Sentarum WR [112°03/0°47 N]; G. PalungNPP [110°05/r06 S]; G. Senuju [109°29/1°30 N]; Hutan Sambas [109°26/1°43 N];Muaraa Kendawangan [110°27/2°28 S]; PT Duadja Corporation II [110°49/0°50 S];PTT Erna Djuliawati [1H°52/1°08 S]; PT Jamaker KalBar Bl. Nanga Sei[111°00/1°000 N]; PT Jamaker KalBar Blok S. Haji [109°30/1°40 N]; PT JamakerKalBarr Blok Unit 1 [109°30/1°50 N]; PT Jamaker KalBar Jaya Bl. Lanjak[112°25/1°000 N]; PT Jamaker KalBar S. Sentimau [109°36/1°25 N]; PT Sinar WestKalimantann Timber [110°43/2°37 S]; PT Sumber Jaya Baru Utama [110°30/1°05 S];S.. Bangkul Besar [110°25/2°45 S]; S. Blamban [110°14/2°43 S]; S. Embaloh[112°23/1°077 N]; S. Embaloh Ulu [112°32/1°23 N]; S. Membuluh [110°18/2°32 S];S.. Mentangan [110°41/2°47 S]; S. Seriang [lll°56/0°56 N]; S. Tang [112°29/0°39N];; Tanjung Satay [109°34/1°12 S]; upper S. Kapuas [112°54/0°56 N]Sources:: MacKinnon and Artha, 1981; MacKinnon and Warsito, 1982; MacKinnonett al., 1996; Noor and Hanafia, 1994; Silvius et al., 1987; Sebastian, 1994; Yanuar etal.,, unp. data; R. Dennis, pers. comm.; S. van Balen pers. comm.; pers. observ.Centrall KalimantanPTT Bina Samaktha [112°00/2°25 S]; PT Bintang Arut [lll°35/2°40 S]; PT BrataJayaa Utama [113°45/3°00 S]; PT Cams Indonesia [113°10/0°37 S]; PT Gadjah SenoSaktii [112°45/2°45 S]; PT Gunung Meranti [114°00/0°30 S]; PT Hutan Mulya[112°50/1°200 S]; PT Rathitara [113°30/1°30 S]; PT Sehati Barito, S. Bila[lll°15/2°355 S]; PT Yusmin Trading [112°45/2°00 S]; S. Dason [114°58/0°07 N];S.. Gula [114°ll/0°44 S]; S. Hanyu [114°02/0°58 S]; S. Kapuas Murung[114°25/2°255 S]; S. Mandau [113°53/0°43 S]; S. Mengkutup [I14°15/2°05 S]; S.Murungg PT LAAS [114°24/0°09 N]; S. Pinang [114°04/0°51 S]; Tanjung Penghujan[lll 0 32/2°599 S]; Tanjung Puting extension [111°50/3°11 S]; Tanjung Puting NP[111°56/2°533 S]; Tumbang Mahub [112°21/1°02 S]Sources:: Bodmer et al., 1991; Chivers and Burton, 1988; MacKinnon and Artha,1981;; MacKinnon et al., 1996; Payne et al., 1985; Silvius et al., 1987; Yeager andBlondal,, 1992; Yanuar et al., unp. data; S. van Balen pers. comm.; pers. observ.140 0

DistributionDistribution and Conservation of the Proboscis MonkeySouthh KalimantanHutann Bakau Pantai Timur [116°02/3°16 S]; Muara Muning [114°50/2°50 S]; P.Kagett [114°31/3°20 S]; P. Kembang [114°32/3°17 S]; P. Laut [116°13/3°48 S]; P.Pinangg [115°03/3°05 S]; Pleihari Martapura [114°56/3°56 S]; Pleihari Tanah Laut[114°41/4°088 S]; S. Kacang [115°10/2°40 S]; S. Negara [114°56/2°47 S]; S. Tapin[115°15/2°55S] ]Sources:: MacKinnon and Artha, 1981; MacKinnon et al., 1996; Silvius et al., 1987;S.. van Balen pers. comm.; pers. observ.;Eastt KalimantanBalikpapann Bay [116°43/1°03 S]; Balikpapan Bay, north [116°42/0°55 S]; BunuaPuhun,, S. Mahakam [116°49/0°16 S]; D. Jempang [116°10/0°34 S]; D. KendangMurungg [116°35/0°23 S]; D. Wis [116°ll/0°30 S]; D. Melitang [116°18/0°22 S]; D.Semayangg [116°25/0°20 S]; Lamin Pulut [116°16/0°01 S]; Lower Mahakam delta[117°21/0°488 S]; Mahakam delta [117°27/0°40 S]; Miau Baru [116°57/1°15 N];Muaraa Kayan [117°32/2°59 N]; Muara Sebuku [117°28/4°10 N]; PT Adindo HutaniLestarii [116°45/3°50 N]; PT Alas Helau [116°45/1°50 N]; PT Daisy Timber[118°40/1°155 N]; PT Dana Mula Bhakti [117°25/3°47 N]; PT ITCI-Weyerha.ser[116°43/0°533 S]; PT Jaya Maha Kerta [117°10/4°05 N]; PT Rejosari Bumi[117°45/2°100 N]; PT Surya Hutani Jaya [117°08/0°O5 N]; PT Timberdana[115°35/0°200 S]; PT Tungal Yudi Sawmill Plywood [115°35/0°30 N]; S. AlangoUluu [115°56/2°52 N]; S. Baai [117°38/1°15 N]; S. Bahau Long Alango[115°51/2°522 N]; S. Bahau Long Peleran [115°50/2°47 N]; S. Bulungan[117°30/2°555 N]; S. Jelau [115°52/0°26 S]; S. Kahala [116°21/0°05 S]; S. Karangan[117°51/1°144 N]; S. Kayan [116°43/2°48 N]; S. Kedang Kepala [ 116°41/0°04 N];S.. Kedang Rantau [116°45/0°01 N]; S. Kelai Long Lanuk [117°17/2°00 N]; S.Kendangg [116°37/0°25 S]; S. Kendang Pahu [115°58/0°21 S]; S. Lurah[115°41/2°411 N]; S. Mahakam, Long Bagun [115°04/0°18 N]; S. Pangean[116°44/2°388 N]; S. Ratah [115°12/0°14 N]; S. Samboja [116°59/1°11 S]; S.Sebukuhh [117°25/4°05 N]; S. Sebukuh [117°05/3°57 N]; S. Sembakung[117°20i/3°48ii N] S. Sengatta, Kutai NP [117°26/0°26 N]; S. Sesayap [116°58/3°37N];; S. Tubu [116°07/3°09 N]; S. Wahau [116°52/1°07 N]; Sangkulirang[118 o 31/l°000 N]; Senggata estuary [117°35/0°27 N]; S. Wain [116 o 47/l°05 S];Tarakann [117°37/3°22 N]; Teluk Apar/ Teluk Adang [116°34/2°13 S]; Teluk Kaba[117°29/0°144 N]; Teratak, S. Mahakam [116°45/0°13 S]; Tubuan [116°18/0°11 S];upperr S. Senggata [117°12/0°36 N]; West of Muara Kaman NR [116°39/0°13 N]Sources:: Alikodra et al., 1992; Azuma and Suzuki, 1984; Jeffrey 1982; MacKinnonandd Artha, 1981; MacKinnon et al., 1996; Momberg et al., 1998; Silvius et al., 1987;Suzuki,, 1984; Yanuar et al., unp. data; Yasuma, 1994; S. van Balen pers. comm.; G.Frederiksson,, pers. comm.; D. Kreb, pers. comm.; G. Limberg pers. comm.;McCarthy,, pers. comm.; R. Puri, pers. comm; R. Sözer, pers. comm.; P. Jepson,pers.. comm.; pers. observ.141 1

ForestForest (and) PrimatesSarawak kBakoo NP [110°29/1°43 N]; Limbang mangroves [115°03/4°49 N]; S. Sarawak[110°27/1°39];; West of Miri

The LocalThe Local Extinction of the Proboscis Monkey in Pulau Kaget Nature ReserveCHAPTERR 10THEE LOCAL EXTINCTION OF PROBOSCIS MONKEYNASALISNASALIS LARVATUS IN PULAU KAGET NATURE RESERVEINDONESIA Awithwith Erik Meijaard, Oryx 34: 66-70 (2000)ABSTRACT TThee population of the threatened proboscis monkey Nasalis larvatus, a Borneanendemic,, in the South Kalimantan Pulau Kaget Nature Reserve of Indonesia isextinct.. Until 1997 this small, isolated population, estimated at c. 300 animals, hadbeenn pushed towards the fringes of the reserve by illegal agricultural expansion. Asfoodd sources were depleted, the population apparently exceeded the decreasingcarryingg capacity of the reserve and was reported to be starving to death. As asolution,, 84 animals were translocated to nearby, unprotected sites, resulting in 13fatalities.. An additional 61 animals were taken to a zoo where 60 per cent diedwithinn four months of their capture. There was neither a proper pre-translocationassessmentt of the suitability of the release sites, nor a proper post-translocationmonitoringg programme of the released animals. We conclude that the Pulau Kagetreservee and its proboscis monkeys have been poorly managed. To improve theeffectivenesss of conservation efforts in Indonesia we provide some suggestions.RINGKASAN NKepunahann lokal Bekantan Nasalis larvatus di Cagar Alam Pulau Kaget, Indonesia(bersamaa Erik Meijaard, Oryx 34: 66-70, 2000): Populasi Bekantan Nasalis larvatussuatuu spesies endemik Borneo yang berstatus terancam, di Cagar Alam Pulau Kaget,Kalimantann Selatan, Indonesia telah punah. Sampai tahun 1997 populasi kecil danterisolasii ini, diperkirakan sekitar 300 ekor, telah tersingkir ke pinggiran kawasancagarr alam oleh perambahan ilegal untuk pertanian. Karena sumber makanan telahdihabisi,, populasi ini tampaknya melebihi daya dukung cagar alam dan dilaporkanmatii kelaparan. Sebagai pemecahan masalahnya, 84 ekor ditranslokasikan ke daerahyangg dekat, yang tidak dilindungi, mengakibatkan 13 kematian. 61 Ekor lain dibawakee kebun binatang dimana 60% meninggal dalam kurun waktu 4 bulan daripenangkapannya.. Sebelum translokasi, tidak ada penilaian terlebih dahulu yangmemadaii terhadap daerah pelepasannya, juga setelah translokasi tidak ada programmonitoringg yang tepat terhadap hewan pindahan itu. Kami berkesimpulan bahwapengelolaannyaa Cagar Alam Pulau Kaget dan bekantannya telah sangat kurang.Untukk meningkatkan keefektifan usaha pelestarian di Indonesia kami memberikanbeberapaa saran.143 3

ForestForest (and) PrimatesINTRODUCTION NInn 1976, 85 ha of the 247 ha large Pulau Kaget [3°26'S, 114°31'E] (pulau = island)wass gazetted by Ministerial decree No. 701/Kpts/Um/l 1/1976 as a Strict NatureReserve,, which prohibits all human use of the reserve's resources. The main reasonforr establishing the reserve was to protect its population of proboscis monkeyNasalisNasalis larvatus. The remainder of the island was designated for agriculturalpurposes.. The island is situated in the middle of the Barito River delta, in SouthKalimantan,, only a few kilometres downstream from the provincial capital ofBanjarmasinn (Fig. 10.1). The area was a popular tourist destination because it waseasyy to see proboscis monkeys from the river. In 1993, the proboscis monkey wasdeclaredd the provincial symbol of South Kalimantan, further adding to the apparentimportancee of Pulau Kaget Nature Reserve as a conservation site for this species.Figuree 10.1 The island of Borneo (insert) and the location of Pulau Kaget and adjacent islands.Thee proboscis monkey, known as bekantan in the Indonesian language, is anendemicc of the island of Borneo, where it inhabits riverine and coastal forest,includingg mangroves. It typically lives in one-male groups varying from 3-23individuals,, which may form large associations of up to 60 individuals (Bennett &Sebastian,, 1988; Yeager, 1990, 1991, 1993; pers. observ.). Reported densities vary144 4

TheThe Local Extinction of the Proboscis Monkey in Pulau Kaget Nature Reservefromm 1.2 to 62.6 individuals km 2 (Bennett & Sebastian, 1988; Alikodra et al., 1992;Yeagerr & Blondal, 1992).Probosciss monkey habitat is the most threatened of all vegetation types inBorneo,, because of logging and conversion to agricultural land (Rijksen & Meijaard,1999).. Habitat destruction has been identified as the major threat to the survival ofthee proboscis monkey (Salter & MacKenzie, 1985; MacKinnon 1987; Meijaard &Nijmann 2000, chapter 9), but other threats include hunting (Pfeffer, 1958; Meijaard&& Nijman 2000, chapter 9), and, to a lesser extent, the illegal pet trade (Fig. 10.2).Thee combination of these threats has reduced proboscis monkey populations inseverall parts of Borneo (Davies & Payne, 1982; Salter & MacKenzie, 1985;Meijaardd & Nijman 2000, chapter 9) and it is suspected that the species is in rapiddeclinee (Meijaard & Nijman 2000 chapter 9). In 1990 the number of proboscismonkeysmonkeys protected in reserves was estimated at some 5000 individuals (Yeager &Blondal,, 1992). The proboscis monkey is classed as Vulnerable by IUCN (1996),andd as early as 1987 it was given a 'very high conservation rating' by the PrimateSpecialistt Group (Eudey, 1987). The species is listed on Appendix I of CITES and isprotectedd by law throughout its range.Figuree 10.2 Male proboscis monkey Nasalis larvatus in illegal private captivity (photo E. Meijaard)145 5

ForestForest (and) PrimatesTHEE CASE OF THE PULAU KAGET PROBOSCIS MONKEYSWhenn E.M. visited Pulau Kaget in November 1996, the central part of the island,includingg the reserve, had been cleared for agriculture, and only a c. 25-m-widefringee around the central fields, was still forested. Proboscis monkeys were abundantinn this strip of forest. On another part of the island, a similar narrow fringe of treeswass still standing, but these trees had lost all their leaves and appeared dead (Fig.10.3).. In 1996 it has been estimated that 27% of all trees in the Pulau Kaget Naturereservee were dead (Bismark, 1999). Only c. 10% of the total land area of the reserveretainedd some tree cover (estimated at 5% in 1993 by Yeager (1996)). During E.M.'svisitt no guards were present in the reserve.Theree appear to be several reasons for the habitat loss at Pulau Kaget. Thereservee comprises rich agricultural soils, and farmers from outside the reserve haveenteredd the area for many years to grow crops, apparently unhampered by thereserve'ss fully protected status. According to local forestry officials, the farmers hadring-barkedd or poisoned many of the remaining trees, presumably to open up moreland.. An alternative explanation was upstream pollution from sawmills and wharves(cf.(cf. Bismark, 1999). Both the heads of the provincial Agency for the Conservation ofNaturall Resources and the regional office of the Forestry Department said that some3000 proboscis monkeys still survived in the remaining area, and that the presentpopulationn was too large for the remaining habitat. This estimate was corroboratedbyy Bismark's (1999) count of 288 individuals in 1996 (but for a different view seeYeagerr (1996) who estimated the reserve's population at 51 individuals). Thesepopulationn estimates suggest an over-capacity, which may have been a third reasonforr the defoliation.Inn 1996 the Governor of South Kalimantan and the Director General for ForestProtectionn and Nature Conservation also assessed the situation and promised furtherresearch.. Short-term conservation measures were suggested, including the provisionoff leaves to the monkeys and the planting of some 5000 Sonneratia sp. seedlings, animportantt food source when fully grown. In the longer term, plans were put forwardtoo downgrade the status of the area to a Wildlife Reserve, which would allow forotherr resource use besides conservation.Accordingg to an Indonesian newspaper report (Kompas, 5 Feb. 1999) rangersstartedd to find dead proboscis monkeys on the island in 1997. In an attempt topreventt the local extinction of the proboscis monkeys, the conservation agenciesdecidedd that the remaining animals had to be translocated to the nearby, unprotected,islandss of Burung (Tempurung Kecil), Tempurung Besar, Kembang and Bakut, alloff which had extant proboscis monkey populations (Fig 10.2). However, accordingtoo official documents (Ministry of Forestry (MoF), 1999) between December 1996andd March 1997, before the translocations, there had already been six attempts todrivee proboscis monkeys from the protected part of the island to the unprotectedpart.. Unfortunately, the documents do not explain the logic behind these actions,whichh displaced a total of 205 animals into unprotected habitat (MoF, 1999). Inearlyy 1997 and late 1998, in two major capture efforts, some 84 proboscis monkeys,146 6

TheThe Local Extinction of the Proboscis Monkey in Pulau Kaget Nature Reserveoff which 13 died during capture, were translocated while an additional 61 weretransportedd to Surabaya Zoo in Java (MoF 1999; Nursahid, 1999). The head of theprovinciall conservation authorities, Mr. Mar Purwasuka was quoted as saying: "thepurposee of this relocation is to show the world that the South Kalimantan proboscismonkeyss still exist, and have not become extinct, as has been rumored" (Kompas, 5Feb.. 1999).Post-translocationn monitoring by the conservation authorities occurred 5 and166 months after the two capture periods. This consisted of short visits to the islandsduringg which suitable food trees were identified. Few proboscis monkeys weresighted,, and most information on the species' presence was obtained from localinformantss (MoF, 1999). No proboscis monkeys were encountered in the PulauKagett Nature Reserve, while on the unprotected part of the island a total estimatedpopulationn of nine animals. According to our information no proper pretranslocationnhabitat assessments were conducted. Of the 61 animals that arrived inthee zoo 24 were still alive after four months, resulting in a survival rate of less than400 per cent (MoF, 1999; Nursahid, 1999). In addition to the officially removedanimalss an unknown number of proboscis monkeys were smuggled out on boats (AlFatah,, 1999). Confirmation for this was provided when the police confiscated fourprobosciss monkeys, which were on route to Surabaya in Java. They were purchasedatt Banjarmasin market on the mainland near Pulau Kaget for $US 25 each(Banjarmasinn Post 27 June 1999). Table 10.1 indicates the significance of thetranslocationn and capture of the Pulau Kaget proboscis monkeys in relation to thetotall protected population.Figuree 10.3 Former prime proboscis monkey Nasalis larvatus habitat on Pulau Kaget (November 1996,photoo E. Meijaard)147 7

ForestForest (and) PrimatesTablee 10.1Summary of the numbers of proboscis monkeys Nasalis larvatus involved in the PulauKagett translocationTotall protected population (1990) 5 ;000Populationn at Pulau Kaget (1996) (percentage of total protected population) 288 (6%)Minimall number of translocated animals 84Totall number of animals taken to Surabaya Zoo 61Numberr of Pulau Kaget animals that died in Surabaya Zoo or during translocations 50Estimatedd population size of Pulau Kaget island after the translocations 9Estimatedd population size of Pulau Kaget Nature Reserve after the translocations QDISCUSSION NThee translocation of proboscis monkeys from a protected to an unprotected area canhardlyy be considered an improvement to their survival prospects. The release sitesalll have high agricultural potential and are close to the town of Banjarmasin. Unlessthesee sites are designated soon as part of the conservation area network, there is noreasonn to expect that the habitat in these sites will not experience the samedeteriorationn witnessed on Pulau Kaget.Becausee little is known about the translocation of proboscis monkeys, wecannott predict the socio-ecological effects of the dispersal of a once contiguouspopulationn over several small islands, where the species occurred already. Wemaintainn that this translocation could be justified only if everything possible hadbeenn tried to save the population in the original reserve. Considering that as early as1993,, primatologists warned the authorities of the deteriorating situation of PulauKagett (Yeager, 1996) and nothing constructive was done since then, we have toconcludee that the situation was not handled adequately. If a translocation was theonlyy feasible solution, it should have fulfilled at least the standard criteria (e.g., Vie,1999;; Yeager & Silver, 1999). It is clear that few of these conditions were met. Thetransferr of the remaining animals to Surabaya Zoo is also unlikely to contribute tothee preservation of the species in the wild. Proboscis monkeys require a highlyspecialisedd diet and are difficult to keep in captivity (Collins & Roberts, 1978; K.Brouwerr in litt., 12 November 1997). Relatively few proboscis monkeys are kept incaptivityy in international zoos, and mortality rates are high (K. Brouwer in litt., 12Novemberr 1997). As long as habitat destruction cannot be controlled, ex-situconservationn will contribute little to nothing to the survival of the species in thewild. .Inn our opinion, the conservation authorities have inadequately addressed thecausess of habitat loss in Pulau Kaget Nature Reserve, leading to the demise of itsprobosciss monkey population. A possible solution would have been to restore thehabitatt or provide in situ support of the population, and buffer the populations fromhumann impact by establishing and implementing no-access zone. However, theauthoritiess instigated and executed the complete removal of the population from theReserve. .148 8

TheThe Local Extinction of the Proboscis Monkey in Pulau Kaget Nature ReserveCONCLUSIONS SThee situation on Pulau Kaget is not exceptional as suitable proboscis monkey habitatiss disappearing at a rapid rate throughout the species's range. In five of the sixprotectedd areas in Indonesia where the species is represented by at least severalhundredd individuals, populations are in decline (Meijaard & Nijman 2000, chapter9).. It seems that the Indonesian conservation authorities are neither able to carry outspeciess protection, nor protect the species' habitat within reserves against theactivitiess of plantation developers, timber concessions, farmers, and hunters (Rijksen&& Meijaard, 1999). If these protective measures cannot be handled for a relativelysmalll and accessible strict nature reserve, what can be expect for the extensive areasoff unprotected habitat and remote reserves? Indeed, most of this unprotected habitatiss scheduled for conversion into agricultural land and plantation, leaving almostnonee for the proboscis monkey (Meijaard & Nijman 2000, chapter 9).Thee reasons why the Indonesian authorities are failing to address conservationissuess are complex. They include institutional deficiencies, a lack of funds, lack ofknowledge,, misconceptions on ecological issues and poorly integrated planning.SolutionsSolutions have to be addressed in an integrated manner. They include: improvementoff the legal framework; reorganisation and technical training of the responsibleinstitutions;; education and awareness campaigns; appropriate integration ofdevelopmentt and conservation, expansion of the protected area network, and thealleviationn of financial impediments (cf. Rijksen & Meijaard, 1999). What areneededd most of all, however, are serious and effective commitment and politicalsupport,, both nationally and internationally for solving conservation problems.Withinn the context of the present political and economic situation in Indonesia,thee conservation community cannot rely solely on the present Indonesianconservationn authorities to prevent the further decline of the proboscis monkey, andprobablyy many other endangered species. A new approach is required, for instance,alongg the lines of the Orangutan Survival Programme (Rijksen & Meijaard, 1999) inwhichh a dedicated, well-financed and fully mandated conservation body co-ordinatesthee work of conservation authorities, local government, non-governmentalorganisations,, businesses, and international donors, with the specific aim ofprotectingg species and its habitat. We hope that the current wave of openness andpoliticall reform in Indonesia will provide such opportunities for improved andeffectivee conservation.ACKNOWLEDGEMENTS SThiss communication stems from a plea by the head of the provincial Agency forNaturall Resources to expose the situation on Pulau Kaget. We thank the Indonesianauthorities,, i.e. the Indonesian Institute of Sciences and the Directorate General ofForestt Protection and Nuture Conseervation, for granting permission to conduct ourresearch,, and for providing us with data. We thank Koen Brouwer (European149 9

ForestForest (and) PrimatesAssociationn of Zoos and Aquariums) for providing data on captive proboscismonkeys.. Thanks due to Ed Colijn (Indonesian Nature Conservation Database) formakingg geographical information available. Arne Mooers (Zoological MuseumAmsterdam),, Tim O'Brien and Margaret Kinnaird (Wildlife Conservation Society -Indonesia)) commented on a draft document. Two anonymous referees are thankedforr their comments on the manuscript.150 0

PatternsPatterns of Primate Diversity on BorneoCHAPTERR 11PATTERNSS OF PRIMATE DIVERSITY ON BORNEO, ANDSELECTIONN OF CONSERVATION PRIORITY AREASwithwith E. MeijaardABSTRACT TWee assessed the spatial patterns of primate diversity in terms of species richness andendemismm for Borneo, and evaluate this in relation to patterns of human land-useandd setting of the protected area network. Based on an extensive data set of localityrecordss for all thirteen species present on the island (n=1414, range 26-273 perspecies),, combined with data on the ecology of the respective species and with theaidd of a Geographic Information System, we prepared detailed distribution maps,andd overlayers. Tropical wet evergreen forest below 500 m a.s.1. was identified asthee most species rich habitat, with in fact, all species occurring in it. Secondly, peatswampp forest came out as a numerically important habitat for primates on Borneo,whereass the smallest number of primate species occur in mangrove forest. The mostspecies-richh area, with eleven species co-existing, was the tropical wet evergreenforestt near large rivers in central-eastern East Kalimantan, Indonesia, covering alandd surface of some 30,000 km 2 . The most endemic species-rich area comprisesessentiallyy the same area albeit slightly larger. Studies on other animals and plantgroupss almost invariably identified northern Borneo (i.e. the Malaysian state ofSabah)) as richest in species and endemics. The newly identified hotspot is situated inonee of the most densely populated areas of Borneo, the remaining forests areinadequatelyy included in the protected area network, and the area has sufferedseverelyy from the great forest fires in 1982-1983 and 1997-1998. Three largeprotectedd areas situated in central-eastern East Kalimantan, each once home of>70%% of all species and between 80-100% of all the endemics, have most if not alloff their forest destroyed by a combination of illegal logging, mining, encroachment,andd the forest fires. Two proposed conservation areas in the area are inhabited by thePunan,, a (formerly) nomadic hunter-gather tribe, which makes effective speciesprotectionn in these areas difficult.RINGKASAN NPolaa keanekaragaman primata di Kalimantan, dan pemilihan daerah konservasi yangberprioritass (dengan E. Meijaard): Pola-pola keanekaragaman primata kami tentukandengann menggunakan kekayaan jenis dan keendemikan untuk Kalimantan, dan inikamii tinjau kembali sehubungan dengan pola-pola tataguna tanah dan jaringan151 1

ForestForest (and) Primateskawasann konservasi. Peta-peta yang terperinci, dan overlayers kami siapkan untuksemuaa 13 jenis yang ada di pulau tersebut, berdasarkan data set dari catatan lokasi(n=1414,, 26 sampai 273 per jenis), digabung dengan data ekologi masing-masingjenis,, dengan menggunakan Sistem Informasi Geografi (GIS). Pertama hutan tropisdii bawah 500m d.p.1. ditentukan sebagai habitat yang paling kaya jenis, di manasebetulnyaa semua jenis dapat ditemukan. Kedua, hutan rawa gambut ternyata habitatpentingg untuk primata dari segi jumlah jenis, sedangkan jumlah primata palingsedikitt dapat ditemukan di hutan bakau. Hutan tropis di dekat sungai besar diKalimantann Timur sebelah timur-tengah adalah wilayah paling kaya akan jenis,dengann sepuluh sampai sebelas jenis yang hidup berdampingan, dan melingkupikawasann seluas sekitarINTRODUCTION NThee purpose of a conservation network is ultimately to ensure persistence of valuedbiodiversityy (Frankel & Soulé, 1981). Persistence is affected by processes dependingonn intrinsic (e.g., ecological, demographic, and genetic) and extrinsic (e.g., habitatclearancee and degradation, over-exploitation, introduced species) factors (Araüjo &Williams,, 2000). From the early 1980s onwards conservationists have recognisedthee importance of regional concentrations of species (hotspots) as a tool foridentificationn of sites for the preservation of biodiversity (e.g., Terborg & Winter,1983;; Myers, 1988; Prendergast et al., 1993; Pressy et al., 1993; Scott et al., 1993;Dobsonn et al., 1997; Mittermeier et al., 2000; Harcourt, 2000). If hotspots coincideforr a great many taxa, in theory, the less area needs conserving to protectbiodiversityy and in turn the more likely biodiversity is protected. However, the hopethatt areas of high diversity overlap for different taxa, soon appeared to be vain inmanyy cases (e.g., Prendergast et al., 1993; van Jaarsveld et al., 1998; Harcourt2000),, and the hotspot approach has moved more strongly to identifyingcomplementaryy sites (Pressy et al., 1993, Williams et al., 1997; Howard et al.,1998).. Since rarely data on all species are available, it is common practice to select asmall,, relatively well known group as representative for all species (Bibby et al.,1992;; Hacker et al., 1998; Sluys, 1999). Selection of conservation priorities can thenbee based on the patterns (endemism, species-richness, etc.) found in these particulargroups. .Byy comparison with many other taxa, the order Primates consists of mostlylarge,, easily observable species, with the possible exception of the nocturnal,generallyy smaller, ones. They are thus relatively well-studied (Rowe, 1996), and weprobablyy have as good information on the global distribution of primate taxa as wedoo for any other tropical taxon (Harcourt, 2000). Primates thus could be goodindicatorr species in biodiversity assessments for countries with less opportunity forbiologicall surveys than others, and understanding their diversity could therefore beespeciallyy useful. Recently, Harcourt (2000) assessed the distribution patterns of152 2

PatternsPatterns of Primate Diversity on Borneoprimatess world-wide. Nevertheless at smaller scale, the knowledge we have on thedistributionn of primates is often imprecise. Borneo is a case in point.MacKinnonn (1986ab; 1987) assessed the distribution of primates in the Indo-Malayann region, including Borneo. Other general distribution maps of Borneanprimatess are given by e.g., Oates & Davies (1994: Colobines), Geissmann (1995:gibbons),, and Niemietz (1984: tarsiers). These maps are generally imprecise and inthee case of Borneo data on the occurrence in the interior or the southern (Indonesian)three-quarterss of the island are lacking for many taxa (e.g., Meijaard & Nijman,2000).. Seven out of thirteen species of primates on Borneo are included in the IUCNlistingg of threatened species (see Table 11.1). Area selection is a relevant aspect ofconservationn planning in primates on Borneo, since habitat loss and site protectionaree widely seen as the key issue in the conservation of primates, and their wideappealappeal may make them ideal flagships for tropical ecosystems.Thee northern part of Borneo (consisting mainly of the Malaysian state ofSabah)) is more mountainous than other parts, and according to the Pleistocenerefugiumm hypothesis (Haffer 1969) the area remained covered in wet forest evenduringg the driest part of the Pleistocene (e.g., Brandon-Jones, 1996; Taylor et al.,1999;; for a critique see Meijaard, in prep.). The area has been long identified as ahotspott for many taxa. Myers (1988; 1990) included it as one of 18 global hotspotsonn the basis of vascular plants. Restricted parts of northern Borneo have beenidentifiedd as centers of endemism and as particularly species rich for a number oftaxaa (see Table 11.2). Also for insect groups such as cicadas the northern part ofBorneoo appears to be particularly species rich, although this might be an artefact ofbiasedd sampling (J.P. Duffels, pers. comm.). Importantly, few other areas on Borneohavee been identified as centres of endemism, other than those associated withparticularr habitat types (e.g., caves, lime stone regions, and kerangas forest: seeMacKinnonn et al., 1996).Tablee 11.1Centers of endemism or species-richness in northern BorneoArea a Group p Source eAroundd north-eastern highland regionNorth-west tMountains sEndemicc mammalsEndemicc plantsColobines sEndemicc mammalsEndemicc and non-endemic plantsmoths sEndemicc birdsRestrictedd range birdsGroves,, 1994Heyy wood, 1987Taylorr etal., 1999Groves,, 1994Heyy wood, 1987Holloway,, 1978MacKinnonn et al., 1996Sujatnikaetal.,, 1995Inn an attempt to assess the spatial patterns of primate diversity in terms of speciesrichnesss and endemism, we compiled a data set of locality records of all primates onBorneo.. Combined with data on the ecology of the respective species (habitatpreference,, altitudinal distribution), we prepared detailed distribution maps. In the153 3

ForestForest (and) Pritnatespresentt study we evaluate patterns of endemism and species richness of primates onBorneoo in relation to patterns of land-use by humans and settings of (proposed)conservationn areas. Hotspots and their characteristics are identified.METHODS SStudyy areaThee island of Borneo with a size of 746,305 km 2 is the third largest island in theworldd (after Greenland and New Guinea). Administratively it is divided in the fourIndonesiann provinces of West, Central, East, and South Kalimantan (covering somethreee quarters of the island's total area), the two autonomous Malaysian states Sabahandd Sarawak and the Brunei Sultanate. Borneo mainly consists of relatively lowlyinggareas (over half of the island lies below 150 m a.s.1.), with running from southwesttto the north-east a central chain of higher hills and mountains. Borneo's highestmountainn is Mt. Kinabalu in Sabah, which is, with its 4101 m, the highest peakbetweenn the Himalayas and the mountains of New Guinea. Borneo is dissected bymanyy large rivers such as the Kapuas River (1143 km), the Barito River (900 km),andd the Mahakam River (775 km). Mountain ranges and rivers on Borneo act asfaunall barriers (MacKinnon et al., 1996; Rijksen & Meijaard, 1999).Borneoo supports the largest expanse of lowland evergreen rain forest in theSundaicc region, with some 60% of the land surface still under natural forest(MacKinnonn et al., 1996) although this percentage has dropped significantly sincethenn and may be as low as 45% at present (pers. observ.). Timber is a major sourceoff revenue for the Malaysian states and Kalimantan; oil-rich Brunei has less need toexploitt its forest for timber. Besides for timber production, every year vast areas areclearedd for agriculture, plantations, human settlements, and transmigration. Fire isincreasinglyy acting as a major threat to forest on Borneo, especially in theIndonesiann parts of the island. Coinciding with El Nino Southern Oscillation events,duringg dry years, vast areas are set alight and millions of hectares of forest havealreadyy been affected (e.g., Fuller & Fulk 1998; Suhartoyo & Toma, 1999).Especiallyy lowland forests are directly threatened by these practices due to theiraccessibilityy and their higher soil fertility compared to higher altitude forests. Lessthann ten per cent of the forest on Borneo is formally protected as conservation forest,andd most of this area is concentrated in the mountains (MacKinnon et al., 1996;Sujatnikaa et al., 1995).Studyy speciesThee island of Borneo harbours 13 species of non-human primates from five differentfamiliess (Table 11.2). The majority (11 species) is diurnal, and only the slow lorisNycticebusNycticebus coucang and the western tarsier Tarsier bancanus lead a nocturnal life.Fivee species are endemic to the island, four of them are colobines (subfamilyColobinae)) and the fifth is a gibbon. Although the orang-utan on Borneo issometimess considered a separate species (Seuanez et al., 1979; Karesh et al., 1997),154 4

PatternsPatterns of Primate Diversity on Borneodifferingg from the one from Sumatra, for the present analysis it is considered to benott endemic to the island.Tablee 11.2Habitat and altitudinal limits of the primates of BorneoHylobatidae eAgilee gibbonHylobatesHylobates agilisBorneann gibbonHylobatesHylobates muelleriHominidae eOrang-utan nPongoPongo pygmeusrucN NStatus sFamily ySpecies sLoridae eSloww lorisNycticebusNycticebus coucangTarsidae eWesternn tarsierTarsiusTarsius bancanusCercopithecidae eLong-tailedd macaqueMacacaMacaca fascicularisLR3(lc) )LR3(lc) )LR2(nt)) )67 761 1219 9Pig-tailedd macaqueVUAl(c)(d) ) 106 6MacacaMacaca nemestrinaBandedd leaf monkeyPresbytisPresbytis femoralisBorneann leaf monkeyPresbytisPresbytis hoseiRedd leaf monkeyPresbytisPresbytis rubicundaWhite-frontedd leaf monkeyPresbytisPresbytis frontataProbosciss monkeyNasalisNasalis larvatusSilveredd leaf monkeyLR2(nt) )LR3(lc) )LR3(lc) )DD DVuu A2(c)LR2(nt) )26 684 4190 072 2153 3100 0TrachypithecusTrachypithecus cristatusLR2(nt) )LR2(nt) )VuAll (c)(d)CI INumber r Habitatt typesoff records70 0164 4273 3TWE,, PSF, FWSTWE EAll,, excluding TMETWE,, TME, PSFTWE ETWE,, TMEAH,, excluding MF, FWSTWE EPSF,, FWS, MF, RFPSF,, FWS, MF, RFTWE,, PSF, FWSTWE,, PSF, FWSAH,, excluding MFAlt. . Notes slimit t1000 01000 01000 0--1000 0~ ~„ „1000 0 Endemic c500 0 Endemic c500 01000 01000 0 Endemic c500 0Endemic cEndemic cKey:: MF = Mangrove forest; FWS = Freshwater swamp; PSF = Peat swamp forest; TWE - Tropical wetevergreenevergreen forest; TME = Tropical montane evergreen forest; RF = Riverine forest. IUCN statusafterr Eudey 1996/1997.Dataa collection and analysisInformationn on the occurrence of primates was obtained by direct observations byE.M.. from 1994-2000, and V.N. in 1996 and 1999-2001. This survey covered allmajorr river systems of West, Central, and East Kalimantan, and the mountainousareass of Central and East Kalimantan. Several visits were made to the Malaysianstatess of Sabah and Sarawak and to Brunei. Total survey effort was more than 400days.. Additionally, we conducted semi-structured interviews with local people155 5

ForestForest (and) Primates(oftenn hunters) in Bahasa Indonesia, which is also understood in the Malaysianstatess and Brunei. Information from local people was included only when at leasttwoo independent sources indicated the presence of a particular species in an area.Environmentall Impact Assessment reports of Kalimantan's logging concessions alsoprovidedd information on the present distribution of primates. A total of 115 reportsweree consulted. The collections of the zoological museums of Amsterdam, Leiden,Bogor,, London and Singapore were consulted. Additional information was obtainedfromm the literature (excluding generalised distribution maps in the primate referencebooks)) and through biologists and conservationists working in the area.Alll records were entered into a computerised Geographic Information System(GIS),, using PC Arclnfo and PC ArcView software. Other data layers containinformationn on the mid-1993s forest cover and vegetation types (WorldConservationn Monitoring Centre (WCMC) data base), topography, cities andvillages,, and established and proposed conservation areas.Thee resulting GIS provides information on the habitat types and altitudinallimitss of primates associated with the records available on their presence. Habitatwass classified as Mangrove forest (MF), Freshwater swamp (FWS), Peat swampforestt (PSF), Tropical wet evergreen forest (TWE) and Tropical montane evergreenforestt (TME). Riverine forest (RF) is normally included in the tropical wetevergreenn forest, but for species that show a strong association with riverine forest,wee created a separate category. Riverine forest is defined as the forest within 2 kmoff a large river and situated below 500 m a.s.1.Usingg the PC ArcView Spatial Analyst software (demo version), we convertedthee forest distribution from a vector to a raster map, which allowed for an accurateoverlayy of the forest type distributions and the primate presence locations. Based onforestt types, associated with the primate species (see Table 11.1) and their presencelocations,, relative accurate distribution range maps could be produced for eachspecies.. Subsequently, these ranges were overlaid to determine the areas where thespecies'' ranges overlap. Thus, we created various combinations, such as the areawithh most endemic species, the areas with 11 overlapping species, etc.RESULTS SDistribution nWee documented 1414 locality records for the thirteen species combined, rangingfromm 26 locality records for the banded leaf monkey to 273 records for the orangutan..The average number of locality records per species is 122.Ass an illustration, figure 11.1 to 11.3 give the distribution of three of theendemicc primates of Borneo. The white-fronted leaf monkey Presbytis frontata (Fig.11.1)) is mostly restricted to the central part of the island, with an isolated populationnearr Gunung Palung National Park (J.M. Lammertink, in litt.). Whether or not thespeciess is indeed absent from the intervening area is at present not clear. The speciesdoess occur in the central part of the island despite the fact that it was widely156 6

PatternsPatterns of Primate Diversity on Borneobelievedd to have a disjunct distribution with populations in Sarawak separated fromthosee in East and South Kalimantan (Eudey, 1987; Oates & Davies, 1994; Rowe,1996).. In fact, the central part of the island (e.g., Lanjak-Entimau, Batang Ai,Betung-Kerihun,, confluence of the Kapuas and the Mahakam), seems to be the onlyareaa where the species is common (Blouch, 1997; J.K. Gurmaya, pers. comm.;chapterr 13).Thee Bornean leaf monkey Presbytis hosei is confined to the northern part ofBorneo,, and supports the assumption that (many) species on Borneo are restricted tothiss part of the island (see Table 11.1). The southern boundary runs somewherenorthh of the Mahakam lakes and south of the Apo Kayan. The Mahakam River itselfrunss significantly south of this southern boundary, and there does not seem to be aclearr geographical barrier to explain the species' distribution.Figuree 11.1 Geographical distribution of white-fronted leaf monkey Presbytis frontata157 7

ForestForest (and) PrimatesFiguree 11.2 Geographical distribution of Bornean leaf monkey Presbytis hoseiThee Kapuas and the Barito rivers form the boundaries for the Bornean gibbonHylobatesHylobates muelleri: it is only found in the area north and east of these two largeriverr systems. The remaining part of Borneo is inhabited by the agile gibbon H.agilis,agilis, a species that also occurs on Sumatra and the Malay peninsula. At the headwaterssof the Barito river an apparent stable hybrid population occurs (Mather,1994). .158 8

PatternsPatterns of Primate Diversity on BorneoFiguree 11.3 Geographical distribution of Bomean gibbon Hylobates muelleriThee gross habitat preferences of primates are listed in Table 11.1. The largestnumberr of species occur in tropical wet evergreen forest below 500 m a.s.1. In factalll species have been recorded in this habitat type (note that riverine forest is part oftropicall wet evergreen forest). The listing also points to the relative importance ofpeatt swamp forest as a habitat for primates on Borneo. The smallest number ofprimatee species occur in mangrove forest, and those that do either have specialisedadaptationss to cope with the rather low nutritious mangrove leaves (proboscismonkeyy Nasalis larvatus and silvered leaf monkey Trachypithecus cristata) orsupplementt their diet by feeding on animal matter (long-tailed macaque Macacafascicularis). fascicularis).159 9

ForestForest (and) PrimatesAltitudinall distribution of primates is, at least in part, related to the productivity andavailabilityy of food sources, and, for arboreal species, the physiognomy of the forest.Primatee densities generally decrease with increasing altitude (see also e.g., Davies &Payne,, 1982). Table 11.1 also includes the altitudinal limit (if any) of each species.Wee hereby have to note that for many species we found a higher than 'normal'altitudinall record for Mt. Kinabalu. Occurrence of primates on these higher altitudesmayy be in part due to the Massenerhebung-effect, in which on high mountains or inthee central parts of mountain ranges, the vegetation zones are broader than on smallisolatedd mountains (van Steenis, 1972). Since Mt. Kinabalu (4101 m a.s.1.) isconsiderablee higher than any other mountain on Borneo and very few mountainsreachh above 3000 m, for analysis we restricted certain species to altitudes lower thanthee highest altitudinal record. Again, those species that are able to make a livingabovee the 1000 m line, generally occur at (considerable) lower densities than in thelowlands.. Few species are able to persist above 2000-2500 m altitude (althoughsomee of them are occasionally recorded at these altitudes); for the analysis the totallandd surface above this altitude was so small that it was ignored.Patternn of species richnessThee largest number of species occurring in a single area is eleven. This area istotallyy enlosed and included in the areas where ten species occur sympatrically.Figuree 11.4 Pattern of primate diversity on Borneo. The map shows those areas where 10 or 11 speciesoccurr sympatrically, in relation to the protected area network.160 0

PatternsPatterns of Primate Diversity on BorneoThee area where the highest number of species, coexist is in the tropical wetevergreenn forest near large rivers in central-eastern East Kalimantan. It covers a landsurfacee of some 30,000 km 2 . The area where at least ten species occur isconsiderablyy larger and encompasses, besides central-eastern East Kalimantan, alsothee south-eastern part of Sabah and northernmost East Kalimantan. Sarawak andBruneii are less species rich, and only in small areas do nine species co-exist. Theprovincee of South Kalimantan is in terms of primate species richness the leastinterestingg part of Borneo.Thee area where the five endemic primates co-exist, essentially comprises thesamee area as the most species rich area (i.e. central-eastern East Kalimantan).Inclusionn of the orang-utan as an endemic species does not change the spatial patterndrastically,, apart from the fact that the northern boundary of the eastern hotspot nowrunss slightly more to the south.Thee most species rich areas are all situated in the lowlands, below 500 m a.s.1.Thee mountain areas of Borneo are considerably less species-rich.Figuree 11.5 Pattern of endemic primate diversity on Borneo. The map shows those areas where the fiveendemicc primates occur in sympatry, in relation to the protected area network.161 1

ForestForest (and) PrimatesConservationn area selectionIff we compare the hotspots of primate species richness and endemism with thepositioningg of national parks (including greater forestry parks) and nature reserves(strictt nature reserve, wildlife reserve, virgin jungle reserves), it becomes clear thattheree is little overlap. Most of the largest reserves are situated in areas that are notparticularlyy rich in primate species. In fact, few contain more than eight sympatricspecies.. Five reserves (> c. 500 km 2 ) provide refuge for nine or more species, inthreee more than ten species have been recorded, and only one (Kutai National Park)iss home to the maximum number of eleven sympatric species (Table 11.3). Ananalysiss of the endemic species leads to a similar reserve listing. Few reservesharbourr population of more than four sympatric endemics and in reserves that do,oftenn one or two are very rare (e.g., Danum Valley and Gunung Palung). The onlyreservee that has populations of all five endemics within its boundaries is again KutaiNationall Park. The real tragedy is, however, that of the five most species-richreserves,, three have been almost completely destroyed by a combination of illegalandd legal logging, mining, encroachment, and the forest fires of 1982-1983 and1997-19988 (MacKinnon et al., 1994, Rijksen & Meijaard, 1999, Suhartoyo & Toma,1999,, Jepson et al., 2001). Additionally, law enforcement with respect to logging,extractionn of non-timber products, hunting, capturing of wildlife etc. is virtuallyabsent;; primates are not exempt.Tablee 11.3List of large reserves that rank(ed) among the highest in primate species richness?Reserve e Sizee Number of Number of(km 3 )) species endemics(133 is 100%) (5 is 100%)Kutai iMuaraa KamanGunungg PalungBukitt SuhartoDanumm Valley2000 0625 5900 0710 0438 8(2476)TT T11 110 010 09 99 95 54 43 34 44 4Notes sForestt largely, if not completely, destroyedForestt largely, if not completely, destroyedP.P. frontata rare and restricted to the eastern partForestt largely, if not completely, destroyedN.N. larvatus rareTT Within the reserves many species show a restricted distribution, and may even be more commonoutsidee the reserve proper.TTT The larger figure represents the Ulu Segama commercial forest reserve of which Danum Valleyformss a part.InIn theory, all species can be included in the protected area network if in addition to(partt of) the central-eastern part of East Kalimantan, parts of West and / or CentralKalimantann south of the Kapuas River (to include the agile gibbon Hylobates agilis)andd the low-lying regions of Sarawak (to include the banded leaf monkey Presbytisfemoralis)femoralis) are added.162 2

PatternsPatterns of Primate Diversity on BorneoFeww reserves have been proposed in the region most rich in primates, those ofsignificancee include the proposed south-eastern extension Kayan MentarangNationall Park (Ulu Kayan Mutlak 3500 km 2 ) and Sangkulirang Peninsula(Mangkilat-Kelompokk Kapur Sangkulirang 2000 km 2 ). However, unfortunately, inbothh of these areas densities of primates are generally low, in part due to the effortsoff the Kenyah Day aks and especially the (formerly) nomadic Penan and Punan.Withh their formidable hunting skills these tribes are able to assure that all but thesmallestt primates remain rare.DISCUSSION NThee number of locality record holds little information on the actual abundance of themajorityy of species. Proboscis monkeys are less common than the number of records(n=153)) indicate (see Meijaard & Nijman, 2000), but their striking appearance andtheirr occurrence near waterways makes them particularly easy to see and identify. Incontrast,, the two nocturnal species are possibly more common then the data suggestbutt they are rarely recorded because of their activity pattern and silent behaviour.Thee large number of records for the orang-utan (n=273) largely derives fromthee fact that one of us (E.M.) has been conducting surveys to document thedistributionn of this very species (see Rijksen & Meijaard, 1999); survey efforts wereconcentratedconcentrated in those areas where the species was expected to occur. In fact, theorang-utann is among the rarest primate in Borneo.Thee banded leaf monkey (n=26) is probably genuinely rare on Borneo for atleastt two reasons. First, it has the most restricted distribution of any primate, andsecond,, it is confined to tropical wet-evergreen forest below 1000 m a.s.1 in an areathatt is largely deforested. Likewise, long-tailed macaques (n=219) are genuinelycommonn as they occur all over the island, in a large range of habitat types and arequitee tolerable to habitat disturbance. Red leaf monkey (n=190), on the contrary,havee a much more restricted range of habitats in which they occur, but they arefoundd almost over the entire island. Both species are also easily identified and quitevocall which also facilitates identification.Thee present study reconfirms the importance of the tropical wet evergreenforestt below 500 m a.s.1., and especially near rivers as one of the most importanthabitatss for wildlife. For primates, including many of the endemics, this habitat typeiss of prime importance. Peat swamp forest comes out as an habitat of importance aswell,, although less so for most of the endemics. Of the two most threatened species(thee orang-utan and the proboscis monkey) considerable populations do occur in thepeatt swamp forests (Meijaard & Nijman, 2000; Meijaard, 1997). Only smallamountss of this forest type have so far been included in the protected area network,despitee the fact that some considerably large area still remain.Restrictedd parts of northern Borneo have been identified as centers ofendemismm and as particularly species rich for a number of taxa including vascularplants,, insects, birds, and mammals. Whether these patterns are a true reflection of163 3

ForestForest (and) Primatesthee distribution of these taxa or that it reflects a strong research bias remains to beseen.. However, quite illustrative are recent findings for birds. Until recently, a greatnumberr of species was considered to be confined to Mt Kinabalu or the northernmountainss (Smythies, 1981; MacKinnon & Phillipps, 1993). Field work in mountainregionss in Kalimantan and in the interior, however, revealed that the 'northernmountainn endemics' are neither confined to the north nor to the heighest mountains(Wilkinsonn et al., 1991; Van Balen 1997, 1999a, 2000) and in fact some specieshavee been recorded as far as the Schwaner range (Rice, 1989), Mt Niut (Prieme &Heeregaard,, 1988), and the Meratus mountains (Davidson, 1997). Expertornithologistss can identify most species by sighting or call and there is generally noneedd to collect specimens. Hence fairly complete species lists can be made withrelativelyy little effort. Many other taxa (including small mammals, insects, andplants)) can only be identified when collected and preserved, and so far, intensivecollectionss have been made more in northern Borneo than in any other part ofBorneo.. Although progress is made in uncovering the distribution patterns of eventhee most elusive of animals, e.g., the bay cat Catopuma badia (Meijaard, 1997),biologically,, large areas of the island remain virtually a terra incognita.Forr primates, we found a centre of species richness and endemism in the centraleasternn part of East Kalimantan. To our knowledge this has not previously beenrecognisedd as such. This finding derives in part from more detailed distributionmapss of especially three colobines viz. proboscis monkey, silvered leaf monkey, andwhite-frontedd leaf monkey, and the orang-utan.Thee notion that eastern-central East Kalimantan is a centre for primateendemismm is only in part related to the taxonomie position taken. Including theorang-utann as an endemic species only emphasises the importance of the area, albeitsmallerr in size. A change of the taxonomy of the banded leaf monkeys Presbytisfemoralis,femoralis, however, would put more emphasis on northern Sarawak as a centre forprimatee endemism. Populations of this species on Borneo are generally consideredtoo be congeneric with taxa occurring on the Natuna Islands, southern MalayPeninsulaa and eastern Sumatra (Brandon-Jones, 1984). However, the populations onBorneoo do differ in their pelage characteristics from populations from other islands(mostt pronounced in P. f. cruciger from northern Sarawak), and in fact the bandedleaff monkey may comprise several species (V. Nijman, unp. data; cf. Eudey, 1987).Thee fact that central-eastern East Kalimantan is a hotspot for primate diversityillustratess the invalidity of high diversity overlap for different taxa, and points to theimportancee of identifying complementary sites (cf. Pressy et al., 1993, Williams etal.,, 1997; Howard et al., 1998). It is expected that for a number of other taxa,especiallyy with a high level of frugivory, this area will turn out to be of equalimportance. .Fromm a conservation perspective our findings are gloomy as well as sobering.Thee regions identified as of prime importance are among the least protected inBorneo.. Large parts of the east-central hotspot have suffered from the large forestfiress both in 1982-1983 and 1997-1998 (Goldammer et al., 1999). Forest that has164 4

PatternsPatterns of Primate Diversity on Borneoburnedd twice is of little importance to primate conservation (pers. observ.). Intheory,, forest areas that have burned once can regenerate and, given the fact thatevenn in the worst affected areas some small patches of 'good' forest with someprimatee groups remain, these areas can be of potential importance for primateconservation.. However, unless one takes an unrealistically positive view, in practice,mostt if not all of these forests will burn again in the next El Nino SouthernOccilationn Event; the large amount of dead wood makes them extremely fire-prone.Thee remaining patches of unburned forest are few and far in between. Unless theseareass are actively protected during the next dry years it is feared that these will beseriouslyy affected by forest fires as well. Given the amount of active forestprotectionn that was given during the previous forest fires and their succes rate, it hastoo be feared that most forests will disappear within the next ten to twenty years.Thee remaining unprotected forest is all earmarked for conversion or selectivelogging;; actually, the total area of consession is considerably larger that theremainingg forest (Rijksen & Meijaard, 1999). Selective logging will make the forestmoree fire-prone. Conservation of primates in the region's protected area networkofferss little more hope for optimism. For example, if not for the signs indicatingenteringg Kutai National Park or Bukit Suharto Greater Forestry Park it would behardd to note one enters a conservation area. Like Muara Kaman Nature Reserve,bothh areas are almost completely deforested (pers. observ.). Combined these areasoriginallyy included almost 3500 km 2 of prime primate habitat but at present they areoff hardly any value for primate conservation.ACKNOWLEDGEMENTS SThee surveys were conducted in co-operation with the Directorate General for ForestProtectionn and Nature Conservation (PKA, formerly PHPA), the Ministry ofForestryy and Estates Crops (MOFEC formerly MOF) and under sponsorship of theIndonesiann Institute for Sciences (LIPI). Steph B.J. Menken (IBED, University ofAmsterdam)) is thanked for comments on previous versions of this paper.165 5

ForestForest (and) Primates166 6

Re-AssessmentRe-Assessment oflUCN Conservation Status of the Endemic PrimatesCHAPTERR 12RE-ASSESSMENTT OF IUCN CONSERVATION STATUS OFTHEE ENDEMIC PRIMATES OF JAVA AND BORNEOABSTRACT TAA re-assessment of the IUCN status of the endemic primates of Java and Borneo wasmadee on the basis of a study from 1994-2001 and additional data from the literature.Fivee (or six) of the nine (or ten) endemics have their current status changed. Fuscousleaff monkey Presbytis frederica is currently classed as Data Deficient, but thespeciess is here synonymised with grizzled leaf monkey P. comata. This species iscurrentlyy classed as Endangered and this status remains unchanged in the reassessment..Bornean leaf monkey P. hosei and Bornean gibbon Hylobates muelleriaree currently both classed as Lower Risk but on the basis of a sharp reduction ofavailablee habitat aggravated by hunting, both species are more appropriately classedass Vulnerable. The white-fronted leaf monkey Presbytis frontata is currently classedass data Deficient, but on the basis of low population densities over the greater part ofitss range, and the sharp reduction of its lowland forest habitat it is classed asVulnerable.. The proboscis monkey Nasalis larvatus is currently classed asVulnerable,, but given a sharp reduction in available habitat and inadequateprotectionn inside reserves, it is more appropriately classed as Endangered. Finally,thee Javan gibbon Hylobates moloch is currently classed as Critically Endangered,butt given a less dramatic decrease of remaining forest on Java as suggested, and thefindingg of significant populations in Central Java, the species is more appropriatelyclassedd as Endangered.RINGKASAN NPeninjauann kembali mengenai status konservasi menurut IUCN dari primataendemikk di Jawa dan Kalimantan: Peninjauan kembali kami buat mengenai statusIUCNN dari primata endemik di Jawa dan Kalimantan berdasarkan hasil sebuahpenelitianlapangann dan survai pada tahun 1994-2001 ditambah data pustaka. Lima(atauu enam) dari sembilan (atau sepuluh) jenis kera telah berubah statuskonservasinyaa saat ini. Rekrakan Presbytis fredericae saat ini diklasifikasi sebagaiKurangg Data, tetapi jenis ini dianggap kami sejenis dengan Surili P. comata. Jenisinii dianggap Genting saat ini, dan status ini tidak berubah pada tinjauan kembalikami.. Baik Bangat P. hosei maupun Kelawat Hylobates muelleri saat inidiklasifikasii Berisiko Rendah, tetapi kedua jenis ini lebih tetap diklasifikasi sebagaiRentan,, berdasarkan penyusutan drastis dari habitat yang ada, yang diperburuk olehpemburuan.. Lutung dahi putih Presbytis frontata saat ini diklasifikasi sebagai167 7

ForestForest (and) PrimatesKurangg Data. Tetapi statusnya kami anggap sebagai Rentan, berdasarkan kepadatanrendahh di bagian terbesar wilayah penyebarannya. Bekantan Nasalis larvatus adalahsatuu jenis saat ini diklasifikasi Rentan tapi terbatas pada kantung-kantung terakhirdarii hutna tropis dataran di pingir sungai dan hutan bakau, lebih tetap diklasifikasibagaibagai Genting. Terakhirnya, Owa Jawa H. moloch adalah satu jenis diklasifikasiKritiss tetapi kerena masih ada beberapa populasi yang cukup besar di Jawa Baratdann Jawa Tengah, lebih tetap diklasifikasi bagai Genting.INTRODUCTION NInn the following section a re-assessment of the IUCN conservation status of theendemicc primates of Java and Borneo is presented. It is based on data presented inthee previous chapters of this thesis, additional and as yet unpublished results fromthee study, and published data. Firstly, for each species its legislative status is given,i.e.. whether or not it is protected by Indonesian and / or Malaysian law. When thespeciess is included on Appendix I or II of the Convention on International Trade inEndangeredd Species (CITES) this is indicated. Secondly, its present IUCN listing(basedd on Eudey, 1996/1997) is given with the criteria according to which it isincludedd in that particular category. This is followed by the suggested IUCN listingandd its criteria. Finally, the justification of the changes (if any) are presented.RESULTSS AND DISCUSSIONGrizzledd leaf monkey Presbytis comataLegislativeLegislative status: Protected by Indonesian Law as Presbytis aygula (SuratKeputusann Menteri Pertanian No 247/Kpts/Um/4/1979, Undang-undang No. 5 /1990,, Surat Keputusan Mentri Kehutanan No 301/KPT-1171991 and No. 882/KPT-11/1992).. Included on Appendix II of the Convention on International Trade inEndangeredd Species (CITES).PresentPresent IUCN status: Endangered based on criteria:AA 1(c): A reduction of at least 50% over the last three generations (

Re-AssessmentRe-Assessment oflUCN Conservation Status of the Endemic PrimatesJustification:Justification: The distribution range is larger than previously assumed, withsubstantiall populations occurring in central Java (chapters 6 and 8). No largechangess in the extent of habitat have occurred as compared to previous assessment.Thee total population is significantly larger than assumed under C2(a). The mostrecentt estimate of 2285 individuals as obtained during a PHVA (Supriatna et al.,1994)) is unrealistic for at least four reasons:(i))It is based on an incomplete data set (only seven of 33 areas known to beinhabitedd by the species were included in the analysis);(ii)) It is based on wrong assumptions. The species would prefer a narrowaltitudinall zone between 1200 and 1800 m a.s.1., rarely occurring below 1200mm a.s.1. In fact it occurs from sea level to 2500 m a.s.1., most likely attaining itshighestt densities in the lowlands (Nijman, 1997; chapter 6);(iii)) During the data compiling process there must have been confusion between thetwoo Javan leaf monkeys. Grizzled leaf monkey would have a preference forecotones,, edges and riverborders, and would not occur inside the core of aforestedd area. This description in all likelihood refers to ebony leaf monkeyTrachypithecusTrachypithecus auratus and certainly not grizzled leaf monkey. During tPHVAA meeting the two endemic leaf monkey were often mixed up. In fact theparticipantss were invited to attend a meeting on the Javan gibbon and silverleaff monkey Trachypithecus auratus [=ebony leaf monkey] (Anonymous,1994)) and not a meeting on Javan gibbons and grizzled leaf monkey Presbytiscomata.comata. The handbook with background information (Anonymous 1994) evenexplainss that the silver leaf monkey consists of three subspecies, againsuggestingg the workshop deals with Trachypithecus auratus of which there arethreee subspecies as opposed to Presbytis comata of which two subspecies havebeenn described. In this same handbook a summary is given of the diet andfeedingg behaviour of ebony leaf monkeys, again suggesting that the meetingdealss with ebony leaf monkey. Finally, in the proceedings of the workshop(Supriatnaa et al., 1994) photographs of ebony leaf monkeys are included butnott of grizzled leaf monkey.(iv)) Under-estimation of population densities. Supriatna et al. (1994) used apopulationn density of four individuals km" corresponding with one group per1.755 km 2 . Indeed in a number of areas the species is known to be rare (e.g.,Ujungg Kulon) or to show a patchy distribution within reserves (e.g., Tukung-Gede).. However, data from Table 12.1 and comparisons with data from otherPresbytisPresbytis species (Oates et al., 1994) suggests densities between 10 to 20individualss km' 2 to be more typical.Dataa presented in table 12.1 also suggest large differences between the two methodsemployedd for censussing this primate. Density estimates obtained with the linetransectt method are typically a fifth of those obtained with the range mappingmethod.. Reported group sizes for grizzled leaf monkeys from line transects (average4.00 individuals: Sugarjito et al., 1997; 4.8 individuals: Sugarjito & Sinaga, 1999; 2.0individuals:: Gurmaya et al., 1995; but 7.0: Nijman & van Balen, 1997) are also169 9

ForestForest (and) Primatesgenerallyy smaller than reported from range mapping studies (average: 4.8individuals:: Harjanti, 1996; 5.8 and 6.0 individuals: Ruhiyat, 1991: 7.0 individuals:Sujatnika,, 1992). In all likelihood the elusive nature of the species makes it difficulttoo detect, leading to an under-estimate of true densities during line transect surveys.Thee range mapping method invariably has been employed in ecological studies andhencee the study areas were selected as to contain a fair number of grizzled leafmonkeyy groups, precluding extrapolation to densities over large areas.Tablee 12.1Estimates of densities of grizzled leaf monkey Presbytis comata in JavaLocality yUjungg KulonMt.. Tukung GedeMts.. HalimunMts.. HalimunMts.. HalimunMts.. HalimunMts.. HalimunMts.. HalimunMt.. GedeMt.. PatuhaKamojang gPatenggang gMts.. DiengAltitude e(masl) )0*400 040-400 0600-1200 01200-1750 0600-1200 01200-1400 01400-1750 0900-1200 01300-1500 02000-2200 01400-1600 01600-1800 0650-850 0Density y(ind.. km" 2 )1.3t t4.3TT T8.2TTT T2.1 12.6 604 41.4 44-5 525 510-15 510-12 235-36# #28 8Method dLine-transect tline-transect tline-transect tline-transect tlinee transectlinee transectlinee transect~ ~mapping gmapping gmapping gmapping gline-transect tSource eGurmayaa et al., 1995Melishh & Dirgayusa, 1996Sugarjitoo etal., 1997Sugarjitoo et al., 1997Sugarjitoo & Si naga, 1999Sugarjitoo & Sinaga, 1999Sugarjitoo & Sinaga, 1999Maitarr in Supriatna et al., 1994Sujatnika,, 1992; pers. comm.Harjanti,, 1996Ruhiyat,, 1983; 1991Ruhiyat,, 1983; 1991Nijmann & van Balen, 1998Estimatee might be rather low as parts of the reserve that are known not to be inhabited by grizzledleaff monkeys were included in the survey (K.J. Gurmaya, pers. comm); Melish & Dirgayusa(1996)) report that, according to park wardens, the population has decreased over the last twodecades. .TT T Line-transectt was situated along the forest fringe and densities in forest interior may differ (Melish&& Dirgayusa, 1996).TTT T Thee two studies by Sugarjito et al. (1997) and Sugarjito & Sinaga (1999) seem to be based on thesamee data set, yet density estimates from the second study are about a third of the first. The reasonforr this discrepancy is unknown.Ruhiyatt (1991) reports that the relatively high density in Patenggang was at least partially causedbyy previous logging operations and/or the recent opening of parts of the forest for tea cultivation,bothh limiting the amount of forest available.Borneann leaf monkey Presbytis hoseiLegislativeLegislative status: Not protected by Indonesian Law (although there is room forspeculationn as P. comata is listed as P. aygula; P. hosei was formerly considered tobee included in this taxon), not protected by Malaysian Law (Sarawak and Sabah);legislativee status in Brunei not known. Included on Appendix II of the Conventiononn International Trade in Endangered Species (CITES).PresentPresent IUCN status: Lower Risk 3 (least concern).170 0

Re-AssessmentRe-Assessment ofWCN Conservation Status of the Endemic PrimatesSuggestedSuggested IUCN status: Vulnerable based on criterion:AA 1(c): A reduction of at least 20% over the last three generations (

ForestForest (and) PrimatesJustification'.Justification'. Presbytis fredericae is synonymised with Presbytis comata (chapterandd as such no IUCN status is justified. Populations of P. comata in the eastern partoff its range are all found in unprotected forest areas.White-frontedd leaf monkey Presbytis frontataLegislativeLegislative status: Protected by Indonesian Law (Surat Keputusan Menteri PertanianNoo 247/Kpts/Um/4/1979, Undang-undang No. 5 / 1990, Surat Keputusan MentriKehutanann No 301/Kpts-II/1991 and No. 882/Kpts-II/1992). Not protected byMalaysiann Law (Wild Life Protection Ordinance 1958). Included on Appendix II ofthee Convention on International Trade in Endangered Species (CITES).PresentPresent IUCN status: Data DeficientSuggestedSuggested IUCN status: Vulnerable based on criterion:AA 1(c): A reduction of at least 20% over the last three generations (

Re-AssessmentRe-Assessment oflUCN Conservation Status of the Endemic PrimatesThee density estimate obtained by Istiadi et al. (1994) is considerably higher thanfromm any other region. This might be due to methodological differences, but theirresultss clearly indicate that the species is common in the Kapuas-Mahakam region(cf.. information from local inhabitants of the S. Rata region, V. Nijman, unp. data).Centrall populations are adequately included in the protected area network assignificantt population are present in the Lanjak Entimau, Batang Ai, and BetungKerihunn reserves (Blouch, 1997; J.K. Gurmaya, pers. comm.), but eastern andwesternn populations are largely located outside reserves. In West Kalimantan whitefronteddleaf monkey is probably patchy distributed with (isolated?) populations nearGunungg Palung National Park. In East Kalimantan it is probably present throughoutthee province, but only locally and in small numbers. Given the species' occurrence at(very)) low population densities over a fairly large area, it might be nomadic(Medwayy 1970), at least in parts of its range. The species is hunted for bezoarstones,, whereas hunting for food is widespread throughout the interior of Borneo.Redd leaf monkey Presbytis rubicundaLegislativeLegislative status: Protected by Indonesian Law (Surat Keputusan Menteri PertanianNoo 90/Kpts/Um/2/1977, Undang-undang No. 5 / 1990, Surat Keputusan MentriKehutanann No 301/Kpts-II/1991, and No. 882/Kpts-II/1992). Not protected byMalaysiann Law, legislative status in Brunei not known. Included on Appendix II ofthee Convention on International Trade in Endangered Species (CITES).PresentPresent IUCN status: Lower risk 3 (least concern)SuggestedSuggested IUCN status: Lower risk 3 (least concern)Justification:Justification: The species is endemic to Borneo and Karimata Island, off the westcoastt of Borneo. On Karimata the species is common (Yanuar et al., 1993). It is themostt widespread of the Bornean colobines, occurring throughout most of thelowlands,, hills, and mountains (Yanuar et al., 1995). The species occurs insecondaryy forest albeit in lower numbers. It occurs mainly below 1500 m a.s.1.(MacKinnon,, 1987), although records from Mt Kinabalu suggest occurrence below20000 m a.s.1. Red leaf monkeys are present in most of the larger reserves and thepresentt protected area network seems to be adequate for the species. As otherPresbytisPresbytis species it is frequently hunted in the interior, both for its bezoar stones andforr food.Ebonyy leaf monkey Trachypithecus auratusLegislativeLegislative status: Protected by Indonesian Law (Surat Keputusan MenteriKehutanann dan Perkebunan No 733/Kpts-II/1999). Included on Appendix II of theConventionn on International Trade in Endangered Species (CITES).

ForestForest (and) PrimatesPresentPresent WCN status: Vulnerable based on criteria:Al(c):: A reduction of at least 20% over the last three generations (

Re-AssessmentRe-Assessment oflUCN Conservation Status of the Endemic Primatesnott known. Included on Appendix II of the Convention on International Trade inEndangeredd Species (CITES).PresentPresent 1UCN status: Vulnerable based on criteria:A2(c):: A reduction of at least 20% projected or suspected to be met within thenextt three generations (

ForestForest (and) PrimatesJavann gibbon Hylobates molochLegislativeLegislative status: Protected by Indonesian Law (Peraturan Perlindungan BinatanLiarr 1931 No. 266, Undang-undang No. 5 / 1990, Surat Keputusan MentriKehutanann No 301/Kpts-II/1991 and No. 882/Kpts-II/1992). Included on Appendix Ioff the Convention on International Trade in Endangered Species (CITES).PresentPresent IUCN status: Critically endangered based on criteria:AA 1(c): A reduction of at least 80% over the last three generations (45 years:Supriatnaa et al., 1994) based on a decline in area of occupancy, extent ofoccurrencee and / or quality of habitat.C2(a):: Population estimated to number less than 250 mature individuals and acontinuingg decline, observed, projected, or inferred, in numbers of matureindividualss and severely fragmented population structure (i.e. no sub-populationestimatedd to contain more than 50 mature individuals).SuggestedSuggested IUCN status: Endangered based on criterion:Al(c):: A reduction of at least 50% over the last three generations (45 years)basedd on a decline in area of occupancy, extent of occurrence and / or quality ofhabitat. .Justification:Justification: The distribution range is larger than previously assumed (Nijm1995,, Nijman & Sözer 1995; Nijman & van Balen 1997). The inferred decline of2400-79000 gibbons in 1978 to 400 gibbons in 1994 (Supriatna et al., 1994) is largelybasedd on differences in methodology used, i.e. extrapolation based on geographicareaa inhabited and density at different altitudinal zones (Kappeler 1981, 1984) vs.numberr of individuals actually observed in a few areas (Supriatna et al., 1994). Iassumee that this inferred decline was the main reason for listing the species ascriticallyy endangered. The lower estimate has been questioned (Asquith 1995, 2001),andd data from the present study makes it increasingly unlikely to be held true. As anexample,, the central Javan populations would consist of 17 individuals (confined toGnn Slamet) according to Supriatna et al. (1994), whereas probably over 800individualss are present.Tablee 12.3 lists the number of gibbons present on Java, broken down to 15 forestareass that are inhabited by more than 50-100 gibbons. From this listing it becomesapparentt that the total number of gibbons in Java is more likely to be in the order of40000 individuals, i.e. an order of magnitude larger than previously estimated(Supriatnaa et al., 1994). Estimates of the number of gibbons in one area (Halimunnationall park) have remained fairly constant over the last 20 years, despite variousreportss on the loss of habitat at both the lower regions of this park as from theenclavee in the center of the park (Whitten et al., 1996). Thus, Kappeler (1981)estimatedd the population of the park to be between 600-1800 individuals in 1978,Kooll (1992) at 852-1320 individuals in 1989, Asquith et al. (1995) at 870 in 1994,andd finally, Sugarjito & Sinaga (1999) at 864-936 individuals in 1997.176 6

Re-AssessmentRe-Assessment oflUCN Conservation Status of the Endemic Primates-TableTable 12.3 Estimated number of Javan gibbons Hylobates moloch present in JavaArea aUjungg Kulon (Gn Honje & TanjungTereleng) )Gnn HalimunGnn SalakTelagaa Warna - MegamendungGedee PangrangoSangabuana aBurangrangg - Tangkuban PerahuGnn SimpangGnn TiluGnn PapandayanGnn WayangPeg.. PembarisanGnn SlametGnn Lawet - Cupu-Simembut- JaranPeg.. DiengTotall populationStatus' 'NP PNP PUnp. .NRR / unp.NP PUnp. .NRR / unp.NR RNR RNR RUnp. .Unp. .Unp. .Unp. .Unp. .Alt.. range0-480 0-480400-1929 9800-2210 0500-1600 0500-3019 9250-1280 0900-2081 1400-1816 6900-2434 4700-2622 2500-1830 0300-1351 1700-3428 8700-1100 0300-2565 5Forestt area 285 5270 070 030 050 050 040 0140 030 0120 085 5120 040 020-30 0120-135 51270-1295 5Total lnumber r560 0850-1320 0140 0>50? ?100 0100 0>50? ?600 0100 0250 0300 0>50? ?100? ?>50? ?519-577 74019-4397 7Numberr ofadults 3 3339 9515-800 085 5>30? ?61 161 1>30? ?364 461 1152 2182 2>30? ?61? ?>30? ?315-350 02436-2665 5Source ea,, ba,, c, da ab bb,, ea,, bb ba aa aa aa ab,, fb,, fb bb,g gStatus:: NP= national park (taman nasional); NR= strict nature reserve (cagar alam); unp. = notprotectedd as conservation forest: smaller sections might be protected as strict nature reserve.Habitatt is the approximately available habitat inhabited by gibbons. Forest above 1500 m a.s.1. isnott included.Numberr of adults is based on an average group size of 3.3 individuals, of which two are adult;floaterss are not included in any of the above estimates.aa = Asquith et al. 1995; b = = Nijman unp. data; c = Kool 1992; d = Sugarjito et al. 1997; e = Harris1996;; f = Nijman 1995; g = = Nijman & Van Balen 1997.Thee new total population estimate is unlikely to be an over-estimate, as overall aconservativee population density of less than one gibbon group km" 2 has been used(i.e.. 4000 gibbons in 1300 km 2 forest). Furthermore, the species is known from atleastt 11 other (mostly small and sometimes fragmented) forest areas (viz. GnJayanti-Tangkubann Perahu, Lengkong, Gn Porang, Cisolok, Bojongpicung, PasirSusuru,, Gn Malang, Gn Halu, Leuweung Sancang, Gn Masegit-Kareumbi, GnManglayang,, and possibly Gn Sawal and Gn Ciremai), from which few data onforestt size or number of gibbons present are currently available.Asquithh et al. (1995) reported the apparent extinction of nine local gibbonpopulations,, mostly due to loss of habitat. Two of these forest areas (Telaga Warnaandd Tangkuban Perahu-Burangrang) in fact are still inhabited by gibbons (pers.observ.).. Given the overall loss of forest in west and central Java, many more gibbonpopulationss have undoubtedly suffered from habitat loss over the last few decades.Largee scale deforestation on Java dates back to the first half of the 19th century,whenn the Dutch colonial government imposed the so-called 'cultuurstelsel' whichforcedd farmers to grow cash crops on communal grounds (often forest). During thefollowingg 100 years, large areas of forest were lost and many became fragmented.Overr the last 50 years or so, however, large scale deforestation has slowed down(seee e.g., Whitten et al., 1996). Hence, there does not seem to be a justification for177 7

ForestForest (and) Primatesinferringg a loss of 80% of the Javan gibbon population (or their habitat) over the last500 years as assumed under criterion A 1(c).Likewise,, there seem to be at least eleven forest areas with an estimatedpopulationn of a 100 gibbons (corresponding to at least 60 mature individuals) ormore,, and four areas with over 500 gibbons each. Listing the Javan gibbon ascriticallyy endangered under criterion C2(a) hence becomes questionable.Borneann gibbon Hylobates muelleriLegislativeLegislative status: Protected by Indonesian Law (Peraturan Perlindungan BinatanLiarr 1931 No. 266 and Undang-undang No. 5 / 1990 and Surat Keputusan MentriKehutanann No 301/Kpts-II/1991 and No. 882/Kpts-II/1992). Protected by MalaysianLaww (Wild Life Protection Ordinance 1958), but specified therein by invalidscientificc name, which may subvert prosecution. Legislative status in Brunei notknown.. Included on Appendix I of the Convention on International Trade inEndangeredd Species (CITES).PresentPresent IUCN status: Lower Risk 2(near threatened)SuggestedSuggested IUCN status: Vulnerable based on criterion:AA 1(c): A reduction of at least 20% over the last three generations (

Re-AssessmentRe-Assessment oflUCN Conservation Status of the Endemic PrimatesLEGISLATIVEE STATUS OF PRIMATES IN INDONESIAAss became clear from the above listing there is little consistency in the protectivestatuss of primates in Indonesia. Some of the species with a very restricted rangewithinn Indonesia, and often World-wide are not protected by law, whereas other,moree wide-ranging and common species, are protected. This even becomes moreapparentt when all primates, and not just the ones endemic to Java and Borneo areincluded. .Manyy primate species are identifiable by specialists only, often on characterslikee vocalisation or minor differences in pelage characteristics. When prioritisingwhichh species deserves legal protection, this should explicitly taken intoconsideration.. This might be illustrated by the different Presbytis taxa that occur inIndonesia,, and their protective status. The leaf monkeys of Sumatra, Java andBorneoo occur in a great variety of colours from almost completely white to black,andd in all sorts of different pelage patterns. If we take a closer look at the greybackeddleaf monkeys only, we end up with populations of at least five species, i.e.Sumatrann leaf monkey P. thomasi, southern populations of P. melalophos onSumatra,, some populations of P. femoralis also on Sumatra, the western populationsoff P. comata on Java, and Bornean leaf monkey P. hosei. At present only P. thomasiandd P. comata are protected by Indonesian law, yet it will be very difficult todistinguishh the different taxa once encountered at a bird market or when in illegalcaptivity.. The same is true for the Trachypithecus leaf monkeys where T. auratus isprotectedd but T. cristata is not, yet to the non-specialist both species may appearveryy similar.Anotherr caveat in protecting primates in Java is the use of outdatednomenclaturee in the legislative literature. Primate taxonomy in Indonesia is adisciplinee in motion, and with the use of molecular systematics and other techniques,andd better understanding of evolutionary relationships between taxa, new taxa arebeingg described regularly, and the geographic boundaries recognised betweenallopatricc species shift regularly.Thesee difficulties in identifying and distinguishing protected from nonprotecteddspecies, and changes in nomenclature, may, and indeed do, create a loopholeefor malevolent keepers and may promote illegal trade. The easiest solution tothiss problem is to protect either all primates, or protect primates by genus. Thegibbonss are already included as such, thus all hylobats are protected by Indonesianlaww (see above). This system can easily be adopted for the other primates are well.Thuss the different leaf monkeys, the proboscis monkey and the pig-tailed langur, canalll be protected as colobines. Indeed proposals as these have been submitted to thecompilerss at the Workshop on Keeping Wild Protected Animals (LokakaryaPenanganann Satwa Liar Peliharaan yang Dilundungi) held in Bogor at 20-21 July2000. .179 9

ForestForest (and) Pritnates180 0

GeneralGeneral DiscussionCHAPTERR 13GENERALL DISCUSSIONInn this last chapter some general points from the three sections of this dissertation,viz.,, background information and research methodology, conservation and ecologyoff the endemic primates of Java, and conservation and ecology of the endemicprimatess of Borneo, will be discussed briefly, as will be the conservation of primatesinn the Sundaic region. Thereafter, a few suggestions for conservation-relatedresearchh will be given.RESEARCHH METHODOLOGYThee first section dealt in part with testing the validity of various census techniques inaa number of areas and under different conditions. Monitoring programmes often relyonn changes in densities of single species to indicate an ecosystem's health. Acomparisonn was made between three commonly used census techniques forestimatingg population densities (and biomass) of single species.Mappingg is generally considered to provide the most accurate approximation oftruee density, not just for rainforest primates but for many other species groups aswelll (NRC, 1981; Skorupa, 1987; Bibby et al, 1992a). Because of the threedimensionallstructure of the closed canopy forests, many arboreal species aredifficultt to locate, and locating all individuals in a certain area may prove to bedifficult,, if not impossible. Range mapping, on the other hand, is time consumingandd labour intensive, and only applicable in relatively small, accessible areas. Thegreatestt source of error in the range mapping technique probably derives from theso-calledd edge effect, viz., the error in determining whether groups (or individuals)onn the edges of the census area are inside or outside that area (Sen, 1982; Krebs,1989).. This error increases as the ratio of edge to area increases, and is thus affectedbyy the census area (error increases with a decreasing census area), configuration ofthee census area (the error is smallest in circular census areas and greatest in anirregularlyy shaped one), and the number of groups present in the census area (theerrorr decreases with increasing group density). Often, only the ranges of one or twogroupss are accurately mapped and this is taken as the closest approximation of 'truedensities'' against which other methods are tested (e.g., Brugiere & Fleury, 2000).Sincee there is no a priori reason to assume range mapping to be more accurate thaneitherr line transects, fixed point counts or any other census technique, and given thepotentiall sources of error (including or excluding groups, drawing the boundaries ofthee mapping area, estimation of group sizes, etc.), the perceived superiority of rangemappingg as a technique for estimating 'true densities' seems unfounded (contra, e.g.,Reynoldss et al., 1980; Brugiere & Fleury, 2000).181 1

ForestForest (and) PrimatesThee most commonly used technique of estimating population densities of rain forestanimalss is the (repeated) line transect (NRC, 1981; Whitesides et al., 1988;Bucklandd et al., 1993; Bibby et al., 1992a). The merits and pitfalls of the techniqueandd various analytical methods of data analysis are discussed in length by Burnhamett al. (1980) and in part in chapter 2. It suffices here to say that although there are agreatt number of sources of error it is often the only technique applicable, given theamountt of time and resources available. Caution is needed, however, in theinterpretationn of the data, especially when comparing data sets collected by differentresearchers,, with different sampling regimes and efforts, in different areas, or atdifferentt times (see also chapter 2). One particular source of bias that becameapparentt during the present study (chapter 2) was the use of ridges and spurs forpositioningg transects. As recommended by amongst others Burnham et al. (1980),transectss should be placed randomly or through a stratified random technique andshouldd follow a straight line, and not follow geographic features or roads. Manyprimatess show a preference for ridges or rivers, at least for parts of the day (Nijman,unp.. data; chapter 2), and by censussing along ridges, spurs, and crests only,populationn densities will be over-estimated or under-estimated, depending on thespeciess involved.Fixedd point counts are frequently used in ornithological studies often in theformm of 'variable circular plot counts' (e.g., Reynolds et al., 1980; Bibby et al.,1992).. Although certain primates do vocalise frequently and predictably, thetechniquee has only rarely been used in primatological studies. The clear advantageoff estimating densities over relatively large areas in a short time span justifies thatmoree effort should be put in testing the accuracy of this technique in comparison tomoree commonly used techniques. The largest source of bias is the variation in thecallingg rates (cf. Brockelman and Ali, 1987). Even within species, this varies greatlybetweenn groups, between days (in part this is related to weather conditions), betweenseasons,, and between populations. The influence of human disturbance on callingbehaviourr of primates has been noted (Johns, 1985c; Berenstain et al., 1986; chapter3),, yet it is rarely appreciated. In chapter 4 we tried to improve the fixed point counttechniquee by identifying individual groups of Javan gibbons in a relatively smallarea.. Identification of individual groups on the basis of their vocal output is reliableandd consistent in this species (Dahlmann & Geissmann, 2001; chapter 4), and it isanticipatedd that fixed point counts as a technique for density estimation and detailedlongitudinall studies can be applied more broadly than at present.InIn general, behavioural studies have been considered to be of limited value forconservationn because of the discordance in the level of focus between behavioural(individualss and populations) and conservation biologists (populations andecosystems)) (Clemmons & Buchholz, 1997). Yet, in monitoring programmes oftensinglee species or species groups are used as indicators for the health of an ecosystem(Vann der Hoeven et al., 2000, and references therein). As indicated above in the caseoff the Javan gibbon (chapter 4) census techniques can be improved by incorporatingbehaviourall information. Primates often alter their behaviour under the influence ofhumann disturbance, and this alteration can have an influence on the outcome of182 2

GeneralGeneral Discussiondensityy estimations (chapter 3). Primates and most likely many other animals as well(e.g.,, terrestrial birds and mammals), do respond differently to the presence ofhumans,, including surveyors, in disturbed habitats as compared to undisturbed ones(cf.. Johns, 1985a; 1986). This has to be taken into account when comparing theresultss of surveys in habitats differing in their degree of disturbance and inmonitoringg programmes where disturbance levels change over time. Habitatdisturbancee often has an effect on density (lowered carrying capacity of the forest,loweredd fecundity, higher mortality, changed rates of immigration or emigration)andd this introduces additional behavioural changes in the groups under study.Althoughh the magnitude in which animals change their behaviour may notnecessarilyy reflect the susceptibility to habitat disturbance (Gill et al., 2001),species-specificc data or detailed case studies on how to determine a proper measureoff susceptibility to habitat disturbance, are lacking.Thee results of chapters 2 and 3 seriously question the validity of directlycomparingg estimates obtained by different census techniques from different areas,especiallyy if these areas differ in their level of disturbance. For example, in thepresentt study differences in density estimates in the order of 10-30% were attributedtoo the interaction between census methodology and study area. When sitesadditionallyy differ in their level of disturbance, it is likely that density estimates maydifferr in the order of 50%, yet true densities are the same. There seems to be anincreasedd need for understanding how the underlying assumptions of various censusandd monitoring techniques are affected by the behavioural plasticity of the speciesunderr study, the effects of inter-observer variability (Mitani et al., 2000), and theareaa in which the study is conducted.CONSERVATIONN AND ECOLOGY OF PRIMATES ON JAVAAnn accurate description of its range of occurrence is essential for the properassessmentassessment of a species' conservation status as well as for monitoring changes inabundance,, range, and status, yet detailed information on the distribution of primatesiss rarely published (Brockelman & Ali, 1987).Asquithh (2001; in litt.) reported on a dichotomy present in the small group ofpeoplee that focus on the conservation and management of Javan gibbons Hylobatesmoloch.moloch. A Population and Habitat Viability Analysis (Supriatna et al., 1994)focussedd almost entirely on genetic management as the strategy to reduce the threatsforr this species, whereas field researchers consistently proposed forest managementandd protection as the right approach. Little effort has been put in accuratelyassessingg the distribution of the Javan gibbon. Kappeler (1984) and Asquith et al.(1994)) surveyed Javan gibbons and found the species to be present mainly in thewestt Javan province. Kappeler (1984) did survey the central Javan province butfoundd only two small populations on Gn Slamet and Gn Lawet. Asquith et al. (1994)apparentlyy assumed the species to be confined to West Java and did not survey inCentrall Java. Yet one of the most unexpected findings of the present study was the183 3

ForestForest (and) Primatesrecordingg of substantial populations of not only the Javan gibbon but also thegrizzledd leaf monkey in Central Java (chapter 8).Javann gibbon was recorded in three areas, viz., the southern slopes of GnSegaraa (Pembarisan mountains), the southern slopes of Gn Slamet, and the Diengmountains.. An indication of population sizes for the two first mentioned areas isdifficultt to present as limited time was spent in the area (Pembarisan mountains) orthee surveys covered limited ground (Gn Slamet), yet by taking into account thealtitudinall range of the forest (gibbon densities decrease with increasing altitude)andd its size we can make some educated guesses. Although gibbons may be presentinn the north-eastern part of the Pembarisan mountains only (Kappeler [1984] reportsthee species to be absent from Gn Pojok in the central part), the size, the altitudinalrangee (300-1351 m a.s.1.), and the relatively good condition of the forests suggest asignificantt population. Likewise, estimates of forest areas at different altitudinalzoness on Gn Slamet (40 km 2 between 700-1000 m a.s.I. and 60 km 2 between 1000-15000 m a.s.1.: Nijman & Sözer, 1996) and consistent observations of gibbons onlocationss between 700 and 1200 m a.s.1. (Seitre & Seitre, 1990; Linsley & Nawimar,1994;; Martarinza, pers. comm.; Sugihartono and F. Nargata, pers. comm.; pers.observ.)) suggest that the number of Javan gibbons on this mountain may range in thedozenss if not hundreds. For the Dieng mountains an estimate of some 500-600individualss was reached (chapter 8). With the (smaller and isolated) populations onGnn Lawet (Kappeler, 1984), Gn Cupu-Simembut (M. Linsley, pers. comm.), and GnJarann (pers. observ.), the central Javan population of Javan gibbons may total some700-8000 individuals (chapter 12). This is opposed to 17 individuals for central Javareachedd at during the PHVA, and is about twice the estimate of the total wildpopulationn (Supriatna et al., 1994). It is concluded that properly designed andexecutedd surveys can add substantially to our knowledge of endangered species, andthatt too often intrusive management actions are suggested without the proper baselineedata available.Priorr to the present study, the knowledge we had of the geographical andaltitudinall distribution of the grizzled leaf monkey Presbytis comata was limited. Itwass mostly considered to be confined to West Java but as with the Javan gibbon,considerablee populations were found in the Central Javan province (chapter 6). Thealtitudinall range of the species is not as narrow as Supriatna et al. (1994) indicated.Givenn the limited amount of forest that remains in the lowlands on Java it isfortunatee that grizzled leaf monkey does occur at altitudes between 1000-2500 ma.s.1.,, although in all likelihood densities in montane areas are (considerably) lowerthann in lowland areas. Little is known about the ecology of the grizzled leaf monkey,althoughh it has been studied in some detail in a few montane areas (Ruhiyat, 1983,1991;; Sujatnika, 1992; Harjanti, 1996; M. Wedana, pers. comm.); no detailedstudiess have been conducted in lowland forests, however.Ebonyy leaf monkeys Trachypithecus auratus have been studied at a number oflowlandd sites in Java and Bali (Brotoisworo, 1983; Kartikasari, 1986; Djuwantoko,1991;; Kool & Croft, 1992; Kool, 1993; T. Voght, pers. comm.). Most studiesfocusedd on the feeding and ranging behaviour and most were restricted to relatively184 4

GeneralGeneral Discussiondryy forest types (teak plantations, deciduous forest). The species is abundant inmanyy of the wetter forest types, but possibly because it is considerably moredifficultt to study them in these environments, we have limited knowledge on itsecologyy in these forest types (cf. Bennett & Davies, 1994).CONSERVATIONN AND ECOLOGY OF PRIMATES ON BORNEOPrimatess are often considered as ideal flagships for species conservation in tropicalareass because of their high appeal to humans (Rowe, 1996; Cowlsihaw & Dunbar,2000).. Yet on Borneo even the two most spectacular primate species, viz., the orangutannand the proboscis monkey, are in great danger of extinction. The conservationstatuss of the orang-utan on Borneo is well documented by Rijksen & Meijaard(1999),, and in chapters 9 and 10 an attempt was made to assess the conservationstatuss of the proboscis monkey. The proboscis monkey was selected because of itsstrikingg appearance (and hence it would rank high on the list of species that people -includingg conservation authorities- would like to preserve) and as an example of anendemicc species with a narrow niche. Like other species that are confined to thelow-lyingg forests of Borneo it is severely affected by habitat alteration, logging, andincreasinglyy by forest fires. In those areas from where it would be expected to besecuree from these threats, viz., conservation areas, it is declining, possibly as fast asinn the unprotected forests. The case study of the local extinction of proboscismonkeyss from the Pulau Kaget nature reserve served to illustrate how localpopulationss of legally protected species can disappear within a few years even fromwithinn protected areas.Inn chapter 11 we assessed the spatial patterns of primate diversity in terms ofspeciess richness and endemism for Borneo. As expected, the tropical wet evergreenforestt below 500 m a.s.1. was identified as the most species rich habitat, with allspeciess occurring in it, with peat swamp forest as second best. Unexpectedly,perhaps,, was the finding that not northern Borneo, i.e., the Malaysian state of Sabah,camee out as the most species-rich area, but central-eastern East Kalimantan. In anareaa of some 30,000 km 2 more than 80% of all primate species, and all theendemics,, co-exist sympatrically.Sobering,, however, is the realisation that the newly identified hotspot issituatedd in one of the most densely populated areas of Borneo. The remaining forestsaree inadequately protected and the area has suffered severely from the great forestfiress in 1982-1983 and 1997-1998. Only a small fraction is included in the protectedareaa network, but deforestation in these protected areas is probably as severe as innon-protectedd areas. The three most species-rich protected areas have most, if notall,, of their forest destroyed by a combination of illegal logging, mining,encroachment,, and the forest fires, whereas two proposed conservation areas incentral-easternn East Kalimantan are inhabited by the Punan, a (formerly) nomadichunter-gathererr tribe, which makes effective species protection in these areasdifficult. .185 5

ForestForest (and) PrimatesInadequatee species protection and inadequate protection of conservation areas, and asharpp reduction of the amount of forest over the last decades throughout most ofBorneo,, justifies that four of the five endemic primates had their current IUCNthreatt status changed (chapter 12). Prior to the present study, very little was knownaboutt the white-fronted leaf monkey P. frontata. In chapter 11 we prepared adetailedd distribution map and collected autecological data. Combined with data onitss density (chapter 12) the assessment reveals that the species is probably bestconsideredd Vulnerable according to IUCN threat criteria. Bornean leaf monkey P.hoseihosei and Bornean gibbon Hylobates muelleri were both considered at Lower Riskoff extinction, but on the basis of a sharp reduction of available habitat, aggravatedbyy hunting, both species are more appropriately classed as Vulnerable. As alreadyindicatedd above, the proboscis monkey is inadequately protected inside reserves andhass experienced a sharp reduction in available habitat. Hence, it should be classed asEndangered. .Ass a corollary of the above-mentioned problems, the conservation of primatesonn Borneo is, and has been, complex. It seems that the Indonesian conservationauthoritiess are neither able to carry out species protection, nor to protect the species'habitatt within reserves against the activities of plantation developers, timberconcessionn holders, farmers, and hunters (Rijksen & Meijaard, 1999; chapters 9, 10,andd 11). Most of the unprotected habitat is scheduled for conversion into agriculturallandd and plantation, leaving almost none for the forest-dependent primates. Asindicatedd in chapter 9, the reasons why the Indonesian authorities are failing toaddresss conservation issues are complex. We have mentioned among other things, alackk of funds, lack of knowledge, misconceptions on ecological issues, poorlyintegratedd planning, and lack of serious and effective commitment and politicalsupport,, for solving conservation problems. Given the (lack of) success of speciesandd habitat conservation in the Malaysian parts of Borneo, the underlyingdeficienciess are probably fairly similar to those in Kalimantan. Solutions have to befoundd nationally and internationally in an integrated manner. For an area intransitionn such as Borneo (Padoch & Peluso, 1996) in times of political reform,decentralisation,, and economic hardship (more so in Indonesia than in Malaysia),speciess and habitat conservation may not be high on the agenda. However, it is theplightt of the authorities on Borneo, the central governments of Indonesia andMalaysia,, and indeed the international community to safeguard the biological wealthoff the island. There are still opportunities to do so as none of the Bornean primatespeciess have become extinct yet, and none of the populations are too small to bebeyondd recovery. Although the current wave of openness and political reform inIndonesiaa might provide such opportunities for improved and effective conservation,att present the decentralisation process has been far from smooth and in in fact quiteoftenn has jeopardised the status of both wildlife and wildlands.186 6

GeneralGeneral DiscussionEXTINCTIONN OF PRIMATES IN THE SUNDAIC REGION FROM ANISLAND-BIOGEOGRAPHICALL PERSPECTIVESmalll areas, be it islands or reserves, are expected to harbour less species than largeareas.. Since the 1920's ecologists have tried to fit equations to such species-arearelations.. The most powerful model that has been in use since the 1960's (e.g.,Preston,, 1960, 1962) is a power function model, usually expressed as a doublelogarithmicc transformation:logg S = log k + z • log A (equationn 13.1)inn which S represents the number of species, A is the island area, and k and z arefittedd parameters that describe intercept and slope. The power function is derivedfromm a log normal distribution of species abundance, and the theory that support theusee of this type of function (e.g., Preston, 1960, 1962; MacArthur & Wilson, 1967)containss an implicit assumption of equilibrium. The values of k and z can beestablishedd empirically by determining a best fit line for the data set. Soonconservationistss realised that the theory of island biogeography was useful tointerprett extinction processes and could aid in conservation management (Frankel &Soulé,, 1981; Meffe & Carroll, 1994).Logg (number ot species+1)1.5 51.4 4Figuree 13.1 Relationship between island size (log Area) and number of primate species in the Sundaicregion,, with 95% confidence intervals. The relationship is described by Log(N+l)=0.242A-0.248,, R 2 =0.78, p

ForestForest (and) PrimatesIff we examine the relationship between land area and the number of primates foreightt different 'islands' in the Sundaic region (from small to large: Mentawai Islands,Belitung,, Bali, Bangka, Java, Peninsular Malaysia, Sumatra, Borneo, and Sundalandass a whole) (Fig. 13.1) we see that both Bali and Java have fewer primates than canbee expected from their area. In fact, from the regression equation we can predict thatJavaa is short of some three to four primate species, and Bali is short of at least onespecies.. Borneo with some 13 species is not short of any primates, nor does it seemtoo be particularly species rich. Van Balen (1999b) reports a similar finding for birds:comparedd to the other islands in the Sundaic region, Java (but not Bali) is short of anumberr of bird species, whereas Borneo is not.log(numberr of endemics+1)Figuree 13.2 Relationship between island size and number of endemic primate species in the Sundaicregion,, with 95% confidence intervals. The relationship is described byLog(E+l)=0.2071ogA-0.575,, R 2 =0.25, p>0.10, where E=number of endemic species andA=Area. .Iff we take a closer look at the number of endemic primates (Fig. 13.2), it turns outthatt both Java and Borneo are not short in endemics. Bali does not harbour anendemicc primate, as can be expected from the endemic-area curve. Both Sundalandass a whole and the Mentawai Islands show up as particularly species-rich. Therelationshipp in Figure 13.2 is weak but this is probably not due to an inappropriatesett of island sizes. In order for a mammal the size of a primate to evolve in situ aminimumm population size and hence a minimum area is needed. This suggests thatsurfacee area alone is not a good predictor for the level of endemism (indeed isolationseemss to be an important factor, the Mentawai Islands are separated from mainlandSumatraa by a deep trench, whereas most of the other smaller islands are situated onthee shallow Sunda Shelf).Inn conclusion it seems that Java has lost three to four, most likely non-endemic(seee Fig 13.2), primates, and Bali just one. Interestingly, three species of non-188 8

GeneralGeneral Discussionendemicc primates are known from prehistoric deposits from Java, viz., orang-utanPongoPongo pygmeus, siamang Symphalangus syndactylies, and pig-tailed macaqueMacacaMacaca nemestrina (Whitten et al., 1996). All three species are still extant in otherpartss of Sundaland. Little is known about the fossil fauna of Bali, but large parts ofthee island experience a significantly longer dry season than other islands on theSundaa Shelf, and the island may have never harboured a true rain forest primatecommunity.. The pig-tailed macaque is known to inhabit dry deciduous forest in thenorthernn parts of its range (e.g., Thailand: Lekagul & McNeely, 1988) and hence,mayy have occurred on Bali. Island species are widely believed to be more vulnerabletoo extinction than their congeners on the mainland (Brooks et al., 1997; Cowlishaw&& Dunbar, 2000), and indeed a disproportionate large number features on lists ofthreatenedd species (Groombridge, 1994; Cowlishaw & Dunbar, 2000; Collar et al.,2001).. Locally, however, paleo-endemics may be expected to be better adapted totheirr environment than their wide-ranging congeners. This may be in part related tothee so-called insular syndrome (Krebs, 1994). A primary attribute of this syndromeiss the higher densities often reached by island populations compared to continentalpopulationss in similar-sized areas (Krebs, 1994). This may be due to lowercompetitivee interactions and reduced intra-specific aggression or territorial defence(Stampss & Buenchner, 1985). A second component of the insular syndrome is nicheexpansion,, mostly documented as an increase in niche breath (Blondel, 1985; Krebs,1994). .Returningg to the extant number of species and the available habitat, we canexploree whether or not these are in equilibrium (an implicit assumption of the theoryoff biogeography: MacArthur & Wilson, 1967), and whether or not the primatecommunityy of the respective islands have already reached the so-called relaxationphase.. According to Brooks et al. (1997), the number of species present in theremainingg forest can be predicted by:S„ 22 = S o2 -(F n /F 0 ) z (equation 13.2)wheree S 0 2 is the number of expected species for an area as derived from a speciesareaacurve (Figure 13.1), S n2 is the number of predicted species on the basis of theremainingg forest, F 0 is the original and F n is the remaining forest area, and z is theslopee of the regression line (0.242: Figure 13.1).Forr lowland forest on Java, Bali, and Borneo these values are, respectively: S 0 2== 8.9, 3.6, and 13.9, F 0 =123,270 km 2 , 4520 km 2 , and 656,776 km 2 , F n =5,230 km 2 ,8800 km 2 , and 308,684 km 2 (data from MacKinnon et al. 1982, MacKinnon & Artha1982,, RePPProT, 1990). Filling in the equations for each of the islands, it turns outthatt on the basis of present forest cover Java should have four primate species (i.e.,onee less than at present), Bali two, and Borneo eleven or (possibly) twelve. Lowlandforestt was chosen as all the primate species occur there (chapters 1 and 11), atprobablyy their highest density, and none of the species occurs in montane forestonly.. Including all forest (i.e., lowland and montane) in the equation, however, doesnott alter the results for any of the islands. Data on the current extent of remaining189 9

ForestForest (and) Primatesforestt on Borneo vary widely, and the most recent data available (MacKinnon et al.,1996)) are already outdated. E. Meijaard (in litt.) estimates that only some 45% of theforestss of Borneo remains. This would leave room for no more than eleven species,i.e.,, two less than at present. The most likely candidates for extinction on Borneo arethee banded leaf monkey Presbytis femoralis (see chapter 11), the proboscis moneyNasalisNasalis larvatus (chapter 9), and the orang-utan Pongo pygmeus (Rijksen &Meijaard,, 1999).Whilee filling in equation 13.2 there was the implicit assumption that theprimatess are evenly distributed over the entire (lowland) forest area, both in thepresentt and in the past. Data presented in chapters 6-8 and 12 showed that this is aninvalidd assumption, i.e., western Java and central-eastern East Kalimantan containmoree species that other parts of the respective islands. Hence loss or conservation offorestt areas in these parts will have a disproportional effect on the number of speciesthatt (theoretically) can persist in the remaining forest on both islands. Likewise,fragmentationn per se will have its effect on the composition and number of theremainingg species. Precisely these two key principles can be used as guidingprincipless in habitat and species conservation as it allows to maximise results withthee limited resources available.Ass already mentioned in the first chapter, Java (and to a lesser extent Bali)representss an area where little forest remains, where the pressure on the remainingpopulationss of primates dates back several centuries, and where many people are nolongerr directly dependent on the forest, whereas Borneo represents an area intransition.. Although still largely covered with forest, rapid changes in land-use andchangingg human attitudes will greatly aggravate the pressures wildlife populationsaree facing. With respect to the extinction of primates on Java and Borneo, probablythee former island has already reached its relaxation phase, whereas the latter has not.Hence,, we can expect some local extinctions on Borneo even if the present forestcoverr remains unchanged. The history of deforestation on Java will most likelyrepeatt itself on the other Sundaic islands, e.g., Sumatra and Borneo and possiblyotherr parts of South-east Asia (in particular Indo-China). These areas have a muchhigherr number of primate species (Rowe, 1996), including some of the rarestprimatess in the World (Eastern black crested gibbon Hylobates sp. cf. nasutus(Geismannn & Than, 2001) and Cat Bai leaf monkey Trachypithecus poliocephalus(Nadlerr & Long, 2000).SUGGESTIONSS FOR FURTHER RESEARCH1.. Strengthening the link between behavioural biology and conservationRecentlyy two books have appeared in which the link between behavioural biologyandd conservation was explored, viz., Behavioral approaches to conservation in thewildwild edited by Clemmons & Buchholz (1997) and Behaviour and conservationeditedd by Gosling & Sutherland (2000). From the various studies in these books itbecomess apparent that a better understanding of animal behaviour can greatly190 0

GeneralGeneral Discussioncontributee to increase the success of conservation projects and, reversibly, howlessonss learned from conservation can contribute to an increase in our knowledge ofanimall behaviour.Behaviourall variation between populations of a species can have greatconservationn implications. Meijaard & Nijman (2000; chapter 9) showed that in theinteriorr of Borneo, local populations of proboscis monkeys have diminished innumberr and extent of occurrence, and in all likelihood the species has disappearedfromm many of its former haunts. Hunting was considered a major factor in theselocall extinctions. One of the reasons why proboscis monkey may be more vulnerabletoo extinction due to hunting than other primates is their river-refuging behaviour: inmostt areas proboscis monkeys return to the water's edge in the evening (Bennett &Sebastian,, 1988; Bennett & Davies, 1994; Yeager, 1991a, 1993). Here theycongregatee in bands, comprising several groups, which may total up to some 50-60individualss (Yeager, 1990, 1991a; pers. observ.). Given that boats on Borneo are themainn mode of transportation, and waterways are essentially the highways in theinterior,interior, it is not surprising that this predictable behaviour of proboscis monkeys,theirr large size and, locally, large numbers, make them easy targets for hunters.Informationn from interviewees confirmed the ease to hunt them, and although manyindividualss will flee once the first individual(s) is (are) shot, it was reported that notrarelyy will they return to the same spot the next day, and the next, until essentiallythee group is is wiped out. However not all proboscis monkey populations expressthiss river-refuging behaviour. Sebastian (1994) reported that in Danau Sentarumprobosciss monkeys did not always choose to sleep near the water's edge. Instead,duringg the dry season, groups were found to use dry riverbeds within the forest andsleepp on trees along these dry open areas.Thee role that bio-acoustics can play in conservation studies is clearly a fieldworthh exploring. Individual recognition, including sexing individuals by their call,allowss longitudinal studies without any intrusive techniques being employed, andallowss future detailed study without habituation or severe intrusion into the habitatoff the species under study. Especially for rare and endangered species, in this era ofinstabilityy where animals are not safe even inside 'protected' areas, the decision ofwhetherr or not to study the animals of interest by frequent intrusion into their habitat(andd the often associated establishment of trail systems) and especially whether ornott animals are to be habituated to human observers, should be taken very carefully.2.. Increase knowledge of year-round ranging patterns of primatesSomee primates are strictly sedentary and will not range far, even when localconditionss have worsened (Johns, 1985c). Others, as for instance the pig-tailedmacaque,, will range habitually over large areas, often in response to local abundanceoff fruit. And in yet other species, e.g. the orang-utan, a certain proportion of thepopulationn may be strictly sedentary, whereas others wander over great distances(Rijksenn & Meijaard, 1999). Sebastian (1994) reported substantial local movementsoff proboscis monkeys within and outside the Danau Sentarum reserve in response tothee changing water levels. These seasonal movements may not be restricted to this191 1

ForestForest (and) Primatesarea,, and may have important implications for the design of protected areas. It isimportantt to explicitly take the ranging patterns of animals (not just primates) intoconsiderationn when formulating conservation priorities. For instance, Momberg etal.. (1998) made boundary proposals for a new to be gazetted national park in theSebaka-Sembukungg region. The proposed boundary was situated c. 5 km away fromlargee rivers, as to include vital proboscis monkey habitat. Although this 5-km stripmayy provide enough habitat for the species, with limited knowledge of rangingpatternss of this and other species, especially in relation to less favourable seasons, itwouldd be worthwhile to collect more data on the ranging behaviour of species duringleann periods. Although a greater insight in the biology, including behaviour, of targetspeciess can greatly help in effective conservation, there has to be a will to use thisknowledgee wisely. The case of the local extinction of the proboscis monkeys of thePulauu Kaget Nature Reserve (chapter 10) demonstrates this clearly.3.. Increase knowledge of the general ecology of endemic primatesForr many of the endemic primates of Java and Borneo basic information on theirbiologyy is lacking. For a fair number of species we have detailed lists of dietaryitems,, e.g., grizzled leaf monkey (Ruhiyat, 1991; Sujatnika, 1992; Wedana, 1993;Harjantii 1996), ebony leaf monkey (Kartikasari 1986; Supriatna et al., 1989; Kool1989,, 1993; Djuwantoko et al., 1994), Javan gibbon (Kappeler 1981, 1984b; Rinaldi1999),, proboscis monkey (Salter et al., 1985; Yeager, 1989b; Bismark, 1994;Woods,, 1995), red leaf monkey (Supriatna et al., 1986; Davies, 1988; Davies et al.,1988),, and Bornean gibbon (Rodman, 1978; Leighton, 1987), yet for others it iscompletelyy lacking (white-fronted leaf monkey, Bornean leaf monkey). Moreimportantly,, from both a conservation and an ecological and evolutionaryperspective,, we have very few insights into how food selection (and dietarypreferences)) varies over different habitats, over altitude, with season, etc. Yet, in achangingg environment, this information may be vital if we are to develop a soundmanagementt system for the conservation of species.4.. Assess the geographical distribution of target speciesInIn the present study we attempted to accurately assess the geographical distributionoff the endemic primates of Java and Borneo. However, especially for the Borneanspeciess the data should only be seen as a first attempt. We have limited informationonn the different densities at which these species occur throughout their range. Thewhite-frontedd leaf monkey, for instance, seems to be sparsely distributed andgenuinelyy rare throughout most of its range, yet in north West Kalimantan and southSarawakk it seems to be much more common (chapter 11 and 12). We do not knowwhetherr the individuals that have repeatedly been observed in two areas east ofGunungg Palung National Park are part of an isolated population or whether thedistributionn range of the species does extend far into West (and Central?)Kalimantan.. White-fronted leaf monkeys are probably patchily distributed nearGunungg Palung as Blundell (1996) did not include it in a list of mammals occurringinn the park based on >110 months of observation effort. Likewise more information192 2

GeneralGeneral Discussionaboutt the inland populations of the proboscis monkeys and the banded leaf monkeyinn West Kalimantan is badly needed.5.. Assess the effects of hunting on wildlife populationsInn the introduction it was already mentioned that the attitudes of humans towardsprimatess in the Sundaic region differ greatly. The one extreme is seen on Bali whereHinduss regularly provide offerings for primates, whereas the other extreme can befoundd in interior Borneo where almost all of the primate species are hunted when theoccasionn arises. The effects of hunting on populations of primates are notsufficientlyy known. The last years it became apparent that hunting in tropical areasoftenn is unsustainable. Attempts to harvest natural resources sustainably inevitablyleadd to over-exploitation often to the point of collapse or extinction of the targetspeciess (Robinson & Bennett, 2000). The data on proboscis monkeys (chapter 9) andthee orang-utan (Rijksen & Meijaard, 1999) indirectly pointed to hunting as one ofthee factors, perhaps even the main factor, to explain the absence of these speciesfromm parts of interior Borneo. Generally, however, there are insufficient or no dataonn the long-term intrinsic population dynamics of many rainforest species (includingprimates)) in the absence of hunting. Likewise, the impact of hunting on most targetspeciess is unknown, let alone the impact on non-target species. On Borneo huntersoftenn hunt opportunistically and take certain non-target species only upon encounter.Huntingg in tropical areas is often associated with other types of disturbances(logging,, settlements, road construction etc.) and the relative impact of huntingversuss other disturbances is virtually unknown. In order to obtain these data longtermmmonitoring research is essential. Without understanding these above-mentioneddeficiencies,, future attempts to estimate and develop sustainable harvests or attemptstoo conserve protected populations and areas will be greatly handicapped andimprecise.. Instead of assuming that indigenous tribes do hunt sustainably, it isimperativee to conduct tightly controlled experiments on hunting impacts. Theseexperimentss should be conducted outside the protected area network, however, andonn species not protected by law.193 3

ForestForest (and) Primates194 4

Summary:Summary: Forest (and) PrimatesSUMMARY YFORESTT (AND) PRIMATES: ECOLOGY AND CONSERVATION OF THEENDEMICC PRIMATES OF JAVA AND BORNEOForr primates, the Sundaic region is one of the most species-rich areas in the World.Dependingg on the taxonomy followed it harbours some 18-20 species endemic to thearea.. On two of the larger islands in the region, namely Java and Borneo, three andfivee single island endemics are found, respectively. Six of these are colobinemonkeyss whereas the remaining two are gibbons. Most of these endemic primatesforr their survival are dependent on natural forest. Java is a densely populated areaandd has a long history of deforestation, whereas Borneo is a sparsely populatedislandd in transition and altering land-use is rapidly changing the appearance of theisland;; until a few decades ago Borneo was still largely covered in forest. Thepresentt study aimed at collecting data on the ecology and conservation of theendemicc primates of Java and Borneo. Hereto studies were conducted and surveysexecutedd over the period 1994-2001.Thee first part of the study focussed largely on testing census techniques used inprimatologicall studies and to assess the effects of behavioural changes in the targetspeciessbrought about by various kinds of disturbance on census results. It wasfoundd that density estimates varied considerably between techniques and sites andconcludedd that caution is needed when comparing census data from different sites,collectedd by different techniques and by different researchers. Primates may altertheirr response to human observers in response to (habitat) disturbance and it seemslikelyy that this in turn will have its effect in monitoring programmes, leading toeitherr under- or overestimation of the true densities.Thee second part of the study focussed on the endemic primates of Java. Firstly,itt was found that the eastern populations of one of the endemics, the grizzled leafmonkeyy Presbytis comata, were not diagnosably distinct from those in the west.Hence,, there is no support for treating these eastern populations (described as P. c.fredericae)fredericae) as a separate species. Secondly, the distribution and conservation statusoff the endemic primates of Java was assessed. The ebony leaf monkeyTrachypithecusTrachypithecus auratus occurs throughout Java, Bali, and Lombok but, contrarypreviouss reports, not on the Kangean Islands. On the basis of its limited range andhighlyy fragmented populations, and some capturing for trade, it should beconsideredd Vulnerable according to the IUCN threat criteria. The grizzled leafmonkeyy is confined to the rainforests of West and Central Java and occurs from sealevell to c. 2500 m a.s.1. Significant populations were found in Central Java, beyonditss expected range, but given the high degree of fragmentation of its population thespeciess is Endangered according to the IUCN threat criteria. The grizzled leafmonkeyy shares its habitat throughout most of its range with the Javan gibbonHylobatesHylobates moloch. Being confined to the last remnants of floristically rich lowlandforestt on this densely populated island, it is the rarest of the three Javan endemics.195 5

ForestForest (and) PrimatesHowever,, population numbers have been severely under-estimated in the past andwithh some 4000-4500 individuals remaining it is Endangered according to thecurrentt IUCN threat criteria.Thee third part of the study focussed on the endemic primates of Borneo. Thedistributionn and conservation status of one of the most charismatic primates ofSouth-eastt Asia, the proboscis monkey Nasalis larvatus, was assessed. It was foundnott only in coastal areas and downstream parts of large rivers, as assumedpreviously,, but throughout the Bornean interior as well. Generally, populations inthee interior were small and thinly spread, a pattern most readily explained by moreintensee hunting in the interior than in coastal areas. The species is not adequatelyprotectedd and most of the larger populations included in the protected area networkaree in decline. Next, we assessed the spatial patterns of primate diversity in terms ofspeciess richness and endemism for Borneo, and evaluated this in relation to patternsoff human land-use and positioning of the protected area network. The tropical wetevergreenn forest near large rivers in central-eastern East Kalimantan, Indonesia,coveringg a land surface of some 30,000 km , was the richest area both in terms ofabsolutee species number (up to eleven sympatric species) and in the number ofendemicss (up to five endemics). There is hardly any overlap between the areas mostrichh in primates and the protected area network. Of the five protected areas most richinn primates (including endemics), three are almost completely devoid of forest,mostlyy due to a combination of illegal logging, mining, encroachment and arson.Twoo of the primates endemic to the northern three-quarters of the island, theBorneann gibbon H. muelleri and the Bornean leaf monkey P. hosei are Vulnerable toextinctionn according to the IUCN threat criteria, on the basis of a sharp reduction inavailablee habitat over the last decades, aggravated by hunting. The white-frontedleaff monkey P. frontata is an enigmatic species. Its distribution range was found tobee significantly larger than previously assumed, but over large parts of its range itseemss to be one of the rarest primates, occurring at low densities. Given thesefindings,, and given a sharp reduction of its lowland habitat over the last decades it isVulnerablee to extinction.Conservationn of primates and their forest both on Borneo and Java has proventoo be problematic largely due to a lack of funds, lack of knowledge, misconceptionsonn ecological issues, poorly integrated planning, and lack of serious and effectivecommitmentt and political support, locally, nationally as well as internationally. Ifwee are to conserve the endemic primates of the Sundaic region it is imperative thatsolutionss have to be addressed in an integrated manner. Future research should focusonn collecting ecological and behavioural data much needed to accurately addressconservationn issues, preferably through long-term monitoring programmes.196 6

Ringkasan:Ringkasan: Hutan (dan) PrimataRINGKASAN NHUTANN (DAN) PRIMATA: EKOLOGI DAN PELESTARIAN PRIMATAENDEMIKK Dl JA WA DAN KALIMANTANWilayahh Sondaik adalah salahsatu kawasan terkaya di dunia untuk keanekaragamanprimataa di mana 18 jenis terbatas penyebarannya pada kawasan ini. Di Jawa danKalimantan,, yang termasuk pulau-pulau yang terbesar, terdapat tiga dan lima jenisendemikk yang terbatas pada satu pulau saja. Enam jenis di antaranya tergolong sukukeraa sub-suku Colobinae, sedangkan dua jenis tergolong suku owa. Kelestarian darikebanyakann kera ini tergantung pada pelestarian hutan. Pulau Jawa adalah wilayahyangg padat penduduknya di mana hutan ditebang sejak lama, sedangkan Kalimantanadalahh pulau yang berada pada masa peralihan di mana perubahan tataguna tanahsecaraa cepat mulai mengkonversikan permukaan pulau ini. Jawa sudah sangatsedikitt hutannya sejak dulu, sedangkan Kalimantan masih ditutupi hutan luas sampaibeberapaa dasawarsa yang lalu.Tujuann penelitian ini ialah mengumpulkan data mengenai ekologi danpelestariann primata endemik di Jawa dan Kalimantan. Untuk ini studi-studidilaksanakann di mana survai lapangan berlangsung selama perioda 1994-2001.Bagiann pertama studi ini berfokus pada pengujian mengenai tehnik sensus padapenelitiann primata yaitu bermaksud untuk menentukan dampak terhadap hasil sensusdarii perubahan perilaku jenis-jenis sasaran yang disebabkan oleh gangguanlingkungann di sekitar primata tersebut. Sebagai hasil penelitian ditemukan bahwapenaksirann kepadatan cukup bervariasi di antara berbagai tehnik dan lokasi.Kesimpulannyaa adalah bahwa kita perlu sangat berhati-hati jika membandingkandataa sensus dari berbagai lokasi yang dikumpulkan oleh berbagai peneliti denganmenggunakann berbagai tehnik. Primata mungkin mengubah responsnya terhadapmanusiaa yang mengamatinya sebagai reaksi terhadap gangguan habitatnya. Tidakmustahill ini ada dampaknya dalam program peninjauan dan sebagai hasilnyamengurangii atau melebihi taksiran kepadatan yang sebenarnya.Bagiann kedua studi ini berfokus pada primata di Pulau Jawa. Pertama,ditunjukkann bahwa populasi dari salahsatu kera endemik, yaitu Rekrakan Presbytiscomatacomata fredericae, yang terdapat di Jawa sebelah timur tidak dapat dipisahkansecaraa jelas sebagai jenisnya sendiri dari populasi di sebelah barat.Kedua,, penyebaran dan status kelestariannya dari primata endemik di Jawaditentukan.. Lutung Jawa atau budeng Trachypithecus auratus ditemukan di seluruhJawa,, Bali dan Lombok, akan tetapi tidak ditemukan di Kepulauan Kangean,meskipunn pernah ada laporannya. Berdasarkan penyebarannya yang terbatas danpopulasi-populasinyaa yang sangat terpencar, ditambah penangkapan untuk dijualbelikan,,jenis kera ini seharusnya dianggap Rentan menurut kriteria ancaman yangdisusunn IUCN. Surili itu terbatas pada hutan tropis di Jawa Barat dan Tengah daripermukaann laut sampai sekitar 2500m dpi. Populasi yang cukup besar ditemukan diJawaa Tengah, di luar penyebaran yang diduga sebelumnya. Meskipun demikian jenis197 7

ForestForest (and) Primatesinii dianggap Genting menurut kriteria acaman IUCN karena derajat terpecahnyapopulasii ini. Surili ini membagi habitatnya dengan Owa Jawa Hylobates moloch disebagiann terbesar wilayahnya. Jenis terakhir ini adalah terjarang dari ketiga keraendemikk di Jawa karena terbatas pada kantung-kantung terakhir dari hutan tropisdataran nBagiann ketiga dari studi ini berfokus pada primata endemik di Kalimantan.Penyebarann dan status kelestariannya ditentukan untuk salahsatu primata palingkarismatikk di Asia Tenggara, yaitu Bekantan Nasalis larvatus. Ternyata jenis initidakk terbatas pada daerah pesisir dan kawasan hilir dari sungai besar, seperti didugasebelumnya,, namun terdapat juga di seluruh pedalaman Kalimantan. Secara umumpopulasi-populasii di pedalaman kecil dan tersebar berjauhan, sebuah pola yangdapatt diuraikan karena pemburuan yang lebih intensif dibanding dengan keadaannyadii daerah pesisir. Jenis ini tidak dilindungi secara memadai dan kebanyakan daripopulasi-populasinyaa yang besar sedang menurun jumlahnya Walaupun beradadalamm kawasan konservasi.Selanjutnyaa kami menentukan pola-pola spasial dari keanekaragaman primatadalamm arti kekayaan jenis dan keendemikan untuk Kalimantan, sertamengevaluasikann ini berhubung dengan pola-pola tataguna tanah oleh manusia, dantataruangg jaringan kawasan konservasi. Hutan tropis sepanjang sungai besar diKalimantann Timur sebelah timur-tengah yang menutupi kawasan berukuran 30,000kmm , adalah kawasan terkaya, baik dari segi jumlah jenis absolut (sampai sebelasjeniss yang hidup berdampingan di sini), maupun dari segi jumlah jenis endemik(sampaii lima jenis terdapat di sini). Dari kelima kawasan konservasi yang terkayaakann jenis (termasuk yang endemik), tiga di antaranya hampir habis hutannya. Initerutamaa disebabkan oleh penggabungan antara penebangan ilegal, penambangan,pelanggarann tapal batas, dan pembakaran. Dua di antara primata yang endemikuntukk bagian tigaperempat dari pulau Kalimantan bagian utara, yaitu KalawatHylobatesHylobates muelleri dan Banggat Presbytis iiosei adalah Rentan Punah menurutIUCN. .Pelestariann dari primata beserta hutannya, baik di Kalimantan maupun di Jawa,terbuktii ada masalahnya terutama karena kekurangan kelembagaan, dana yangkurang,, pengetahuan yang tidak memadai, salah-pengertian mengenai isyu-isyuekologis,, perencanaan yang kurang pemaduannya, dan kurangnya komitmen yangsungguh-sungguhh serta efektif dan dukungan politik, baik setempat, nasional daninternasional.. Pemecahan masalah-masalah tersebut dengan pendekatan secaraintegrall merupakan syarat mutlak, jika kita ingin melestarikan primata endemik diWilayahh Sondaik. Penelitian di masa depan seharusnya berfokus pada pengumpulandata-dataa ekologi dan perilaku yang begitu dibutuhkan untuk menanggapi isyu-isyukonservasi,, dan sebaiknya berlangsung melalui program peninjauan jangka panjang.198 8

Samenvatting:Samenvatting: Bos (en) (en) ApSAMENVATTING GBOSS (EN) PRIMATEN: ECOLOGIE EN BESCHERMING VAN DEENDEMISCHEE PRIMATEN VAN JAVA AND BORNEOVoorr primaten is het Sunda-gebied één van de meest soortenrijke gebieden in dewereld.. Het herbergt ongeveer 18 endemische soorten, dat wil zeggen soorten diealleenn in dat specifieke gebied voorkomen. Op twee van de grootste eilanden in hetgebied,, Java en Borneo, komen respectievelijk drie en vijf endemische primatenvoor.. Daarvan behoren er zes tot de groep van de slankapen en de overige twee zijngibbons.. De meeste van deze endemische primaten zijn voor hun voortbestaanafhankelijkk van de instandhouding van het bos. Java is een dichtbevolkt eiland meteenn lange geschiedenis van ontbossing, terwijl Borneo een dunbevolkt eiland inovergangg is en een intensivering van het landgebruik het eiland in snel tempoverandert.. Java is grotendeels ontbost, terwijl tot enkele tientallen jaren geledenBorneoo nog grotendeels bedekt was met tropisch regenwoud. Deze studie had totdoell om gegevens te verzamelen over de ecologie en bescherming van deendemischee primaten van Java en Borneo. Hiertoe werden studies uitgevoerdgedurendee de periode 1994-2001.Hett eerste deel van de studie richtte zich grotendeels op het testen vancensustechniekenn die gebruikt worden in primatologische studies en het in kaartbrengenn van de effecten die gedragsverandering in primaten ten gevolge vanverstoringg kunnen hebben op censusresultaten. Afhankelijk van de gebruiktetechniekenn werd gevonden dat dichtheidsschattingen behoorlijk varieerden en erwerdd geconcludeerd dat voorzichtigheid is geboden bij het vergelijken vancensusdataa vanuit verschillende onderzoeksgebieden. Primaten veranderen hunreactiee naar onderzoekers ten gevolge van (habitat) verstoring en het lijktwaarschijnlijkk dat dit op zijn beurt weer een effect heeft op monitoringprogramma's,daarr het leidt tot onder dan wel overschatting van dichtheden.Hett tweede deel van de studie richtte zich op de endemische apen van Java.Eénn van de eerste resultaten was dat de oostelijke populaties van de JavaanseLangoerr Presbytis comata niet diagnostisch verschillen van populaties in het westenenn de hypothese dat de oostelijke populaties (beschreven als P. c. fredericaé) eenapartee soort vormen werd verworpen. Vervolgens werd de verspreiding en de statusvann de endemische apen van Java in kaart gebracht. De Javaanse MutslangoerTrachypithecusTrachypithecus auratus komt verspreid voor over Java, Bali, en Lombok, maar,tegenstellingg tot eerdere aanwijzingen, niet op de Kangean eilanden. Naar aanleidingvann het beperkte verspreidingsgebied van de soort, het voorkomen in een grootaantall gefragmenteerde populaties en in beperkte mate het wegvangen voor dehandel,, dient de Javaanse Mutslangoer volgens de criteria van de IUCN als een'kwetsbaree soort' beschouwd te worden. De Javaanse Langoer is beperkt in zijnverspreidingg tot de regenwouden van West en Midden Java, waar de soort voorkomtvann zeeniveau tot ca. 2500 m boven zeeniveau. Belangrijke populaties werden199 9

ForestForest (and) Primatesgevondenn in Midden Java, oostelijk van het tot dan toe bekendeverspreidingsgebied,, maar de grote mate van fragmentatie van populatiesrechtvaardigtt de classificatie van 'bedreigd' volgens de criteria van de IUCN. DeJavaansee Langoer deelt zijn habitat met de Javaanse Gibbon Hylobates moloch.Alleenn voorkomend in de laatste stukjes onverstoord laagland bos die nog te vindenzijnn op het dichtbevolkte eiland, is dit de meest zeldzame soort van de drie Javaanseendemen.. Ondanks dat het populatieaantal van deze soort recentelijk sterkonderschatt is (slechts 400 individuen in het wild) en als 'ernstig bedreigd' werdbeschouwd,, moet met de huidige populatieschatting van ongeveer 4000-4500gibbons,, de status van de soort nog steeds als 'bedreigd' worden opgevat.Hett derde deel van de studie richtte zich op de endemische apen van Borneo.Dee verspreiding van één van de meest charismatische apen van zuidoost Azië —deNeusaapp Nasalis larvatus— werd in kaart gebracht. Er werd gevonden dat de soortniett alleen in kustgebieden en langs de benedenloop van de grote rivierenvoorkwam,, maar ook ver in de binnenlanden. Over het algemeen waren depopulatiess in het binnenland klein in aantal en dun verspreid, iets wat te verklaren isdoorr de hogere jachtdruk in de binnenlanden vergeleken met de kustgebieden. DeNeusaapp is niet adequaat beschermd en de meeste van de grotere populaties inbeschermdee gebieden vertonen een dalende trend. Vervolgens zijn de ruimtelijkepatronenn van de diversiteit (zowel soortenrijkdom als endemisme) van apen opBorneoo in kaart gebracht en is dit in verband gebracht met het landgebruik van demenss en de situering van natuurreservaten en nationale parken. Het tropischregenwoudd aan beide zijden van de grote rivieren in een betrekkelijk klein gebiedvann ca. 30.000 km 2 in het centrale deel van oostelijk Oost Kalimantan, is het meestsoortenrijkk (11 sympatrische apensoorten) en bevat de meeste endemen (vijfsoorten).. Een combinatie van illegale houtkap, mijnbouw, landbouw, en hetongecontroleerdd afbranden van bos, heeft ertoe geleid dat er in drie van de vijf meestsoortenrijkee beschermde gebieden (natuurreservaten en nationale parken) vrijwelgeenn bos meer over is. Twee van de primaten, endemisch voor het noordelijke deelvann Borneo, de Borneo Gibbon H. muelleri en de Borneo Langoer P. hosei, zijn'kwetsbaar'' daar de laatste decennia het beschikbare habitat zeer sterk is afgenomenenn de jachtdruk onverminderd hoog is gebleven en mogelijk zelfs toegenomen. DeWitvoorhoofdlangoerr P. frontata is een raadselachtig dier. Er werd gevonden datzijnn verspreidingsgebied beduidend groter is dan werd aangenomen, maar over grotedelenn hiervan komt de soort in zeer lage dichtheden voor en is het één van de meestzeldzamee primaten. Dit in ogenschouw nemende, aangevuld met de kennis dat hetbeschikbaree habitat drastisch is gereduceerd over de laatste decennia, maakt dat dezesoortt kwetsbaar is voor uitsterven.Uitt de studie komt naar voren dat de bescherming van endemische primaten enhunn bos op zowel Borneo als Java problematisch is. Dit komt door institutionelegebreken,, een tekort aan financiële middelen, misopvattingen over ecologischeprocessen,, slecht geïntergreerde planning, een gebrek aan serieuze en effectievebetrokkenheidd en politieke steun, zowel lokaal, nationaal als internationaal. Als wewillenn dat de endemische primaten van het Sunda-gebied behouden blijven, dan is200 0

Samenvatting:Samenvatting: Bos (en) Apenhethet noodzakelijk dat oplossingen in een geïntegreerde manier worden behandeld.Vervolgonderzoekk zou zich kunnen richten op het verzamelen van ecologische enethologischee data die nodig zijn voor beschermingsdoeleinden en dit dient bijvoorkeurr te gebeuren in lange termijn onderzoeksprogramma's.201 1

ForestForest (and) Primates202 2

References ReferencesREFERENCES SAaa P.J.B.C. Robidé van der. 1884. Korte aantekeningen over de zoogdieren vanBorneo.. Pp 105-112 in Bock C. Reis in Oost- en Zuid-Borneo. M. Nijhoff, 'sGravenhage. .Aimii M. & Bakar A. 1992. Taxonomy and distribution of Presbytis melalophosgroupp in Sumatera, Indonesia. Primates 33: 191-206.Aimii M. & Bakar A. 1996. Distribution and deployment of Presbytis melalophosgroupp in Sumatera, Indonesia. Primates 37: 399-409.All Fatah Y. 1999. Studi kasus evaluasi Bekantan dan peran masyarakat terhadappelestariann Bekantan. In Peningkatan Kesadaran dan Peran MasyarakatTerhadapp Pelestarian Bekantan. KSBK and KEHATI, Surabaya.Alikodraa H.S., Mustari A.H. & Yasuma S. 1992. Studi ekologi dan konservasiBekantann (N. larvatus Wurmb) di delta Mahakam, Kalimantan Timur: habitatdann populasi. Laporan akhir proyek peningkatan penguruan tinggi UniversitasMulawarman.. Japan International Cooperation Agency & MulawarmanUniversity,, Samarinda.Altmannn J. 1974. Observational study of behavior: sampling methods. Behaviour49:: 277-267.Andreww P. 1992. The birds of Indonesia - a checklist (Peters' sequence).Indonesiann Ornithological Society, Jakarta.Anonymouss 1994. Javan gibbon and Javan langur population and habitat viabilityanalysis.. Taman Safari, Cisarua.Anonymouss 1996. Pola pengelolaan kawasan suaka alam, kawasan pelestarianalam,, taman bum, dan hutan lindung. Dirjen PHPA/Forestry Department,Jakarta. .Anonymouss 2000. Lutung Jawa akhirnya dilindungi. Suara Satwa 5:17Appelmann F.J. 1939. Het schiereiland Poerwo: bosch en wild in Java's Zuidoosthoek..Pp 293-298 in 3 Jaren Indisch Natuurleven, Elfde jaarverslag (1936-1938).. Nederlandsch Indische Vereeniging tot Natuurbescherming, Batavia.Argelooo M. 1992. The maleo - more than just a symbol. World Birdwatch 14: 8-9.Argelooo M. 1993. Black-headed gulls wintering in Sulawesi (and notes onoccurrencee elsewhere in the Indo-australian region). Kukila 6: 110-114.Argelooo M. & Dekker R.W.R.J. 1996. Bulwer's petrel in Indonesia. Kukila 8: 132-135. .Asquithh N.M. 2001. Misdirections in conservation biology. Conservation Biology15:15: 345-352.Asquithh N.M., Martarinza, & Sinaga R.M. 1995. The Javan gibbon (Hylobatesmoloch):moloch): status and conservation recommendations. Tropical Biodiversity 3: 1-14. .Araüjoo M.B. & Williams P.H. 2000. Selecting areas for species persistence usingoccurrencee data. Biological Conservation 96: 331-345.203 3

ForestForest (and) PrimatesAzumaa S. & Suzuki A. 1984. The distribution of primates in Sebulu and R.Mahakam.. Kyoto University Overseas Report of Studies on Asian Non-humanPrimatess 3: 45-54.Babtistaa L.F. & Gaunt S.L.L. 1997. Bioacoustics as a tool in conservation studies.Pp.. 212-242 in Clemmons J.R. & Buchholz R. (eds) Behavioral approaches toconservationn in the wild. Cambridge University Press, Cambridge.Balenn S. van 1988. Forest fragmentation and the survival of forest birds in Java: apreliminaryy report. Pp 115-165 in Proceedings Deutscher AkademischerNachkontaktt Seminar 9-11 December 1987. Institut Pertanian Bogor, Bogor.Balenn S. van 1997. Faunistic notes from Kayan Mentarang, with new records forKalimantan.. Kukila 9: 108-113.Balenn S. van 1999a. Note on the distribution of the Kinabalu serpent-eagle with afirstt record for Kalimantan. Kukila 10: 154-156.Balenn S. van 1999b. Birds on fragmented islands, persistence in the forest of Javaandd Bali. Tropical Resource Management Paper 30, Wageningen.Balenn S. van 2000. A record of long-tailed broadbill from Kalimantan. Kukila 11:146-148. .Balenn S. van, Suswelo I.S., Hadi D.S., Soepomo D., Marlon R. & Mutiarina 1993.Thee decline of the Brahminy kite Haliastur indus on Java. Forktail 8: 83-88.Bankss E. 1931. A popular account of the mammals of Borneo. Journal of theMalayann Branch of the Royal Asiatic Society. Printers Ltd, Singapore.Battelss M. 1937. Zür Kenntnis der Verbreitung und der Lebensweise javanischerSaugetiere.. Treubia 16: 149-164.Baushopp T. & Martucci R.W. 1968. Ruminant-like digestion of the langur monkey.Sciencee 161: 689-700.Beissingerr S.R. 1997. Integrating behaviour into conservation biology: potentialsandd limitations. Pp 23-47 in Clemmons J.R. & Buchholz R. (eds) Behavioralapproachess to conservation in the wild. Cambridge University Press,Cambridge. .Bekkeringg T.D. & Kucera K.P. 1990. The Lebakharjo forest area - natural resourcesandd human interference. Konto River Project Working Paper No. 32, Malang.Beckingg J.H., 1989. Henri Jacob Victor Sody (1892-1959). His live and work. Abiographicall and bibliographical study. Brill, Leiden.Bemmel-Lennemann N. van & Bemmel A.C.V. van 1940. De vogels van hetTenggergebergte.. Tropische Natuur 29: 93-101.Bennettt E.L. 1988. Proboscis monkeys and their swamp forests in Sarawak. Oryx22:: 69-74.Bennettt E.L. 1994. Gibbons and monkeys. P. 301 in Cranbrook, Earl of & EdwardsP.S.. (eds) A tropical rainforest. The nature of biodiversity in Borneo atBelalong,, Brunei. The Royal Geographical Society and Sun Tree Publishers,Londonn and Singapore.Bennettt E.L, Caldecott J., Kavanagh M. & Sebastian A. 1987a. Current status ofprimatess in Sarawak. Primate Conservation 8: 184-187.204 4

References ReferencesBennettt E.L, Caldecott J., Kavanagh M. & Sebastian A. 1987b. Current status ofprimatess in Sarawak. Primate Eye 29: 25-30.Bennettt E.L, Caldecott J. & Davisson G.W.H. 1987c. A wildlife survey of UluTemburong,, Brunei. Brunei museum Journal 6: 121-169.Bennettt E.L & Dahaban Z. 1995. Wildlife responses to disturbances in Sarawak andtheirr implications for wildlife management. Pp 66-86 in Primack R.B. andLovejoyy T.E. (eds) Ecology, conservation and management of Southeast Asianrainforests.. Yale University Press, New Haven and London.Bennettt E.L & Davies A.G. 1994. The ecology of Asian Colobines. Pp. 129-171 inDaviess A.G. & Oates J.F. (eds.) Colobine monkeys: their ecology, behaviourandd evolution. Cambridge University Press, Cambridge.Bennettt E.L & Gombek F. 1993. Proboscis monkeys of Borneo. Natural HistoryPublicationss (Borneo) Snd. Bhd. Kota Kinabalu.Bennettt E.L, Nyani A.J. & Somput J. 1994. Primates on the menu: hunting and itseffectss in Malaysian Borneo. Pp 133 in Handbook and abstracts XVth congressoff the International Primatological Society 3-8 August 1994, Bali, Indonesia.Bennettt E.L & Sebastian A.C. 1986. Social organisation and ecology of theProbosciss monkey N. larvatus in mixed coastal forest in Sarawak. InternationalJournall of Primatology 9: 233-255.Berenstainn L., Mitani J.C. & Tenaza R.R. 1986. Effects of El Nino on habitat andprimatess in East Kalimantan. Primate Conservation 7: 54-55.Bennettt E.L & Bree P.J.H. van 1986. On a collection of bats and rats (Mammalia:Chiropteraa and Rodentia) from the Kangean islands. Zeitschrift fürSaugetierkundee 51: 329-344.Bennettt E.L & Rozendaal F.G. 1982. Notes on Rhinolophus Lacépéde 1799 fromSulawesi.. Bijdragen Dierkunde 52: 169-174.Bennettt E.L & Rozendaal F.G. 1988. Notes on a collection of fruit bats fromSulawesii and some off-lying islands (Mammalia, megachiroptera). ZoologischeMededelingen,, Leiden 248: 1-74.Beudelss R.C. & Hardi H.B. 1980. Bromo-Tengger/Gunung Semeru proposednationall park management plan 1981-1985. Food and Agricultural Organisationoff the United Nations, Denpasar.Bibbyy C.J., Burgess N.D. & Hill D.A. 1992a. Bird census techniques. AcademicPress,, London.Bibbyy C.J., Collar N.J., Crosby M.J., Heath M.F., Imboden Ch., Johnson T.H.,Longg A.J., Stattersfield A.J. & Thirgood S.J. 1992b. Putting biodiversity on themap:: priority areas for global conservation. International Council for BirdPreservation,, Cambridge.Bismarkk M. 1994. Konsumsi pakan Bekantan {N. larvatus) di hutan mangrove,Tamann Nasional Kutai, Kalimantan Timur. Kongres I Apapi dan SeminarNasionall Primata III. Depok 13-14 May 1994. Pusat Studi BiodiversitasUniversitass Indonesia, Depok.Bismarkk M. 1999 Bekantan dan pelestariannya. Suara Satwa 3: 9-11.205 5

ForestForest (and) PrimatesBlondall J. 1985. Habitat selection in island versus mainland birds. Pp 477-5166 in Cody M.L. (ed). Habitat selection in birds. Academic Press,Neww York.Blouchh R.A. 1997. Distribution and abundance of orangutan {Pongo pygmeus) andotherr primates in the Lanjak Entimau wildlife reserve, Sarawak, Malaysia.Tropicall Biodiversity 3: 259-274.Blundelll A.G. 1996. A preliminary checklist of mammals at Canbang Panti researchstation,, Gunung Palung National Park, West Kalimantan. Tropical Biodiversity3:: 251-259.Bodmerr R.E., Mather R.J. & Chivers D.J. 1991. Rain forests of central Borneothreateneddby modern development. Oryx 25: 21 -26.Bookhoutt T. A. 1994. Research and management techniques for wildlife andhabitats.. The Wildlife Society. Bethesda, Maryland.Boonratana,, R. 2000. Ranging behavior of proboscis monkeys (Nasalis larvatus) inthee Lower Kinabatangan, Northern Borneo. International Journal ofPrimatologyy 21: 497-518.Brandon-Joness D. 1978. The evolution of recent Asian Colobinae. Pp. 323-325 inChiverss D.J. & Joysey K.A. (eds) Recent advances in primatology, Vol 3:Primatee evolution. Proceedings of the sixth congress of the InternationalPrimatologicall Society, 1976. Academic Press, London.Brandon-Joness D. 1984. Colobus and leaf monkeys. Pp 398-408 in Macdonald D.(ed.)) The encyclopaedia of mammals, Vol. 1. Allen and Unwin, London.Brandon-Joness D. 1993. The taxonomie affinities of the Mentawai Islands Surili,PresbytisPresbytis potenziani (Bonaparte, 1856) (Mammalia: Primates:Cercopithecidae).. Raffles Bulletin of Zoology 41: 331-357.Brandon-Joness D. 1995a. A revision of the Asian pied leaf monkeys (Mammalia:Cercopithecidae:: Superspecies Semnopithecus auratus), with a description of aneww subspecies. Raffles Bulletin of Zoology 43: 3-43.Brandon-Joness D. 1995b. Presbytis fredericae (Sody, 1930), an endangeredColobinee species endemic to Central Java, Indonesia. Primate Conservation 16:68-70. .Brandon-Joness D. 1996a. The Asian colobinae (Mammalia; Cercopithecidae) asindicatorss of Quartenary climatic change. Biological Journal Linnean Society59:: 327-350.Brandon-Joness D. 1996b. Presbytis species sympatry in Borneo versus alloparty inSumatra:: an interpretation. Pp 71-76 in Tropical rainforest research - currentissues.. Edwards, S. (ed.). Kluwer, Dordrecht.Brandon-Joness D. 1997. The zoogeography of sexual dichromatism in the Borneangrizzledd surili, Presbytis comata (Desmarest 1822). Sarawak Museum Journal50:: 177-200.Brockelmann W.Y. & Ali R. 1987. Methods of surveying and sampling forestprimatee populations. Pp 23-62 in Marsh C.W. & Mittermeier R.A. (eds) Primateconservationn in the tropical rain forest. Alan Liss, New York.206 6

References ReferencesBrockelmann W.Y. & Srikosamatara S. 1993. Estimation of density of gibbongroupss by use of loud calls. American Journal Primatology 29: 93-108.Brockelmann W.Y., Reichard U., Treesucon U. & Raemaekers J.J. 1998. Dispersal,pairr formation and social structure in gibbons (Hylobates lar). BehaviouralEcologyy and Sociobiology 42: 329-339.Brookss T.M., Pimm S.L. & Collar N.J. 1997. Deforestation predicts the number ofthreatenedd birds in insular South-east Asia. Conservation Biology 11: 382-394.Brotoisworoo E. 1983. Population dynamic of lutung (Presbytis cristata) inPananjung-Pangandarann nature reserve, West Java. Pp 1-24 in Training courseonn wildlife ecology, May 5-June 15, 1983. Biotrop, Bogor.Brotoisworoo E. & Dirgayusa I.W.A. 1991. Ranging and feeding behavior ofPresbytisPresbytis cristata in the Pangandaran nature reserve, West Java, Indonesia. Pp115-1188 in Ehara A., Kimura T., Takenaka O. & Dirgayusa M. (eds)Proceedingss of the Xlllth Congress of the International Primatological Society.Elsevierr Science, The Hague.Brugieree D. & Fleury M.-C. 2000. Estimating primate densities using home rangeandd line transect methods: a comparative test with the black colobus monkeyColobusColobus satanas. Primates 41: 373-382.Bucklandd ST., Anderson D.R., Burnham K.P. & Laake J.L. 1993. Distancesampling.. Estimating abundance of biological populations. Chapman and Hall,London. .Biinnemeyerr H.A.B. 1918. Een tocht naar het Diëngplateau (20-29 januari, 1917).Tropischee Natuur 8: 43-48 / 69-74 / 101-104 / 122-124 / 135-138.Burnhamm C.P. 1984. Soils. Pp 137-152 in Whitmore T.C. (ed). Tropical forests ofthee Far East. Oxford University Press, Oxford.Caldecottt J. 1992. Hunting pattern and their significance in Sarawak. Pp 245-260 inIsmaill G., Mohamed M. & Omar, S. (eds) Forest biology and conservation inBorneo.. Center for Borneo Studies Publication No. 2, Kota Kinabalu.Chariff R.A., Mitchell S. & Clark C.W. 1995. Canary 1.2 user's manual. CornellLaboratoryy of Ornithology, Ithaca, New York.Chasenn F.N. 1940. A handlist of Malaysian mammals. Bulletin Raffles Museum 15:1-209. .Chiverss D.J. 1974. The Siamang in Malaysia: a field study of a primate in tropicalrainn forest. Contributions to Primatology 4. Karger, Basel.Chiverss D.J. 1992. Socio-ecology and conservation of gibbons in Southeast Asiawithh special reference to Borneo. Pp 230-244 in Ismail G., Mohamed M. &Omarr S. (eds). Forest biology and conservation in Borneo. Center for BorneoStudiess Publication No. 2. Yayasan Sabah, Kota Kinabalu.Chiverss D.J. & Burton K.M. 1988. Some observations on the primates ofKalimantann Tengah, Indonesia. Primate Conservation 9: 138-146.Chiverss D.J. & Raemaekers J.J. 1980. Long-term changes in behaviour. Pp 209-260inn Chivers D.J. (ed) Malayan forest primates. Ten years' study in tropical rainforest.. Plenum Press, New-York and London.207 7

ForestForest (and) PrimatesClearyy M. & Eaton E. 1992. Borneo, change and development. Oxford UniversityPress,, Oxford.Clemmonss J.R. & Buchholz R. 1997. Linking conservation and behavior. Pp 3-22inn Clemmons J.R. & Buchholz R. (eds) Behavioral approaches to conservationinn the wild. Cambridge University Press, Cambridge.Collarr N.J. et al. 2001. Threatened birds of Asia. BirdLife International, Cambridge(inn press).Collinss L. & Roberts M. 1978. Arboreal folivores in captivity -maintenance of adelicatee minority. Pp 5-12 in Montgomery G.G. (ed) The ecology of arborealfolivores.. Smithsonian Institute Press, Washington.Cowlishaww G. 1992. Song function in gibbons. Behaviour 121:131-153.Cowiishaww G. & Dunbar R.I.M. 2000. Primate conservation biology. University ofChicagoo Press, London and Chicago.Corbett G.B. & Hill J.E. 1992. The mammals of the Indomalayan region: asystematicc review. Natural History Museum Publications, Oxford UniversityPress,, Oxford.Dallmannn R. & Geissmann T. 2001. Individuality in the female songs of wildsilveryy gibbons {Hylobates moloch) on Java, Indonesia. Contributions toZoologyy 70: 41-50.Daviess A.G. 1987. Adult male replacement and group formation in Presbytisrubicunda.rubicunda. Folia Primatologica 49: 111-114.Daviess A.G. 1988. Seed-eating by red leaf monkeys {Presbytis rubicunda) indipterocarpp rain forest of northern Borneo. International Journal of Primatology12:: 119-144.Daviess A.G. & Baillie L.C. 1988. Soil-eating by the red leaf monkey {Presbytisrubicunda)rubicunda) in Sabah, North Borneo. Biotropica 20: 252-258.Daviess A.G. & Payne J. 1982. A faunal survey of Sabah. WWF-Malaysia andSabahh Foundation, Kota Kinabalu.Daviess A.G., Bennett E.L. & Waterman P.G. 1988. Food selection by two South-Eastt Asian colobine monkeys {Presbytis rubicunda and P. melalophos) inrelationn to plant chemistry. Biological Journal of the Linnaean Society 34: 33-56. .Daviss D.D. 1962. Mammals of the lowland rain-forest of North Borneo. BulletinNaturall Museum Singapore 31: 1-130.Davisonn G.W.J. 1997. Bird observations in the Muratus mountains, SouthKalimantan.. Kukila 9: 114-121.Deflerr T.R. & Pintor D. 1985. Censussing primates by transects in a forest ofknownn population density. International Journal of Primatology 6: 243-259.Dekkerr R.W.R.J. 1990a. Conservation and biology of Megapodes (Megapodiidae,Galliformes,, Aves). PhD thesis, University of Amsterdam.Dekkerr R.W.R.J. 1990b. The distribution and status of nesting grounds of the maleoMacrocephalusMacrocephalus maleo in Sulawesi, Indonesia. Biological Conservation 51:150. .208 8

References ReferencesDjuwantokoo 1991. Habitat use of silver leaf monkey (Semnopithecus auratus E.Geoffroy,, 1812) in teak (Tectona grandis Linneaus F.) plantation of Cepu,Centrall Java, Indonesia. Unpubl. Ph.D. thesis, University of the Phillipines, LosBanos. .Djuwantoko,, Sulthoni A. Yuliani U. & Komarudin H. 1994. Diet and feedingbehaviourr of Silvered langurs in Teak plantation forest. Kongres I Apapi danSeminarr Nasional Primata III. Depok 13-14 May 1994. Pusat StudiBiodiversitass Universitas Indonesia, Depok.Dobsonn A.P., Rodriques J.P., Roberts W.M. & Wilcove D.S. 1997. Geographicdistributionn of endangered species in the United States. Science 275: 550-553.Docterss van Leeuwen W. 1926. Uit het leven van planten en dieren op de top vandee Pangrango. Ilia De dieren. Tropische Natuur 15: 57-65.Duckworthh J.W., Timmins R.J., Andersson G.Q.A., Thewlis R.M., Nemeth E.,Evanss T.D., Dvorak M. & Cozza K.E.A. 1995. Notes on the status andconservationn of the gibbon Hylobates (Nomascus) gabriellae in Laos. TropicalBiodiversityy 3: 15-27.Erftemeijerr P., Balen S. van & Djuharsa E. 1988. The importance of Segara Anakanforr nature conservation, with special reference to its avifauna. Report No. 5.PHPP A-Asian Wetland Bureau-Inter wader, Bogor.Eudeyy A.A. 1987a. Action Plan for Asian Primate Conservation: 1987-1991.IUCN/SSCC Primate Specialist Group, Gland.Eudeyy A.A. 1987b. Priorities in Asian primate conservation. Primate Conservation8:172-174. .Eudeyy A.A. 1996/1997. Asian primate conservation - The species and theIUCN/SSCC primate specialist network. Primate Conservation 17:101-110.Fashingss P.J. & Cords M. 2000. Duirnal primate densities and biomass in theKakamegaa Forest: an evaluation of census methods and a comparison withotherr forests. American Journal of Primatology 50: 139-152.Foeadd N. 1995. Exploration report 1993-1994 Kayan Mentarang. WWF-Indonesia,Jakarta. .Frankell O.H. & Soulé M.E. 1981. Conservation and evolution. CambridgeUniversityy Press, Cambridge.Frederikssonn G.M. & de Kam T. 1999. Strategic plan for the conservation of theSungaii Wain protection forest, East Kalimantan. International Ministry ofForestryy and Estate Crops - Tropenbos Kalimantan Project, Balikpapan.Fullerr D.O. & Fuik M. 1998. Satelite remote sensing of the 1997-198 fires inIndonesia:: data, methods and future perspectives. WWF-Indonesia, Jakarta.Gastonn K.J. 1996. Species-range-size distributions: patterns, mechanisms andinplications.. Trends Ecology Evolution 11: 197-201.Gautierr J.-P. 1988. Interspecific affinities among guenons as deduced fromvocalizations.. Pp. 194-226 in Gautier-Hion A., Bourlière F., Gautier J.-P. &209 9

ForestForest (and) Prima tesKingdonn J. (eds) A primate radiation. Evolutionary biology of the Africanguenons.. Cambridge University Press, Cambridge and New York.GECC 1998. Guidelines for monitoring and evaluation for biodiversity projects.Biodiversityy Series Paper no. 065. Global Environment Coordination, WorldBank,, Washington.Geissmannn T. 1993. Evolution of communication in gibbons (Hylobatidae). Ph.D.thesis,, Anthropological Institute, Philosoph. Faculty II, Zurich University.Geissmannn T. 1994. Systematik der Gibbons. Zeitschrift des Kölner Zoo 37:65-77.Geissmannn T. 1995. Gibbon systematics and species identification. InternationalZooo News 42:467-501.Geissmannn T. 1999. Duet songs of the siamang, Hylobates syndactylus: II. Testingthee pair-bonding hypothesis during a partner exchange. Behaviour 136:1005-1039. .Geissmannn T. 2000. Gibbon songs and human music in an evolutionary perspective.Pp.. 103-123 in Wallin N.L., Merker B. & Brown S. (eds) The origins of music.MITT Press, Cambridge, Massachusetts.Geissmannn T. 2001. Taxonomy and evolution of gibbons. EvolutionaryAnthropologyy (Supplement), (in press).Geissmannn T. & Nijman V. 1999. Do male Javan gibbons have anything to say?Foliaa Primatologica 71: 225Geissmannn T. & Orgeldinger M. 1995. Neonatal weight in gibbons {Hylobatesspp.).. American Journal of Primatology 37: 179-189.Geissmannn T. & Than V.N. 2001. Preliminary results of a primate survey innortheasternn Vietnam with special reference to gibbons. Asian Primates 7: 1-4.Gittinss S.P. 1984a. The vocal repertoire and song of the agile gibbon, pp. 354-375inn Preuschoft H., Chivers D.J., Cheney D.C., Seyfarth R.M., Wrangham P.W. &Strushakerr T.T. (eds) The Lesser Apes: evolutionary and behavioral biology.Universityy of Chicago Press, ChicagoGittinss S.P. 1984b. Territorial advertisement and defence in gibbons, pp. 420-424 inPreuschoftt H., Chivers D.J., Cheney D.C., Seyfarth R.M., Wrangham P.W. &Strushakerr T.T. (eds) The Lesser Apes: evolutionary and behavioral biology.Universityy of Chicago Press, ChicagoGittinss S.P. & Raemaekers J.J. 1980. Siamang, lar and agile gibbons. Pp 63-105 inChivers,, D.J. (ed) Malayan forest primates, ten years' study in tropical rainforest.. Plenum Press, New York and London.Glanzz W. E. 1982. The terrestrial mammal fauna of Barro Colorado Island: censusandd long-term changes. Pp 455-468 in Leigh E.G., Rand, A.S. & Windsor,D.M.. (eds) The ecology of a tropical forest. Smithsonian Institute Press,Washington. .Goldammerr J.G., Schindele W., Seibert B., Hoffmann A.A. & Abbeger H. 1999.Impactss of fire on dipterocarp forest ecosystems in South East Asia. Pp 15-39 inSuhartoyoo H. & Toma T. (eds) Impacts of fire and human activities on forestecosystemss in the tropics. Proceedings 3rd international symposium on Asiantropicall forest management. Mularwarman and JIKA, Samarinda.210 0

References ReferencesGoslingg L.M. & Sutherland W.J. 2000. Behaviour and conservation. CambridgeUniversityy Press, Cambridge.Greenn K.M. 1978. Primate censussing in northern Colombia: a comparison of twotechniques.. Primates 19: 537-550.Grieser-Johnss A. 1997. Timber production and biodiversity conservation in tropicalrainn forests. Cambridge University Press, Cambridge.Groombridgee B. (ed.) 1993. 1994 IUCN red data list of threatened animals. IUCNGland,, Switzerland and Cambridge, UK.Grovess C.P. 1970. The forgotten leaf-eaters, and the phylogeny of the Colobinae.Ppp 555-587 in Napier J.R. & Napier P.H. (eds) Old World monkeys: evolution,systematicss and behavior. Academic Press, New York.Grovess C.P. 1994. Endemism in Bornean mammals. Pp 152-168 in Ismail G.,Mohamedd M. & Omar S. (eds). Forest biology and conservation in Borneo.Centerr for Borneo Studies, Kota Kinabalu.Gurmayaa K.J., Saryatiman A.B., Danardono S.M., Sibuea T.T.H. & AdiputraI.M.W.. 1992. A preliminary study on ecology and conservation of the Javaprimatess in Ujung Kulon National Park, West Java, Indonesia. Dept. Biology,Padjadjarann University, Bandung.Gurmayaa K.J., Adiputra I.M.W., Saryatiman A.B., Danardono S.M. & SibueaT.T.H.. 1995. Primate survey, population and ecology: Gunung Honje rangeUjungg Kulon National Park. Ujung Kulon National Park Project Phase II, 1993-1995.. Departemen Kehutanan and New Zealand Ministry of Foreign Affairsandd Trade, Jakarta.Gyldenstopee N. 1920. On a collection of mammals made in eastern and centralBorneoo by Mr Carl Lumholtz. Kungl. Svenska VetenskapsakademiensHandlingarr 60: 1-60.Hackerr J.E., Cowlishaw G. & Williams P.H. 1998. Patterns of African primatediversityy and their evaluation for the selection of conservation areas. BiologicalConservationn 84: 251-262.Hafferr J. 1969. Speciation in Amazonian forest birds. Science 165: 131-137.Haimofff E.H. 1984. Acoustic and organizational features of gibbon songs. Pp. 333-3533 in Preuschoft H., Chivers D.J., Cheney D.C., Seyfarth R.M., WranghamP.W.. & Strushaker T.T. (eds) The Lesser Apes: evolutionary and behavioralbiology.. University of Chicago Press, Chicago.Haimofff E.H. 1985. The organization of song in Müller's gibbon (Hylobatesmuelleri).muelleri). International Journal of Primatology 6:173-192.Haimofff E.H., Yang X.-J., He S.-J. & Chen N. 1986. Census and survey of wildblack-crestedd gibbons (Hylobates concolor concolor) in Yunnan Province,People'ss Republic of China. Folia Primatologica 46:205-214, 1986.Harcourtt A.H. 2000. Coincidence and mismatch of biodiversity hotspots, a globalsurveyy for the order, primates. Biological Conservation 93: 163-175.211 1

ForestForest (and) PrimatesHarjantii T.D. 1996. Perilaku makan dan jenis makanan surili {Presbytis comataDesmarestt 1822) di hutan Brussel, Gunung Patuha, Ciwidey, Jawa Barat.Unpubl.. B.Sc. thesis, Universitas Padjadjaran, Bandung.Harriss K. 1996. Mt Gede Pangrango National Park. Information Book Series 2.Gede-Pangrangoo National Park, Cipanas-Cianjur.Hartertt E. 1896. List of a collection of birds made in Lombok by Mr Alfred Everett.Novit.. Zoologicum 3: 591-599.Herskovitzz P. 1968. Metachromism or the principle of evolutionary change inmammaliann tegumentary colors. Evolution 22: 556-575.Herzogg M.O. & Hohmann G.M. 1984. Male loud calls in Macaca silenus andPresbytisPresbytis johnii. A comparison. Folia Primatologica 43:189-197.Heywoodd J.C.V. 1987. Centres of plant endemism, a guide and strategy for theirconservationn (outline). IUCN, Giant.Hollowayy J.D. 1978. Butterflies and moths. Pp 255-265 in Luping M., Chin N. &Dingleyy E.R. (eds) Kinabalu, summit of Borneo. The Sabah Society, KotaKinabalu. .Hoogerwerff A. 1970. Udjung Kulon, the land of the last Javan Rhinoceros, withlocall and general data on the most important faunal species and theirpreservationn in Indonesia. Brill, Leiden.Hoogerwerff A. 1972. Verslag over een bezoek aan het Meru Beteri complex, hetBlambangan-Purwoo of Zuid Banjuwangi wildreservaat, het Ijang hoogland enhett Udjung Kulon wildreservaat Java, Indonesië, in de maanden augustus t/mnovemberr 1971. Nederlandse Commisie voor InternationaleNatuurbescherming,, Austerlitz.HooijerHooijer D.A. 1962 Quarternary langurs and macaques from the Malay Archipelago.Zoologischee Verhandelingen, Leiden 55: 1-64.HorsfieldHorsfield T. 1824. Zoological researches in Java, and the neighbouring islands.Kingsbury,, Parbury and Allen, London.Horstt O. 1935. Een tocht naar de Segara Anak, het kratermeer van den Rindjani,Lombok.. Tropische Natuur 24: 179-186.Howardd P.C., Viskanic P., Davenport T.R.B., Kigenyi F.W., Baltzer M., DickinsonC.J.,, Lwanga J.S., Matthews R.A. & Balmford A. 1998. Complementarity andthee use of indicator groups for reserve selection in Uganda. Nature 394: 472-475. .Ionghh H.H. de, Helvoort B. van, Atmosoedidjo S. & Sutanto H. 1982. Anecologicall survey of the Kangean island archipelago in Indonesia. Unpubl.report,, IJselstein.Ionghh H.H. de, Bierhuizen, B. & Van Orden B. 1997. Observations on thebehaviourr of the dugong (Dugong dugon Miller, 1776) from the waters of theLeasee Islands, eastern Indonesia. Contributions to Zoology 67: 71-77.Istiadii Y. Priatna D. & Panekenan N. 1994. Inventarisasi dan analisis populasijenis-jeniss mamalia dan burung di Pegunungan Muller, Kalimantan Barat-212 2

References ReferencesKalimantann Timur. Expedisi Kapuas-Mahakam 1994. Kompas Gamedia,Jakarta. .IUCNN 1994. Preliminary list of Asian primate taxa (November 1994). IUCN/SSCPrimatee Specialist Group, Gland.IUCNN 1996. 1996 IUCN red list of threatened animals. IUCN, Gland.Jaarsveldd A.S. van, Freitag S., Chown S.L., Muller C, Koch S., Hull H., BellamyC,, Krüger M., Endroody-Younga S., Mansell M.M. & Scholtz C.H 1998.Biodiversityy assessment and conservation strategies. Science 279: 2106-2108.Jablonskii D. 1987. Heritability at the species level: analysis of geographic ranges ofCreataceouss Mollusks. Science 238: 360-363.Jeffreyy S. 1982. Threats to the Proboscis monkey. Oryx 16: 337-339.Jentinkk F.A. 1897. Zoological Results of the Dutch Scientific Expedition to CentralBorneo.. The mammals. Notes Leyden Museum Vol. XIX: 26 - 76.Jepsonn P., Jarvie J.K., MacKinnon K. & Monk K.A. 2001. The end of Indonesia'slowlandd forests? Science 292: 859-861.Johnss A.D. 1985a. Differential detectability of primates between primary andselectivelyy logged habitats and implications for population surveys. AmericanJournall of Primatology 8: 31-36.Johnss A.D. 1985b. Selective logging and wildlife conservation in tropicalrainforest:: problems and recommendations. Biological Conservation 31: 355-375. .Johnss A.D. 1985c. Behavioral responses of two Malaysian primates (Hylobates larandd Presbytis melalophos) to selective logging: vocal behaviour, territoriality,andd nonemigration. International Journal of Primatology 6: 423-433.Johnss A.D. 1986. Effects of selective logging on the behavioural ecology of WestMalaysiann primates. Ecology 67: 684-694.Johnss A.D. 1992. Species conservation in managed forest. Pp 15-53 in WhitmoreT.C.. & Sayer, J.A. (eds) Tropical deforestation and species extinction.Chapmann & Hall, London.Johnss A.D. & Skorupa J.P. 1987. Responses of rain-forest primates to habitatdisturbance:: a review. International Journal of Primatology 8: 157-191.Johnsonn S.E. & Overdorff D.J. 1999. Census of Brown lemurs {Eulemur fulvussspp.)) in southeastern Madagascar: method-testing and conservationimplications.. American Journal of Primatology 47: 51-60.Joness C.B. 1998. Baseline range size distributions in primates. PrimateConservationConservation 18: 7-9.Joness D-, Dekker R.W.R.J., & Roselaar CS. 1995. The megapodes -Megapodidae.Oxfordd University Press, Oxford.Junghuhnn F. 1854. Java zijn gedaante, zijn plantentooi en zijn inwendige bouw.Deell 2. 2nd ed. C.W. Mieling, 's Gravenhage.213 3

ForestForest (and) PrimatesKartikasarii S.N. 1986. Studi populasi dan perilaku lutung {Presbytis cristata,Raffles)) di Taman Nasional Baluran, Jawa Timor. Unpublished thesis. InstitutPertaniann Bogor, Bogor.Kappelerr M. 1981. The Javan silvery gibbon (Hylobates lar moloch). Ph.D. thesis,Universitatt Basel.Kappelerr M. 1984a. The gibbon in Java. Pp 19-31 in Preuschoft H., Chivers D.J.,Cheneyy D.C., Seyfarth R.M., Wrangham P.W. & Strushaker T.T. (eds) TheLesserr Apes: evolutionary and behavioral biology. University of Chicago Press,Chicago. .Kappelerr M. 1984b. Diet and feeding behaviour of the moloch gibbon. Pp. 228-241inn Preuschoft H., Chivers D.J., Cheney D.C., Seyfarth R.M., Wrangham P.W. &Strushakerr T.T. (eds) The Lesser Apes: evolutionary and behavioral biology.Universityy of Chicago Press, ChicagoKappelerr M. 1984c. Vocal bouts and territorial maintenance in the moloch gibbon.Pp.. 376-389 in in Preuschoft H„ Chivers D.J., Cheney D.C., Seyfarth R.M.,Wranghamm P.W. & Strushaker T.T. (eds) The Lesser Apes: evolutionary andbehaviorall biology. University of Chicago Press, Chicago.KareshKaresh W.B., Frazier H. Sahjuti D., Andau M. Gombek E., Zhi I., Janczewski D. &O'Brienn S.J. 1997. Orangutan genetic diversity. In Sodaro C. (ed): Orangutanspeciess survival plan, husbandry manual. Chicago Zoological Park, Chicago.Kavanagh,, M. 1980. Invasion of the forest by an African savannah monkey:behaviourall adaptations. Behaviour 73: 238-260.Kayy R.N.B. & Davies A.G. 1994. Digestive physiology. Pp 229-249 in Davies A.G.&& Oates J.F. (eds.) Colobine monkeys: their ecology, behaviour and evolution.Cambridgee University Press, Cambridge.Kawabee M. & Mano T. 1972. Ecology and behaviour of the wild proboscis monkeyN.N. larvatus (Wurmb), in Sabah, Malaysia. Primates 13: 213-228.Kernn J.A. 1962. Observations on the habits of proboscis monkey, N, larvatus(Wurmb),, made in the Brunei Bay area, Borneo. Zoologica 49: 213-277.Kitchenerr D.J., Boeadi, Charlton L., & Maharadatunkamsi. 1990. Wild mammals ofLombokk island. Records of the Western Australain Museum, Suppl. 33: 1-129.Kohlbruggee J.H.F. 1896. Bijdragen tot de natuurlijke geschiedenis van menschen endierenn IV. Zoogdieren van den Tengger. Natuurkundig TijdschriftNederlandsch-Indiëë 55: 261-298.KoolKool K.M. 1989. Behavioural ecology of the siler leaf monkey, Trachypithecusauratusauratus sondaicus, in the Pangandaran Nature reserve, West Java, Indonesia.Unpublishedd PhD thesis, University of New South Wales, Sydney.Kooll K.M. 1992. The status of endangered primates in Gunung Halimun reserve,Indonesia.. Oryx 26: 29-33.Kooll K.M. 1993. The diet and feeding behavior of the silver leaf monkey(Trachypitecus(Trachypitecus auratus sondaicus) in Indonesia. International JournalPrimatologyy 14: 667-700.KoolKool K.M. & Croft D.B. 1992. Estimators of home range areas of arborealColobinee monkeys. Folia Primatologica 58: 210-214.214 4

References ReferencesKortee J. de 1991. Status and conservation of Indonesia's seabird colonies. Pp 225-2477 in Croxall J.P. (ed) Seabird status and conservation. ICBP TechnicalPublicationn 11. International Council for Bird Preservation, Cambridge.Kortee J. de 1989. Threats to Indonesian seabird colonies. Conservation Biology 3:527-545. .Kortee J. de & Silvius M.J. 1994. Pelicaniformes in Indonesia: status, recent changeandd management. Pp 77-93 in Croxall J.P. (ed) Seabird status and conservation.ICBPP Technical Publication 11. International Council for Bird Preservation,Cambridge. .Krebb D. 1999. Observations on the occurrence of Irrawady dolphin, Orcaellabrevirostris,brevirostris, in the Mahakam River, East Kalimantan, Indonesia. Zeitschrift fürSaiigetierkundee 64: 54-58.Krebss C.J. 1989. Ecological methodology. Harper and Row Publishers, New York.Krebss C.J. 1994. Ecology, the experimental analysis of distribution and abundance.4thh ed. Harper Collins, New-York.Ladjarr L.N. & Simanjuntak C.N. 1994. Monitoring Macaca fascicularis danPresbytisPresbytis cristata pada lokasi Citirem sampai Cibuaya, suaka margasatwaCikepuh,, Sukabumi, Jawa Barat. Kongres I Apapi dan Seminar NasionalPrimataa III. Depok 13-14 May 1994. Pusat Studi Biodiversitas UniversitasIndonesia,, Depok.Lammertinkk J.M. 1998. Woodpeckers as a tool for guiding forest management.Ostrichh 69: 435.Lammertinkk J.M. 2001. Responses of woodpeckers to selective logging and forestfragmentationn in Kalimantan -~ preliminary data. Pp 169-178 in Hillegers P.J.M.&& de Iongh H.H. (eds) The balance between biodiversity conservation andsustainablee use of tropical rain forests. Tropenbos, Wageningen.Langubb J. 1996. Penan response to change and development. Pp 103-120 in PadochC.. & Peluso P.L. (eds) Borneo in transition. People, forest, conservation, anddevelopment.. Oxford University Press, Oxford.Leightonn D.R. 1987. Gibbons: terrioriality and monogamy. Pp 135-145 in SmutsB.B.,, Cheney D.L., Seyfarth R.M., Wrangham R.W. & Struhsaker T.T (eds)Primatee societies. University of Chicago Press, Chicago and London.Lekagull B. & McNeely J.A. 1988. Mammals of Thailand. 2nd ed. Association forthee Conservation of Wildlife, Bangkok.Linsleyy M. & Nawimar A. 1994. Survey for endemic primate taxa in central Java.Unpubl.. manuscript.Lyonn M.W. 1911. Mammals collected by Dr. W. L. Abbott on Borneo and some ofthee small adjacent islands. Proceedings U.S. National Museum 40: 53 -146.MacArthurr R.H. & Wilson E.O. 1967. The theory of island biogeography.Princetonn University Press, Princeton.MacDonaldd D.W. 1982. Notes on the size and composition of groups of proboscismonkeyy (N. larvatus). Folia Primatologica 37: 95-98.215 5

ForestForest (and) PrimatesMacKinnon,, J.R. 1973. Orang-utans in Sumatra. Oryx 12: 234-242.MacKinnon,, J.R. 1974. The behaviour and ecology of wild orang-utans. AnimalBehaviourr 22: 3-74.MacKinnon,, J.R. 1984. Thee distribution and status of gibbons in Indonesia. Pp. 16-188 in Preuschoft H., Chivers D.J., Cheney D.C., Seyfarth R.M., WranghamP.W.. & Strushaker T.T. (eds) The Lesser Apes: evolutionary and behavioralbiology.. University of Chicago Press, Chicago.MacKinnon,, J.R. & Artha M.B, 1981. A national conservation plan for Indonesia,Voll V: Kalimantan. Food and Agricultural Organisation of the United Nations,Bogor. .MacKinnon,, J.R. & Artha M.B. 1982. A national conservation plan for Indonesia,Voll IV: Nusa Tenggara. Food and Agricultural Organisation of the UnitedNations,, Bogor.MacKinnon,, J.R. & MacKinnon K. 1986. Review of the protected area system inthee Indo-Malayan Realm. IUCN, Gland.MacKinnon,, J.R. & Phillipps K. 1993. A field guide to the birds of Borneo,Sumatra,, Java and Bali. Oxford University Press, Oxford.MacKinnon,, J.R., Phillipps K. & van Balen S. 1999. Burung-burung di Sumatera,Jawa,, Bali dan Kalimantan (termasuk Sabah, Sarawak dan Brunei Darussalam).Revisedd Indonesian edition. LIPI/BirdLife International, Jakarta.MacKinnon,, J.R., Smiet F. & Artha M.B. 1982. A national conservation plan forIndonesia,, Vol III Java and Bali. Food and Agricultural Organisation of theUnitedd Nations, Bogor.MacKinnon,, J.R. & Warsito 1982. Gunung Palung Nature Reserve, KalimantanBarat.. Preliminary Management Plan. UNDP/FAO Field Report, Jakarta.MacKinnonn K. 1986a. The conservation status of nonhuman primates in Indonesia.Ppp 99-126 in Benirschke K. (ed) Primates, the road to self-sustainingpopulations.. Springer Verlag, New York.MacKinnonn K. 1986b. Conservation status of Indonesian primates. Primate Eye 29:30-35. .MacKinnonn K. 1987. Conservation status of primates in Malasia with specialreferencee to Indonesia. Primate Conservation 8: 175-183.MacKinnonn K., Irving A. & Bachruddin M.A. 1994. A last chance for KutaiNationall Park - local industry support for conservation. Oryx 28: 191-198.MacKinnonn K., Hatta G., Halim H. & Mangalik A. 1996. The ecology ofKalimantan.. The Ecology of Indonesia Series Vol III. Periplus, Singapore.Marguless CR., Nicholls A.O., & Pressy R.L. 1988. Selecting networks of reservestoo maximise biological diversity. Biological Conservation 43: 63-76.Markhamm R.J. 1980. The husbandry and management of captive orangutans:problemss and opportunities. Pp. 118-131 in: Proceedings on the Great Apeconference.. Jakarta and Pangkalanbun.Mariee J.G. van & Voous K.H. 1988. The birds of Sumatra: an annotated check-list.BOUU checklist No. lO.British Ornithologists' Union, London.216 6

References ReferencesMarlerr P. & Hobbett L.1975. Individuality in a long-range vocalization of wildchimpanzees.. Zeitschrift fiir Tierpsychologie 38:97-109.Marshh C.W. 1995. Danum valley conservation area, Sabah, Malaysia, managementplann 1995-2000. Yayasan Sabah / Innoprise Corporation Sdn Bhd, KotaKinabalu. .Marshh C.W. & Wilson W.L. 1981. Effects of natural habitat differences anddisturbancee on the abundance of Malaysian primates. Malayasian Journal forappliedd Biology 10: 227-249.Maryantoo I., Mansjoer I., Sajuthi D. & Supriatna J. 1997. Morphological variationinn the Ebony and Silver leaf monkeys [Trachypithecus auratus (E. Geoffroy,1812)) and Trachypithecus cristatus (Raffles, 1821)] from Southeast Asia.Treubia31:: 113-131.Matherr R. 1992. Distribution and abundance of primates in northern KalimantanTengah:: comparisons with other parts of Borneo, and peninsular Malaysia. Pp175-1899 in Ismail G., Mohamed M. & Omar S. (eds). Forest biology andconservationn in Borneo. Center for Borneo Studies Publication No. 2. YayasanSabah,, Kota Kinabalu.McCarthyy A. (ed.). 1991. Conservation areas of Indonesia. Final Draft, WorldConservationn Monitoring Centre, Cambridge.Medwayy Lord 1970. The monkeys of Sundaland: ecology and systematics of thecercopithecidss of a humid equatorial environment. Pp 513-553 in Napier J.R &Napierr P.H. (eds) Old World monkeys: evolution, systematics and behavior.Academicc Press, New York.Medwayy Lord 1977. Mammals of Borneo. Field keys and annotated checklist.Monographss Malaysian Branch Royal Asiatic Society No 7.Meess G.F. 1989. Remarks on the ornithological parts of Horsfield's 'Zoologicalresearchess in Java'. Proceedings van de Koninklijke Nederlandse Acadademievann Wetenschappen C 92: 367-378.Meffee G.K. & Carroll C.R. 1994. Principles of conservation biology. Sinauer,Sunderland. .Meijaardd E. 1997a. The bay cat in Borneo. Cat News Letter 27: 21-23.Meijaardd E. 1997b. The importance of swamp forest for the conservation of orangutanss(Pongo pygmeus) in Kalimantan, Indonesia. In Page S.E. & Rieley J.O.(eds).. Proceedings of the international symposium on the biodiversity,environmentall importance and sustainability of tropical peat and peatlands.Meijaardd E. & Nijman V. 2000. Distribution and conservation of the proboscismonkeyy (Nasalis larvatus) in Kalimantan, Indonesia. Biological Conservation92:: 15-24.Megantaraa E.N. 1994. A preliminary study on social behaviour of lutung{Trachypithecus{Trachypithecus auratus sondaicus) in Pangandaran nature reserve. KongresApapii dan Seminar Nasional Primata III. Depok 13-14 May 1994. Pusat StudiBiodiversitass Universitas Indonesia, Depok.217 7

ForestForest (and) PrimatesMelishh R. & Dirgayusa I.W.A. 1996. Notes on the grizzled leaf monkey {Presbytiscomata)comata) from two nature reserves in West Java, Indonesia. Asian Primates 6: 5-11. .Millerr G.S. 1903. Seventy new Malayan mammals. Smithsonian MiscellaneousCollectionss 45: 1-73.Ministryy of Forestry 1994. Tanjung Puting National Park Management Plan 1994-2019.. Volume II. Ministry of Forestry, Directorate General of Forest Protectionandd Nature Conservation. World Bank, Loan No. 3423 - IND. Indonesia,Bogor. .Ministryy of Forestry 1999. Kronologis evakuasi bekantan dan rehabilitasi cagaralamm Pulau Kaget. In Peningkatan Kesadaran dan Peran Masyarakat TerhadapPelestariann Bekantan. KSBK and KEHATI, Surabaya.Mitanii J.C. 1984. The behavioral regulation of monogamy in gibbons {Hylobatesmuelleri).muelleri). Behavioral Ecology and Sociobiology 15:225-229.Mitanii J.C. 1985a. Gibbon song duets and intergroup spacing. Behaviour 92:59-96.Mitanii J.C. 1985b. Location-specific responses of gibbons {Hylobates muelleri) tomalee songs. Zeitschrift fiir Tierpsychologie 70:219-224.Mitanii J.C. 1985c. Sexual selection and adult male orangutan long calls. AnimalBehaviourr 33:272-283.Mitanii J.C. 1987. Territoriality and monogamy among agile gibbons {Hylobatesagilis).agilis). Behavioral Ecology and Sociobiology 20:265-269.Mitanii J.C. 1988. Male gibbon {Hylobates agilis) singing behavior: natural history,songg variations and function. Ethology 79: 177-194.Mitanii J.C. 1990. Demography of agile gibbons {Hylobates agilis). InternationalJournall of Primatology 11: 411-424.Mitanii J.C, Strushaker T.T. & Lwanga J.S. 2000. Primate community dynamics inoldd growth forest over 23.5 years at Ngogo, Kibale National Park, Uganda:implicationss for conservation and census methods. International Journal ofPrimatologyy 21: 269-286.Mittermeierr R.A. 1987. Effects of hunting on rain forest primates. Pp 109-146 inMarshh C.W. & Mittermeier R.A. (eds). Primate conservation in tropical rainforest.. Alan R. Liss, New York.Mittermeierr R.A. & Konstant W.R. 1996/1997. Primate conservation: aretroperspectivee and a look into the 21st century. Primate Conservation 17: 7-17. .Mombergg F., Jepson R. & van Noord H. 1998. Justification and boundary proposalforr a new protected area in the Sebaka-Sembukung region, East Kalimantan, anareaa with international significance of global diversity. WWF/EPIQ/USAID,Jakarta. .Myerss N. 1988. Threatened biotas: 'hotspots' in tropical forests. Environmentalist 8:187-208 8Myerss N. 1989. A major extinction spasm: predictable or inevitable. Pp 42-49 inWesternn D. & Pearl M.C. (eds) Conservation in the twenty-first century. OxfordUniversityy Press, New York and Oxford.218 8

References ReferencesMyerss N. 1990. The biodiversity challenge: expanded hotspot analysis.Environmentalistt 10: 243-256.Myerss N., Mittermeier R.A., Mittermeier C.G., da Fonseca G.A.B. & Kent J. 2000.Biodiversityy hotsports for conservation priorities. Nature 403: 853-858.Nadlerr T. & Long H.T. 2000. The Cat Bai langur: past, present and future. Thedefinitivee report on Trachypithecus poliocephalus, the World's rarest primate.Frankfurtt Zoological Society, Frankfurt.Napierr P.H. 1985. Catalogue of primates in the British Museum (Natural History)andd elsewhere in the British Isles. Part III: Familie Cercopithecidae, subfamilyColobinae.. British Museum (Natural History), London.Newtonn P.N & Dunbar R.I.M. 1994. Colobine monkey society. Pp 311-346 inDaviess G.A. & Oates J.F. (eds) Colobine monkeys, their ecology, behaviourandd evolution. Cambridge University Press, Cambridge.Niemitzz C. 1984. Biology of Tarsiers. Gustav Fischer, Stuttgart.Nijmann V. 1995. Remarks on the occurrence of gibbons in Central Java. PrimateConservationn 16: 66-67.Nijmann V. 1997a. Geographical variation in pelage characteristics in Presbytiscomatacomata (Desmarest, 1822) (Mammalia: Primates: Cercopithecidae). Zeitschriftftirr Saiigetierkunde 62: 257-264.Nijmann V. 1997b. On the occurrence and distribution of Presbytis comata(Desmarest,, 1822) (Mammalia: Primates: Cercopithecidae) on Java, Indonesia.Contributionss to Zoology 66: 247-256.Nijmann V. 1997c. Preliminary survey on colobine monkeys and other primates innorth-easternn Kalimantan. Zoological Museum University of Amsterdam andWorldd Wide Fund for Nature-Indonesia, Amsterdam and Jakarta.Nijmann V. 2001. Effect of behavioural changes due to habitat disturbance ondensityy estimation in rain forest vertebrates, as illustrated by gibbons(Hylobatidae).. Pp 217-225 in Hillegers P.J.M. & de Iongh H.H. (eds) Thebalancee between biodiversity conservation and sustainable use of tropical rainforests.. Tropenbos, Wageningen.Nijmann V. & van Balen S. 1998. A faunal survey of the Dieng Mountains, CentralJava,, Indonesia: distribution and conservation of endemic primate taxa. Oryx32:: 145-156.Nijmann V. & Setiawan I. 2001. Penelaian sepintas keragaman fauna di PegununganDiengg / Rapid assessment of faunal diversity in the Dieng Mountains. YPAL,Bandung. .Nijmann V. & Sözer R. 1995. Recent observations of the Grizzled leaf monkeyPresbytisPresbytis comata and an extension of the range of the Javan gibbon Hylobatesmolochmoloch in Central Jawa. Tropical Biodiversity 3: 45-48.Nijmann V. & Sözer R. 1996. Konservasi Elang Jawa dan jenis-jenis burungendemikk Jawa lainnya: Daerah prioritas kawasan konservasi di Jawa Tengah /ConservationConservation of the Javan Hawk-eagle and other endemic bird species on Java:219 9

ForestForest (and) PrimatesPriorityy areas for protection in Central Java. PHPA/BirdLife International-Indonesiaa Programme Technical Memorandum 11.Noorr Y.R. & Hanafia E.W. 1994. A preliminary survey on the ecological potentialoff the Cagar Alam Muara Kendawangan, West Kalimantan. Directorate Generaloff Forest Protection and Nature Conservation (PHPA) and Asian WetlandBureau,, Bogor.NRCC (National Research Council) 1981. Techniques for the study of primatepopulationn ecology. National Academy of Science, Washington, DC.Nursaidd R. 1998. Pentunjuk praktis monitoring pasar burung. KSBK, Malang.Nursaidd R. 1999. Dibalik kasus evakuasi bakantan dari Pulau Kaget. In PeningkatanKesadarann dan Peran Masyarakat Terhadap Pelestarian Bekantan. KSBK andKEHATI,, Surabaya.Nursaidd R. & Astuti M. 1996. Survey perdagangan burung di pasar Malang(januari-julii 1996). KSBK, Malang.Nursaidd R., Astuti M., Tohari H. & Jasri M.I. 1996. Inventarisasi burung danmamaliaa di Pulau Sempu Jawa Timur: KSBK, Malang.Oatess J.F. & Trocco, T.F. 1983. Taxonomy and phylogeny of black-and-whitecolobuss monkeys. Inferences from an analysis of loud call variation. FoliaPrimatologicaa 40:83-113.Oatess J.F., Davies G.A. & Delson E. 1994. The diversity of living colobines. Pp 45-744 in Davies G.A. & Oates J.F. (eds) Colobine monkeys, their ecology,behaviourr and evolution. Cambridge University Press, Cambridge.Okaa T., Iskandar E. & Ghozali D.I. 2000. Impact of logging on the behaviour ofgibbons.. Pp 229-238 in Fatawi M., Sutisna M., Mori T. & Ohta S. (eds). Rainforestt ecosystems of East Kalimantan. Springer Verlag, Tokyo.Padochh C. & Peluso N.L. 1996. Borneo in transition: people, forest, conservationandd development. Oxford University Press, Kuala Lumpur.Park,, C.C. 1994. Tropical rainforests. Routledge, London and New York.Paynee J., Francis CM. & Phillipps K. 1985. A field guide to the mammals ofBorneo.. World Wildlife Fund and Sabah Society, Kuala Lumpur and KotaKinabalu. .Pocockk R.I. 1935. The monkeys of the genera Pithecus (or Presbytis) and Pygathrixfoundd to the east of the Bay of Bengal. Proceedings of the Zoological SocietyLondonn 1934:895-961.Pfefferr P. 1958. Situation actuelle de quelques animaux menaces d'Indonesie. LaTen-eett la Vie 105: 128 - 145.Pfefferr P. 1965. Esquisse ecologique de la Réserve de Baluran (Java Est). La TerreetlaViee 112: 197-215.Plumtree AJ. 2000. Monitoring mammal populations with line transect techniques inAfricann forest. Journal of Applied Ecology 37: 356-368.220 0

References ReferencesPrendergastt J.R., Quinn R.M., Lawton J.H., Eversham B.C. & Gibbons D.W., 1993.Raree species, the coincidence of diversity hotspots and conservation strategies.Naturee 365: 335-337.Presseyy R.L., Humphries C.J., Margules C.R., Vane-Wright R.I. & Williams P.H.1993.. Beyond opportunism: key principles for systematic Reserve selection.Trendss Ecology Evolution 8: 124-128.Prestonn F.W. 1960. Time and space and the variation of species. Ecology 41: 611-627. .Prestonn F.W. 1962. The canonical distribution of commoness and rarity. Ecology43:: 185-215.Priemee A. & Heeregaard M. 1988. A visit to Gunung Niut in West Kalimantan.Kukila3:: 138-140.Raemaekerss J.J. & Raemaekers P.M. 1985a. Field playback of loud calls to gibbons(Hylobates(Hylobates lar): territorial, sex-specific and species-specific responses. AnimalBehaviorr 33:481-493.Raemaekerss J.J., Raemaekers P.M. & Haimoff E.H. 1984. Loud calls of the gibbon(Hylobates(Hylobates lar): Repertoire, organization and context. Behaviour 91:146-189.Raemaekerss P.M. & Raemaekers J.J. 1985b. Long-range vocal interactions betweengroupss of gibbons (Hylobates lar). Behaviour 44: 26-44.Rajj D. 1968. Sampling theory. MacGraw-Hil, New-York.Rappartt F.W. 1941. Loetoengs (Trachypithecus pyrrhus). Tropische Natuur 30: 55-58. .RePPProTT 1990. The land resources of Indonesia: a national overview from theregionall and physical planning program for transmigration: plates I-XIV. LandResourcess Departement, National Institute Overseas DevelopmentAdministrationn and Directorat Bina Program, Directorat PenyiapanPemukiman,, Departmen Transmigrasi, London and Jakarta.Reynoldss R.T., Scott J.M. & Nussbaum R.A. 1980. A variable circular plot methodforr estimating bird numbers. Condor 82: 309-313.Ricee C.G. 1989. A further range extension of the black-breasted trushChlamydochaeraChlamydochaera jefferyi in Kalimantan. Kukila4: 47-48.Rijksenn H.D. & Meijaard E. 2000. Our vanishing relative. The status of wild orangutanssat the close of the twentieth century. Kluwer, Dordecht.Rinaldii D. 1999. Food preferences and habitat utilization of Java gibbon (Hylobatesmolochmoloch Audebert) in Ujung Kulon National Park, West Java, Indonesia. M.Sc.thesiss Georg-August University Gottingen, Germany.Robinsonn J.G. & Bennett E.L. 2000. Hunting for sustainability in tropical forests.Columbiaa University Press, Vancouver.Robinsonn H.C & Kloss C.B. 1919. On five new mammals from Java. Ann. Mag.Nat.. Hist. (9) 4: 364-378.Rodmann P.S. 1978. Diets, densities and distributions of Bornean primates. Pp 465-4788 in Montgomery G.G. (ed) The ecology of arboreal folivores. SmithsonianInstitutee Press, Washington.221 1

ForestForest (and) PrimatesRodmann P.S. 1988. Resources and group sizes of primates. Pp. 83-108 inSlobodchikofff C.N. (ed) The ecology of social behavior. Academic Press, SanDiegoo etc.Rombangg W.M. & Rudyanto 1999. Dearah penting bagi burung di Jawa dan Bali.PKA/BirdLifee International Indonesia Programme, Bogor.Rosenblumm L.L., Supriatna J., Hasan M.N. & Melnick D.J. 1997. Highmitochondriall DNA diversity with little structure within and among leaf monkeypopulationss {Trachypithecus cristatus and Trachypithecus auratus).Internationall Journal of Primatology 18: 1005-1028.Rowee N. 1996. The pictorial guide to the living primates. Pogonias Press, EastHampton,, NY.Ruhiyatt Y. 1983. Socio-ecological study of Presbytis aygula in West Java. Primates24:: 344-359.Ruhiyatt Y. 1991. Observations of Presbytis aygula in two localities of Java.Comparativee Primatological Monographs 3:149-191.Salterr R.E. & MacKenzie N.A. 1985. Conservation status of proboscis monkey inSarawak.. Biological Conservation 33: 119-132.Salterr R.E., MacKenzie N.A., Nightingale N., Aken K.M. & Chai P.P.K. 1985.Habitatt use, ranging behaviour and food habits of the Proboscis monkey N.larvatuslarvatus (van Wurmb) in Sarawak. Primates 26: 436-451.Schaikk C.P. van & Noordwijk M.A. van 1985. Evolutionary effect of the absence offelidss on the social organisation of the macaques on the island of Simeulue(Macaca(Macaca fascicularis fusca, Miller 1903). Folia Primatologica 44: 138-147.Schaikk C.P. van, Noordwijk M.A. van, Warsono B. & Sutriono E. 1983. Party sizeandd early detection of predators in Sumatran forest primates. Primates 24: 211-221. .Scottt J.M., Anderson H., Davis F., Caicoo S., Csuti B., Edwards T.C.J., Noss R.,Ullimann J., Groves C. & Wright R.G. 1993. Gap analysis: a geographicapproachh to protection of biological biodiversity. Wildlife Monographs 123: 1-41. .Sebastiann A.C. 1994. A preliminary investigation of the proboscis monkeypopulationn in Danau Sentarum Wildlife Reserve, Western Kalimantan,Indonesia.. Directorate General for Forest Protection and Nature Conservation(PHPA)) and Asian Wetland Bureau, Bogor.Seibtt U. & Wickler, W. 1982. Rolle des Duettierens im Leben der Vogel. Pp. 351-3522 in Max-Planck-Gesellschaft Jahrbuch 1982. Verlag Vandenhoeck andRuprecht,, Göttingen.Seitree L. & Seitre J. 1990. Recent sightings of rare primates on Java. PrimateConservationn 11: 18.Senn A.R. 1982. A review of some important techniques in sampling wildlife.Canadiann Wildlife Service Occasional paper 49: 1-16.222 2

References ReferencesSeuanezz H. , Evans H.J. Martin D.E. & Fletcher J. 1979. An inversion inchromosomee 2 that distinguishes between Bornean and Sumatran orangutans.Cytogeneticc Cellulair Genetics 23: 137-140.Siegell S. 1956. Nonparametric statistics for the behavioral sciences. McGraw-Hill,Auckland. .Silviuss M.J., Steeman A.P.J.M., Berczy E.T., Djurharsa E. & Taufik A.W. 1987.Thee Indonesia wetland inventory. A preliminary compilation of excistinginformationn on wetlands of Indonesia. PHPA - AWB/Interwader - Edwin,Bogor. .Siraitt M., Prasodjo S., Podger N., Flavele A. & Fox J. 1994. Mapping customarylandd in East Kalimantan, Indonesia: a tool for forest management. Ambio 23:411-417. .Skorupaa J.P. 1987. Do line transects systematically underestimate primate densitiesinn logged forest? American Journal of Primatology 13: 1-9.Sluyss R. 1999. Global diversity of land planarians (Platyhelminthes. Tricladida.Terricola):: a new indicator-taxon for global biodiversity and conservationstudies.. Biodiversity and Conservation 8: 1663-1681.Smiett A.C. 1990. Forest ecolgy on Java: conversion and usage in a historicalperspective.. Journal of Tropical Forest Science 2: 286-302.Smiett A.C. 1992. Forest ecology on Java: human impact and vegetation of montaneforest.. Journal of Tropical Ecology 8: 129-152.Smutss B.B., Cheney D.L., Seyfarth R.M., Wrangham R.W. & Struhsaker T.T.1986.. Primate societies. University of Chicago Press, Chicago and London.Smythiess B.E. 1981. The birds of Borneo (3th ed.). The Sabah Society and theMalayann Nature Society, Kuala Lumpur.Sodyy H.J.V. 1930a. Pithecus aygula fredericae n. subsp. Tropische Natuur 19: 68.Sodyy H.J.V. 1930b. On some new and insufficiently known mammals from Java,Borneoo and Celebes. Natuurkundig Tijdschrift voor Nederlandsch Indië 90:258-273. .Sodyy H.J.V. 1949. Notes on some primates, carnivora, and the babirusa from theIndo-Malayann and Indo-Australian regions. Treubia 20: 121-190.Sözerr R. 1997. Fabulous pheasants. Pp 112-113 in Jepson P. & Ounsted R. (eds).Birdingg Indonesia, a birdwatchers guide to the world's largest archipelago.Periplus,, Hongkong.Sozerr R., Nijman, V., Balen S. van, Setiawan I., Prawiradilaga D.M. & Subujanto J.(1998).. Javan Hawk-eagle recovery plan. Bogor: Directorate General of ForestProtectionn and Nature Conservation (PHPA) - Indonesian Institute of Sciences(LIPI)) / BirdLife International Indonesia Programme.Sözerr R., Setiawan I. & Setiadi A.P. 2000. Local knowledge of the Borneanpeacock-pheasantt Polyplectron schleiermacheri: a critique of O'Brien et al.(1998a).. Bird Conservation International 10: 311-316.Sözerr R., Shepherd, C & Darjono 2001. First description of male Hoogerwerfspheasantt Lophura hoogerwerfi (Chasen 1939), with notes on distribution.Bulletinn British' Ornithologists' Club (in press).223 3

ForestForest (and) PrimatesStampss J.A. & Buencher M. 1985. The territorial defence hypothesis and theecologyy of insular vertebrates. Quarterly Journal of Biology 60: 155-181.Steenbeekk R. & Assink P. 1998. Individual differences in long-distance calls ofmalee wild Thomas langurs {Presbytis thomasi). Folia Primatologica 69:77-80.Steeniss C.G.G.J, van 1972. The mountain flora of Java. Brill, Leiden.Steeniss C.G.G.J, van & Schippers-Lammertse, A.F.1965. Concise plant-geographyoff Java. In Backer C.A. & Bakhuizen van den Brink R.C. (eds) Flora of Java,Vol.. 2: 1-72. Noordhoff, Groningen.Steenis-Krusemann M.J. van 1950. Malaysian plant collectors and collections beingaa cyclopedia of botanical explorations in Malaysia and a guide to the concernedliteraturee up to the year 1950. Fauna Malesiana I. Noordhoff Kolff, Jakarta.Sugarjitoo J. & Sinaga, M.H. 1999. Conservation status and population distributionoff primates in Gunung Halimun National Park, West Java, Indonesia. Pp 6-12 inSupriatna,, J. & Manullang, B.O. (eds). Proceeding of the InternationalWorkshopp on Javan gibbon (Hylobates moloch): rescue and rehabilitation.Conservationn International Indonesia Program and Center for Biodiversity andConservationn Studies, Jakarta.Sugarjitoo J., Sinaga, M.H. & Yoneda M. 1997. Survey of the distribution anddensityy of primates in Gn Halimun National Park West Java, Indonesia. Pp 56-622 in The inventory of national resources in Gunung Halimun National Park.Voll II. LIPI, JICA, PHPA, Bogor.Suhartoyoo H. & Toma T. 1999. Impacts of fire and human activities on forestecosystemss in the tropics. Proceedings 3rd international symposium on Asiantropicall forest management. Mularwarman and JIKA, Samarinda.Sujatnikaa 1992. Studi habitat surili (Presbytis aygula Linneaus, 1758) dan polapenggunaanyaa di Taman Nasional Gunung Gede-Pangrango dan kawasan hutanHaurbentes-Jasinga.. Unpubl B.Sc. thesis, Institut Pertanian Bogor.Sujatnika,, Jepson P., Soehartono T.R., Crosby, M.J., & Mardiastuti A. 1995.Melestrarikann keanekaragaman hayati Indonesia: pendekatan Daerah BurungEndemikk / Conserving Indonesian biodiversity: the Endemic Bird Areaapproach.. PHPA/BirdLife International-Indonesia Programme, Jakarta.Sunderlinn W.D. & Resosudarmo I.A.P. 1996. Rates and causes of deforestation inIndonesia:: towards resolutions of ambiguities. CIFOR Occasional Paper No. 9.Supriatnaa J, Manulang B.O. & Soekara E. 1986. Group composition, home rangeandd diet of the maroon leaf monkey (Presbytis rubicunda) at Tanjung PutingReserve,, Central Kalimantan, Indonesia. Primates 27: 185-190.Supriatnaa J., Adimuntja C, Mitrasetia T., Willy E., Rufendi D., Manulang B.O.1989.. Chemical analysis of food plant parts of two sympatric monkeys(Presbytis(Presbytis aurata and Macaca fascicularis) in the mangrove forests of MuaraGembong,, West Java. Pp 161-169 in Soerianegara I., Zamora P.M.,Kartawinataa K., Umaly R.C, Tjitrosomo S., Sitompul D.M. & Syafii U.R.D.(eds)) Symposium on mangrove management: its ecological and economicalconsiderations.. Biotrop Special Publication No. 37. SEAMEO-Biotrop, Bogor.224 4

References ReferencesSupriatnaa J., Tilson R., Gurmaya K.J., Manansang J., Wardojo W., Sriyanto A.,Tearee A., Castle K. & Seal U. (eds) 1994. Javan gibbon and Javan langur:Populationn and habitat viability anal sysis report. IUCN/SSC ConservationBreedingg Specialist Group, Apple Valley, Minnesota.Suzukii A. 1984. The distribution of primates and the survey on the affection offorestt fires, 1983, in and around Kutai Nature Reserve of East Kalimantan,Indonesia.. Kyoto University Overseas Report of Studies on Asian Non-humanPrimatess 3: 55-65.Tembrockk G. 1977. Tierstimmenforschung. Die Neue Brehm-Bucherei, Heft 250.A.. Ziemsen Verlag, Wittenberg Lutherstadt.Tenazaa R.R. 1975. Territoriality and monogamy among Kloss' gibbons (Hylobatesklossi)klossi) in Siberut Island, Indonesia. Folia Primatologica 24: 60-80.Tenazaa R.R. 1976. Songs, choruses and countersinging among Kloss' gibbons{Hylobates{Hylobates klossi) in Siberut island, Indonesia. Zeitschrift fiir Tierpsychologie40:37-52. .Tenazaa R.R. 1989. Intergroup calls of male pig-tailed langurs (Simias concolof).Primatess 30:199-206.Terborghh J. & Winter B. 1983. A method for siting parks and reserves with specialreferencee to Columbia and Ecuador.Biological Conservation 27: 45-58.Theunissenn B. 1985. Eugene Dubois and the ape-man of Java: a contribution to thehistoryy of paleoantropology [in Dutch with English summary]. Ph.D. thesis,Utrechtt University.Thorpee W.H. 1961. Bird-song. The biology of vocal communication and expressioninn birds. Cambridge monographs in experimental biology No. 12. CambridgeUniversityy Press, Cambridge.Veenn R. van der. 1940. Het sterven van dieren op vulkaantoppen. Tropische Natuur20:: 27-28.Viéé J.-C. 1999. Wildlife rescues -the case of the Petit Saut hydroelectric dam inFrenchh Guiana. Oryx 33: 115-126.Voouss K.H. 1950. The breeding season of birds in Indonesia. Ibis 92: 279-287.Wallacee A.R. 1869. The Malay Archipelago: the land of the Orang-utan, and theBirdd of Paradise. Harper and Brothers, New York.Watanabee K. 1981. Variations in group composition and population density of thetwoo sympatric Mentawaian leaf monkeys. Primates 22: 145-160.Watermann P.G. & Kool K.M. 1994. Colobine food selection and plant chemistry.Ppp 251-284 in Davies A.G. & Oates J.F. (eds.) Colobine monkeys: theirecology,, behaviour and evolution. Cambridge University Press, Cambridge.Watermann P.G., Ross J.A., Bennett E.L. & Davies G.A. 1988. A comperison of thefloristicc and leaf chemistry of the tree flora in two Malaysian rain forests andthee influence of leaf chemistry on populations of colobine monkeys in the OldWorld.. Biological Journal of the Linnaean Society 34: 1-32.225 5

ForestForest (and) PrimatesWedanaa I.M. 1993. Perilaku makan pada surili {Presbytis comata comataDesmarestt 1822) di cagar alam Situ Patengan Jawa Barat. Unpubl. B.Sc. thesis,Universitass Padjadjaran, Bandung.Weitzell V. & Groves C.P. 1985. The nomenclature and taxonomy of the Colobtnemonkeyss of Java. International Journal of Primatology 6: 399-409.Weitzell V., Yang CM. & Groves C.P. 1988. A catalogue of primates in theSingaporee Zoological Reference Collection, Department of Zoology, NationalUniversityy of Singapore (formerly the Zoological Collection of the RafflesMuseum).. Raffles Bulletin of Zoology 36: 1-166.Westermannn J.H. 1938. Natuur in Zuid en Oost Borneo. Pp 334-397 in 3 jarenIndischh Natuurleven, llde jaarverslag (1936-1938). Nederlands IndischeVereenigingg tot Natuurbescherming, Batavia.Wheatleyy B.P. 1999. The sacred monkeys of Bali. Waveland Press, ProspectHeights,, Illinois.Wheatleyy B.P., Fuentes A. & Harya Putra D.K. 1993. The primates of Bali. AsianPrimatess 3: 1-2.Whitesidess G.H., Oates J.F., Green S.M. & Kluberdanz, R.P. 1988. Estimatingprimatee densities from transects in a West African rain forest: a comparison oftechniques.. Journal of Animal Ecology 57: 345-367.Whittenn A.J. 1980. The Kloss gibbon in Siberut rain forest. Ph.D. thesis, Universityoff Cambridge.Whittenn A.J. 1982a. A numerical analysis of tropical rain forest, using floristic andstructurall data, and its application to an analysis of gibbon ranging behaviour.Journall of Ecology 70: 249-271.Whittenn A.J. 1982b. The ecology of singing in Kloss gibbons {Hylobates klossii) onSiberutt Island, Indonesia. International Journal of Primatology 3:33-51.Whittenn A.J. 1982c. The gibbons of Siberut. J.M. Dent, London.Whittenn A.J. 1984. The trilling handicap in Kloss gibbons. Pp. 416-419 inPreuschoftt H., Chivers D.J., Cheney D.C., Seyfarth R.M., Wrangham P.W. &Strushakerr T.T. (eds) The Lesser Apes: evolutionary and behavioral biology.Universityy of Chicago Press, Chicago.Whittenn A.J., Soeriaatmadja R.E. & Afiff S.A. 1996. The ecology of Java and Bali,thee ecology of Indonesia series Vol II. Periplus Editions, Singapore.Wicklerr W. 1974. Duette und Paarbindung bei Tieren. Mitteilungen der Max-Planck-Gesellschaftt 1974:237-252.Wienss J.A. 1992. The ecology of bird communities Vol 1: foundations and patterns.Cambridgee studies in ecology. Cambridge University Press, Cambridge.Wilkinsonn R., Dutson G. Sheldon B., Darjono & Noor Y.R. 1991. The avifauna ofthee Barito Ulu region, Central Kalimantan. Kukila 5: 99-116.Williamss P.H., Gaston K.J. & Humphries CJ. 1997. Mapping biodiversity valueworldwide:: combining higher-taxon richness from different groups. ProceedingsRoyall Society London Series B 264: 141-148.Wilsonn C.C. & Wilson W.L. 1975. The influence of selective logging on primatesandd some other animals in East Kalimantan. Folia Primatologica 23: 245-274.226 6

References ReferencesWilsonn C.C. & Wilson W.L. 1977. Behavioral and morphological variation amongprimatee populations in Sumatra. Yearbook Physical Antropology 20: 207-233.Wilsonn W.L. 1978. Variation among primate populations in Sumatra. Pp 311-313 inChii vers D.J. & Joysey K.A. (eds) Recent advances in primatology, Vol 3:Primatee evolution, Proceedings of the sixth congress of the InternationalPrimatologicall Society, 1976. Academic Press, London.Wiltjes-Hissinkk E.A. 1953. Twee excursies naar de Tangkuban Perahu. TropischeNatuurr 33: 115-119.Woodss A. 1995. Observations on the dietary habits of proboscis monkey N.larvatus,larvatus, at Danau Sentarum Wildlife Reserve, Kalimantan Barat, Republic ofIndonesia.. Unpubl. thesis, University of Canberra.Wolfheimm J.H. 1983. Primates of the World. Distribution, abundance, andconservation.. University of Washington Press, Seattle and London.Yanuarr A., Bekti D. & Saleh C. 1993. The status of the Karimata primatesPresbytisPresbytis rubicunda carimatae and Macaca fascicularis carimatensis inKarimataa Island, Indonesia. Tropical Biodiversity 1: 157-162.Yanuarr A., Saleh C, Sugarjito J. & Wedana I.M. 1995. Density and abundance ofprimatess with special focus on West, Central, and East Kalimantan's rainforest.Indonesiann Wildlife Operation, Jakarta.Yasumaa S. 1994. An invitation to the mammals of East Kalimantan. PUSREHUTSpeciall Publication No. 3. Tropical Rain Forest Project. Japan InternationCooperationn Agency and Directorate General of Higher Education Republic ofIndonesia,, Samarinda.Yasumaa S. & Alikodra H.S. 1990. Mammals of Bukit Suharto protection forest.PUSREHUTT Special Publication 1. PUSREHUT, Samarinda.Yeagerr C.P. 1989a. Does intraspecific variation in social systems explain reporteddifferencess in the social structure of the proboscis monkey (N. larvatus).Primatess 36: 575-582.Yeagerr C.P. 1989b. Feeding ecology of the proboscis monkey (TV. larvatus).Internationall Journal of Primatology 10: 497-530.Yeagerr C.P. 1990. Proboscis monkey (N. larvatus) social organisation: groupstructure.. American Journal of Primatology 20: 95-106.Yeagerr C.P. 1991a. Proboscis monkey (N. larvatus) social organisation: nature andpossiblee functions of intergroup pattern of association. American Journal ofPrimatologyy 23: 73-86.Yeagerr C.P. 1991b. Kayan Mentarang report. Word Wildlife Fund-Indonesia,Jakarta. .Yeagerr C.P. 1993. Ecological constraints on the intergroup associations in theprobosciss monkey N. larvatus. Tropical Biodiversity 1: 89-100.Yeagerr C.P. 1996. Conservation status of proboscis monkey groups and the effectsoff habitat degradation. Asian Primates Newsletter 5: 3-5.227 7

ForestForest (and) PrimatesYeagerr C.P. 1998. Fire impact on vegetational diversity and abundance inKalimantan,, Indonesia during 1997/1998. Word Wildlife Fund-Indonesia,Jakarta. .Yeagerr C.P. & Blondal T.K. 1992. Conservation status of the proboscis monkey (N.larvatus)larvatus) at Tanjung Puting National Park, Kalimantan Tengah, Indonesia. Pp220-2288 in Ismail, G., Mohamed M. & Omar S. (eds) Forest biology andconservationn in Borneo. Center for Borneo Studies Publication No. 2, KotaKinabalu. .Yeagerr C.P. & Frederiksson G.M. 1998. Fire impacts on primates and other wildlifeinn Kalimantan, Indonesia during 1997/1998. Word Wildlife Fund-Indonesia,Jakarta. .Yeagerr C.P. & Silver S.D. 1999. Translocation and rehabilitation as primateconservationn tool: are they worth the costs? In Dolhinow P. & Fuentes A (eds)Thee Non-human primates. Mayfield Press, New YorkZonn A.P.M, van der 1978. Mammals of Indonesia. FO/INS/78/061 UNDP/FAONationall Park Development Project, Bogor.Zondagg J.L.P. 1931. Het voorkomen van enige diersoorten in de zuider-en oosterafdelingg van Borneo. Tropische Natuur 20: 221-223.228 8

CurriculumCurriculum VitaeCURRICULUMM VITAEVincentt Johannes Nijman was born on 15 December 1970 in Oudorp, theNetherlands.. In September 1990 he started with his study Biology at the Universityoff Amsterdam. In 1991-1992 he also studied Science Dynamics at the sameuniversity.. The requirements for a B.Sc. in Biology were fulfilled with a thesis onnaturee development in riverine landscapes (1993: Department of EvolutionaryBotany).. Research for his M.Sc. degree were on the genetic variation of isolatedpopulationss of sand lizards Lacerta agilis (1993: Institute of Taxonomie Zoology)andd on the ecology and conservation of the endemic Javan hawk-eagle Spizaetusbartelsibartelsi (1994-1995: Zoological Museum Amsterdam and BirdLife InternationalIndonesiaa Programme). During the latter study, arrangements were made for theresearchh that resulted in this Ph.D. thesis, and the first data were collected. In 1995hee started a M.Sc. in Behavioural Ecology / Conservation Biology at the ManchesterMetropolitann University (UK). In 1996 he obtained his M.Sc. degrees in Ecology,Evolutionaryy Biology, and Environmental Biology (Amsterdam) and BehaviouralEcologyy (Manchester). From 1994-2001 he made eight visits to Indonesia,altogetherr spending some thirty-five months collecting data on birds, primates, andtheirr environments. During this period he tried to raise awareness for theconservationn of forest in the Dieng mountains and attempted to have the areaprotected.. For the present study, in addition to the field research, primates werestudiedd in the collections of the zoological museums of Amsterdam (ZoölogischMuseumm Amsterdam), Leiden (Naturalis, formerly Rijksmuseum van NatuurlijkeHistorie),, London (Natural History Museum, formerly British Museum (NaturalHistory)),, Singapore (Zoological Reference Collection), and Bogor-Cisarua(Museumm Zoologi Bogor). Working from the Zoological Museum of the Universityoff Amsterdam, he was employed as short-term consultant by BirdLife InternationalIndonesiaa Programme (with secondments to the Japanese International CooperationAgencyy and the Berau Forest Management Project) and World Wide Fund forNature-Indonesia.. In 1995-1999, he worked as a part-time lecturer at the Departmentoff Animal Behaviour, University of Amsterdam, where he also conducted researchonn the relation between dominance and aggression in fish species and supervisedM.Sc.. students for their theses and apprentices. From 1999-2001 he was employedass a Ph.D. student by the Institute for Biodiversity and Ecosystem Dynamics /Zoologicall Museum of the University of Amsterdam, where the major part of thepreparationss and writing of this thesis took place. Currently he is working on theconservationn of raptors in the Sundaic region, and keeps a keen interest in wildlifeconservationn in South-east Asia.229 9

ForestForest (and) PrimatesLISTT OF PUBLICATIONS(in(in peer-reviewed journals)Balen,, S. van and Nijman, V. 1996. Notes on the breeding biology of the CrestedJayy Platylopus galericulatus. Bulletin British Ornitologists' Club 116: 173-174.Balen,, S. van, Nijman, V. and Prins, H.H.T. 2000. The Javan Hawk-eagle:misconceptionss about rareness and threat. Biological Conservation 96: 297-304.[Alsoo published slightly revised on pp 119-129 in S. van Balen (1999) Birds infragmentedd islands, persistence in the forests of Java and Bali. TropicalResourcee Management Paper no. 30. Wageningen University, the Netherlands].Balen,, S. van, Sözer, R., Nijman, V., Meijaard, E., Dennis, R. and Jepson, P.R.1999.. Juvenile plumage of Javan Crested Honey-buzzard, with comments onmimicryy in South-eastern Asian Pernis and Spizaetus. Dutch Birding 21: 192-198. .Balen,, S. van, Nijman, V. and Sözer, R. 1999. Distribution and conservation of theJavann Hawk-eagle Spizaetus bartelsi. Bird Conservation International 9: 333-349.. [Also published on pp 95-108 in: S. van Balen (1999) Birds in fragmentedislands,, persistence in the forests of Java and Bali. Tropical ResourceManagementt Paper no. 30. Wageningen University, the Netherlands.Balen,, S. van, Nijman, V. and Sözer, R. 2001. Population status of the endemicJavann Hawk-eagle Spizaetus bartelsi. Pp 109-117 in S. van Balen (1999) Birdsinn fragmented islands, persistence in the forests of Java and Bali. TropicalResourcee Management Paper no. 30. Wageningen University, the Netherlands].Heuts,, B.A. and Nijman, V. 1998. Aggressive behaviour of two swordtail colourbreedss {Xiphophorus, Poeciliidae) in a prior residence situation. BehaviouralProcessesProcesses 43: 251-255.Meijaard,, E. and Nijman, V. 1999. Distribution and conservation of the proboscismonkeyy Nasalis larvatus in Kalimantan, Indonesia. Biological Conservation 92:15-24. .Meijaard,, E. and Nijman, V. 2000. The local extinction of the proboscis monkeyNasalisNasalis larvatus in Pulau Kaget Nature Reserve, Indonesia. Oryx 33: 66-70.Nijman,, V. (1995). Remarks on the occurrence of gibbons in Central Java. PrimateConservationConservation 16: 66-67.Nijman,, V. 1997. On the occurrence and distribution of Presbytis comata(Desmarestt 1822) (Mammalia: Primates: Cercopithecidae) on Java, Indonesia.ContributionsContributions to Zoology 66:247-256.Nijman,, V. 1997. Geographical variation in pelage characteristics in Presbytiscomatacomata (Desmarest 1822) (Mammalia: Primates: Cercopithecidae). Zeitschriftfurfur Saugetierkunde 62: 257-264.Nijman,, V. 1998. Habitat preference of Great Argus pheasant Argusianus argus inKayann Mentarang National Park, East Kalimantan, Indonesia. Journal fürOrnithologieOrnithologie 139: 313-323.230 0

ListList of PublicationsNijman,, V. 2000. Geographical distribution of ebony leaf monkey Trachypithecusauratusauratus (Geoffroy Saint Hilaire 1812) (Mammalia: Primates: Cercopithecidae).ContributionsContributions to Zoology 69: 157-177.Nijman,, V. 2001. Autumn migration of raptors on Java, Indonesia: composition,directionn and behaviour. Ibis 143: 99-106.Nijman,, V. 2001. Temporal and spatial variation in migrant raptors on Java,Indonesia.. Emu 101 (in press).Nijman,, V. 2001. Status of northern migrant raptors rarely observed on Java,Indonesia.. Kukila 12 (in press).Nijman,, V. and Balen, S. van. 1998. A faunal survey of the Dieng mountains,Centrall Java, Indonesia: status and distribution of endemic primate taxa. Oryx32:: 145-156.Nijmann V., Balen, S. van and Sözer R. 2000. Breeding biology of the Javan HawkeagleeSpizaetus bartelsi in West Java, Indonesia. Emu 100: 125-132.Nijman,, V. and Heuts, B.A. 2000. Effect of environmental enrichment uponresourcee holding power in fish in prior residence situations. BehaviouralProcessesProcesses 49: 77-83.Nijman,, V. and Sözer, R. 1995. Recent observations of the Grizzled leaf monkey(Presbytis(Presbytis comata) and an extension of the range of the Javan gibbon (Hylobatesmoloch)moloch) in Central Jawa. Tropical Biodiversity 3: 45-48.Nijman,, V. and Sözer, R. 1995. Aggressive behaviour displayed towards the JavanHawk-eagle.. Kukila 7: 152-154.Nijman,, V. and Sözer, R. 1996. New information on the distribution of Chestnutbellieddpartridge Arborophila javanica in the central parts of Java. BirdConservationConservation International 7: 27-33.Nijman,, V. and Sözer, R. 1996. Sexual dimorphism in the Javan Hawk-eagle.BulletinBulletin British Ornitologists' Club 117: 251-253Nijman,, V. and Sözer, R. 1997. Field identification of the Javan Hawk EagleSpizaetusSpizaetus bartelsi. Forktail 14: 13-16Sözer,, R. and Nijman, V. 1995. The Javan Hawk-eagle: new information on itsdistributionn in Central Jawa and notes on its threats. Tropical Biodiversity 3: 49-55. .(Books,(Books, book chapters, and reports)Balen,, S. van and Nijman, V. 2001. "Forest fragmentation and the conservation ofraptorss on Java, Indonesia", in: D.M. Prawiradilaga et al. (eds.), ProceedingsInternationalInternational Congress Asian Raptor Research and Conservation, Bandung, 25-2727 July 2000. LJPI / KKPEJ, Bandung, Indonesia (in press).231 1

ForestForest (and) PrimatesHoeven,, C.A. van der, Iongh, H.H. de, Nijman, V. and Balen, S. van. 2000.BiodiversityBiodiversity in disturbed ecosystems. A literature review of the use of faunindicatorsindicators for the assessment and monitoring of the levels of human disturbanceinin Bornean tropical lowland rainforest. Tropenbos Documents 16. TropenbosFoundation,, Wageningen.Nijman,, V. 1996. Genetic study of the sand lizard Lacerta agilis: results andimplicationss for management [in Dutch with English summary]. Verslagen &TechnischeTechnische Gegevens 66:1-23.Nijman,, V. 1997. Preliminary survey on colobine monkeys and other primates innorth-easternnorth-eastern Kalimantan. Zoological Museum University of Amsterdam/WoWidee Fund for Nature-Indonesia, Amsterdam/Jakarta, the Netherlands/Indonesia. .Nijman,, V. 2001. "Effect of behavioural changes due to habitat disturbance ondensityy estimation in rain forest vertebrates, as illustrated by gibbons(Hylobatidae)",, pp. 217-225 in: P.J.M. Hillegers and H.H. de Iongh (eds.), Thebalancebalance between biodiversity conservation and sustainable use of tropical rainforests.forests. The Tropenbos Foundation, Wageningen, the Netherlands.Nijman,, V. 2001. "Composition and numbers of northern migrant raptors onwesternn Java, Indonesia", in D.M. Prawiradilaga et al. (eds.), ProceedingsInternationalInternational Congress Asian Raptor Research and Conservation, Bandung,2727 July 2000. LIPI / KKPEJ, Bandung, Indonesia (in press).Nijman,, V. and Setiawan, I. 2001. Usulan keterpaduan kawasan pelestarianPegununganPegunungan Dieng, Jawa Tengah: pendekatan keterpaduan kepentingan lokadandan nasional / Proposal for a conservation area in the Dieng Mountains,CentralCentral Java: a new approach integrating local and national needs. BirdLifeInternationall Indonesia Programme, Bogor, Indonesia.Nijman,, V. and Setiawan, I. 2001. Penelaian sepintas keragaman fauna diPegununganPegunungan Dieng / Rapid assessment of faunal diversity in the DienMountains.Mountains. YPAL, Bandung, Indonesia.Nijman,, V. and Sözer, R. 1996. Konservasi Elang Jawa dan jenis-jenis burungendemikk Jawa lainnya: Daerah prioritas kawasan konservasi di Jawa Tengah /Conservationn of the Javan Hawk-eagle and other endemic bird species on Java:Priorityy areas for protection in Central Java. PHPA/BirdLife International-IndonesiaIndonesia Programme Technical Memorandum 11.Sözer,, R. and Nijman, V. 1995. Behavioural ecology, distribution and conservationoff the Javan Hawk-eagle Spizaetus bartelsi Stresemann 1924. Verslagen &TechnischeTechnische Gegevens 62:1-122.Sözer,, R., Nijman, V., Balen, S. van, Setiawan, I., Prawiradilaga, D.M. andSubijanto,, J. 1998. Rencana Pemulian Elang Jawa / Javan Hawk-eagleRecoveryRecovery Plan. KMNLH / PHPA / LIPI / BirdLife International IndonesiaProgramme,, Bogor, Indonesia.Sözer,, R., Nijman, V. and Setiawan, I. 1999. Panduan identifikasi Elang JawaSpizaetuss bartelsi. Biodiversity Conservation Project, LIPI, JICA, PKA, Bogor,Indonesia. .232 2

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