Crocodile Specialist Group

CROCODILES 

krrcelrlirft$ of al* lllh Wortiry Mtrtir{ of lhe Crocodile Specidba Gntup 

of tl|c SFi{! $r vrl Cotnmbsi,on of ahc ruCN - fhc World Cot|scrvrtk n Udon 

aodvllrcd |. 

Vicro.ir Ft|lls, Zimbrbwe, 2 lo 7 August lt!t! 

Volune 2 

(Uncdilrd und Unrericted) 

ruCN - The World Conscrvrtion Uniott 

Avefir du Mo|rt Blnn , CH-llf' Ghnd' S*it .rtond 

:r.

FOREWORD 

The two volumes of this PROCEEDINGS are a record of the presentatiotrs 

discussions 

and 

tlat occurred at the I I rh 

^Workiug Meetirj .f,i" ii*Jil\*i"fi.t 

Group iD Victoria Fa s, 

Zirrtbabwe, 3-7th Au"gust LS9i.- Ti;,ruui;"s 

uore\lewed and uDedited. Tbe CSG pROCEEDINGS. 

by definition, ire records "* 

what 

of 

occured a-t the-meetiDg. They are not tomes filled s/ith articl€s that were 

reuewed, edtted, revised atrd polished subsequent to tbe meetiDq. ADan from 

preparDg a tabte ot coDteDts. ot_and_pasting captiotrs to figures, compiling 

articles 

the 

alphabetically by author, and numbeiing'the p"g". 3"nr"*tiuJfi' tl" p"p"r, 

.T,ry.blt:}.d j":, rhe way tbey were submittedl por'this reasou. ,t"y 

vanety 

Jfp.", ,o 

ot tormats aDd typefaces. laD Cames was the mauaging editoi " 

' 

The opinioas expressed 

herein are those of the individual authors and are not ttre 

:piqions-oJ IUCN - The World Conservation Union, ", it, Sp""i", Su-JLf 

L Olllmtsslon. 

IUCN - The World Conservation Union was foutrded itr 194g, and has 

headquarters 

its 

in Gland, Switzerland; it is an ildepetrdetrt iot"routioout ioay *tor" 

T:b-"j:hll j-"11ryjes stales,(irrespecJive of rheir potiricat 

goverument departmeDts. and private iDstitutioDs, as well as ""a international "*i"f"yrt"..), 

orgaDrzahors. lt represenrs those who ale concerned about man's modification 

natural environment 

of the 

tbrough the rapidiry of urbatr ioaurt iui a"r,"top_"ot 

the excessive 

uoa 

exploitatiotr o-f th" ."rih', outurul ,.ro"r""r".;;;;;l.t'ii" "oa 

foundations 

*. 

of his survival. IUCN,s main purpose i, i. ;;;;;" ;;;;;ort 

which 

actioo 

will eosure the perpetuation of wird nature uoa oitur"i ,.rouri"'Jon 

wide 

a worrd- 

basis, rot onry for their i,tritrsic curturar *i"tti-ti" *i."" i"iiiso 

long-tetm 

ror tae 

ecotromic and social welfare of mankind. "t 

This objective can be achieved through active conservation programmes for 

use 

the 

of natural 

v.ise 

resources in areas wheie the flora and fuuo"'"r"'of oliii"ur", 

a.nd 

lTf"th:". 

where the laDdscape is especially teautinrl or strifins. 

trEroncar 

or of 

curturar, or sciendfic sigoificance. IUCN berieves that 

aclieved 

its ;ims can be 

mosr effeclively by inter-natiooal effor, i. Ur[ 

rorertrauouat 

.ii., 

agencies, such as UNESCO. FAO. and "."p.r"ri." Ulgp, ana interDatioDal 

orgauisations, such as World Wide Fund for Nature (WWFj. - 

Survi!".t 

3.-iltj.^". ?l ]YaNs.Species 

Commissiou (SSC) is ro prevetrr the 

exotrcuon ol specres, subspecies, aDd_ discrete populations of fauna and 

maintaiuing 

flora thereby 

th_e generic diversity of tbe-living ip."i., pl"n.i 

mission, 

fl carry 

the "ftt" 

out 

SSC 

its 

relies on a network of oueiZJ0O uotunt."ifrof.".io-rj. 

through. 

*"rt 

more ttran 

og 

90 Specialist Groups and a large numbei 6i unifiui"irg"oirrtioo., 

regional represettatives, and consultants, scatterej through o""riy-*".y 

"o,rotry ot 

tbe world.

Mkanda, 

Malawi. 

Moler, P: 

USA 

TABLE OF CONTENTS 

Volume 2 

F X: Ranching the Nile crocodile Crocodylus 

niloticus in 

Growth and **ival of Crocodylus 

acatrs in south Florida, 

Murpurgo, B: Growth rates aud food conversion efficiency in Nile 

crocodile hatchlings fed pelletized food. 

Murpurgo, B: Age composition of captive female Nile crocodiles and 

tbe effect on parricipation of young fimales in reproduclive activity. 

Murpurgo, B: Pond structure; the relation to hierarchv and 

reproductive acrivity in male caplive Nile crocodiles. 

Ouboter, P E: Status and conselvation of crocodilians 

in no heastern 

Belize. 

Perciral, H F, Masson, G R, Rice, K G & Woodnard A R: Arnerican 

alligator Ulligaror hississippinsk) clutclr viability from seven study 

arcas tn ftoflda. uJA. 

Rahman, M M: Utilization of crocodile resource for rural 

development programme in Bangladesb. 

Rao R J: Conservation status of crocodiles in the Madhva pradesh. 

India. 

Rice, K E, Perciral, H F, & A R Woodward: Alligator trest detection 

probabilities du ng aerial survey 

in Florida. 

Ratanakorn P: Crocodiles 

in Carnbodia. 

Santos, S A, Nogueria, M J S, Pinheiro, M S, Mourao. G M & 

Campos. Z M S: Condition factor o[ Caiman crocodil$ yacqre in 

different habitats of Pantanal Malo-Gtossense. 

Santos, S A & Pinheiro. M S: Composition and energy values of some 

tood rfems ingested by Caiman crocdilus yacare in the Brazilian 

Panata[al resion. 

lll 

l4 

15 

16 

18 

30 

31 

46 

64 

77 

78

Seiias, A E: Status of Orinoco crocodile populations in some localities 

itr the Venezuelan llanos. 

Shrestha T K: Ranching crocodiles in the himalayan waters of Nepal. 

Singh, L A K: Indian mugger - tenitorial resource partitioning and its 

implicatioDs 

in sanctuary managemeDt. 

Staton M A: Crocodilian conservation and commerce: Common 

interests prevail in sustained use managemant. 

Strton M A, vernon B P, & B Bon: The influence of dietary prawn on 

the production perfonnance of young saltwater crocodiles 

(Crocodvlus oorosust. 

Stuebing R B, & S A Mohd.Sah: Distribution, population strucrure 

and some aspects of the ecolog/ of the estua ne crocodile 

(Crocod],lus porosus Schneider) iu the Kilas River, Sabah 

Taylor, R D, Blake, D K & Loveridge, J P: Crocodile numbers on 

Lake Kariba, Zirnbabwe and factors influencing them. 

Vac M H, Verdade L M, Meirelles C F, Larsen R E, Michelotti F, 

Rangel M C, Salem C Z, & A Lavorenti: Ultrasound evaluation of the 

follicle development in adult female broad-nosed caiman (Caiman 

latirost s) 

Velazco A, & J Ayarzaguena: Population status of the spectacled 

caiman (Caiman crocodilus) in the venezuelan plain lSiatus de las 

poblaciones d.e baba (gSlrnSfLlp9pdi!@) someti.las a aprovechamiento) 

Verdade L M: Agonistic social behaviour of broad-nosed caiman 

(Caiman latirostris) in captivity: implications to reproductive 

management. 

Verdade L M, & M E B Santiago: Status of captive population of 

broad-nosed 

caiman (Caiman latirost s) in Brazil. 

Verdade L M, Lavorenti A, Michelotti F, Rangel M C, Cullen L, & M 

M Ernandes: Preliminary notes on nesting biology of the broad-nosed 

caiman (Caiman latirostris) in Sao Paulo, Brazil. 

Webb G J W Manolis S C, Ottey B, & A HeFrard: Crocodile 

m?tnagement and researclr in the noithern ter torv: 1990-1992. 

iv 

79 

80 

88 

134 

148 

149 

1,63 

176 

184 

200 

218 

226

CROCODILES 

Proceedings 

of the llth Working M€€ting of the Cmcodile Speci$list Group 

of the Species Survival Commission of the ruCN _ The World Conser-vation Union 

conv€ned Rt 

Victoria Falls, Zimbabwe, 2 to 7 August 1992 

Volume 2 

(Unedited and Unr€vierved) 

IUCN - The Wortd Conservation 

Uniur 

Avenue du Mont Btanc, CH-1196, ctand, Switzertand

Literature citatiots should be rod as follows: 

For indiridual articles: 

tAutho.I. 1992. lArticle Titrel. pp. tnumbers] r, C.ocodils. Pro{€dinss or the llih workina Meting of th€ 

Lro"ooil spoiuri"t c-up of trre specie srrvi,al conmission of rhe lucN - The world conseriarion union, Grand, 

Switzcrland. votune 2. ISBN 2-81r7-0r33-l 

['or the volume: 

crocodile sp€cialisr Group. 1992. Crocodit€.. P.oce€din8s of the llth working Me€tin8 of the cncodile specialist 

cmuD. tUiN - Th€ worid Conservaiion Union, Gtatrd, Switze.land. volune 2 ISBN 2-8117-0133-3 

(d 1992 IUCN Int€rDttional Union fot thc Conservatio! of Naiure ard Naiural Rcaorrc6 

R€Prcductionofthispoblicationforeducationdadothernon{omnercialpurposeeisauthoris€dwithoutpe.nigsion 

fmn the @pftbr holder' provid€d the source is cited nnd the copJright holdg r€ceiv€' a copv of the 'eproduc€d 

Repm{tuctionforr€sa|eorothercommerclalpurpos€sisp.ohibited*ithourpriorwritt$pernissionofthecop'ri8ht 

hold€r 

rsBN 2-8Jr7-0133-3 

Pnblilhed by: IUCN/SSC Cro.odil€ Specialilt Group

Wilken D W Staton M A, Vernon B P, & B Bon: Artificial incubatjon 

of saltwater crocodile lCrocodvlus porosus.; eggs. 

Woodward A R, Moore T C, Delany M & T Hinesi The effects of 

cropping on Amedcan alligator populations 

in Florida, USA. 

List of Participants 

2',76 

277 

2'79

9cllgr 

Rahch.trE ths nile crocodila 

in l'lala!,1 

9:99-o-dy-f 9: 

F.X. flkanda 

KasurEU Na tloml Pa !k 

Box 4f, 

K€aurqu 

llA LAI,J I 

nilo ticus 

fhe Dranglra cEocodlle ranch presently hatches bebresn i?OO ano 2OUU 

hatchlirgs, oogtly frorn €ggs co.llected in th6 uild. Its orln b.e6_ 

dlnq s tock of 4 mals6 and 9 f€nElgs ploducBd 29? 6gqs f.om 1t 

clr.rtch6a du.inq th6 psllod 19A4-1gAg. lb produce 2OO0 hatchtirEs 

at a hatchtrg sfrcco66 of 80d,'fi nortatlfy, and 1q st€rility, tna 

tanch lnus t col.lact 2800 eggs. About Z4 n6sts with an avalaqo 

clutch sizs of l8 eqqs hav6 tD be excavatod. 

lha .anch'a prcJ6cted targgt is 1600 sktn6 p€r annuflr. Ihis is th€ 

export qoota app.ov€d by CI TES (Ole Convenllon on Int€rratioml 

T.ade in EndarEersd Sp6cl.es of Flora and launa). To achisve this 

tho ranch has already bred 4? f6|tEles to briro ths to tal. blooding 

stock to 60. In 1988 Sre mnch ar,po.ted ?00 skins. Fifty yourq 

crocodiles had baon .6hrrn€d to tho Nkhotakota Came RsservE in 

'1987 as a corBor\ration lneasure. Ftfty rrols clocodilBs ate due fo! 

r€le88e into ths rdseEve in 1990. 

&_tlgd!g_t_I:o! 

p16t,iously u,ildllfe ranchirA lras associat€d solely utth co,nn€rciat 

,no tiv€s. Ho!,rver, 1t is slou,Iy b6ln9 acknour'l6dg€d as s cons6lvation 

measure. It ls s naans of rel.t€ving prsssrrr€ on the urild nonulaticn:r 

as nuch aa savlng spaciss lfiat ar6 thraaten6d ulth srtinction. 

Frankel and SouU (1981) quotgd th€ Declalstion of B.?edirp ot 

Ehdanqefod sp6cl6s as an Atd t! thol. survival tiat'itia br€.dir4 of 

endangsrod species and subspecies of a"imal6 in captivity is likol].

to b€ crucial to ths suavival of many folms' It must lh€r'ofote 

be used as a method of prov€ntl'q €xtincttont alorqsidE ti€ 

fiElntomnco of ths ll,itd 6 tocks in thel! natlral habitad'' 

pionddr t/o.k on lri!.dllfs .anchlrq v'as conducted in zltnb6bue (th6 

then Rhod€616) in ttre 195os (wtllianEon and payn€' 19?8)' capttve 

'1?'8) 

br€artlrq of c.ocodiles (IggoOyfus nlloticus Laursnti fol 

purposss of rostockim dopl6t€d u'a teF'ays u'ar first achiev€d in 

19?4 nt r\t.tlrnu Cane Resetve .in South AFrica. A total of 898 yourg 

c.ocodilss have b6en r€l€ased lntD sevetat difl€t6nt locaIltl€B 

u.d6a thls schomo operat€d by tha Natll parke Eo6ld (pooleyt 1980a)' 

lhe schsE€ h63 slnc€ spread out to other pa!t! oF Afrtcat fo' €xample 

th€ captlve bt6€d1rg of crocodlleB In Nigerta for pu'pos€s of re-s tt- 

ck1ru urat€.oays and releasi in paFdam 6ama Res€'vE (tlorgan - Ltavigs, 

198o). crocodua falntnq for com|nercl6l purpose is btirg invostigat€d 

1n Ivory Coast, Zaobiar l4ozambique' and South Africa (pooloy, 1980b)' 

Crocod1l6 lanching Is a ne!, concept in t't6l6u'i' th€ fi'st mnch u'as 

6stabllshFd by the Ooa rpu,a Sugar CorPoDatlon in 1984 in lJkhotakota 

district (Fts. 1). A second on€ has recantly bBen Establlshod in 

tilan.tochl. gec€use of tlte Buccsss achiev€d to &tG the &rargt'a mnch 

acts as 6 modsl. Yet f6!i ptoplo krou of its 6xis t€ncet let alon€ its 

activltl€s. thl3 paper th..afors pre3snts 1'forrl'atioh on the backglound 

to the Oxa.gua crocodilg ranch and th6 progr€Es nad€ so fa" 

qpjlr.tiyg. !|9- .1_t-r9r919 fo! th6 ranch 

Tho prinary ohjBcttve of tho ranch 13 to contributo to the conseiva tion 

ol the .ila crocodilo ln l1ala{ii (S tlover' pers. cornm. 

)' 

objective, urhtch ls palt of divsrstflcatlon of ti6 oetatsrs 

fhe subsldiarv 

actlviti6s' 1s to utlllzd thd crocodil€ sus tairably fo! oconomlc bendlit6' 

If tho ranch ls to bs nanaged affectivslly' lt !s only ratioFal that tt 

i5 6co rnlcally viablo. 

Altho'roh the crocodilo i3 prottctdd und€r lhe Crocodil€ Actt Cap' '

Figl; Mop of Mobwi: shoryiing t ktbnol porks, Gorna Raszrvcs ond locouon of 

Dwongi\^,o 

crocodile mrch. 

KtrY 

. tl|z D^/orgws crodila mnch 

: @na Rzsarv"s 

fln[t Nbtbndl PorKs 

0 50 1@ 15OKm 

1 Dryornbrol River 

2 D^/ongwo Rivar 

J t]Ja Riva- 

4 Krynb@ Rivar 

Lu\^/eyo Ri\^zr 

o t -Ou,rzr Shir"z 

3

f!:oction ol ths tDtal poPulatton is resldsnt in I nut of tho 9 

protsct€d ardas ma.agsd by the D€pa!t'n€nt of Natior'al Parks 

an.J lilldllfd 

(Di,rt'J 

). fha t protect€d arsas u,it}r clocodil€ popu- 

lations arel Litlonda Na tional parkr ikjat€ Cams R€ao.v€r and 

Nkhotakota cane Ras6rvs (Ftg. 1). 

thor€ are conlltcts botuden crocodtlbs Bnd th€ hunan populEtlon. 

For irstancg crocodilBs dss troy flshtrq nsta ruch to the anrro- 

yance of fish€rman. lhay also d6s troy livestockr hudian lif€, and 

somBtln€s main peopl€. thoee co"f-Ilct€ ar€ anouoh fo! the publlc 

to rJev6lop nsgativ6 attitudes tbu,atda croco.Jites. llence th6 formsr 

suize evory opportu.ity t €xcavate crocodlle nr6 tE aFd des t.oy 

thoir arns. In somr i:aslrs thD eqqs may bc colltcted for othdr purDoses' 

or they ars simply dis turb.rd uhil€ In ths osst. lhsre is evldeFc€ 

th6t ohcF Êsts havs boon,.xcavated and eqqs car-Eles":ly handled th€ 

embr.vos do -dt cortihuo to .lavelop. Strov€r (1989) rpPortsd of t 

casas ,uh.re ooos uFra u.FartlPd a..l dishrrbed by Iocal flshermRh. 

lh€ omtr.yos in such Boits st pp.rrl cl6veloPl nq. In a.lrlttion ht eag 

d€sj:ructionr collection or disturbance by nanr uiat€r monltor llzatds 

Va.r?j99 j.'i l9.r]9!r9 rob croco.lil€ "est3 (HacJikhula' n!.3. comn). 

FurlhEr nan-crocodilo co.fticts involv€ crocodjlp habi ta t .Jos tructioF. 

J^ ltra.! auri tha ctocodi16 occu.s 1n a vari6ty of frslrh{ra tar habitats 

such as lakos, la!(16 rivF!s, suamps, marshes, ard riv.rr droulis. lhese 

arEas are also es6c.tial for aqr-icu1fu.e, fisherirs' and hydroelectrtc 

pDu'!i.r 

oonera tion. 

Some ftarsh6s havB isla-ds tuhich a!E lcieal lor dry season cL'ltivation. 

Exannlos ale the Elepha"t snd lttil-dl marsh€s ubich havo ths ders€st 

crocodile cD.ce.tration in the lottt -"t Shlre Rlver. Dry soason culti- 

vatjoF e.ha.ces food sscurity and it ls increasi.q in 1ts ltnportancB 

(Fr6|lnan, 19?4). lhls lncrdase ts p.obably due to the mou^tlrg honan 

oress',re on cultivabl6 land. As a resultr more islaFds v,lll bs 

sub.jocred tD cultivation tn€rsby rlas troyi.q ooe of the crocorllle 

Sa-dv b4achos ar€ .astirgr ]oafi.g, 

Yet thc lrarns FIac€s ara flehEr|nB"rs 

hn ror.j..t croco.lllos to retrrat t! 

sLl tahl e hahitats. 

and baekl.q r!rouFds for crocddtl6.. 

la.dirq arounds. this co.fl ici. mioht 

safe! arEas hut nrobebly not

lhpoundlrg riva13 for purnoses of slectrlclty qsne!atlon or 'rr1- 

qation can bltrq about €Fvlrorneotal chanq6s both .lourns tream and 

uos traam' A sfudy tn tia ilaha poola Game Rbserve in ths hld-Za- 

nbo?l Ualley shoured th.t flood .€lea6€sr durirg the d.y saasont 

ot volumBs q.e6ter th6n th€ n6an dry leason flou, of ths pte-inpo- 

und'rsnt perlod ulll cleny loaflrq, baskirg, aod fe.dtrg of amphtbia,s, 

birds, and reptiles (Abr€ll, 1970). rhe relcasa utll also des troy 

th€Ee utlldllfa as much as thetr egqs 'r,hen they nest near to dry 

scason u,ater levele of th€ riv€. and ox-bou6. 

'lh-"se 

lmpacb may a€ 

uetl ba takidl effect on the Rlver Shlre uher€ trsfe is a. impou- 

lhere are 2 folns of crocodil€ hunttrq in t4alauilt control shDottrg 

tr safeguard hum6n llfe and prop€rty, and llce.cod huatlrla. 

cro.odils poachirg has "ot bee. dstectFd durtnq the last 10 yrntg 

(Dspartm6nt of National park6 a^d tilldllfe, 1989). 

Follotuing a major concern tn }ourist devBloplnsnt on Lake llala'tt uith 

pt.ticular r6sp6ct to oat€. sport, tt uas .J€cl.lsd that aIl c.oco.,tl,!'! 

bo oxlsd.lnatsd froD tourlst ar66s on Lak€ Malauri (Anon. 1971). To 

dat€ cohirol shoottro ts done, as paDt of Govsrrnent policy on 

crocodil€, -ot oFly in torr16 t r€3ort3 but 'lhF.RvFr maraudirD c.ocodiles 

IicencBd huntlrlq i3 subject to an 6xport quota approvGd by CITFS. 

Cur.EFtly th€ra br6 1l c.ocodil.e hunts.s tlhose activities €pan acro.s 

the country. Each ono hos a spgclflc atea ol oper?ttion. DatE obtained 

fro'n tha Cold S torage CorFany oF tlalaul, thE only loca] compaFy that 

buys and export6 ctocodiles 6kiri6r shorrs tha t b6fu€en 1976 a6d 19A6, a 

tota: of 41J, skin6 ur€re expo.t€d. lhe htqhs6t '?xport uas 1019 sklns 

tn 1981 (Flq.2). Aft€r th6 t.6nsfEr of tha ^tl€ crocodtlo lron lpr'^ .jlr 

1 to Appsndlx II l,lalaulrs quota uas 5O0 sktns tn 1985. In 198? an 

incFeas€d quo ta of 700 skins f.on the urild 'r6s apnrovod fo. €ach year 

urttl i'r'1989 uhon tt tas leduc€d to 250 fo! the year 1990. This off- 

tak€ is su8 tat.6bls (Departnent of NatiDnal parks and I,rildtlt€, 1989). 

tr.t1l 1989, hot ever, thsr6 u,aE no rcls.tlllc basls fof petaht iihlr(| 

off-tika quotas. Fot such purpo3ea th€ populatioh status of th€ nll. 

crocodlle in llalaurt has rot b€e. sstabllsh€d. lhs .rxis tlrg es tlma tas 

diffor hy a v.ry u,Ide marqin. l4phand6 (198.) rs ttrB t€d a mlniftum of

o 

Fgz Crocodlla skins @xport@d by Mohwi 1976-1966

dr^ r^d from Mth^ ^da (1r1i.

4.00 crocodtlelt ulth an tppsr llnit of 15'000 and a u'orkirg Ponulattnn 

nf 8000. thls has bsen critiatz6d as conseFvative. Anon. (1986) 

.lLjotrd by Department of ua tional Parks and Wildtifs (1989) 83tinatEd 

the crocodlle popula tlon to hsvd been Zlt3OO in 1"84. lhts larS6 

difforanca. b6tlteen as tlna t€s pos!:: dlfficulties in €stablishirO 

huntir'g quotas basod on 161iabl€ data. Hsnce th€r€ might hav€ bsen 

a danqe! assosistad urith tite hunting. 

Fo! sr,ch hig populationsr an averaqa off-take oF 411 skins bet!€an 

191A a^d'l9a6t Uh€n 7O0 skir€ frcm 1987 to ro89 Yot'Id hou,6v€l not 

havn afFscted the poFulation n€qattvsly. ln $is case though tt i3 

imposîbl6 to ssgsss the impact of licercsd huntirq on ths population' 

ritslly because ol difficultlBs wtti the populatic,n estlmatae. 

SccoFdly, tiets have bssn no studies on tn€ blology (aqs structlr€)' 

..x ratios, rqprorjuctlor, mo.tal l ty ntc) o" lho ':r''{. dl1o in Utq 

ItouevEr, it trould appB6r Ulat a larqe proDortion of th€ off-take for 

thr pa6t 11 ysars comFrised crocodiles betttteen 1.5 m and Itn (Ftg. , 

and 4) u,hich ar6 nostly 6ub-adults and adults. A small percdntaqe 

corslstad of l6rgo crocodiles (mora than I m lor{t) urhich in t}le case 

of f€males lay tndrs and latg€r eggs than thosd that have Just startld 

breo6i.g. IF this is rsflBctivc of ths 39s strtrcfutEt one lJould b€ 

jncltned to conclude th6t thB population ts .ot 6 heal tlty one. lhea€ 

has protrably bsFn ovat-€xploitation of old clocodilosr cor€iderinn 

ihat comm6':cial crocodlls hrr^tlng has be6n dons Einc€ lfie fi.st 

ssttlnrs arrl.ved in th6 country (D6parbr€nt of lId tioiol parks and 

utldltfe, 1989). Clfss (19?8) stated that Exptoitation of otd a-inal:r 

ts qehora.lly inversoly relatsd to th€ bata of t}|e futurs (aqe) pyramid; 

that ts tho mor6 int€'siv6 th€ €xploltatlon, tjis natrouot tho pyramld 

aqa tras6. F{q. 4 Buits thls s ta tsnBnt. In flala'"i hu.tirg ls selactivo 

l^ favour of big crocodilee. lhlB ls b€caus€ Ure CoId s to[age Companyt 

pays sccordli8 to lanqth of th6 3kin. lhis k incEntiva Brough lor 

hrintgrs to shoot blg crocodlle6. lhd inc.eassr betlrean 1.r-2.1m skin - 

lergth clas!, in th6 psrcentaqo of export€d sl

of sub-adults ard adJltt mrght ltnit r6cn'ibn6nt of largel fdFl€' 

0hlcfr 6te €rsentlal lol population osouth. 

tJith all tha fots-going actlvittes thr€tt€îrE lfte long-t€rfi su'vl- 

val of the crocadll. ln l|at6otr rsnc'htrg s€en's to be 6 viable corF6t_ 

va tion and |||6.€gdtsnt proposltion. 

rbrE g gl-6.r'j-.oi-f :9S-o-d-49--t-$919i9! 

lhera are sevelal t|an€rg€n€nt ptsctic63 bairE carliod out by tho r'Fch' 

tt ts rot th€ pt rposc of thiE pap€r to d6tail all of therl. lhelefoDs 

onlv those practlcea de€oed televant tD highlightlt4 ths achievsnsnlp 

of thE ranch ale d€scrlbed in the succadlrq paraglapl€. lhea€ a'€t 

strcklrEr btoedirg, fcsdirEt ttnd cropplr€. 

lhs Dlang$a clocodlle ranch is 6ttratrd Juat abov€ the delta of tha 

CDar€oa Rtve! (Fig. f). fha lttarEua delt! ha! been horne of crocddil€s 

for :gee. lhe d.velopnsnt of aq.lculhrrll actlvltias in Ule sally 

1980s forced the crocodllee to tetrsat fulthat dolrrp t'e€m. Houl€vel 

adult3 and srrb-adulta lamol||bsrlr€ th€ta traditioral haunt€ and sBeklm 

nett hohes mov€d upstlaam and sought lefugE in tho Ftqht storago datE 

of th6 €st t€ (s trovorr 

'1989). 

thts ls hou the Eane'h acqulrsd its 

orlglnol 

e tock. 

tn 1984 the ranch colt€ct€d 20? egqa from the tr'lld 6nd i'crJbatsd thdn 

l. a medijn, of the factory ash. lhe tatrperaturt !,as mainttlFsd betll'eFn 

too rr.t rroc. Since then nolE ogor h6va been cotlectsd €tnd hatchod 

l^ the sane uoy (hbt. 1). Ptcee"tly the t6.ch hs tch6s batnebn 1700 

6.d 2000 h6tchltros per y66t. lha hatchlrq aucceas hals rar0od betoeer 

21.6 6.d 1oM dsps^dlr€ on th. Bourc. of tht .99s (Dble l). Hatchlra 

'rortallty 13 faltly lotr lfie hlghost bel'g 9t tn'1985 and 1989 (Tabfe ?)' 

'rhs ranch utll ultldEt€ly ttcraforh lnto.'fatn t}l(|s producirg it! oon 

egga (S trovarr par€. colflt. ). It thu! alnt at havirq a br€adlrtg 6tdck 

of (0 females. In th€ |tt66rrtJhi1€ it h.. only 4 brEEdtrg |nal€s 6nd 9 

fEfial*. lh€ prodrctlon ttE96t 13 proJectod Et 1600 skiis pel aF'un.

10 

lEble lr Hatchlrq auccess dat!, Dnangrra crocodllo rahch .19g4-1989. 

Loca tio n 

ftlsanrala 

Lq',rEr Shire 

r}l,anb6. i 

8re-rllrq pond 

&ra Rlv6! 

Likuchl 

Oe,na 

CIutrh€a 

72 

1 

11 

27 

6 

'l 

1 

1 

:::" 

1847 

112A 

2?72 

(n 

ttt 

100 

2A? 

11 66 

20t 

4t 

37 

.gge/cl u tch t -cuha ted hatched 

1718 

107 4 

2 604 

58 

41 

9? 

2AIt 

1097 

1 

41 

t6 

51 

To tal 2O4 7? ta ,8 470 

l!hl. 2t Hatchlirp nortality; Dlanguja crocadila ra.ch 1985 - 1989. 

19At 

194 6 

1987 

1988 

1949 

Sorrac€ ! st ov€r (1989) 

Hatchltrqs LOASeg 

178 

642 

1(7t 

2fitt 

1744 

J1 

54 

a5 

1t7 

(278 t6t 

f8 

t6 

'D 

4t 

50 

26 

4t 

t4 

4t 

,? 

4.4 

4.2 

'| 44? A4,2 

954 88.8 

21't3 at,4 

4? 81.0 

tJ ao.5 

77 ?9.4 

zlt 75.O 

1077 99.2 

169 A'.a 

4r ,0o.0 

2a ?1.8 

11 21.6

lho infrabt uc hrlo ol tfie es ta t€ provld.s storaee (brl, rnd abun(Ent 

uatF! lot p.odrrctlon of a re6dy food source (Strovsr, 1989). Food 

la .ot offered to the hatchllr{s unttl tha yolk t5 fully rb8orbed. 

For the flr6t 10 - 11 rnonthe, uhttl tho h.tchllr0 ale movgd to ths 

groui'ig out pede, lfie dlet ls €rctuslvsly flBh. ysaDlirqs ar6 k{_,p 

t 

pre.lonina4tly on.fl.sh di6t but suppl€iE.ted ,rri 

th chickon and oBre! 

llvestock mortallttes that oecur. lhe total annu€rl corFufitptlon of 

fE.d lor the ranch ls 80-100 toF-€s. 

Crocodil.ea of bebreun 1l ana 2l ysaF old aDt croppeda In i9O8 t}re 

ranch cxnorted 700 skirp to ltaty. I. 1989 the quota oas laissd !o 

1600. lhe croppire foldcast for 1998 ls 1620 crocodilgs. tt tg 

rE.luirad ol tie .anch 10F of tha 2-y6a. olds hat hsd fron €qqs qotlsct€d 

in irkhotal

t2 

:.oF j.r.rlaa,r tr -t,i-e tctt tlre.: tt39 a/ c--'::'eak ':f ^':ai_1csi9 '_!-_' 

rar'_acisd ha!.:li.9s and g.nLin-o stcck. Il ac:'u'too lor the 1o3s dl' 

l?? vEaflinqs and 2 - Y6ar olda. 

Du.i.g thE oast 2 s!334.s 199a/191 z devastatiê '._Citiei occur:ed 

i- clrrtthEs collactsd lram th€ 8ua live!. It has be'n dia,onosed a3 

a cal.ciuo imt:obiliz?tion y_dtom". It b believ6d tfiat this cordlton 

ls herect.ttary and b€lr€ pelpEtjat€d by th€ saiE 8ua clocodllas 

(Slrover, pats. com'n. 

). tris Ciseasa 3ccourt€C lot 4l of tfie hatchllrq 

loss€6 in 198? and about 45/" \n 196A. No €gqst theseforer {'€!e colle- 

cted floin t'le t€s6!t€ in 1968 and thale luslo .o cases of th€ corditlon 

in th6 1989 ha tchJ.irg6. 

Co-clus io n 

the iilo crocodile is undel thrsat ln l'Llatl,i fron hulEn actj.vitlEg 

such as huntirlr habitat d€3t$ction, and €99 d€structlon o! collg- 

ction. Crocodile lanchlrg off€ls an aIt€rnativ€ tE utlllzation of 

the u,ild population. S ta t$ tlca shdl, that l'|6 OirarE0,a lanch haa 

ranaq6d its clocodil6 Population ve.y a€ll. Such unde!lakir8sr tlt6!6- 

fo!6, should b6 further oncouraged in the countly. 

A.on. (19?1 ). Record of a ne€tirE on Crocodile 

I{6l,au, i Cov€rnm6nL 

ln Laks t'tala0rl. 

A o:ells R.I.G. (19?O). son€ off€cts of Laks Xa.ibe on Itre scology 

of a floodolat. of th. mld-Zanbezl Valley of 

Rhodesia. -8i-"_99:9: 2 11)| 

1Be -1e6. 

D€patbrent of 

rlatio.el Palks and l{ildll?. {1989). tlainter.ance i.n 

Aope"dix II of the l4alauti pooulation of g:....9q]!9 

.iloticus. A propossl suboitt€d tt ths Tttr ttle€tlng 

6?-Eiit6.ference of 8rE pa.tiee. 

Lausa.r€, Su,itz6rland. 

Flark6l, O.H. a.d SouLer X.E. (1981). Cor€€tvation and evolutlon 

Cahbridqo t 

"iveFity 

Press. Ch. 6.

Frr€maF, '1. i1974). r srpIi:r,1âry irte6ticatji^ rf cihba c.J I ti- 

vatio. in ttrs Lo{r6. ShIle Ua!,1.€y. a reoo! I t! 

l4alau,1 Govs.n'|tenL 

Ciles, R.H. (19?8). Wildfife nrar€qsm€nt. fle€.nan and Coftpany San 

Fra.cisco. Ch.2. 

llolgan - Davi€s, A.n. (1980). 

t71 - t1t. 

Tla€locattng crocodlles. Oryx 15 (4)t 

l$hande, J.N.8. (1986). sbb.ls of th6 nile clocodilo tn lblaut. 

A r€polt to tia Depaltnent of tbtioral parks 

and tlildlif.. 

pool€y, A.c. (1980a). clocodil. rss6atdr in llaputaland. 

Inr Srston, !l.t!. ard Coop6!, k.g. (g*). S trOiea 

on ti6 €cology of lt publand. 29t - 299. 

Pooley, A.C. (1980b). Ih. dBcline of c.ocodite6 in AFlica. 

rlelj_r_c_ g!!] BuIr. rl (e-e!'!10)3 er - 94. 

S t!ov6!, P.tt. 

Yilllar6on, C. 

.1989). O|,arE{!. Ssga! CoDporatlon Ltmited, Crocodll€ 

clutch aacord€. Typ€scrip L 

ANO pAYiE, 1.r.3.a. (19?8). An tnt odrction tE aninal 

husbandry ln th. ttopr,6. fld ed. 

Longran Croup, Liott d, London. Ch.ll 

13

l4 

GROWIII AND SURVTVAL OF Crocdyhs acuas 

IN SOUTII FI,ORIDA" USA 

Paul E. Moler 

Wildlife Research Lab. 4005 South Main St. 

Gailesvile Florid,a 32601, USA 

C.L. Abercrombie 

Wofford College, Spartanburg, 

South Carolina 29303. USA 

A tolal of 391 crocodiles were tagged on Key IJrgo, Florida, USA betweer 1978 

and 1991. Ttvo hundred of ttrese were recaptured a total of 530 tirres. All but 2 of 

these recaptures were of low'n-age animals. Hatchling survival varied markedly 

from year to year, being lon er in years of low rainfall. Estimated first yeat survival 

for the period 1979-1988 was m.4%, but age-specific survival increased to 64.97o in 

tle second year. Annual survival of American crocodiles nore than 5 years of age 

excee.ds 80Vo and may approach 100%. Hatchlings grow rapidly for the first four 

nonths, but then growth essentially stops with the advent of cooler winter 

temperatur€s iD early December, Some fudividuals may reach minimun 

reproductive size by an age of 8-10 years, but it is not knovn whetler crocodiles are 

repr,oductively competett at this age.

GroMh rates and lood conversion efficiency in Nite crocodile 

Benjamin Morpurgo 

halchlings fed on pellelized food. 

Center For Reproduction 

of Endangered 

Specles 

San Diego, CA, 92112 

USA 

Afler five years ol rearing Nile crocodile hatchlings in lhe 

Gan-Shmuel Crocodile Farm, tsrael, a new dietary reg;men was 

examined. Until 1990, the diet of lhe crocodites, from ;atching to 

sfaughtering al age 24 monlhs, was composed o, two ingredients. 

For the first lO months - ground meat with supplements. From tO - 

24 months dead and live chicks and ,ish were fed. ln strivtng for a 

more commercial diet, due to the increase in number o, hatchlings, 

lhe use ot pelletized tood was examined. 

A cohort ot g-day old Nile crocodiles was divided into three 

equal groups ot 21 animals. Each group was fed on a difrerent tatio 

of high protein pellets and ground meat (g}%_70%t SOo/"_SO%t 7Oo/._ 

30o/o). During the seven months of lhe experiment, all the crocodites 

were weighed and measured at monlhly intervals. Food intaKe was 

recorded . 

During the 7 months of lhe experiment, the crocodiles grew an 

average of 32.4 cm, and weight increased by 711|,45 g. These resutrs 

are be er than those recorded the year before (S9O g: 2g.2 cmr. 

No signilicant differences were found in growth among the 

groups. There was a signiticant ditference in lhe variance between 

the groups. The variance was smaller as lhe pellet portion of the 

diet was increased. 

15

Age comPosition of 

captive female Nile 

particiPalionof 

young females 

Beniamin MorPur9o 

Center For Reproduction of Endangered Species 

San Diego, CA' 92112 

USA 

crocodiles and the ellect on 

in reproduclive activity 

During two years, the question of the influence ol adult lemale 

;;.;;." on reproductive activity ol immalure females was. studied' 

Twelve adult males were divlded into Mo equal groups and housed in 

a |.ectungular, 8OO m2 pond. In lhe first group' the female population 

was composed ol 45 individuals' 25 were 9-lo years old' and 20 

were 6 years old. ln tne second group' the population was composed 

ol 45, 6 Year-old lemales' 

Euring the lirst year of lhe lwo-year study' the young females in lhe 

mixedandthemonosizegroupsdidnotparticipateinreproductive 

activity, although courtship was made by the males in the monoslze 

pond. In the second year, in the mixed age lemale population only the 

adult lemales mated ln the 6 year'old female group' during the 

second year,7 out ol 45 maled during the reproductive season' 

It appears ihat the presence of adult females inhibits mating 

acriviiy Uy the younger females In the absence ot adult lemales' 

young lemales show some reproductive activity'

Pond structure; The relation to hierarchy and reproductive activity 

Beniamin Morpurgo 

Center For Reproduction 

of 

San Diego, CA, 921'12 

USA 

in male captive Nile crocodiles. 

Endangered Species 

Pond structure for reproductive herd is a very important ingredient 

in crocodile tarming, especially in areas where there is no wild 

population, such as in lsrael, where the present study was made. 

Twelve male Nile crocodiles were divided into lwo equal groups. The 

6 crocodiles in each group were 9-10 year-old, and their sizes were 

3.15 to 3.50 m. 

The first group was housed with 35, 5-9 year-otd temales, in a gOO 

m2 enclosure, 60% ol its area a rectangular shaped pond. The secono 

group was housed with 35, 5-9 year-old lemales, in a 8OO m2 

enclosure, 60% ol its area an irregularly shaped pond. 

In the reclangular pond, only one male was {ully functional, two 

others mated only when lhe dominant male was oulside the water, 

and the other three did not exhibit any reproductive activity 

throughout the season. OI 35 females in the pond, only S mated. In 

the irregularly shaped pond, all six males maled, each one In a 

lerritory he created around a bay. At teast 29 lemales mated during 

the season. 

The conclusion of this two-year study is that unless the populalion 

is one male and several females in a rectangular pond, irregularly 

shaped ponds are preferred. 

t'7

18 

Ndr theas tern Belize 

Department of 

Sur iname t 

P.O.B, 9212, 

Pau I E. Oubo l€ L 

Zoology' Anton de Kom Universitv of 

Paramaribo' 

Strriname. 

I NTROOUCT I ON 

Althouqh several authors reported on crocodiles of Belize 

(NeilI & Allenr196l; Potnell, 1971; AbPrcrombie et ar" 

19BO' 1942), the northeBstern Part of the countrv kas 

almost conpletelv omitted bv thPse earlier survevs' This 

is curious since this part includes numerous larqer and 

soaller geaside and inland lagoons Nhich seem to ProvrdE 

good potential habitat for crocodiles' A possible reason 

is the inacces6ibilitv of this area which has few roads' 

Between 26 April and 30 May 1991 (drv seasonl a survev 

took place in and around the Shipstern Nature RPserve' 

Both Et:9!glbl!l]e noreletii and Crocodv lus q!1$ll9 were 

found in the area. The status of both species worldwidP 

is bad, sothat any report in ttrerr 

dietributictn range sofar uriPxamined is of i Portance- 

ME'] HODS 

Creeks, lagoons and pond-- to be investigated were 

selected {rom maps' airphcjtographs and Landsat sateltite 

images. Criteria used in selPcting were Io'al 

reports crocodi I e siqhtings ' habi tat featurEs 

(heteroqenuity' depth ot vrater' Ntnd direction' etc') and

accesslbility. The last criteriutn excluded several 

lnteresting inland lagoons which could only be reached 

through a labyrinth of mengrove marsheE or travellinq a 

lonq distance overland on {oot. 

In selected arear surveys were carried out during 

the day and the night, DLrring the night crocodiles Nere 

epotted by eyeshine usinq a handheld 12 V spotlight or 

4rS v halogen headtight. MoE't surveys. were carried out by 

canoe, some by motorboatg powered by an outboard motor, 

STUDY AREA 

The northeastern part of Be!.ize i5 the Yuceran 

tlatJorm and mainly :oneists of beds of limestoanE 

covered by subtrupical hardwood forests' wet savanna< rnd 

lagoons, l'lost aquatic habitats are ealine, salinitieq 

ranging from 6 to 33 promille , Lagoons (4,7,8'lO and 1l 

in fig. l and tab. 1) are usuelly very shallow and 

surrounded by red mangrove (Rhizoohora !E!l-S-!€-). Most df 

these are directly or indirectly connected to the sea' so 

not subject to dryinq during the dry season. Cenotes 

(sinkholes) (5 and 6 in fi9' l end tab. l) are usuallv 

much deeper. Creeks connecting lagoons are uEually deeper 

than the lagoons itself' ranqinq to more than 2 m in some 

localities. John PileE Creek, Wakaxkav and Dhacan Chac 

l'lol (1,2 and 3 in fi9, l and tab, 1) are less saline (6 

to 11 Dromille). 

19

20 

fIESULTS 

An ov€rview of habitat features oi the different 

localities is presented j.n table 1. 

Re5ults of the surveys ar_e Presented in table 2' 

Crocodvlus moreletii is PrPsent in the less saljne 

habitats, John Piles Creekr ChaEan Chac l'lol and 

corozalito Lagoons, In all th?_ee localities Juveniles 

l@.4 - @.7 m) and adults were seen (it is supposed trhat 

C. moreletii can reproduce at a size of 1'5 m)' 

CrocodvluE qg]Ilg5 sEen were all in the more 5aline 

habitatE. The crocodile eeen in Corozalito Crtek was 

quite hear to the q1 moreletii PoPulation in the lagoons. 

This gpecinen was dark in coloration although it had the 

very slender snout of a qr acutus' It i5 treated here as 

unidenti{ied. Of the four q. acutus actually seen two 

,rere 6ubadult6, two juvenj 1eE. These juveniles were Jound 

in Barracouta Pondr a de|?p lagoon with relatively high 

beacheg all around. A nestr presumeble trom c. acutust 

was lound on the northern side of the lagoon (the eggs 

lrere not counted in order not to disturb the nest too 

nuch ) . 

DISCUSSIT]N 

ln Belize a moratorium on the killinq oJ crocod.ilts was 

proclaimed tn 19Sl (Abercrombie et al ' 19t12) ' Locar 

people were of the opinion th.at sinEe that time tttP 

nu6ber of crocodiles had increased enormouElyr becauEe 

crocodileE Nere no lottger hunted for 'their skin. Stories

of areas |4ith large numbers ol crocodiles or of very 

large specimens are widestrread. Dur.ing this survey onfy 

small numbers ot g:,noreltllijl b,ere encountered and even 

sttaller numbers of q: Cllrtus. Some informants told me 

that every crocodile seen by the locals is kil!ed as 

verrnin and it was sometinreE' even posEj.ble to sell the 

Bkin to foreigners. This makes it unlikety that (ne 

droratorium will have any effect in HeIl frequented areas. 

In remote areas it could be effective since peoolp dre 

not lnclined to take the trouble to 9o there for illegal 

crocodile huntingi they only kilt the crocodileg 

encountered accidental ly while occupied in other 

actj.vitiee (usually fishing). ThiE meens that crocodile 

populatlons near human occupation can only be protected 

by includtng them in nature or other protecred 

[jnfortunately al I crocodi Ie poPulations 

encountered in NE Eelize were outside the Shipstern 

Nature Reserve. To incl\rde two of the C. moreletii 

populatlons (Chacan Chac t'tol and Corozol.ito) and the C. 

acutus breeding cite (Barracouta pond) in some sort of 

regerve (poE5j.bly enlarging the Shipstern Nature Reserve) 

could be a good solution to this Drobtem. 

21 

The statue of L g_g!4.!tE" 

on the maintand of Belrze 

has beeh extrefiely bad. powell (1971) reportecl q: Bculu5 

to be rare oo the mainland, somewhat ,nore common on the 

otfehor€ i5IandE. Abercrohbie et at. (f9AO, f9A2) 

encounter€d only qs morel€,tii no C. acutus durtng thalr

22 

alnland surveys. On the basis of these data King et al' 

(1982) conctuded that E: agglg-a i5 almogt absPnt on the 

mainland. Zisman (1989) mentioned the occurrence of both 

C, moreletii and Q: 4!glg-9 in the Northern and SoLrthern 

Lagoons' but breeding only occured in two areas of the 

keys. This nakeg the finding of several eubadLrlt and 

juvenile specimens of E: i!q4!5. in the NE interest1ng' 

However, apart trom Barracouta Pond' the "poPuIation" 

seems widely scattered. Even when given JuIl protectiont 

the area could only harbor a small poPLrlation' 

Most ponds and lagoons are very smal I ' shal lo$! and 

isolated from other waterbodies' OnIv the Shipstern 

Laqoon and borderinq lagoons prowicJe an extenslve area' 

UnJortunately these lagoon_' are not very fertile and nost 

lack any signif.icant amount of fish (pers' obs' ) 

Nothwithstanding this pessimism' protection of the 

Barracouta Pond area, tncluding th€ adjoininq seacoast' 

could helP the survival of the American croEodile rn 

Bel ize. 

C. moreletii and q: iEutus are sympatric in Belize' 

tn most publications (NeiI' 1971; Alvarez del Toro' 1974; 

Groolnbridge, 79a7 ) c' Doreletii is supposed to be 

conlined to {reshwater habitats' This study showet ae wag 

already reported bv Abercrombie et al ' (19A2] ' that !: 

moreletii populatione do occlrr in brackish water' the 

ueual habitat of q.= es!-ggE ' Medem (1981) mentioned the 

increase ol Caiman crosodilus in brackigh h'Fi!_ts of

sone riwers of Colombia {ollowino the extinction of ,er 

acutus. It is likely that Eomething sinilar has happened 

in Belize: C, moreletii resistant to hunting due 

tn i +q .nnnl Fw and 

reproduction at a younqer age. AJter the erteflninalion of 

q: acutuE rt eraE able to clipprse to brackish habitats 

previouBly occrlpied by C: e-c-g!Jl-s-. 

AC KNoUlLl. DG E llE r,J T S 

This study waq initiated b/ the lnternational Tropical 

Conservation Foundation and frnancially stlpported by the 

Van Tienhoven Stichting. t I ike to tharrk Jorqe Verde ' 

Auriol Samos dnd Benito Flc,res for the inform.ltion thet 

presented on the Iocal crotodi le si tuation, and Jao ,:nd 

Tineke Meer.nan for their 9€neral support. 

ABS TRACT 

Surveys in LaQoons' cenote_- and creeks o1 Northeastern 

Eelize reveared several sm.all PoPUlations o{ bq/,odv lu:-.: 

moreletii and some specineo'i o{ CrocodvlLrs acutus. All !l 

noreletii populations were in the less saline habitats. 

Reproduction ot E: {c-q!rg Eeened to occur in the arpi of 

Barracouta Pond,

u 

REFE RENCES 

Abercrornbip' C.L. ' Davidson' D. ' Hope, C.A' & Scott' D't'' 

(l9AO). Status of horelet'e crocodile Crocodvlus 

noreleti in Belize. B-!qt: Conserv. ' !Z! 1o3 - l3' 

Abercrombie, C.L. ' HoPe' C A. ' Holnes' .t 'm. ' Scott' D' & 

Lane' J.E. (1942). tnvestiqatrons into the st:tus of 

more tet's crocodile {CrocodYlus noreletii) 

BeIize' 198O. Proq. 5th l'Jork lleet. Croc. Soecr' 12 - 

16 Auougt leaq, qs-i!r? 5v i I1..e,' USA' luq! 8!-b!. N,cr4 

qe!' 11 - 30 . 

AIvarez del loro' l'1. ( 1974 ) . Loe -C-rq.sq|)-!-r-q de 

A.C,, hexico, D.F. ' lostituto mexicano de 

Natural es Renov ab I es. 

Croombridqe' B, (1987). The DiEtribution and Status of 

lr,orld CrocodiIianE. In uiildlite !q! cs€llefl!: 

Crocodiles and AtIioalolg, ed5. G.J.tî' Webb' S'c' 

l'1anoIis. & P.J. t'Jhitehead. Surrev Beattv' ChipPrtrg 

Norton'PP.9-21. 

Kinq, F.W.' Campbell ' H.trJ. & f'1oler, P.E. (1942)' Rewll.'w 

of the status of the American crocodile' Proc' 5th 

Ulork l'1eet. Croc. Soec', 12-16 Auoust 1-?-gl' 

Gainesville, USA. IIJCN PubI. NC!4 gCI:! Aa - 98' 

Medem' F. (1941). L=gE Crocedl! lle de Sur America, !, Los 

Crocodvlia glq Colombig. Colciencias' BogotA' 

NeilI, t'i.T. (1971). l-b-C .laEt of llbg rulina reFtiles' 

Columbia Univ. Pressr Ne!'r York'

Neill' W.T' & Allen' E'R' (1951) ' Further studies on the 

herpetotogY of Br i t i5t\ Honduras' 

Heroetolooica' !2, 37 - 52' 

Potaell, J.H. (1971)' The status of crocodilianE in the 

United States' mexrco' Central America' and the t'Jeet 

25 

Indies. Plgf. 1Et Work .IESL' Croc' SDec" l5 -17 

March 1971' New York' IUCN Publ ' New ser' ' 2' 72 - 

e2. 

Zisman' S. (19S9)' The dir€?ctorY of protected areas and 

sites of nature cr,nst:rvation interest in BeItze' 

Dep. Geographv' Univ' Edinburgh' Occ' Publ' 1o'

26 

Figure 1. Map of the stlrdy area. 

specimens seen at each 

indicated with each si9n. 

The number ot 

loca I ity i5 

Tab le 1 Habitat features of al I waterbodies 

Eurveyed in Northeastern Belize, Specimens 

from locality B t^,ere sern and identified 

by local people, 

Crocodil ians seen 

in Nor theastern 

I oca 1i ty B were 

I ocal peop I e. 

at di.flerent we terbodies 

Bel ize. Spesimens f rorn 

6een and identified by

. r; 

\ 

q\ 

:i 

€ C 

_ta- 

,. E?ndi 

q 

: 

; 

'? -- 

4d 

9:o 

27 

s!.flI: 

i3 E.5 

o o.-! o 

or:E{, 

ox9;o 

.i90:6 

zdd: i 

El .oo> 

>i 

Et! i

28 

Locrlitt 

2, 

5, 

lrEr.9r 

depth l.) 

Join Pil?6 l.? 

C.e.l 

lrlir||Y 

0.1 

Ch.r.n Ci.t 0.5 

Itol 

Irr..routr 

Pond 

o.! 

5, l.rree light 0'5 

C€note 

6. Sirt?n.jt 

Cmot! 

7. L.goons 

Shipst.rn 

lorest 

0. L.goons 

ShiPstrrn 

deeP 

0.1 

0.1 

t, Corol.lito 0'l 

Cr?sl 

10, Cororrlito l'0 

[4oon5 

ll. Ship5trrn 0.5 

L.9oon 

12. llorthern 

5e. 

Co.st 

TiblE l, 

ll.ri.u. 

dlptn 1., 

)3 

0.8 

>2 

)l 

d3?D 

0,3 

t.0 

0,7 

l,l 

1.2 

lidtll 

la, 

20 

300 

t00 

t500 

l?0 

100 

100 

l.tar collr|r S.lioitt Shor! v.gtt.tior Se'ri!5 Pr'*nt 

trro.ill!l 

9rlln 

9a?.n!5n 

9rl?nrsn 

rllrr 

broffish 

ht!|ni3lr 

(lPar 

6-lt 

l0 

7 

2l 

5.ltt 

5rlt, 

srltt 

rrd $nqrova/ 

hardtood 

!r455 

!ril5 

red aangroll/ 

barfilod 

rad rangrovl 

red |.ngrova 

r€d r.nqroY. 

C..lr.lttii 

C..o.rlrtii 

C. a(utls 

C. atutug 

300 (har !.lty red Dngrovr {[. ecutusl 

?00 

2000 

brornish 

tl!ir 

(hrr 

br.rlisn 

brr.liri 

h.rdrood 

rcd a r0role, 

rEd fingrovl 

hrrdmod 

lhbrt.t t?.turt5 ot rll r.t!rbodiee rurY"'d.in lortnlr5t'rn B'lrr'' 

;;.;;";;;; ioirtitr s ..re 'em 'nd idlntilr€d ht loc'l p'oprr' 

unidlttili!d 

unid?ntiJi.d 

C..orll.tia 

mideniilied

Lot.liit St ci.! ftl|!.t ol splli|trt 

a(t!.llt 3!€n 

lh.trtln hrrcl.ts incl, 

llnidlnlirild 3D!(i..n51. 

l. JolD lilE Ct.el 

2. bl.tt., 

3, Ch!.n Cln. llol 

l, g.rr.Gout. Potd 

5, lrrr4 Bilht ClnltP 

6. Srrtlnair Ceilt? 

7. 1.900n3 Siitstlrn 

torr5t 

g. lrqooni Shipstern 

9. Cotor.ltto Ct!!l 

10. Corol.lito Lrloon 

ll Shig.tlrn L.goon 

U lbrtlErn Srr Cortt 

t..ortt.lii 

C. rot.htii 

C..rutll5 

B. itrtuB 

||nidlttiJi!d 

lC. rcutusl 

unid.utili!d 

C, |ot.l.lii 

unidlttiti.d 

2t6) 

9u0l 

3 

I 

0 

0ll) 

0 

0lll 

6t9l 

0 

0trl 

l.bl. 2. CrDcodili.trs s..n rt dilf'rtnl r'tlrbodi$ in lDitlE$tlrn lelir!' 

'--'- -' 

im.ire* lro. lo(.litt I rer! t.!n .l|d idFliti'd bt loc'l ,.opl!' 

ourh.l ol S9tcirtn3 6irl rrn!' 

3!ln bt lo(alt 

|tnt 

5 

I 

2 

l 

I 

I 

29 

0.5-1.9 

0.7-2.3 

0.6-1.5 

1.2-l.t 

1.5 

0.1-1.5

30 

AMERICAN ALLIGATOR (AWgotq mississippiensis) CLUTCH 

VIABILITY FROM SEVEN STUDY AREAS IN FI.ORIDA" USA 

H. Franklin Percival Greg R. Masson, Ketrnetl G, Rice* and 

Allau R. 

Woodward 

Florida Cooperative Fish and Wildlife Research Unit 

University of Florida, 117 Newins-Ziegler Hall, 

Gainewille, Florida 32611-0307. 

*Presenting 

the paper 

Seven study areas in three Florida drainages were considered in this four year study. 

These were the Otlawaha River drainage (I-akes Apopka and Griffin); St. Johns 

River drainage (Lakes George and Jessup); and Okeechobee/Everglades system (two 

Lake Okeechobee areas and Conservation Areas 2A and 3A), Collection efforts 

totalled 1215 nests yielding L259 clurches or 52515 alligator eggs (meatr clutch size = 

43.2). A mean hatch rate of 0.592 produced 23,100 hatchlings. Preliminary analyses 

itrdicate significant differences iu viability rate (overall x = 0.488) among drainages, 

among lakes and within lakes by year. The OkeechobeeTEverglades system sho$/s the 

highest viability rate of 0.596 over the four years, followed by the St. Johns drainage 

with 0.46 and the Oklawaha river drainage with a 0.206 viability rate. Iike Apopka 

has continually had the lowest viability rate (x = 0.198), while tle Conservation Area 

maintained the highest (x = 0.657). Each study area demonshated a great deal of 

annual variability in viability. More than 2/3 of the enbryonic nortality occurred 

prior to the 20th day of incubatior. Furthermore, 807" of this category is 

attnibutable to zygote mortality (in utero mortatty). h fact 40Vo of all embryonic 

deaths occurred prior to ovipositiou.

UTILIZATION OF CROCODILE RESOURCE FOR RURAL DEVEIOPMENT 

PROGRAMME IN BANGI,q,DESH 

M.M. Rahman 

Research Ofricer (Wildlife Section) 

Bangladesh Forest Research lostitute 

GPO Bor - 273, Chittagong - 4000, 

Bangladesh 

A 10-year research sho*'s that three species of ctocodile had been a pote[tial 

resource for the illegal ta{ers as its products are pdzed in th€ national and world 

market The res€arch also itrdicates that a large population of the animal was killed 

by the illegal skin traders about 30 years ago in the coutrtry. Consquently, crocodiles 

were becomiag so rare iu Bangladesh, 

A sinall populatiou of crocodile was located in the padma/tamuna river and 

estuarine a,reas-of the country. A species of marsh croocdiile (Crocdylw plutris) 

has been already disappeared ftom the natural habitat but the animal:t l exists in 

captive condition ooly iD the country. 

The status of tle atrinal breeding aspects and distribution so far studied are 

presented itr this paper. The possibilities of rehabilitating this animal in other areas 

of Bangladesh depending ou the food availability have also b€etr discuss€d. It also 

suggest for the utilization of crocodile resource in rural dev€lopment prograDme. 

31

c o N sERvAlol;i1iluPiiJ,:fi:fi oD rrEs,N rH E 

ABSTRACT 

Or. R. J. Rao 

School ol Zoology 

tl?iJi'l?,i'rt'' (,'n P) rNDr^ 

1-lrc Ctoco(Iilc l'roJect ts onc dJfthc strcccssJirt Il,il'lli/c Projccts iIt ltclia The 

success oi tiris Project is moinlg due to the elforts token bg indiuidudl States in 

the ccuntry, Tlrc Crocodiles h tne M.rdhga Praclesh State ho:ue receloed qctive 

f,otcction-tn 

sPecl(lllg created Prctected areqs' A total oJ Crococlile 

.tlvee 

sonchr(rries nolnelg, Natlonol Chambol Sanctuary' Son Gl'ariol SanctLrcrrg' c"ncl 

t:an Gll(.ri(ri Sancfuqry lr.rue been declcired where nranogemettt programmes 

\auebeettta|cenJorconservatlonoJGhc|:icLldndMugger.TheNCsisoneoJthe 

best lobitatJbr Crococllles in In'lto' As pects relatecl to conseruotiotr nv ragemetrt 

o-f Crocodilcsin these Scnctucrl€s ore cliscussed h tlrls pdper RecetilA' therc 

trc seDercrl rePortson nuisqnce Mtt99 cr tn tlrcstc:te' Measures ltdDe been talrcn 

tc rehabliit.te these nlugg€rs, Results or ue no|litoring studies indicate tlrat t|re 

con:tervqtlotr progr(lmtnes nove d' positioe ifllPcct o't tlrc poptLlcLLial]s of 

CrocoCiles in t,.e il{aclhya Pra'leslr'

&EodrEtiql 

In India three species of crocodj-Les ocolrr. They are c haria-I 

( Gavia-ljs gangeticus), nugger (Crocodylus pa.Lustris ) and sa-Itwater 

crocodile (Crocody.lu,s porosus). Due to codnercial hunlilrg for ahe 

Iuxury leather trade, the j.dtroducLion to nylon gi,II netLing and habitat 

loss popu-lalions of crocodiLe species uere greatly depleted (H.R.Bustard 

in FAO, 1974). Al.1 the three Indian crocodj.Iian species aie t lsted 

as 'eodangered, 

in the IUCN Red Data Book (].972). They have also 

been lisLed in Appendix I of CITES (ConvenLion on InternaLional Trade 

in Endangered species of Wild Fauna & Flora). Recognising their endangered 

status, the Government of India ha,s given proteclion to the crocoaliles 

by including them in the Schedule I of the Indian Wildlj.fe ( plptecticn ) 

Acf of 1972. A massive rehabi.IitaLiqr programme for crocoali-Ies was 

started by the covernment of India during l9?5 under Crocodile projec! 

(Rao, 1985, singh gq al 1984; C houdhury & Choudhury, 1986). Different 

state Govemments have adopted thi.s programme. covernnert of M.p. 

a-IEo started crocodil"e ccnservaliod projects jn 1978. In Madhya pradesh, 

tl'o species of crocodiles - gharial and nugger occur. This paper 

highlights the crocodile cooservation project in Madhya pradeeh. 

Crocodile Prcrject in U -P. 

The gladhya project covernment has undertaken rehabiLitatioi 

programme for the highLy endangered crocodile specj.es _ the gharial 

under the Crocodi.Ie Ccnservation project. The important ghariat habitats 

rrere identilied and given protecti.on by declaring them a.s sancEuarres.

34 

Crocodiles are afso being protected in Ci!:erent sanctllaries and National 

Parks of the StaEe. Rehabilitation of cLocodi-Ies ',tas stalted during 

I9?8 by adopLing :he rgrow and releaser cechnique suggested by Bustard 

(FAo, 1975). T hj.s technique is aimed a! ltild laid eqg collection for 

hatching and rel.easing oi the juvenites ioto protected habitats after 

seveaal years of captive rearinq to glve the$ a better chance of surviva_l' 

Monitoring of the released crocodile6 in different sanctuaries has been 

taken up to evafuale the success of the rehabi-litation programmeg' 

Crocodile s-rctuari.es in n-P- 

The Madhya Praalesh Government has declared three sanctuaries 

for the conservaticd of crocodiles. They are (Fig. I) :_ 

l. 

7 

National Chambal SanctuarY 

son Gharial Sanctuary 

Ken Gharial Sanctuary. 

In these sanctuaries managemeol 

for the cooservalioo of the gharial- 

Ndiqral Chambal Sancba4' 

program nes emphasised 

The National Chamba-I SanctuarY (a tri state - Iv!'P-' U'P'' 

Raj. - sanctuary ) is one of the najor crocodilian sanctuaries id rndia' 

spedally created during Lg78-'79 for the conservaEion management of 

gharials did ocher wild aninals. The sanctuary extends over the chambal' 

river from Ja!,/ahar Sagar Dam to Kota barrage and after a gap of

13 kms free zone/ irom Keshoraipatan (Raj.) through Pa-li to Pachhnada 

(U.P.) where Kun!./ari, ?ahuj and Sindh rivers form a confluence vith 

the Yamuna ri.ver. The tota-L lenqth of lhe r.iver insrde tne Sanctuary 

is about 600 km. The Hidth of the river that is included insi.de the 

Sanctuary is 1000m trom either bank in Rajasthan and l,ladhya Pradesh 

whiLe Uttar Pradesh has a greater width totaling to an area of 635 sq.km. 

(Singh, 1985). GeographicalLy, the Sanctua.l lies betlreen Lat.25'23'N 

and 26'52tN and Lonq.76"2E'E aod 79'01tE. 

Sanctuarv Manaqement 

tha NaLicnal chanbal sancLuary is managed by the Forest 

Departments ( wildlife L'ing ) of Rajasthan, Madhya Pradesh and Utlar Praalesh. 

The Sancb.ra r head quarters of M.P., U.P. add Rajasthan are at Deori, 

Dist. Morer r; Agra and Kota, respecLively. Stopping of fishiog acLivrty / 

naintaining ful-I protecLion from poaching, extending protectjoo to habilal 

and rehabi-Litatsion of gharial under rgro!, and relea3er scheme are 

the nanagenent strategies adopted in the NaLionaf Chambal Sanctuary. 

The protectioo and tiel.d stalf work under the adminGtration control 

of the Chief l4lildlife warden of their respective States. The management 

staff posted alL along lhe Chamba.l river keep a regu.Lar vigil to stop 

any il-legal f*hing and poaching of gharia-l and other wi-Idlife. In 

additicn to protecLion, the field staff codduct crocodj-Le and other 

wildlife surveys and a-lso locace tharlal nests in the Sanctuary - The 

gharia.L eggs are collected by U.P. and fl.P. Forest DepartmenE for 

rehabilitaLion programme dnder tne jrocodile Project. Charral e99s 

were afso collected by the Orissa Forest Depaltment from the NaLional 

Cha.nbaf SancEuary during 1980-82. 

35

JO 

GhariaL RehabiLltaticn 

RehabdieaLico of gharial has been taken up in the NalionaL 

Chamba-I Sanclu3ry fFom 1978. So far/ a tota.l of 1,762 captive reared 

ghariaL at Kukrail crocodil-e rehabilitaCion centle, Lucknov, U.p . , 

have been reLeased jn the Chambal river by Uttar Pradesh Forest 

Department (Rao, 1988; Hussain/ 1991). During February 1989, Madhya 

Pradesh Forest Department had released 5 capLive reared ghariaL at 

Deori GhariaL Rearing Centre, Morena, M.P. i.n the Chanbal ri.ver. 

Young qharia-I from Che Nafj.cna-l Chambal Sancbrary have aLso been 

released in Ken and Son gharj.al- sanctuaries of the State. 

SEatus of Ghari.al in NCS 

Accordirq to Singh (1985), the gharia-l populaLion in Chambal 

(4m kn) during 1978 was esLinated to be around 107 $rifh a sighting 

density of O.29 per kn. Singh a-lso repoEted the gharial population 

in the ChambaL river during 1983-84 and 1984-85 as 451 and 605 wilh 

a density of l.O8lkm and 1.42lkm 7 respectively. Accordiog to Rao 

(1988), sighting populalion of gharia.I in chambal river during 1985-86 

was 618 and during 198?-88 the nuft ber was 804. The populaLion density 

was eslinatd to be 1.6/kn in 1985-86 and I.89/kn in 1987-88. The 

population estimates revealed Ehal lhe gharia.l popul.atiod in the Chambal 

river has been recovering over the past decade from an earlier decLining 

statLrs. The j..rcrease in density. of ghariaL from 0.26lkn in 19?8 to 

1.89/km in 1934 indicat€ lhat the gharial. popuLati.on in Chambaf is 

in a recovering -ohase (Rao, 1988).

Status of Mugger in NCS 

The mugger (crocodylus pa-Lustli.s), a.lso knoirn marsh 

crocodj-Ie/ i.s presen!, allhowh Less i.n number in lhe Chambal river' 

They m oetty prefer rocky isLets for basking and they nest on sand 

banks covered !,tith rocks and bushes. According to 1984 estimates 

(sinqh, 1985), around 12 nugger nests have been located in lhe chalnbal 

river. Mugger ne€ts have been Located very clase to thariaL colonial 

nesting sites. Durjng Apri-l 1984/ a total nunber of 28 mugger that 

had originated from eggs collecled from the chambaf river were release'l 

i.n the NatiooaL ChambaL sanctuary (Si.ngh, 1985). one nest of inugger 

eas coUecteal by the t4adhya Pradesh Forest Department for captive 

rearirg programne durinq 1987. to avoid any possibLe effecc on gfrarial 

populatim sjngh (1985) reported that mugger in a gharial' sanctuary 

be not supplemented through rgro\t and release prcgramme!. 

Crocodjle Captive Rearing Proqranme a! NcS 

Uflder the crocodile tehabiLitation proqramne, crocodi_Ie captive 

reari.ng centre has been establGhed at village Deori, District Morena' 

I'1.P. during L980. Searches sere made in lhe chambal river to focate 

ghariat nests. Durinq 1981, a singfe nest of gharial (35 eggs) as 

located at Baroi.i nesting sile ancl the eggs were ttansferred to Deori 

for arlificia] incubation. From 198f onl/ards, every year (exc€Pt 198-l 

and 1986) gharial eggs are collected ior harchery incubaLi.on (See Table I)' 

ltatchlings elnergeal from the eggs !,tere calefullY reared at the Deori 

charial. Rearing centre ( DGRC ) 

37 

(Rao, 1986. nao and Sharmar 1986).

38 

Resufts of the 

Table l. Some 

Ken rivers (see 

captive rearing 

Iab.Le I ). 

programme a! 

gharial have 

During 1987, a clutch of Tugger 

the Chambal river. The eggs were hatched at 

hatchlings are being reared at the Centre 

to release the muggers in protected aaeas in the 

Scrt Gheial Salr(fraE\/ 

Natural poprj-lalion of gharial 

be around 1I of different sr.zes. 

DGRC are given in the 

been re-Leased in Son and 

eggs were 

the DGRC and the emerged 

(lable 2). 

State. 

col-Iected from 

It js proposed 

To prolecC Ehe remainjng population of ghariaL, the Soo chariat 

Sanctuary was declared over the Son river by the Madhya pradesh 

Government. The Sanctuary head-quarters is at. Si.dhi. The Sanctuary 

includes a stretch from the Ban Sagar Dam, which G under ccnstrucliod, 

to Uttar Pradesh border at the South of the Mirzapur DisEict. The 

length of the Sanctuary over the Son river is around f6O km and small 

stretches of t.wo tributories - Banas rivet \22.5 km) aod Gopadh ri.ver 

(25.7 km) are also included in the Sanctuary r thus totalung around 

2O9 kn of the area that is under the management of the Son Gharial. 

Sanctr.rary. The 'ridth of the river thaC is inc.Iuded inside the Sanctuary 

is 2O0m from both sides of the river badk- ceographicaLly, the Sancfitary 

Lies beLween the Lat.24'15tN and 24"40'N and Long.81"20'E and 82"50,E. 

Sbatus of Gharial i.n SGS 

in the Son river wa3 eslimated 

Afler decLaring the Sanctuary,

el.eases of gharial have been taken . place in Ehe Son river. So far, 

r t-rrl af 7. ^r^-ivF rarrod ,1:r'rl h^'6 \a6. --.,.cd in che son 

rrver rncluding 20 tharEL released during February 1988, \thich \tere 

caFtive reared aE the Deori Gharial Rearing Cmtre/ l'lorena ' Madhya 

Pradesh (Rao, 1988). AII the gharia-ls were ori.ginated from the eggs 

collected 1n the Nationa-l chanibal- Sanctuary. The Son river is a good 

habitat for gharia.l. No adult/breeding ma]e gharial was reported in 

the son river. Natural. breeding of gharial in son river j.,3 nct occ[rj.ng, 

ho\rever, !:he gharial refeased under rehabilitaLion paogran lne !ril-1 

start breedi.ng after sone nore years. Under the rehabiLieaLion Programme 

more captive reared ghari.a.L !ti-11 be released in the Son Ghari.al Sanctuary 

during coning years. 

Status of Mugger in SGS 

one pair of mugger nas released in the son river durirg 

1983. The muggers \rere captive reared a! the Kukrail Crocodile Rehabi-lita- 

Lion certre/ Lucknow, Uttar Pradesh. According to the estimate of 

the fieLd staff at the son Gharia.l sanctuary, a totaL of 4 nugger was 

present in the Sanctuary r including the 2 released nuggers (Rao, 1988). 

there are nany areas j.n the Son river/ q/hich are suitable for muggers. 

Ken Gharial SancbEy 

The Ken Gharia.I Santuary was declared over the Ken river, 

a tributory of River Yanuna, where gharial rehabilitation programme is in 

operaLion. The Sanctuary head quarLers is at Kajhuraho in Di6t. Chatarpur. 

The Length of the Sanctuary over the Ken river i-s around 45 km. 

39

40 

Statls of Crocodi-les ir KGS 

No systenattc crocodile status surveys have been under:laken 

in the Ken Ghariaf Sanctuary. Durirq f9B5 and f9B?, a total of 20 

captive reared gharial fron Deori chalial Rearing Centre, NcS, have 

been aeleased in KGS. Infornation o.l mugger populalion in KGS is not 

avaiLable. Ken river inside the Sanctuary is comparaliveLy more suitable 

for mugger than ghariaL. The area is havj.ng more rocky stretches 

and ninimaL water f[ow due to construction of dans i.n the upper reaches. 

St*lg d Crocodiles in Ot}l€r p;rtected Areas in it.p- 

Crocodjle population in Madhya pradesh, other lhan the 

populaLion in Crocodile Santuaries, are very less in number. A totaL 

of 25 nugger were released j.n Che Chandpata Lake inside the lladhav 

NationaL Park (De vos, 1986). During 1986, a tora.I of fO capeive reared 

gharial flom the Deori. Gharia-l Rearing Centre have been released 

in the van Vihar Naeional park at Bhopa-l (Rao, 1986). one pair of 

mugger from captive collectj.ons at Jaj"pur Zoo, Rajasthan has been 

re]eased in the Van Vihar, M.P., during October 1988. Muggers are 

also maintained in captivity in dj.fferent. zoos in M.p. A tctaL of 4 

mugger are under caplivity at Munj.cipaL Zoo, Gwalior. There are reports 

of presence of mugger in difEerent reservoirs, Iakes and rivers in 

the State, however, no data is available ol! thej.r status. 

Research 

Prior to 1983, scj.entiiic studies on crocodiles m madhya 

Pradesh have not been taken up. From June 1983, extensive studies

on ecology of gharial and flugqer ccoLl]at-Lons in lhe NaLiona-I Chanb3l" 

:.a nFin. .arrrc.l oui ..v _i6 _a:o:-.^ r-ra .. ,;,tdlije insLicule 

Jt lnd!d, Dehrad ja rn coLldoora:lon wiL.] )4adhya Pradesh Eoresr DepaflTenL. 

This incl'lded the use of Radio-tracking nethod and population nonitoring 

(Singh, 1985 and Rao, .1983). From cctcber 1.933, lhe auihor rem a-ined 

involved in monitoring of the ghariaL populaLicn includmg scudy on 

ghariaf neslinq actjvlties in Natiooaf Chanbal Sanctuary (Rao, 1988). 

The resu-Ils of the studies are usefuf for taking suilable neasures 

for the conservation management of the gharia-l and mugger in the Chanbal 

river and in other crocod ian habitats. The research 'nork in Chamba-I 

river highlighted for the first time Lhe mulLipfe role of crocodile 

Project because of the sinu-ltaneous conservalion of aIL aquaLic flora 

and fauna in a crocodile sancttlary. Here the stress was giveo to gangetic 

dolphin ( Plantj.nista gangelica)r otLers (Lutra 9P.), freshwaler turtles, etc. 

cdrdrlsion 

The best remaining popufation of ghariaL in the country is in 

M.P.7 where three santuaries are specially creaEed for the conservatioo 

of gharla.l. The onfy breeding tharial popu-Latlon in M.P- exists in 

the Chambal river, which borders M-P. with Rajasthan and ljttar Pradeqh. 

Hopefu.lLy 

/ after some more years breeding of gharia-l ltilL commense 

in olher rivers, parLicJ-Ially in Son river. lluggers are present in 

ditferedt \,ret-lands throughout lhe State. More sYstematic statlls surveys 

should be carried out, especial-Iy at reservoirs forned by the constructrcn 

of Dans and barrages. This ttil.L give a chance !o identify places 

for future rehabilitalicn of mugger. Surveys jn Bet\ta river, a tributory 

4l

42 

of rrver Jamuna shouLd be cond'lc.-eC t: lccate any remarning popufation 

or gcaridl and also Eo roelErry lne s{iEao.L-L.rE! o[ E'.]e ri.,'er ior gharia_L 

reha bi-iitatron. )loniErrrnl oi re.Leased crocodi-les has t. be ccntinued 

by the field sEaff of the Sanctuary/Protected areas where crocodi.Les 

are released. This has to be given high priority to eval"uate the success 

of the rehabi-litatjon progranmes in 14adhya Pradesh. Research sLudies 

on crocodile conservation are encoutaged for the betEer management 

of crocodjl.es in the Madhya Pradesh. 

R€fiererEeg 

Choudhury/ B.C. and Cho\rdhury/ S. 1986. Lessons from crocodrle 

reintroducLion projects in India. The Indian Forester, Vol.Il2, 

No.Io : 8a1-890. 

De Vos, A 1982. An evalualion of the UNDP,/FAO croccdile breeding 

and management project in lndia. FAO, Rome. Fie1d Document 

No.8FO:IND/74l046. 

FAO/ 1974. A preliminary survey of the prospects for crocodile farming. 

(Based on Ehe work of Dr.H.R.BusErd) FO:IND/7]/03:. 

FAO, 1975. India. Gharial. and crocodile conservatj.on management in 

Orissa (Based on the \rork of Dr.H.R.Bustard) - E'O:IND,/71l033 

pp. 1-15. 

Hussain, S.A., 1991. Ecology of gharia-I (cavialis gangeLicus 

) in the 

Nationa-l Chambal Sanctuary. M.Phil thesis, A.Ligharh Muslin 

Universlty, A-Iigarh. 

IUCN, 1972. Red Data Bcok - Repti-Ie6, Morges, Switzerfand. 

Rao, R.J. 1986. Management of crocodi-les and lurtfes in wet-Iand sanctL.raries 

of India- Tiger pa9er, 12(4):I-5. 

Rao, R.J. 1986. Captive rearing of gharial and turtles j.n National 

chambal Sanctuary. Zoo's orinc, I(Io): L7-18. 

Rao, R.J. 1988. Gharia.l rehabi-liEalion in the Son Gharial Sanctuary. 

Mi,neo, pp-12. 

Rao, R.J. 194d. N esLing ecology of gharia-I in NaLiona-L Chamoal SancEuary. 

Study report, I'limeo, pp.L05.

Rao, R-J- and Sharna, 1.K- 1985. :harisl rena.illcalicn in Madhya 

r.i.lo.-dDer/ IJ .)|2--.. 

iirgh/ L.A.K. .1i35. inarFl ?opu.Lali.on :rend in Na::onal lhamba-I Santuar-1 

with ncEes on radio leleiTretry. itudY aeport/ l4imeo. 

Si.ngi!/ L.A.K.; Kar/ S.K. and Choudhurv / B.C. 1984. Indian Crocodi-Iians: 

A 1.0 year review of nanagement. Paper presented at the 

\rorking meeLing of te IUCN /SSC crocodj.le soecia-IisL group. 

Caracass. venezuefa. Oct. 1984. 

Table I : ResuLts oi captive rearrng programme of tharial at Deori 

Gharial Rearinq ceotre durinq 1981-1991 

Year 

198I 

r9a2 

L983 

1984 

1985 

1936 

I987 

t_988 

r989 

I990 

I']9I 

No. of 

coLlectec 

35 

35 

40 

4{) 

63 

L8 

a2 

61 

40 

No. of 

eggs 

hatched 

26 

35 

3'7 

63 

T\2 

BO 

29 

39 

No. of 

animals 

dead 

10 

L2 

16 

38 

48 

No. of gharia-l released Present 

Stock 

Year Area No. 

1985 

r986 

.I986 

r9B? 

1988 

I98B 

19d9 

1989 

1988 

KGS 

V anvihar 

Vanvihar 

KGS 

SGS 

SGS 

NCS 

NCS 

NCS 

524 46.r 10 2t9 

t0 

6 

l0 

4 

l6 

I 

15 

4 

25 

49 

80 

.Lt 

39

Table 2 : Res"rILE of captive rearing programme of :^n uqge. DGRC 

1987 

1990 

col-IecEed hatched 

27 

20 

22 

It 

),io. of animals 

dead 

l 

Present 

stcck 

rI

o.-il9-. r- 

l- tlaLiaEl Charbal S dErt| 

2. Xst CharLl SdEtsry 

3. Sa! chirll Srd|Dry 

45

4(' 

ALLIGATOR NEST DETECTION PROBAAIIIIIES 

DI'RIIIC AIRIAL SURVEI IN ALORIDAI 

Kenneth c. Rice'. H. Frankl.in Percival', and Allan R. Woodrald" 

' 

u.s. aish a!|d wildlife service, Florlda coopelatlve Pteh and wtldltfe 

Research unlt, Dept. of wildlife and Range Sciencea, Unlver6lty of 

Flortda, cainesville, alorj.da. 

"rtoriaa oame and Fresh Wate! Flsh ConmtBsion, caineEvitle. Florida. 

Detectlon probabtl.tties of aLllgalor nesta or other obJects of 

lntereEt nay differ due to variatlong tn vegetatlon, topogrephy, obaelver 

€xpelience, a.al other €nwlromsntal factorE (Nofton-crifflths 19?5). 

Thelefore, the probabtl,tty of detectlng aII neatg tn any sanpltng unlt 

nill uEualLy not equal. I (caughl.ey and crlce 1942). Adjustment of counts 

by some faclor is essential to elirninate btas assocfated with unknoitn o! 

varlable detectlon probabillti€s. ln Florlda, femaLe alligatolE nea! in 

very dl-verse habitat6. Most notabLy. r!€Ets aPPear rnore difftcult to 

detect fron the atr tn areaE with heavy tree canopy. 

D€tecll.on probabtlittes may elEo b. aff€ct€d by dtff€rences 1n 

ob.elver experience (Norton-srif f iths 1975). The develognent of e 

spectflc search lnage and the ablllty to dlscern t€rr€Bttlal obJect. fron 

the ei! are garneled through experience. rn additlon, some indivlduals 

rnay develop these skills at differing rateE and attatn differing levela of 

competence due to viEual aculty o! other tnher€nt factors (Ueace 1969). 

Expertence may be eapecLaLly irnportant uhen searchLng fo! partLelly hldden 

or canouflaged alligato! neEtE. AddltlonalLy, ptlot expeliBnce tnay affect 

these probablllties. 8xp€rienced pilots may provLde for a more efficient 

surv€y by fLying only lrithin neststng habitat wtthout repeated lngtructlon 

fron the observer (Norton-cllffithE 1975). rhis allows the obEelve! to 

rPresenteal at the 

the IUCN, at Vl.ctorLa 

llth vrorking Meeting of the crocodll€ sp€cialiEt croup of 

lalla. zlnibab$e, Augnrst

4',7 

concentrate sol€ly ott n€st search.lng and not on navlgatlon, 6Paed, end 

.ltituale. ifhile these differences naY not lncrea6e EallPling €rtor, th€v 

l|ay biaE the €atimato!. 

once al€tectlon Probabillttes have been calculated, they l|ay be uaed 

to consuuct nest productfon 3.tl-nat€s via an adjustnent to . dlroct count 

o! l.n conJunction with othel nethods such aE tran6ect cou!!t€. An tnltial 

aleciElon was nade to concentrat€ sanPllng effortE along several line6 of 

htrpothests t€Btlng. the p!i-na!y line of gu€stioning lnvolved dev€Lopltrg 

d€tectlon probabl-Iiti€s for all'igatot n€st surways and estlmatlon of neit 

populatlon€. s€condalily, ne tested the nulL hyPotheEts of no dtffe!6nce' 

1n the6e plobabilitles acrios. yelrg lrd priinary habitat ty!,es. und€r thla 

te6t, ne assuned that all obBerv€Es $ere erPelienceal r,lth alllgato! 

n€sting surv€y3. goweve!, with Eev€!.l new btologi.t. €nt€ling an 

s.pandtnq rlll.gator tnanag€rEnt proglam tn Florlds, lJe .a!, ttrs raed to t6at 

th€ h)rpothesis of no diff€lences ln detection Probabilltlas trnong 

experience lev€ls. The avaflabtllty of observers dictated the amount of 

€ffort applied to €ach questlon. Einally, w€ tested th€ null h!Poth€61's 

of no differenc€ in det€ction ProbabtlltieE betl'€en two lev€la of Puot 

exPellence. 

AddltiodaLly, xre nere LnteleEteal in the f€aslbilltY of the uae of 

aerl-al, Iin€ tran€ect m€thodologY tn nest e.ti-natlon. Ih€refore, we t€st€d 

the null htrPothesls of no dlffsrence bet*€sn e€tl$.tes obtalned tlttoqgh 

cooPlete and tlangect countE. 

ltethodoloov 

Studw areaB. arro types of nalsh sy6temg anal lhree tl.Pe6 of nerah 

cov€r u€re d€ftned to rePlesel|t maJor afligato! nestlng eleat ln llotlda. 

An €.:t6rd.d '.ar'h sysxen itas defined !s an area t'l.th extanslv6, 

homogeneou. vegetatlon as alll-gator nestlng habltat. A a€cond systa&. 

crlled a Dourded staip ateat conEisted of a relatlvely natloit 6trlp of

n€sting habitat betwe€n open wat€! and upland veg€tatlon or other.brupt 

cbangea tn habltat. ltarsh cove lthln bounded 6trlp ar€aa \ras diwtded 

lnto op€a, patXieT.Ty pooded, anal rood€d ayatens. Open Bysten€ nere 

mar6heE with sot canopy. Study areai w€re choEen 

that haal a hl-Etory of relrttvely dense nestlng !o provlde adequate sa$pLe 

Elz€ udder 5 Limited budgets. 

Lake Okeechobee, a shallow, 191,223 ha lake ir south-central Florida 

(Okeechobee, clade6. sondry, Palm Beach, and Uartln countteg) repregeDted 

an extended marah siBtem {rtgure 1.). An extenEive mar€h along th€ 

w€atern ahor€ of the Iahe contained the najolity of alllgator nestlng 

(pelaonal obaelvation). l.{arahes assocLated h'tth leveeE on tbe nolthern, 

eaatetn, .nd southeln peltmeteis of the Lake w€re limited anal contain€d 

f€i, neats. Co1l€ctlvely, inarghes constltuted an area of 3a,OOO ba. 

Vegetatlon conglsted chlefly of Typha alodengeasia, Eleochatia celTufo'a, 

Rhynchogpora Xracyi, Sa]it carolinianat Scirpug calito'.aictce, CLaaliu'a 

Jaaaic.aab I and rntxed gra.sos (Milla€on 1987). 

Llke J€ssup, ln €as!-centrll alortdr (sentnote coqnty), waa 

categorlzed aE a boulded Etlip alea and an open Bysten { Ftgnrre 1). Lake 

JeaEup rraa a 4,805 ha, euttophlc, al.kaline, natural lake ln the St. Johns 

Riv€r akainage ba.in (Canfi€l.d 19Al). the pridary ne€tirg erea was a 996 

ha narBh o|! the northeaEtern portion of the lak€. Sand cordgrass 

(spattira lakei.i ) anal giant leed lPhragnites aust1alis) were the 

predoninant v€getation types (Jennings et al. 19841. 

qrange l-ake, locateal in nolthc€ntral Floaida (Alachua Countsy), 

r€ptaE€nt€d r bound€d strrP ar€a and a paEtielly wooded syatem (Flgule 1). 

ThiE ay8ten, 5254 ha, incLuded 1188 ha of potentl.at alllgator negtlng 

habitat. Characteristic of the narsh area was an accunulation of peat, 

resultLng in extenstve fl.oattng islandB of vegetatlon. Vegetation 

con€isted prfuilnallly of Sagittatia Lahcifol.ia, C]a,tiun j a,aic6'rsig,

Ilyclrocoxyla wnbeTlaxa, tyrica cerifera, cephaLatthue occident.Ii.s, and 

Decoaloa verticiuatu.E (Deltz and aine6 1980). 

Lake crtffin, a 5575 ha, eutrophic' hardwater natural Lake l-n central 

llolida (!ake County), lepleBented both a bounded Etrlp area and e r^tood€al 

system (canfield 1981) (Figure 1). A s25 ha woodad swanp occurr€d in a 

narrow band proxinal to open vrateli ma!3h (1231 ha) occurred beyond th€ 

eooded marsh (Jennings et al. 1988). vegetation consisted Pritnarll'y of 

SaJ.ix Bpp., yrica cerifera, sagixxaria Laneitolia, and C.ladiut 

laynes Prairie state Pleserv€, a 73oo ha wetland ln north-centr.l 

Alorida (Alachua county), waE utilized for the transect aanpling portlon 

of the study (Figule 1). Nestlng areas t,e!e catagorlzed as mixed 

persistent and noope!8iEtent, emergent, paluEtrine w€tlandB l-ntellaced 

with Ecrub-shrub. Plimary vegetation in thts region consl6ted ot Paai-cun 

henixonont PoAteileria coralata, PoTygonun spp.,, sa.li:. .tPp., cephtTaathuB 

occidenxafist and sal1'bucus canadensis (Nesbitt and wLl}Larns 1990). 

Alliaator nest survevs. Aerial survey6 were conduct€d ftom 2-.eat, 

piEton-engLned helicopterg during June and July of 1949-1991 to cenaus 

alligator nests on the 4 baaic habitat tl.Pes identified above. Portlona 

of each survey were dupllcated by 2 or more observelB to conatruct end 

conpare nes! sfghting probabil.lties. ahe numbelB and ttp€s of observelg 

plesen! on any s\rrvey rere controlled by avallabtltty of obdervers of 

lequired experience levels. 

The inltial observ€r conducted a 6ulwey along the lakeEhore or ltalsh 

ln suitabl€ nesting habitat. The survey continu€d until th€ obsslv€t had 

counted approxlmately 30 nests. 

Flighte lasted 1to 1.5 hours to insure adequate Eearch ttme while 

remal.nirq withid budgetary constraints. surveyB wele conducted at 40-50 

metels altituda and 25 to 30 knots airspeed. lhe Pilot wa€ directed to 

fo!.Low the lnBtructiong of each observe! except to lrsure tba! all 

EubEequent obeervers lemained withir the area deflned by tbe initiat 

49

50 

observer. aherefore, surweys could hawe dlff€l.ed ln such factord .s 

diEtance flon oPen rratet, ti.ne €pent searchlng ln e giwen vegetetlon type, 

etc. the pilot could adjust any factol fo! gafety concerns. 

At €ach neBt location, tha plLot vtould hover ovar th€ sl-t€ to allot 

ths obgerver to obtaln a loran locat.lon and to record the locatlon on 

1";eOO' aettaL photograPhs {Flortda Department of TransPortatlon, 

laLlahasBee, rrortda). On rake Okeechobee' Ioran locationa were uEed 

Durlng the Period of these surweys (June-July) ' sub€tanttal nest 

constructlon occurred ovelnight. Therefole, all obsetverB on a given 

survey conducted flights on the 6alne dav to alleviate estimation problem6 

aBgociated wtth open Pop\rlationg. ao insure Etnlllat viEibtl'ltv conditlons 

Ln r€Iation to fog' shaalows, and thunderEtorns, alM.lghtB we'e flo6 

lrithin a 3 to s hour period beginning mld-morntng (usuallv o9OO). 

calcutation of €iqhtind probabllltLes. llests nele marked 

individuatLy by naPping and by loran, !€sultLng in knoltn Palallel3 ln 

stghting by observers. For those sulweyE conducted by onLY 2 obEerve!9, 

u€lng notation floill I,lagnuBson et al. (1978), we [oted tho.e nett6 se€n 

onty by observe! 1 (5r), tbose seen otrly by obaerve! 2 (5r), and those ae€n 

by bolh observers (a). sighting probabillties 

(p) of each observer wele egtimated by: 

and 

Because ti was a etandard binorolal eetimator, alandard etlola were 

estsimated by: 

A= 

B 

(B+s")

and 

sE (p2'J = 

,9E', (F1) = 

UultLple-surveys by 2 obeelvers allowed for the use of a nodlfied Peterson 

esti.rnator (chaplaD 19s1), lthich ie degtgned to reduce bias a€6oclated with 

6nall sarnple Eizes. lhe e6tltnator nay be wrltten as : 

(s1+B+1) ( s2 +E+1) 

(B+1) 

.5'.9, (s1+B+1) (S2 +E+1) 

var tnt = _-__iB_a\_@;l 

trhere t iE an estimate of PoPulation size. 

Vrhen 3 or 4 independent obgerwers w€re avallable for counta' an 

estirnate of populatLon size !ta6 obtalned with Progran CaPture (Otl-a et aL, 

19?8). Estimates of proportiong of nests Eighted by anY observer (ii) were 

obtained by rr,ri where ,i was the count made bv obEerwer -r and tr 'as the 

DoDulatlon esthate. lhe Etandard elror o! fr was calculated by: 

gE (brl 

ffi 

These proportlons (detectton ProbabilitteB) ltere used to nak€ conparasona 

of sighttng frequencles amonq indi.vtduals, €xPerlence 1evel6, years, and 

habi.tat6. The calculated poPulation eEtinates obtained qtere conpared 

to total counlE of nesls ltith gimPle linea! leqressfor techniques. total 

countg nele established after repeated surveyg durlng e99 coLlectlon. 

51

obeelver experience. obselwers were divtded into groups dellneated 

by experience level. ExpetienceCl observerg lrere tltoge wlth extenEive 

survey tjjn6 on a qiwen Etudy area. uediun-ezperiehced ob8€lverg l'ele 

experienced with alligator nest Burweys but unfanlliar with the Patticura! 

stualy area. Inexpetieaceal obselvers nere qualified btoloqistB that were 

unacqualnteil uith al.Ii.gator nest Eurveys and had only mlnlmal exPerlence 

wlth alligato! neEting. The effect of PLLot 

experlenc€ on the sigtlting 

probablllties of both exPelienced and inexperlenced obBerwers 'as aIEo 

teet€d. Pllots were categorlzed aa experience)l (havlng f1oll,r many nest 

Eurveys) or jnexParieaced (having newer florrn a ne6t sulvev) ' 

I,ine transect. The section of Pavnes Plairie State Preserve bounded 

by I-75 on the west and us44l on the eaBt was divid€d I'nto 20 €qual 

transects of 150 m wialth. Two observets conducted nest counts on aLl 20 

tranBect6. Tlansects rere later randomly chosen to construct egtinates of 

the n€st populatLon at levele colresPondisg to 25 and 5Ot of the total 

Eurvey area. A eeParate populatlon estinate lras obtained vla the chapman 

esti.nator from the 2 individual surveys. The 2 transect-based estioates 

were conpared sepalately and by observar to the Cbagnan estimate uitb ttre 

standard z-Etatistic for cornParison of two neans (ott 1988). 

Analveis. An analysls of warlancs Procedure nas ueed to test the 

aliffelence in aletectLon Probablli'ties between the 3 obselver exPelience 

lewel6 (SAS Instltute Cary, NC). A contlaEt proceduro was used to compare 

the linear and quadrattc proPErties of the relationshiP b€tween det€ction 

probabiLitieg among the exPerience levefg. Notably, we €mPloved 'os aE 

the crltlcal value for rejectlng the null hYpothesia of no difference 

ainong expeli€nce levelg. soweve!, for multiple comParisons, thi6 walue 

$as adjusted by the nunber of compalisons to .016? (Bonfeftori 

adjustment). 

Theoretical quantile-quantlle plots wele empLoyed to conpare ttre 

alepartureE fron nornality of 3 methodE of data transfolnatlon' Ihese 

plots conEigted of Plottlng the quantiles or ranks of the resldualg of tbe

tlaosformed data against the coriegponding quantilea of a theoretical 

distrrbutton, which in this instance, was tbe normal dlstltbutlon 

(chanbers dt aI. 1943). Ahe plot, if the data ls normally dlstrlbuted, 

should follow the line y=x througb the oliqin. Vfe l,ere concerned L'tth 

serioug departureg floh th€ normal distlibution and cho6e a tranaformation 

whlcb best fulfflled the assumptton of normality. The Etandald 

transformation for proportionaf data ia the alcsine (ott 19e8). re chose 

to conpare thig againEt a weighted transformation. The ploporttons lrere 

calculated as blnonial functionE allowing fo! the calculation of a 

standard error. A weighting function waa then caLculated by the tnvelse 

of the vafiance. The thild rnethod of tranafornation evaluated wa6 a 

conbi"nation of both the arcstne and i'eighted trang forrnatlonB. 

Untran6f ormed proportioDa u6!e algo evaluated. 

We utffized an analysls of varlance procedure to detect habltat, 

yearty' and individual effects. slmple effects (pairwige comparlsonE) 

were te6ted witb both the Duncantg nultiple-range teet anal l€a6t squares 

means procedures (sAs Instltute cary, Nc). 

A chi-Equare teEt of independence waB enployed to test the nuLl 

hypotheBia of no differen:e in detection plobabilitles between expertenced 

and inexperienced observers and experienced (5 yeals) and lnexperienced 

p!1otE. 

Resutts 

Obselvations. Thirty-two observations were lecorded durtng thig 

Etudy. Each obgerwation coDgiEted of an estinate of the detsection 

plobabll1ty for a partlcular obserwer on a given aulvey. Theae 

obserwationg were paltitioned anong 9 individuaL observers, 3 experience 

lev€Is, 4 habitat types, and acrosg 3 neBting €eaaong (Table 1). lvelv€ 

separate tlenE€cts w€re surveyed and evaluat€d. obEerwations by 

expertenced ob6ervers nu$elous due to preEence of suitalrl€ 

obBerYera at a given aite. 

53

54 

Detection plabebiMleg= ltean detection probabilMes, Etandard 

errors, anal 95$ confidence intervals were i = 0.7567. SE = 0.0931, and CI 

= 0.?315 to O.aola for exPertenced ob€ervers, i = 0.5759, sE = 0.1188, and 

Cl = O.4362 to 0.7156 for nedium-expelienced obselvers, and * = 0.4488. sE 

= O.1409. and CI = 0.3453 to 0'5523 for inexperlenced obBelverE. 

Population estimateE w€re calculat€d for each transect wia the Cbalnan 

estlmator (2 obEervers) or Prograo capture (3 or more obaerwers) ' lhe6e 

eEtimateg were si,nira! to totat nest countg after repeated sulvevE durlng 

egg col!.ectlon (/ = 0.933) (Ftgure 2). 

Transfolmalion. After comParing quantile plots, t 6 uEed ! lteighting 

function (inverse of the variance) to tlanEfortn ploPortion data (Flgure 

3). The othe! transfonnalions (arcslne and a coribination of arcsine and 

wetghted) antt the untransforned data aPPeared to slightly skew the data 

anay from th€ line y=x. In addltion, these nethodE seemed to suggest the 

plegence of outllerB. we further plotled the resldual wE. exPected walu€s 

from the chosen transfornation (ANOVA model of proportlon stghted - 

obEerver experience lewel) and f,ound no violation of the assufiption of 

equallty of varianc€s (Figure 4)- 

obEerwer experience. Proportslon of nests observed differed anlong 

experiedce levelg (P

!-!!e-l!e!!9g!: No dlfferences were lound belween estlmate. ot'tain€'l 

wlth Li.ne transects at elther the 25 or 5Ot LeYel and tbe chapnan 

esti.rnato! (z=O.036 and 0.049, reapectiwely; P>0.05). 

DlEcusslon and concluslona 

Nest detection plobabtllties. For any managernent legime based uPon 

counting an unknown proportion of a resource, tbe probability of detectlng 

an inallvldual nust be ewaluated and quantified. lb€ wartatlon asEoclatsd 

r.rtth this probability due to diffellng observ€rE, habltatB, and seaEona 

nust al€,o be addlessed. Alligator nesting in Florida wetlands occulE over 

vory div€'se vegetation types, cov€r, and tretland!. During a n€stins 

6urvey, the actual count Ehould be adjusted bv an approPriate detection 

plobability to account !o! these factora. 

A nean of the delection probabitittes fron this study can be used !o 

construct a coriection factor for fital Population €Btl'mate3 involving 

alllgator ne6t Eurveys in Florida. This corlection may be written aa: 

tr= 

where c iE the initial count flon the nest survev, i is the estlnate of 

detection plobability (o.7567 wlth sE=o.0931), and f tE th€ flnaL 

Populatton 

estimate. 

obE€rver experience. we found expelieDced obEelvers to exhibit a 

bigher det€ction probability. conc€iwably' develoFtr€nt of, . 8€arch 1$ag€ 

fo! a partlcular Ette-specLflc nest tyPe was the dstellnlnlng fector_ i{e 

have not€d both er.pelience and indiwidual baEed laarnlng aliffelenttalE' 

Although we found no difference in neEt detection probabilitieg rretreen 

medLun and inexperieDc€d observerE, the contrast was almogt algnificant 

{P=0.o349). Thi6 could indicate that the folmer grouP of obsetvers. 

through conlinueal surveys on a glven area, uould deveLop the aPploprlate 

search iinaqe and survey reglne at a hlgher rate than the inexPellenced 

observer gloup, rhe tneditrm-experienced observer gloup was perhapg 

; 

55

56 

undeftepresented in thiE experinent due to lirnited awailability for a 

Indlwidual learning valiations were also evident. The confidence 

lntervalB of tbe 3 experience levelg were empirically dlfferent. A 

comparlEon of the confldence interwal limlts indicated I€ss valiability in 

the exper!€nced category. thls could be attribulable to .anPllng effort 

o!, more likely, individual learning rates. ExPeri.enced obEerver6 may 

have developed site-apecj.fic Eearch images through Eeveral surveys on a 

giv€n area. ahis longterm develognent may haw€ reduced individual 

variation by allowlng all obserwers to lealn at differing rates. 

EventuaLly, the individual. acquired an effectlve search Pattern that 

approxiinated others in the group. The other obeerwer groups are placed ilr 

r€latiwely new situationg. Inherent indj.vidual learning rates ale 

displayed thlough larser confidence intervalB (or variances). rhrB 16 

lmportant to management p€rsonnel, as this intervat would be used to s€t 

halv€st quotas. Whil"e we can predict the detectlon probability for all 

obEervar groups, the wariances exp.essed aa confidence lntelvaLs fot 

medium and inexperienc6d ob6erverg nay be too graat for management needB. 

Pllot experience. Pllot experience alial not affect detection 

probability in our llnited experiment. Presumably, this iE attributable 

to our 6tudy design .i.n which the pilote foltowed direction given by the 

ob6erve! rather than declding on fligbt patterns th€mselves. ThiE furtber 

gupported our conclugion that any diffelences in detectlon plobab!:-ities 

between obgerver6 were directly attrlbutable to varying experlence level. 

Although experience of the pilot did not affect the ProporlLon of nestE 

stghted, experience certaLnly affected safety and confort. 

labltat variation. OnIy exPerienced obaervers were used to conpare 

habitats and yearly varlation due to ganpllng effort. we did not final a 

dtfference in neEt detectlon probability for the 4 habitat types. Ihtg 

probablllty, or correctlon factor, aPPIies only to thoae neEtE observable 

from the air. lt does not apPly to those nsBta that are completely

obatruct€d by vagetatlon or oth.!nL6€ und.tect!b1.. Th. p.oportlon of 

n.tta th.t ere unobsstvrble f.d th. al.r n y dlff€r b€t$s€n h!bl-trt.. 

Y€arlw v.rlatlon. lfe iurpect.al th.t vegetrtlon dlrtrlbutlon rnd 

d€nstty change du. to wrt.r Iev6I v..lrtlon rnd other €nwlronaent.l. 

frcto!. dlght Lnfluenco d€tectlon plob.btlttt€r. Howew.!, r'r€ dld not ltnd 

.ny yeatly vatl.tlon Ln n6Et al.t.ctl.on paobablllty. Enh.nc.d 

observ..blLlty of ne.t. alu6 to riodlflcrtl-on of the L@€dl.te er€. 

surroundtng r na.tlng ait. by fsmrls aLLtgato$ nry haw. off.et .ny 

n.turrl varlatlon ln habi.t.t qomposltlon. 

Lln€ tranaect. On rr€ag wlth large, falrly hooogsn€oua n€atlng 

a!€as, line tleng€cts cad provLd. rn afftct;nt anal r€I1ebl6 estlfiet€ of 

!,ofnrL.tlon .!re. Wlth . c.rtel.n .nount of pr.-pllnntnq, r ne.t e.tlnat. 

could bo obt.h€d by actu.lly countlng 251 or 1,.r. of th€ .tca. lr. foudd 

no reagon to bell.ev€ theae eatltnet€! souLd b. rny las. r.li..bl. than totrl 

count€ of th€ area. We alo f€€I that th6 uss of thts tochntgu. .hould b€ 

expanded to lnclude very l.rge rr.a. (.uch .. th. Evergl.de. .nd 

@ns€rvatlon A'raar) . 

Sggg!.g31ggCs Ah. pac.€nt huveat tur lLolld. of .!rly rg€-clr!! 

alllgetorr (eqg .nd h.tchllngr) I. b..cd upon r 50t r.oov.l of totrl 

9roductLon. rh. orlglnal ..tl-ortc. of proaluctlon alurLng . llorLal. 

CooPer.tlv6 !l3h .nd rLldlll. A€.earch UnIt r....rch proj.ct r.rc b..ed 

uPolr r€peatod nelt countl on a 9lv6n alea ov€r the coursc of the neltlng 

aeaaon (il€nnLng. 6t aI. lga8). Ih... €.tLm.t.. c@p.!. rreLl to . ringl. 

count whlch h.. b6en corr.ct.d by th. d.t.ction probrbiLlty gle.n .bov.. 

Ho$cvar. prcaclt Drttrgsnt artl t€r ara bea€d upon r al,Dgla auravay that 

1. not cort.cted by thl. plob.bl,llty (D. D.vld tr.!.. co@un. ) r.d, 

th.!.forc, tr negrtlvcly bl..€d. otsh.r f.ctor. th.t .hould b. .aldr.....al 

.t .dc I,olnt lnd that lnflu.nc. tot.l prodsctlon rt|. .1.t.-rp.cr,llc 

alcpr.d.tion, floodtnq, rnd ai.porltloa !atc.. ah. ..tl!.tlon of a!.t.ctlo.. 

probrbllltl.. lr onLy r f1!.t .tsp Ln forolng . coopr.henrle. aod.:, lor 

alllgrtor !..t ploaluct loa. 

51

58 

IITERATURA CITED 

canfieLd, D, E. itr. 1941. Chemlcal and trophlc state cbaracterlgtlcs of 

alorlda lakes 1n letation to regLoral geol-ogy. FIa. cooP. liah and 

tfll.dl. Bes. unlt alnal Rep., unlv. of Fl.a., Galnesvllle. 444PP. 

Caughley, c., and D. Grice. 1982. A correction factor for counting 

emus fliom the alr, and i.tss aPPlicatton to counta in We6tern 

Australl-a. Austr. Wtldl. Rea. 9: 253-259. 

Charnbels, J. l{.' w. s. clev€land, B. Klelner, and P. a. Tukey. 1983. 

crephical nethods for data analysls. Brooka/cole Publ. co. Pacific 

Grove, Callfolni.a. 395PP. 

Chagnan, D. G. 1951. Som€ propeltieE of the h)Perqeomettic 

dlgtflbuti.on with appltcatlons to zoologlcal cen€uses. uniw. 

calif. Pubric. stat. 1:131-150. 

Deitz, D. C., and l. c. gineE. 1980. Alligator nesttng in north-centlal 

Florlda. copeia ].9AO (2t 1249-254. 

JenningE, !t. L., H. r. Perclval, and A. R. woodward. 1984. 

Evaluatlon of alligator hatchling end egg removal frorn tb].ee 

alorlda lakeg. Proc. Ann. conf. s'8. Assoc. Fiah and wildl. 

Agencieg 42: 283-294. 

l.tagnuEson, w. 8., G. J. caughley, and G. c. crigg. 1978. A double- 

€urwey estlmate of popuLation slze from inconplete counts. J. 

rilldl. Manage. 42t 174-r'75. 

l{enee, A. J. 1959. Psychological. problema of conducting aetial 

cen6uEes from light aircraft. E. Afr. Agrid. For. J. 

34 ( Bpectal lssue):44-45. 

l.tllLeeon, at. P. 1987. vsgetative changes in the lake okeechobe€ littolal 

zone. south alorida water [anagement Dlstrlct aech. Pub. 87-3. 

IteEbitt, s. A., and K. s. wtlllans. 1990. Bone range and habita! uae ot 

alorida sandhill craneE. J. wlldl.. uanage. 54(1):92_95. 

lolton-erifflths, !{. 19?5. countlng aDlmaIE. Afrlcan wll.dllfe 

!€aderghip Foundatlon, Nalrobi, Kenya. 134 pp. 

otis, D. L., K. P. Bulnharn, G. c, tthite, and D. R. Anderaor!. 1978. 

statiBtlcal inferences fron capture data on closed Populatlon6. 

Wildl. I.lonogr. 52. 135pp. 

ott, r. 1948. An introduction to stati.tical methoda and d.ta 

analysig, Thtrd ed. Pws-Kent PubL. Co., BoEton. 835PP.

Tabl6 1. Proportton of alliqator nestg obEerved by study area, trenBect, 

€xpeltence lewel, and observer. 

STUDY ARTA 

€riffin 

6riffin 

YEIR 

1939 

1989 

1989 

1989 

t9a9 

lgSo 

t9a9 

l9a9 

1990 

1990 

1990 

1990 

1990 

l99o 

1990 

1990 

1990 

t990 

l9o0 

t99o 

1991 

1991 

1991 

l99l 

1991 

l99l 

1991 

t99l 

l99l 

t99l 

TMlistcrr 

__!q!E! 

Itrrn3.ct3 

i€.e nq6.r.d con3.c{tiv.ly tlruugho{t studyi 

tl-.rD.ri.m.d, 

r€.. nDb.md iidivid!.lly fo. lrtor .dly3is. 

t 

I 

I 

3 

3 

2 

a 

I 

1 

1 

5 

5 

5 

5 

8 

8 

l0 

l0 

to 

9 

t2 

t2 

t2 

It 

1l 

ETPER.' 

LEVTL 

! 

I 

I 

2 

3 

1 

2 

I 

I 

t 

3 

3 

I 

I 

3 

3 

I 

2 

3 

1 

2 

I 

I 

1 

1 

I 

I 

I 

1 

2 

I 

2 

! 

I 

I 

z 

3 

5 

6 

1 

2 

2 

I 

3 

5 

I 

2 

I 

I 

2 

2 

I 

I 

PROMRTIOII 

OBSERVTD 

.7360 

.7179 

.1426 

.ttla 

.5870 

.6071 

.50q, 

.8571 

,6923 

,8491 

.!204 

.3396 

.lr23l 

.a7u 

.4103 

.564! 

-62a5 

,6458 

.t583 

.29t7 

-aa31 

,7209 

.62t9 

.647t 

.6rtt1 

.804t 

.7405 

.w, 

7t57 

.tl,l3 

.8214 

2r.dtr, 3in.rpEi.nc.dr 

59 

STAIiD. 

_!@B 

.0711 

.0fzL 

.0638 

.0687 

.0921 

.@57 

.l'6a 

.0905 

.t,626 

,0656 

,0669 

.0453 

.0555 

.079t 

.oaoo 

.@15 

.081r 

.@75 

.@ll 

.0too 

.0491 

.t58a 

.0734 

.@1, 

.06t9 

.0626 

.0652 

.04t5 

.079,1 

.08@ 

.0t16 

tob!.rv..3

Florida, U.S.A. 

Figure 1. Location of study areaE in Florida.

TOTAL COUNT 

55 

Figure 2. ConParison 

nultiple surveYs v9. 

s'rllveys. 

35 /tO 

ESTIMATED NESTS 

of estinated nuDberE 

total nests counted 

61 

of nestE froD 

after repeated

62 

a 

{3) 

(o.31 (0.2) (o.1) 0 

RESIDUALS 

Figure 3. Theoretical quantile 

observed lreighted by the inverse 

,{' 

o.1 

a 

plot of proportj.on 

of the variance. 

o.2 

of nests 

o.3

RESIDUAL 

o.3 

o,2 

o.1 

o 

(o.1) a I 

(0.21 

I 

(0.31 

o.4 o.5 0.6 0,7 

EXPECTED 

a 

ra 

a 

a 

t 

a 

I 

a 

I 

a 

I 

63 

o.8 o.9 

Figure 4. Residual vs. Expected values fron ANOVA nodel of 

proportion sighted = expelj-ence 1evel, with proportions of 

nests sighted veighted by the j.nver6e of the variance.

@ 

crocod i les in Canbodi.a 

Parntep Ratanakorn 

wildlife Research Laboiatory, Departnent of 

Zoo|ogy, Fdculty of scletrce, Kasetsart University' 

Bangkhen, Ban€kok 1o9oo, ThaiIsnd. Tel, 6a2-5791022, 

Fax 662-5611645 

Abstract 

CAMBODIA, A NEIGHBOURINC COUNTRY OF THAILAND WHICH STILL 

HAS PLENTY OF I'ILD FLORA AND FAUNA SPECIES 16 VELCO}IING 

THA] SCIENTISTS TO JOIN THEIR STUDIES ESPECIALLY WILDLIFE. 

CROCOD]LE IS ONE OF THE MOST POPULAR SPECIES THAT THE 

CAMBODIAN INTERESTED IN ITS ECONOMIC AND CONSERVATION 

VALUES.SINCE INDOCHINA AND VIETNAM WARS' NO oNE fNOitIS 

ABOUT WHAT I{APPENDED TO CROCODILE IN CAHBODIA. ONLY 

IIATCHLINGS I{ERE BROUGHT FROI{ THIS COUNTRY EVERY YEARS. 

AI,L OVER THE WORLD BELIEVE THAT THOSE ANIMALS CA}IE FROM 

TIIE WILD. AFTXR, OUR VISITING TO CAIIBODIA. WE CAN SHOI{ 

TIIAT CROCODILE FARMING IN THIS COUNTRY ]S A I.IAJOR, SOUR,CE 

OF HATCHLINGS AND SOUE EVIDENCES TO CONVINCE US THAT 

CROCODILES IN THE UILD ARE PRESENTING. FURTHER SURYEY 

SITOULD BE CONDUCTED IN THE NEAR FUTURE.

Introduciion 

99994y.!gq siaoensis and glgj:ggy.lgg llllgjlgg are 

Llro !laior crocodili an species endeoic in south-east Asta 

region. These crocodilia.ns are hiEh in conservatioD and 

econoDic values. AccordinE to over exploitation of natural 

resources; huntilte, ftollution 8nd dosLruction of habitat 

eLc., lead to extinctio$ of nany species' crocodilians r,lill 

be extincted soon in the near future if e do not have a 

good and strong conservat,io[ policy- 

canbodia one of the hone range of these two croco- 

-dilians species which still has both populations in th€ 

lrild and in captivity should be a Eood place for conservatrott 

of these endaDgered apecies. Because of llars' no infor'[&Lio$ 

cotrcerning to crocodlle is herard fron lhis country' we only 

knor,. ihat hatchlings cone out of canbodia every years through 

Thai-canbodia boider ' 

Ir llarch 1992' 8. group of wildlife acienti6is con- 

-sisted ol A[erican and Thai uere invited to visit caobodia 

iu order to coperate with then in rrildife research' crocod- 

-ilie6 alere ote of a very interesting wild species to be 

6tudied especiallv surveyind of population in nature and 

estabtished of nanageneDt P lan. 

Due to a 6hort period of 6taying, we could collect 

eone dat,a by interviewing of Eovernnent officers, farners 

aud otber autborities. Then nany up date and useful inforn- 

-ations atere brought back aDd released outside thi6 country 

for t,he f irst tiDe. 

t))

66 

Ui [d crocodiles iD ceDbodia 

very lltte infornations concerui'lg Lo wild croco_ 

-diles in Caobodia uas knosn. sone useful infolnatiorrs were 

obtained by inlervieuing of governnent officers and. crocodile 

farners. As ve ktteu that two croco

A fei,, big farns developed there nanagernent into a modern farm. 

They used semi-artificj.al incubation of eggs by incubating them 

in artificial nests which vere ginilar to natural one. Nesting 

naterials cotlposed of dried leaves vegetations and mud collected 

from natural habitat of crocodile. Tenperature and hurnidity rtere 

controlled by pouring of vater on nest and checking tenperature 

tlJice a day bt inserting of lonq thertloneter into nest until 

reaching eggs level. Incubation tenperature was about 30oc and 

period around 68-78 days, 

In 1991 Phnon-Penh farm had 500 eggs uith 75 percents 

fertility. They got 300 hatchlings and survival rate was 95 

percents. 

Sien-Reap provinciat farn produced 1,500-1,8O0 head of 

hatchlings every year. Hatchability about 64.5 percents. 

Hortality rate of hatchling in the first year around 20-30 

percents. (Table 3). 

Ton Ley sap, a big lake is an excellent food source for 

crocodile farning. Because of plenty of fresh {ater fish, aI1 

carnbodians fed their crocodiles with fresh nater fish. In one 

mediun size farn, they fed 30 crocodiles with 20 kilograrn of fish 

every 2 veeks. 

croqoilite FaniDg in caDbgatia 

crocodile farning in carnbodia has been started since 

Canbodia !'as occupied by French in 1945. Most of lhe farrns 

localized around a big fake name rrTon Ley Sap'r which is one of 

the largest natural freshuater lake in the world. The oldest and 

biggest farn was in siem-Reap provj.nce. 

After Vietnan var, in 19?5 Pol Pot government ruled 

Canbodia. They collected all crocodiles fron private farms 

together and put in one farn in siem-Reap rthich be cones as 

provincial farn at this nonent. This place was used to be a 

hunan carcasses disposal by feeding to crocodiles. 

wtten Pol Pot governnent went down, sieh-Reap provincial 

crocodile farn was turned back to be a real crocodile farm 

again. By assistance fron Cuba, Cambodian staff was trained in 

cuban crocodile farrn for 3.5 nonths. Today there are about 500 

crocodile farms in canbodj.a. (Table 1). They keep only fresh 

water crocodile (crocodvlus si-arnensis). we can classify these 

farn6 into 3 classes according to size and lnanagenent. 

c1a6s 1. srnall size, snall number of crocodile, 2 to 

20 heads, keep in pond or wooden cage. 

cla6s 2, rnedium size, 20-7o heads, keep in social- pond, 

class 3, large size, over 10o heads, keep j"n social 

pond. 

Cta6s 1 This class rnay call fanily farminq because of small 

6'7

68 

size and nunbel of cr.ocodile. Cambodian villagers keep 1-z 

pairs o{ breeder sl, l.he baclr of t,her'e houses. llost of thexi 

siLuated oD the river bank irr,d lal.:e l'hich ir; a good source 

of ltater and food supplt. Sone .rillager:s rrho live on boat, 

they preferred Lo keep crocodiles iD nooden cage thal can 

float in vater around l,heir boats. ost. of the faros in Can- 

-bodia are in class 1. This class of farn usually sale their 

hatchlitrg every year. There are about 2OO of class I farn6 

which is a najority of crocodile farns. 

Class 2 

1ake. crocodiles qat.hered in social pond nade of |!ud and 

cenent. Nesting pens are provided for breeding porposes but 

for raising or holdi[g purposes they just ra.ised tben and 

soId. 

clas6 3 

These farns a.re not go closed to water. river and 

Farn 'rhich is lrig in size and nunber of croeodile. 

Usually more thao 10O heads. Thoy k('!)t, breeding sl,ock in 

social ponds and provid.ed per[6.nenL nestirrg pens, 

Near'ly all biE faros produced and sold batching 

out to broker for export, There are only 2-3 big f a.rns in 

caDbodia. (TabIe 2) 

Ninety percents of crocodile farms lrere operated 

ilr the old fashion ; poor drainage and hygiene, very linited 

space, no appropriate data recording, high nortality rate 

and survival rate of hatchling and nulritional problen6.

A fev big {atns developed there nanaAenent iDlo a nodeln 

farn. They used seni-artificial incubation of eggs by 

incubat,ing then in artificial nests !,hich I'ere sinilar to 

latura] one. NestiDg oateri:Lls cooposed of dried leaves 

vegetatioirs and mud collected frotn uaLural hatritat of cro- 

-codile. Teoperature aDd hunidiLy !,er'e conlrolled by pouring 

of uelLel' oll nesL and checkiog tenperature Leice aday by ins- 

erting of long thernooeter inlo nest until reaching eEgs 

Ievel, Incubation tenDerature vas about 30 _c and period 

aiound 68-78 days. 

In 1991 Phnom-Penh farn had 500 ege6 with 75 

percent,s fertility. They goL 30O hatchlitrgs arld survival 

ral,e was 95 percents, 

Sien-lleap provincial farn produced 1,500-1,80o 

head of haLchlings every year- Hatchability about 6{,s 

percents. Mortality rate ol hatchljlrg iII the first yeai 

around 20-30 percenls. (Table 3) 

Ton Lo) Sap, a bi{ lake is an excellenl foo.l 

source for crocodile farning. Because of plenty of fresh 

water fish, all Cal0bodians fed their crocodile:; !rith fresh 

wat,er fish. In ooe nediun size farn, they fed 30 crocodil.es 

nith 20 kilogran of fish every 2 reeks. 

69

70 

Crocodi les l{anagenent in CaDbodia 

Matragenent of crocodiles in canbodia is under 

contiolled by Ministriy of Agriculture. Two offices of this 

oitlistly involved, Fishery departnent is incharge of captive 

clocodiles while l-orestry departoenL takes care of wild 

crocodi i les . 

captive crocodile or crocodile farning is conlro- 

-lled. by liishery law. The re€ulaLion is bhaL; some'one rho has 

crocodile in captivity nore than 5 heads nust register their 

farn and crocodiles to local Fishery office or Fishery depar- 

-tnent in Pltnotr-Penh. 

Export fee for live crocodile nostly halchliDg is 

3,000 Reals (canbodian currency) per head uhich is equal to 

6 U.S. Dollais, ExporLer [ust pay to governnent, Prohibil o{ 

wild crocodile hunting is also incllded in Fishery lau and 

enforced by Forestry depart[ent and Fishery departnent. Nov 

bunting of crocodil.e is decrased because any illegal busiuess 

Dust be serious punished. No vild crocodiles survey and nana- 

-genelt p18n ever done in caebodia. 

crocodile arketitrg 

Local narkel for crocodile in canbodia is quite 

aaturaied because they all keep only breedels for producing 

of haLchling6. Al1 hatchlings are exported and the large6l 

narket i6 Thailand. Then value of crocodile i[ C&nbodia

clepends on denand of crocodile6 itr Thailand. 

In 1990 Phnon-Penh crocodile farn sold 1 nonth 

old hatchling about 2o0 U.s. Dollar6 per head, in 199- 

price increased to 30o U.S. Dollars becauoe of crocodile 

farni[g in Thailand r,ras expanded rapidly. But this year, 

1992, drop to 150 U.S. Dol1ars. 

Captive tloro crocodiles usually caoe to Thailand 

throuEh 2 rout,es; Port of Co Cong and Battanbang border. 

Registered farns usually export through Co conE but nost 

fron s[a1l unregislered fatns are sDugg]ed via Thalland- 

canbodia border vhich is very long and occupied by differ- 

-etrce Cambodian €roups, 

71.

'72 

corlclus ion 

Caobodia should be one of lhe test place in ihe 

world for crocodile conservatiott especiaily c.eianensis 

becauge Lhey already have population in the IJi1d, appro- 

-priate habitat, captive t'reeding operations and lau to 

protect then. But they are still lacking of lnfornations 

and [anagenent p.Iannitg. we are looking forward Lo have 

sone organizations to conduct and sssist caDbodia to do so 

i! the near fuiuie. Then ve can save crocodilials itr canb- 

-odia ard this reEion of the world. 

Acknorledgerent 

we would like to thank Eleaner Briggs for her 

kind assistance in interviewilg and taking pictures ai sien 

Riep province and also crocodile Ma[agenent Association of 

thaila[d (c.M.A.T.) who sponsored oe to do this gurvey. 

1. 

RefereDceg 

Canbodian Jurists, A Group of. 1979. People Revolutionary 

Tribunal HeId in Phnoo-Penh for The Trial of The Geno- 

-cide of The Pol Pot-IetrE sary clique Docu[elts. p.Iv- 

22? 

chu. Po seng. 1992. chef du bureau contentieux, Fishery 

depart[ent, Phtron-Penh' Pergonsl conn.

3. Han, Ly KiD. 1992. Dilector of Fishery departneDt, Itj.nt- 

7. 

-stry of AEriculture, Phnon-Penh, Personal con[. 

Taylor, E.H. 1970. Tuitle6 and crocodilians of Thailand 

and adjacent waters, with a synoptic helpetological 

bibliography. Univer6iLy of l(ansa.s science Bulletin. 

LAlrrence.49787-779. 

Thouk, Nao. 1989. A Lesson in Crocodile Fa!'ning. sien 

Re&p provilrce crocodile faro. 

ToDn, chheng l(in. 1992. crocodile feeding ceDter,Phnotr- 

Penh. Personal coon. 

webb, G.J.w.. s.c. l.lanolis and P.J. whitehead. 1987. 

Wildl.ife l.Ialrageeeot: Crocodiles aDd Alligators. Surrey 

Beatty and sons, chipping Norton, Australia. 

'73

Talle 1 

Diatribution of Crocodil.e Farra 

Prov iDce 

1.. Phno|-Petrh , private farr 

i! Carbodia, 1992 * 

2. Sietr-Reap, Governnent and private faro 

3. Battanbang, oovernnent and private farn 

4. tronpong Chatrang, Governnent and private farn 

Total averae c 

nuDoer 

130 

300 

491 farns 

Chheng fiio Tonn, Crocodtle Feeding CenLer, phnon penh

1. PhDor-Penh 

2. Sie.-Reap 

Populrtion 

3. BaDteay l{eanchey 

4. Batta.batc 

5. Pursath 

6. Korpong ChaDaDg 

7. KorpouE Sor 

Registerod 

Ptovince 

loLat 

Po Se[g Chu, Chef du 

Dgpartaent 

TEDI. t 

of C8pilve 

to Fiahery 

in 1992 | 

CrooodllGs 

Departrert 

nu&ber 

2,4O8 

1, 800 

1,62O 

bureau Contentieux, F i shery 

32 

70 

't5 

gJlllll heads

Table 3 

Nurber of Eatchlirgs in 1992 

Province nunber ( ap"rirox. ) 

1. Phnor-PeDn 250 

2.. Siea-Be8p 2, 500 

3. Bautarbarg 1,250 

4. trotpong ChatraDE L,20O 

Total 5, 200 leads 

* Ky Leant Hak, Factory anager, UK International co. , Ltd.

CONDflON FACTOR OF Caiman cr temporary channels = fresh 

water ponds. Condition factors were siguificantly different in relation -to body size of 

caymans from salt water ponds, rivers ard fresh water ponds. The young caynans 

showed highest condition factors ir salt water ponds and the big caymars had highest 

values in rivers, 

77

78 

COMPOSMON AND ENERGY VALUES OF SOME FOOD ITEMS 

INGESTED BY Caiman crocd,iha yo.care lN TI:[E 

BRAZILIAN PANTANAL REGION 

S.A Santos and M.S. Pinheiro 

Rua: 21 de Setembro, 1880 

Caixa Postal 109, Corunba, MS, 

Brasil. CEP 79300 

Caiman crocdilus yaccre is found in the Pantanal region in Brazil in various 

habitatq including rivers, temponry charnels, fresh water ponds, salt wster ponds, 

marsh and artificial roadside ponds. The stomach cotrtents of cayman of these 

habitats was collected and identified the loPest taxonomic unit feasible. With the 

objective to determine the composition of foods ingested by caymans, the most 

important prey were collected in different habitats: 1. Hemiptera (Belostomatidae); 

2. Coleopten (hidrofilidae); 3. brvas of tus€cta (odotrata); 4. Mollusca 

(Pomoceae); 5. Crustac€a (Trichodac9lidae); 6. Pisces (Calichthyidae); and 7. 

Amphibia (Pseudidae). The composition of thes€ componetrts (dry matter basis) 

were: dry matter, 29.6,37.9, 19.6,39.2,22.7, ?5.6 ard, l5.3Vo, crude protein, 64.1, 

65.4, 61.1, 18.8, 65.9, 64.2 ad 67.I%; gross energr, 5.4, 5.1, 5.8, f3, 4.5, 4.8 and 4.5 

tcafkg; calcio (Ca),0.25,0.?5,0.3, 24.9, 0.3,7.8 ard 4.67o; phosphoro (P) 0.6, 0.5, 

0.45, 0.06, 1.2, 3.5, ard 3.2Vo, resp€ctively. It was observ€d tlat most prey ingested 

by cayman had a high protein and energetic ralue, but improper Ca to P ratios 

according to body chemical composition of Cc yacarc of 2:1.

STATUS OF ORII'O@ CROCODILE POPUI'\TTONS IN 

SOXE L@ALITIES ITI IgB VEI{EZUEIIW LLAXOS 

Andr6a EIov Sei-ia-s. I,I{ELLBZ. X€aa de C.vacaa, Guanare, 

Portuguesa. VoDeruela. 

Since l99O f have b€en conductir{t suave:rs in several 

localities in the Veneruclan Llanos, to aaresg the statug 

of the Orinoco crocodile populations. The .ore i.Dortant 

of these sites are the Co.jedes and Sarare rivers, in 

Cojedes state. These sites rere previously surveyedr fror 

198? to 1990, by Jos6 Ayarzatiiena, *ho estirated e 

populetion o? up to 50O non-hatchlin* caocodiles scatteaed 

in branches, artificial channels and srall tributaries of 

these rivers. During 1991 and 1992 I hsve visited three 

tides Caio de Agua, one of the branchee of the Co.iedes 

river. Eighty three non-hatchling ctocodiles were sighted 

in that locality, no less than 13 of ther adults, l.{y dats 

do not indicated a decline respect to the nurber of 

crocodiles observed in 1987 by Jos6 Ayarzagiiena in the 

sa[e place, but the lost inportant threat on the survival 

of this popul&tion (t.ater pollution) re.aids the sane. Our 

efforts should be directed to pao.ote a plen lor the 

protection and full recovery of the surely aost dense, snd 

al8o probably largest, Orinoco crocodile population in the 

corlntry. 

Another locality I have visited fror 1990 to 1992. is 

Tucupido Rese?voir, in Pottutuesa state. Before the 

tucupido River was darred, in 198?, several authors 

reported an Orinoco crocodile population of a little rore 

than 100 individuals. In twelve visits to the reservoir at 

least 8 crocodiles have been sifhted. All but one of ther 

adults. The only ,iuvenile seen (and captur€d) ros borDe 

before the da.n I'as constructed lrhich teans th&t there has 

not been recruit.ent of Orinoco crocodidles in the 

reservoir, r4ybe due to huaan depredation of nesta. 

trinally, the Anaro River, in Barinas atatet t.as 

visited in JaDuary 1992. Anecdotal iltforration indicates 

that there is a srell population of Orihoco crocodile 

there. Fisherren depredate several nest of th€ specles 

every year. The habitat in this river is, horever, shosr 

iDtact. The possibilities to use the Anaro river to 

relessed ceptive reared crocodiLes should ba serlously 

congidered. 

79

RanchtnE Crocoglles ln !.he Hlnslayan Waterd gf Nep91 

lej Kuear Shreathe 

Central Depertoent of Zoology 

Trlbhuven Unlverelty 

Klrtlpur, Kathoandu, Nepal 

Absttdct 

Numbers of Mugger and Charlel crocodlles aie dltlndllng o!,1ng to ovet-exploltatlon, 

po1lutlon and habitat oodlflcatioa by pover dans. Rsnchlng Pos€tbtllttes of 

crocodLle tn rl1d and Ecerlc tlvels by slmulatlng nsturel rlverlng hsbttst le a 

nost promLslng task for Long-terh conservatlon of crocodlle Bene pool ln llll|alaya 

natursl forktng chennels and oxboss ld the Karnall rlver ney be best utl1lzed 

for creatlng crocodlle rsnctl. A novel nod€1 of crocodlle rsnch to b€ developed 

tn f.arns11 rlver ls presented. The edvantages of rauchlng to the trad{tlonal 

fernlng or crocodlle husbandry 13 h1gh1lghted. 

Inttod.ucltgn 

The crocodiles are best knoon reptile con6ldered elther threaten€d or 

enalangered all over the vorld. A volunlnous volk exlsts otl ecology, behavlour 

crocodlles (mrttakar and Bssu 1988' Shrestha 1986r 1990, Mtslrre and Maskev t98l)' 

There ls e scsnty lBfornslion about crocodlle ranchlng and tlrelr mengSenent 1n 

the wtld. In thls Paper feeslblllly snd deslrabtl{ty of ctocodlles ln 6cen1c 

$ild rivere of Nepel are dlgcussed to tbrot 1lght o! the need and oPPortuolty 

of such scElvltles h the netural hebitat dtsplaced by daoa' Durlng recent 

yeals Elderiilge 1985' suni'elo 1973, l'{ecNell 1975' Kl$gslerd 1985, Ha11er 1990' 

lleller aoil Baer l99O conpleted thelr ldea of DodeUtng oetute for beneftts for 

rtldltfe and nas. 

There ale a nuDber of pros and cons concelnlng the rearlng of crocodlle6 

specles ln ceptlvlty. IiI general cePtlve breedlng end reerlng programres 6te 

lll.-coavhceil beceuse stllnals 1o6e irlld nature. One elo of caPtlve rearlng 

crocodiles ls to eupPly enlosls to zoos end 'Jtldltfe parksr thus avotdtn8 croco- 

d11es beioa taken froD ttld. the Dore zooa that have crocodlles' the greater 

rhe auillence that !.'tll becone farlllar wlth theE and thelr p118ht lesdlng to e 

greater synpathy for thelr cotroetvatlon ln t1ld. the othei baln teason for 

captlve rearlng ls for te-lnttoductlon of crocodlles to the !tt1d. In s develop- 

lrig couutry llke Nepalr the probletrts of captlve breedl$g and rearlng ere qulte 

allfferent and therefore Po3s1bl1tty of crocodlle tdnchlng ls conteoplated'

Concepjal Desisn 

Mugger:s and chartals are lrell known crocodlllen of the Hlmslayan rlvers 

of Nepal, Fe' reptlles of the Hinalsyan rlvers lllustrate lntftnslc of sdapts- 

tton of crocodlles better than tbese t\ro crocodiles. The ctocodlle6 have 

decllned ouch due to ecologlcel chenges 1n wsternays broughl by balrier eflecta 

of dans Inroads of pollutlon and harnful flshlng practlces. At nsny places rlver 

cou.ses have changed and nestlng beds hsve been destroyed, Destructlofl of nest- 

1ng areas afld resultaat falLure ol nestlng have affected hdtchltng resourcea 

greatly. If the natural breedlng habttsts of crocodlles Eoea urunonltored, 

vsluable resource ot Nepsl wlll become extlnct. Crocodlles do rlot bteed $e11 

ln s closed systess of lnpoundoents elthougtr they can grow to naturlty there. 

They need free-flovlng snowfed and rain-fed water. Thelt nestlng sltes muat 

have good-slzed pools snd rsplds, 6and-bars and gravels. In a closed systen of 

crocodlle farEs, a1l- these basLc habltat needs sre not neti thetefore' crocodtlee 

refuse to breed. An lonovatlve aen concept of taDlrg trt1ld ltlnaleyen rlver for 

creallng open waier' ranch ceo be evolved. In osay ptlstlne rlvers of Nepel Pools, 

back I'ater replds, sand baflks eod prononotorles of rocks snd stone habltst are 

destroyed by huuan encioachuent snd cteellon o! polret dshs' To evolv€ sucb 

orighal habitsts takes aeons of tlne. As a coDpensatlon to lt senlneturol 

crocodlle ranchlng statlon cas be made by dtverlIng orlltEal rtver course ot 

channel at deslreble spot, ln rlvers of Nepal 6uch ldea1 lanch sre hany and 

csn be utlllzed vlth lllll.e effort. The ranch so created may act es crocodlle 

and fish sancluary, buffer zone or escape ared and help6 to relse and releaae 

young crocoallles year efter year. Many oxbons and d1ver61oo ol lrrlgatlolr 

facllitles can be osde so ss to create e fullfledged tlverlne ranchlng spoi, 

where nlgratory crocodlles csn be ranched year afte. year. lhls w111 greetly 

help to cotrserve crococllle lesoutce6 anal brlog bick depleted crocodlle 6tock 

to origloal level- of abunderce. 

the open-ltater lanchlng eysten alns at al'l habitst needs and hes adventege 

over the tradltlonel 

t'Put 

aad TakeI gystens. In thls systebr Eature breedets 

are sublecte.l !o breedlng and resrlog thelr young theoselve. Crocodtles could 

be rslsed ln ranch to a yesrllng stage oo a nass scale and releaeed back to the 

river to spawa llrto nee genetstlon of crocodlle after three yeers' Thls effort 

,11.1 rebulld crocodlle population ln the rlver sod counterdct forces of ovet- 

exploltatlon, 

Thls aevt systen ls ceUed on open water "Ralse and Relesse" systen. 

as this syste0r enhances cont!o11ed breedlng of crocodlles and he1P6 to Pteoetve 

gene pools or rste stock of the nugger aIId thatlal 

crocodlleg' 

81

82 

j]ul.ecrtves of Rraochlng crocodiles 

Now lhat scleotlsts all over the world are aware of precArlous condltlons 

of the existence of crocodlles, sclertlsts ln Nepal hust strrdy nrays end Eeans of 

thelr pxopagation snd populstlon growtlr, Thls cerr be done by ranching. the 

coaceptual deslgn of crocodlle ranchhg should be based on i\ro conve tloiral 

approach systems, ecology and populsElon ecology arld behavlour. Based o$ ny 

studlea of clocodlles, tn the Ksrnell rlver (Shreslha 1990), I have cone up 

wlth the fouowlng constluctlve rsnchlng, rehabllltatlon and enbanceh€nt pro- 

gramle!. 

The objecttves of the cr:ocodtle rsnchlng proBrame are! (r) ro save 

:ienalnlng natulal populatlon, (2) to naxlslse natural recrultnencs through 

"grow and relesse techn1que6", (3) to propegete alrd re-stock crocodlLtans ln 

areas whele tbey once occurred and the potenttallty for thelr survlvel ls sttll 

exlstlng, (4) to lnltlate natural as well as captlve breedlng, (5) to enberk 

on research {n the dlflerent a€pects of the bloloay snd nanagement of the 

crocodlllansr and (6) to produce tralned personnel et dlf!e!eflt 1eve16, 

Crocodlle Ranchlnq Areas of Top P(torltv 

In Royal Bardla Natlonal Park, toprpst prlorlty la to be glven to perfect 

the rrgron and reledse'r technlque fot rlver habltatsl Lt 16 llkely to b€ changed 

by hlgh da[ and result 1n rdtld populalton urgertly. Sone of the lnportsnt 

aspects to be coveled are: (a) lnterp!etatlon of the vsrlous d6ta collecred 

durlng flelds survey and census, (b) ralslng wlld crocodlle ln seBlnstural 

condltlon. Supply of llve llsh food ls ltDportant, so gene flsh found lrl the 

rlver ls to be culllvated In the hatchery, (c) rearlng young crocodlllans In 

senlostural wllderness lncludttrg lood requlrenent and food converslon lrlth 

growth studies, and (d) behavloulal blology lncludlng re!'roductlon, ther.0ro- 

regulatiofl, feedlng, orlentatloD and locoDotlon In senLnatursl hebltet of 

crocodlle Ranchftic stetlon Eor to Estsbllsh 

Fundanenlal detells of the proposed crocodlle ranch eiet there are dany 

feeder rivers Jotnl.ng tbe Karnall rlver vlth lleny nestlng Brounds. Nestl.ng 

beds of Karnali river ele located nearby Bardla Day be se!.ected for thls purpose.

i-' 

\/l 

'I '-'1 

,, NI'I'/rI, 

'\M 

-q^ 

t-x6^r 

l / \ 

\9lTy 

....-..'-. 

KATARNIA GI]AT 

fj;:" 

,l 

._t 

q") 

tk 

o.rirl cttlt 

83

Ihls atea ls 1dea1 because htstorical crocodlle stocktng pools sre located very 

near the Karral.l rlver and lts feeder streams. The gorge sectlon of the Ksinslt 

liver ls an ldea1 slte for collectlon of crocodlles uhlch have been used by us 

for collectlon of mature crocodlles. In entlre stretch of the Khorsha branch of 

rhe Kalnall rlver up to 3 kns upsttean, there prevstl ldesl envllonnental condt- 

tlons for crocodlle such as grsvel beds, rater f1ow, oxygen, wstet quallty and 

lt 1s adBlrably suited for breedlng. If thls strean 1s changed lnto artlftclal 

crocodlLe runnlng channel ln conlunctlon wlth an exlstlng crocodlle faxm, 1t 

would certainly help the nass produetlon of crocodlles ln senl-natursl condltlon. 

Crocodlles renchlng would represent a vl91b1e step in lransltlon from s huntlng 

ta farnlng econony in the Elnslayan waters of Nepa1. 

Pdpulstlog 

In lhe proposed open-wster rarchlng sy6ten, rnuch depeods upon the hydro- 

biologlcal regl$e of the liountaln rlver, such as flood and drought. The cbangtng 

rlver conditlons affect abundance of crocodlles for good 6nd evll. Such seasonal 

verlatlon l1es beyond the conlroloi'nan but can be nsnlPulated to 6orne extent' 

Other factors howeve! are wlthln our power. The baslc tenet of crocodlle tenchlng 

ls that the crocodlle populalion oI each rlvet and feeder strean must be treated 

es seperste breedlng unlt sanctuary and for eech a sufflclent numbet of adults 

oust be allowed !o escape ln clesr, undanaged envlroonent. If thts ls done year 

after yearj gratlfylng surges of ctocodlles u111 appea! h numbers sonetlnes 

exceedlng past runs. 

Crocodiles lsnchlng caD be achleved by Etocklng youngllngs ln natural earer 

in the same Benner ss hes been done ln case of deer ln the USA' Ranchlng croco- 

dll,es 1n open lrater ri1ll be better than farnlng in enclosures both aesthetlcally 

aDd econolnlcalLy. 

t iker,rlse, the eggs fron female crocodiles 6te collected fton Nerayani rive! 

and subjected to lncubetlonr hatched and toung are reared to youngerllog stsge 

la speclally deslgned llverslde hatchery near Royel' Chltoan Ndtlonal Psrk. The 

youogll[gs 60 produced sould be relesEed bsck into rlver to 8ro!t 

furthei and come 

back to deposlt egg ln the rlvel vhere they tere born' Expetleflce of Past decades 

wlthln crocodlle fsts ln Chltwan has sho n that feoale crocodlles glor,t to neturlty 

ln stagnant water of pond but do not develop thelr gonad to bteea glccessful1y. 

HofiDonal lnductloll 1s the Dost useful nethod of cspt{ve breedlng'

4 

F] 

4 

E 

H 

F: '{ 

Ei O. 

z 

z 

H f.{ 

Y}!{ 

VE 

!iB 

a 

H 

( 

$,#gc{

gilielgne !9t!geg_crsc.9g4e Egnlhrl8 gtd_IaIg1lg 

In crocodlle ranchlng, as opposed to fsrnlng, crocodlles are kept h 

captlvlty for early part of thelr ltfe. Crocodtlesr (ehlch use htSh ground of 

rlvers bul spenal nost of thelr 1lves ln ft h;e a strong mlgrstory lnsttrct and 

are well-suiteai for rsnchlng. Mugger and Chsrlal crocodlles are conflfled lo 

ranching statlon untl1 they teach yearllng state (sbout one yeer old) et ithlch 

tloe they are relesseil for thelr Journey !o the llver6 where they w111 stay end 

grov to nlaturlty an

References 

Elderdge. N. (1985). Unflnlshed synthesls. Oxford Unlverslry press. 

Ha11er,_R.D. (1990). Integtstlng crocodlle fernlng lnto on exlltlng llvestock 

and Ttlapia !arn. tlabere ye Baobab. Daobab. iaro N€us 59/12.90. Monbase. 

Halle!, R.D. and Baer, S. (1.990). Integrated Aquaculture SyBteD. Ttlapta, 

crocodile and rlce cultur:e workshop on Aquaculturet ICi"AnAfi. Maotl;, 

Pb111pplnes. 

Klagsland, S.E. (1985). Modelllng Nature. Urlverstty for Chtcago press. 

Msskey, T.M. and Mlshr6, l{.R. (1981), Conservetlon of Chartal in Nepsl. Inl 

Wlld 1s beeurlful. Edlted by T.C. l,taJupurla, r.ethtoandu, Nepsl. 

MeNeil, W.J. and Belly, J.E, (f975), SallIon rsncherB roanual. flsherle€ Centre. 

Auk. Bay. Flsherles Laborarory publtcarlon. 

Shrestha, T,K. (1981). Ecogeographlc dtslrlbutton of reptlfes Ln Nepat. In: 

Majupu!1a, T.C. ( ed.). wl1d ts Beautiful. Introductlon to Fauna and 

Wlldlife of Nepa1, 142-146, Lashker. 

Shrestha, T.K. (1990). Status, ecology, conservallon end bansRemen! of crocodlles 

ln Hlmalayan rlvers of Nepal, pp. 332-349. In Hioaleyer Envlronnent, Re6oulcea 

and Developnent (N.K. Sah, S.D. Bhattr R.K, Pandey ed6.) Shree Alnorih Book 

Depot, Aloorar ladia. 

Su&re1o, I.S. (1973). Notes on turtle rsnchlng at Tldung Islsnd, U.rlversltes 

Naalonal r l-3, Jakertd. 

whttakar and 3asu, D, (1982). The aharls.l (qEy141q g€ngettcus_): A revtew, 

Bonbay Nat. HisE. Soc. 79 (3), 531-548,- 

87

88 

INOIAN MUGGER 

Ctocodylus palusttis Lesson 

(Rootilia, Crocodilia) 

TERBITORIAL RESOURCE.PARTITIONING ANO 

ITS IMPLICATIONS IN SANCTUARY MANAGEMENT 

1. Suoocry 

2. lntroductlon 

by, 

LALA A. K.SINGH 

COTJTEIiTS 

2.1 . A problor ln arocodll. r.nrgr|lnt 

2.2. T!r!dto!r..l bshcvlour 

?.3. Prgelnt rtudy 

5. Glols.ry ql t elalnglogy 

4. 6tudy qrac 

5. flat.rialc Erd lqthod! 

5.1 . SrrEd 1n9 cncl,ocure 

5.2.5tudy lniBEIg 

5.5. Data sht3t 

5.tlo Drta coll.ct,lon 

5.5. Data lrtrsps!tat loh 

Fldcllty to uate! 

Fldsllty to basktrE 8lts 

Colpatiblllty cod doqtoEncc 

Resoulco utllr,8.tlon and toaal,toalallty 

6. R..ults 

7. Ol,.cuaalon 

E. Ac knoalodg 

€aont r 

9. natrtrEa

In 3 6!:rup 

1. 5 U rl lt1 ri il Y 

cf tll,t oal,€ and ?our femalo muggcro 

Gfgg-9s!!.lrl tglggllil) hi.!!archial dominency lEadirE to 

rsgourco purtltloning u,sro ob9€rvad in h19h6! incidencss of 

occupylng the uat€r, favoulcd basklnS spot(s), Inost 6uitab16 

nosting spctr and maltitainlng cootacts urith namber6 of tho 

oths! grx. Th! dooinant flnal. !€strictsd th6 use o? 

avsllable t!soulca by oth6! f€nals6. Recraslv6 froal6s 

hcd contact factors lhoUlng norB afflnlty to tho frnsla 

eeeond in th! hiolaschial ordor. urhrn nors than ona |iqgg€! 

occupisd tha 3aD. ronr of plaf.r.ncc, Partltlonlng of apnc' 

occuttcd at a fintr IgvEI anong thg occupant6. 

ALl lacasslvs femalEs oholred contact factorg !'itb 

oal,as, at lev€ls 44.0-4?.3. Bscauaq of p!.vontloo by ths 

dooinant f.ma1r othcr ?6t|aI!s could rd|lotain 'contact' 

nostly uith thc racond lc. Thr eaclnd maJ'!t thsrsfdrcr. 

had r totct feia Ic-contqct-lscto! of 116.4 .. agaLnet only 

97'5 of ths tlrlt oal.. Tht poesr'blllty ct 6a!Ly seos3cenc' 

dus to lsproductlvr ov!r-ue! during tho lil6 span of thc 

mals s6cond ln th! ordsr of hiqratchlal domlnaf'cy 15 

discuased. Th6 soall6et ldeal breeding group oay bs 3mt5tr j-f 

6H:6s ls costtr to "* eo 

Stghtlngs ucr. tns 6: 

ff,i"sfou".i;s. Si3",fn"#1";." " on 

u/hen t€op€ratur63 uarE lou and thE nunbsrs of r3lny dayg 

uor. tha olnlluo. Activr s€tsctlon gf nosting gi'tost 6vid'nt 

rs .trlcl nlattnl. trcr! aoen froo 20-25 dayE beforo sctusl 

ncatinq. Adjacsnt nBgting sltqs uelt oqt u8€d by t0'o 

89

90 

famallg on th. laEr night. A pr.f6r!6d n.sting sit6 u,.s 

consletonlly uerd lvary ycar by tho dom!16q1 fdnals. Th6 

sltc {ras 6ha!6d uith thE 

o n Iy a f t € ! t h a I a 

nostlog by hcr sclf. 

lcc6Ssiv! fsfla166 

p s {t of a feu days froo 

In ths uild uherc tood ia oot a Linitlng factor, 

t!rrLtosial baskirE spots ld.ntiftrd in tho r!intsa s.assn 

can b€ qlt€rad rs a ttandalcl plEctlcc Ef hsbltat [qnlpulatlon 

to ctoata . tru patqotlal b.rktaE sitrr Losa!6d. an lltnor 

benks of thc habltat. Thls Ectlon by th! |lanagsmlnt le 

axptctrd to atdqcr thr tengc of Eovrmont ot tho croc,)dll,o, 

cnd thur rlducr the chancqt rf msn-csgcodil, conllict ln 

d natulal h.bltrt.

TNTRODUCTION 

2.1 . A PROEL€I IN ER{X,OO ILE MANAGE&ENT 

Durlng 1975 covernB.nt of Indla coooonc6d clocodj.l! 

qonsarvatlon pt.og!ammaa 

In vs!ioua stat6s !rlth agsigt6ncr 

froo ths Unj,t6d Nations Drvcl,opn€nt programm€, and Food 

aod ,lg!icultuE! 0rEanloatLon of th6 Unlt!d Natlono 

(F.A.0., 19?4i 8u6rard, 1980). Th. prog!ar c 'r,as ba.6q 

an | .gtgr and ral€€a. t.chnlquc. to robulld na!ural 

gopul,ctlcna of cracodillans la protect€d .r!.S. lUhil! 

!!vis!,lr€ th! |o-ylar old plograqr€, Singh, (aa and 

Choudhury (1985) orntloncd thst .lthouih clocodil.. u,r!! 

bctto! plotectrd in 20r399 sq.kn q1 19ild[i fe q 16a3 

incl,udlng thlrt..n numb.trr of spcclsl crocodilo Banctt,.rl.! 

ov.r 8346 cq.kn., th€ Indlan public u.ra still, in ths 

Proce€€ sf conplctsly [,!anlng auay s n€gatlva 6!tltud! 

tourEJde csocod116!. Slnghr Choudhury rnd XBr (1990) havt 

sleo r€ntLoncd thqt ulth the lner.ca! Ln the nunbrlr .t 

crocodiIra io .vqi.labl€, alr.ady Bhrunkoo. hsbltatg 

s,0ncarn for nuialncr crocadil€s uoa! on th6 Lncroagar 

aven though partlculsrly for thr, sdltuatcr c!ocodils, 

Crocodvlus ElggE. 

Rlth, Slngh .od KBi (1 990) havc 

Et!gsscd th. n!!d to tackl! nuj.s6nc€ crocodilos and 

!6dqc. tran-clocodils confllct ulth 6u!tablc nariag6D!nt 

grogtaDB. ln th. stat. of 0sl,eg.. 

9l

The ouggsr sr06odll,6, t:!ocodvlu8 Dir]!strl9 is 

IJlatlvlly hatelse8 to huoaosrand ts kndsn to hav! 

coaxictrd in uato! bodl.s corlnlnally trr€d also by hunons 

and c.ttl,€s (iutiitator, 19?4t Achar-jyo and mohspatrn, 19Zg; 

.L 

Singh, 198-1, and Singh rnd Sagar, 1990) 

fnapit. of th. abov! kno'r,l,.dg6 Lt has al,u,.ys b€en 

nscrascry lor thr naneg c,ngnt to !6ducr D6n-crocodil,. 

contacts und.f th! dlfflcult oltuatlon that thc |l|atsr 

bodh8 drclarrd a! crocodil! aenctuorl.! c6anot br 

conplctcly trabd otf troo hu|lao actlvltl.r. 

Thr nqsd tor thc oarEgsDsnt, thor!?sr!, ia to 

rtt'lk! r Conpa.!l!. by*ld.nttfying op€qj.flc muggoI, uon!o 

Cb) 

'r,j,thin ths aroctsary, (naturall,y !sEtriotlrE tha movEnont 

of sild muggcts thtqsgh habit.t nanipulation practlcrsrard 

(e) b6 impo;in7 

'ho-.ntry 

.ocaon and arcaj'ooly vhcn 

and sh.r! thc san-saocodllc conlllcts ara most llk!Iy 

to occqs. AssordlrEly, ,,t ls gortlncnt to obt.in a 

bettrr undrfgtandtng of thq clocodil6s. b6havi,gu! o? 

rslte- ftdrtlty. (Lang, 198?t 9278). 

2.2. TERRITORIAL gC H AVI OUR 

rSlt. tidcllty. La deoonitlEtld from the ablltty 

to honr, ae ln the Aorltcan alllgator, Alllaator 

olssl.oslprtrnsis (tlulphy, 1982), and in 

Crocodvlu! oalust.rlq (stngh, 'l 983bt llhltake! .nd 

uJhltaker., '1 989). Crocodilians nay movc ovet LonJ 

disLsno.g to r.dch th.lt tiaditlsoal broeding.nd nostlng 

grounde, B e ln 3. -g!E19g.ipli9.li1: 

(chabstck, 1965) ' 

cavlalls oa.n6tiquo (5lnghe 1985:p7'l-?3), and c. ,

Foloeu9_ (5. y.ar, psr9. cDon.). ljnder norr€L conditlon3 

tho brskirl

94 

juvrnilos ba6klnq togeth6r (Saga! and Sloqh, 1990a_). 

Although tho dlstanc6s covcrgd !1|Jrs not 6noI'mDus y6L r€srt 

!r$fo dor)tr!h Lo $oU!6rt dopofturr tfo|n,rn 6.rrLIL,r qfsUu!1!)u:r 

habIt. Th6 g!eg.rious habit may tr!eak auray earIi6! if a 

lrndirt4tbed 

epacioue(habltat ls availdb1!. 

tlrJggs!s trnieh hav6 !6naj.ned t,o!ethsr ovo! m{ny oonths 

o! y6atrs ats assurned to havs eEtablighdd th€ir hi€tarchial 

oadc!. Und6r euch a si.Luat:on if, s nd!, .nugger le lotrgd'Jced 

1t is nornally not tqlerltEd, and th! lssult io fotalfrlgnts. 

Exampl,ss hsvo bsan rocorded ai Nandankaoan Biologlca!. park 

and Reratllthar both in oalsea, durlr€ Octob€r 1980 and 

NovsabE! 1990, rcepcctlvely. Severe flghts hau€ a16,) De€n 

!ocordsd at Tadoba in maharashtra undBr si.rnilar situation. 

A gtudy conoucted at RaiEtirtha (sagar and 5lrqh, 

1992.) shoord that a youngcr bctch of hatchllngs pr€f6rred 

to lleain ln tunn6rs or dlsappoarr urhsn subJdcted to 

gtou along with an oldlr batch ol Juvrnllo muggcrs. 

As a standald practics ln captivo huabandty, young 

crocodi,les atE eizs-sorted to ave!t any pFychological 

disadvaotags and chansca of otf-fosd uy slou-grouring 

Juvcntleel elihough of ths same yrqr of, hatchlng. 

.Tcrritorial fightgr a!E g6ne!ally sern vrlth nugg€!a 

uhlch ars at 1ei3t tnre! yod!3 old. Cut mrrk:' on tkln' 

partlculerly 

ne( An't 

thef,baeq of tho tall, are ths common outccm' 

of such fights. Intlusi.on by a sgcond flrala maif lead to 

f19ht and 'c1lck' c serles of courting behaviour durirrl 

brs 6d ln3 season (Sin!h, 1983b)'

coomural n6stingr is a behaviorilal accoopli.shmsnt 

ll,het€ tr!ritorial hostillty is 0rrni.nrun 3nd ao availablo 

n€sLlng srto Ls us€d fur l.rying ol ogijs by severdl 

fonolEs. It hs€ bgen recoldsd in spt,cios Lika C. nilorrcus 

(cott, 1961), !. 

johnstoni (i!6bb, 1ggt) and !. gglgjtr;ls 

(Sin9h, 1978; Rao and 5ingh, 1991). Thit Indd,an oujget, 

Crocodvlus. odlustrl.s fi\ay b€cona a comrj,{rn,t L nester .irhol6 

condltlons !!quirg. In an aroa ot 15 8q.r|. st Hilan Lakc 

in Gir National 9arkl Quj6561 ctght negts r!er. lald, and 

uithi.n a ehorr 1in. of 20m ot Set,hanur, Tshilnadu thorc 

r!€!6 thr!. n.!sts of !. palust!is (8. C. Choudh'JrV, 

pers. comm, 1986). Th.r!fo!., al.thorrgh a tol.rLtorlal 

sp6cL€e, g. !3-!-stE !g 

can b6 mado to bccoo! a cunmunal 

nos!!! aimLng at a logtricted aaaa of mov€nr€nt. Thig 

can bc doae throqqh Euitable hsbltat msnipul.ation 

practicc bqgsd on.o implovcd knouLodgc of tho gp.cls8' 

lntra- epecif ic b.ha./iour. 

A? PRES€NI 9TUDY 

- 

Thc pllsont stuqy uas envlsagcd to dra',! quanti,tatlv! 

dqta llom a populdtlon of Eix adult nugg6rs malntainod 

undcr €iriulatad natural condiilons !t Ramatlrtha, and 

highlight th6 epocicar te!rltorlal partitionlng of 

habltat rasourcoE' nancly ul!t€!, bdski,€ 3i.to and nsstlng 

sitt. 0aesd on tho rcsulis rEcottl6snd.rliong hdv! boon 

I'ul" l,d,r 

nad. to rooucc itaa-clocodllo tonfllct ln uhe!' d 

r 

complots ban cannot bo mada to huoan actlvltlttg- 

95

96 

3. G L|.IiSARI (F TEItIOI|IOLGY 

Coo&uoal oeEti,no. Nssting by lore than tug ouggels Ln I 

sdlall arC! of a Lolgsr habltat. 

Contsct Factor. (S.qtt.on E.5i Trb16, 5 and 4) Nunescls 

sugg€stIng prltolrnc€ o! eqrpatlbllity b.tsr.n too 

!u996!r. lt !.! d.slv.d troo the root (F,4, ot th€ 

psoduct ot lttgbtlngr ::.cordrd tqr .ach Duggsr at 

on€ o! eolr (n) locctlonr. 

Hl$archlal ord.r . ThE ordrr o? aoclal doolnancy aoofE 

ruggrrr llvlng ln o group. 

lhn-CrocsdLh conlllct. Slttattonr uhera Sctlve o! passtva 

con?Itct batr.an Lqn end srocodlle Eay b. ee6n ovra 

tha usa of cn ar€l rogardad by gach of theo qs a 

t9EorJtgt bagc fo! th6i! ouB usE. Fq:i sxstrplo, nestlng 

and balklng !lto! ot clocodth vs. c.oplng slt.s of 

ll,shlrmn, Fo6dlng :onsr ot ouggrr vs. flEhlrq 

rctlvltht by propl.. 

lluisance crqcodLlE, CraeodllBs orhich comr near hum6n habl,_ 

tatlon atrd causa uolrtre and anl!,dy to loeal 

iahab ltante. 

R.sourE6 paltltlonim. Dlrtlnctlva zona! qt use of the 

lrsourcr!, 1lkr ba8klt€ cltrl n;siing litE ahd llat.t 

surfac. rtc. ln a !,atger hqbltet occlpi.d by Dora 

than ona cuggaa. 

Slto fidllltv. Echaviour eqggeetLt€ a ougget's attcchoEnt to 

c pertlcular place by ltr s€gulallty in p!3e.ncs at or 

rrtlrn to thc cqor loc.tlon ln a habltrt. 

ElLtlggf-4Slqg.F l{ht ! b.ta.6n ouggrrr for po$rcclon and 

uaa o? seloutctt ln a hsbitst. 

Tllal nastlno. The proc€ls of dt991nq oest holre elthout 

.ctually l.y tng rggE.

:lt':r',: 

fi:is s;udy ras c daried gut at the jiugijef llesea't:b ao.l 

c oo.sei-va ti @. I,'uitr Ragatlrtha ( 35o5;r9, 21035tll 4prrox.). 

'iire 

p:ai: e :3 j.4 eas :.::1 :::,i;a 1-a tvlle s i;a re of Cri ssa, ( lis^. t 

n-:d :; llre place e)

98 

"""'n' o9 

?FG 

a 

l! 

E 

o 

Il 

MUGGER RESEARCH /i CONSERVATION 

. UNIT, RAMATIRTHA 

{.o 

CtT 

!H 

Ow 

fin *p 

rT-] 

R a ver 

BF- 

.t.- s. 

( lr 

7: 

tr;.FT" 

E5 

Flg. 2. Dhglanstlc lalr-out ol varlout f.cl,l,l,tlee at 

RaratlrthE. Bpr gs€edlrE p.n ul,th thaae 

pools (ArBrA). Dr Stud.ntc. Dornltory. Fl 

F.€d pr.pantlen. Ht H.ich.ry. Hpt H.tchlln0 

P.n. lr Intlrpsrtlt tovltblary (proposed). 

Lt Laboistoty (developtr€r. r florth. Or 

altflc.. 

pl puqp tor dtaqlng s.ter. 

Rr Rarl,danc.!. St Stosaq. Tr Ucshlng Taok. 

!r Ulatet Ras.rvott Tan(. Solld ll,nes; road. 

Dotted llnor ?rnce. 1r TsDllnadu. 2rRaacttrtha. 

-F

5.I. BRE€OIM 

EIICL(EURE 

TATERIALS AI{D tlEr HOD6 

It lt fn opro-roo? i.rCtotutar boundad 

rl,l .tound 

by .n 1.5|l hlgh cro.otrC brick uall. Thc perlphcral 

lrngth auar to l8?r. Tho tot l rr a, th! prn t3 

2?84 sq.[. sith r lat.r-heldlrq .(lrlaq! cf s.xttur 

1810 rg.!. l][t.r i. held Ln thrt. {nt.scoonocicd pool! 

s? dllfcsant rhrpl 1n6 sLz! (F.ig.2 ). Th6 qapeotty o, 

th.r. poolr rr!, pool-ll g251000 lttrrop peol-Br 23J,000 

llt!r3, .nd pool-Cr llggr0o0 liis6r, etandtng .t . trrtrqr 

dcpth ol 1.25o. 

Fraah Bitlr lr pucpad tnto a lerltvolt, taok lro! 

th. !lv.s Nhalal tloulng on th. north €t th. br..dtrB 

rnclolurl rlsnE I raatarl,y dlractten. Fso! tha t nk 

gt.vtty llct o? !.t.r la [lntrin.d upt. th. bsr.dfuE 

pools tbsough 75r! g.lvrnlt.d pip.r rtth chlsl vrlv... 

oparrtlrE kryr asa allq providad to rrgul.t! ftor o? ratar 

tRo! poolt 6 fnd C to pool-A, rh.ta a v.rtlcrl lron grta 

opaSatrt on ccsEo-kcyr to lced getcr ft'or thc,ool, to 

outsld!. 

Tha tsolt .rr rcaub-elrtnad rnd rafltbC onq. cvlry 

lortntgbt durlng .utD.a rnd rlnt.r, .nd av.sy Eonth dustng 

th. arl,nr. Osrl,ng F.baualy aod llrlch th! poqls asr not 

illan.d rlth rn tntlntl,on to rtnLoi'r di.tusbancr to tha 

?arrl.! th€D th.y E!. sclrctlnq r olBtlng aLt. or a!! 

qctu. 1l,y laylng cag r. 

99

100 

Tha lnqleaur. (.p!n) lr rdrqurt.ly pbntld to off.s 

r.vatrl rpota of rhrd! rq!,d ltr.tchrr for dlrrci aunrhlna. 

Thr pl.nt. lnsludc rplcl.s llk! &gE, Az.dLracta, Ca€u.!ln.. 

srntatuo albua' Adh.todd vrslc.. mrre. orradl6iacs, .nd 

gs rgPs. 

5.2. ST UDY ANT0ALS 

Thr rtudy grsut at anlo.Ir conslstld of slx adult 

rugg.rsr loua tcDrba rod tut n l.a, .ll rrlth p.aentrgc 

tro! th. rtrt! ot T.rllnadu ln rcothrrn Indh (f19. | ). 

Th.!. h.d h.tshld durlng 1978 .nd first brld ln captlvlty 

at R.nrtlrth. tn t9Aa. Thoir body l.r€th Ln Fcbrtlary 

1988 rara b.tlcrn 2.1o and 5.06r .ppaorllnatoly. 

Thlsa tlx |!u99.!s orrr th! asoaindar of a l.rgra 

group rhlch cr blosght lol r.stocklng ln natur! ln thr 

5irtl!,p.I llga! Rctalva. Th. ld.ntltlcatloo Earkt uott 

cllpptnqr on th! trll !q!t. (F19.3 ). 0n th! l.ft .ld! 

of th6 doubla ohotl ot tha t.ll th6 scut!8, count.d flor 

thr rcar toeards flont' |,o!! cllpped rt thr nuablr3 8th 

(raala no. 0ls), 'lrt.nd8th (o.1. no. [18)' lst.nd 2nd 

(frorlc no. J2r. 1.t rnd 4th (l!arl. no. f4)1 lst and 6th 

(fcorlc no. f5)'.td 13t rnd 9th (frqrl. no. F9). 

5 .3. DATA SHEET 

E.ch d.tr rh.at !^3 llrtrt lor I data. It 

halv.., ooc tc llll up ln thc dolnltE and th. 

thr .ft.rnoon. Eaqh hall cgnt.io6d 6 dlagrsn 

b!a.dlng .nclo!qr! d.plctlng thr pool!r thrit 

h.d tlro 

oth.r ln 

ot thc 

L nt!r co nna-

qtionr, tha sloPc. etd thc b6skttE ar!a., cll' '.t ulthln 

a osrksd bound.nr (Fig.2 ). 

Thr lnlotootlon uhlch u.r. tlllsd ln tqr t'ch 

101 

oba.rv.tlon r.tst (.) th. dat.r (b) th. '!.sth.r' (c) tha 

tlB. lhrn ob.!!vatlon ra! r.cord.dr (d) thr rt0bllnt 

t.!p6!.t!!c ln shad!, .nd (.) th! d€pth of tlatsr In tho 

pool uhlch th. .nl..I3 noraally u.td' 1..;' thc pool-A 

durlnq Fcblurry 1988 to DrcaEblr 1998' rnd pool-C tlll 

*" 

th. lnd of th. rtudv ' 1...' J!n. 1990' un:t"'l 

f: 

lr. av -;ll. ttss {han 3oa- t,ata' bera'r< 'l Ftoaa't'o.

02 

F 

s 

F 

I 

g 

F 

F 

) 

l. 

T o 

lt 

F. 

o 

l( 

o 

$ 

5 

I 

( 

o 

I 

a 

3 

g 

o! 

>t 

Jf 

|{o 

!0t 

EC 

q., 

+c 

o 

:a tt 

Orl 

or< 

tl 

g1

It u.. posribh to ldontlfy . olggca tn uctrr It 

103 

li r.r t9, lhlcb h.d a dlrt1n€lry l,lght.r body col,our, o! 

uhcn Fg !ra rlth anotblr nuggli ln uttc! uhilr fout otn!!! 

toralnrd out.ldc. 

Date in tho oornlt€ $G!a colllctld aftcr 90 oLnurra 

of rqnaie! duli.ng th. uint!! and ralna, and Juat aroqoo 

tunrlac durlng ruonra. Aft.rnoon d.t. uctc collactrd 

$ound runlrt duriq ell t!saon!. Thr tlal(E! e!r! ?ixtd 

to coatoar clth th! ttla rhln rt lc.st tour Duggllr rrrc 

oltald. fatas. Thr t,lrlnlt u.!r not changrd durlng rny 

prttlcular r!rk. Shl,ttr urrr ulry gr.du.l to rccorodat! 

tlllngt of runsLla tnd Bunrrt, 1nd uer6 usually utthLn 

lLlt..n Ilnqtra bstu.ln .ny tuo usgkly 3h1tts. 

'.5. DATA IIItrERPRETAT IOI{. 

Fldolitv to stt.sr Data on s&htlngs u.sr t.bultrd 

to rhor (r) tha tot.J, nunb.rr ol oblarvrilon. takln 

dutirq tht nonth, and (b) thr p.rcantrgc of l,netancar 

thon th! .u99€rt srr! rightad outtlda ortrr duttrB .rch 

crlandsa .oqth (Tabla 1,). Th.[ datr rarc lntlrDrltrd ro 

rhsr fld.llty to rt.r by Lndlvtdu.L rugg.ls ol both 

r!x|' (T!bl! l) ard I g!n!r.I lldcllty to uat.r durtng 

thrca rrln goqaona. !l.nt!r, ruoorr rnd rtln (Trbt! 2) 

(f!9. 4). Th. dqlatlonr of th! r.saona r€r!, ov..bra to 

Fablualy, 0hrch tc Jun., rnd July to octob.r, lrrp.ctlvlly. 

For cosrlbtl,on ot tha rlghtlng dai. to lnvironaantt!. 

p.Frot.t3. thc drpth ol lstrr in thr pool, th! ..bl.ot 

tarpaa.tu!! .nd srlntrll rero rlso lrcordad (T.bI. 2).

104 

TnB LE-l . Crocldvluo cslusrtrjl: at. RdD.ttrthrr monthl,y 

lncldlnc.. ot llghtr,q { (S) out ol totql 

nuEbrrr ol obroavrtion! takrn (0). F?. F4, 

F6.-F9, A8 .d ott I .r. th. ld.oliticatloo 

nuoblrs ol .dult s!gg.r. houeod Ln thr 

brc.dlng psn (r!r t.xt at s6ctl.n_5.2). 

Y.rr Obrclv.tkn - Slghtlnq I (S) ot.to;a{,.u-te, 

Eonth 

nuDb€E. (O) 

F2 F4 F6 F9 l||8 fln8 

| 988 

Frb. 

lrt. 

Apa. 

my 

Jun. 

Jul. 

lq. 

S.p. 

tlct. 

lov. 

O!c. 

1989 

Jrnr 

F.b. 

fa r. 

A pr. 

ly 

Jun. 

fuI. 

4? 

54 

59 

62 

58 

58 

51 

57 

52 

48 

4? 

4l 

100 94 96 89 95 98 

82 80 78 A2 72 ?S 

83 99 90 97 84 98 

85 9? 95 92 9? 90 

50 80 83 E9 69 50 

2? ?1 86 92 55 45 

5E 95 92 90 51 60 

40 8.t 90 90 48 53 

59 81 ?9 75 70 72 

96 96 88 .96 94 92 

4? 88 79 72 58 74 

95 95 93 85 95 91 

87 94 90 88 88 90 

?0 68 80 71 80 54 

50 62. 6s 65 69 50 

38 46 21 29 63 23 

30 15 34 40 2A 50 

21 ?E 51 80 41 54 

contloucd..

TA BLE-I . oonttn{tcd 

Ylra 0b36!vatlon slghtlttg ,( (s) 

414. 

Sop. 

Oct. 

ll.uo 

Oa€. 

19!X) 

Ia. 

fd. 

!aa r 

Al8. 

r.y 

Jun. 

isit'i't 

Staodasc 

Drvi.tlong 

51 

so 

57 

53 

57 

JO 

50 

60 

5? 

5a 

55 

s4.F 

4.9 

1220202088 

10 40 26 28 10 30 

39 09 40 {0 42 40 

89 gr ?9 74 ?5 81 

88958p 869691 

97 9€ 95 100 97 66 

92 90 96 94 96 88 

?5 ?8 8? 73 77 ?3 

r7 a9 37 ?2 45 35 

39 32 15 ?0 4g 32 

17 68 51 74 53 34 

2g 22 25 ?6 

105 

61 7S 71 74 66 62 

26

106 

1A$LE-2. Crocodvlur qalust!ir j! n.l:ratlrthd; 

ljJIM ER 

so!ron.I lnqldcnqes of sighting (f) 

Jo:tpoct io totrc6ponding atublont tsop.ratur! 

(f-C), tot!1, rElnfa11 (ttcn) and !,3ta! lovol 

(UJcl{) 

Ln th! pool ln s8c. 

. I ro. 

Sightingll;---1;-l-!r'---,----) | | t 

I I 

- - --- --: -i seslr!9-:l!V9!r!9 -- | I Rurn9---_g_99__ 

mran sqllmrsn SDrimron Sqlnc,al oqyglmrrn SO+ 

_ -_ --_ _ r _ - _:_ __ _ _ r_ _ _ -_ ___:_ 

'lEt y!.r 96 4 23 2 26 2 - - 35 2 

2nd yeat 87 1,2 13 2 21. Z i.s S 94 48 

3rd ysar 90 ,l 14 2 20 3 8.9 6 12s 0 

Ifeao 91 5 17 6 22 S 3.? 6 85 46 

+3.1 31 

EUSEE 

i8t y.ar gu 20 ZS g go 4 66.u 24 gg I 

2nd yocr 51. 19 22 4 29 6 7s.6 32 

'125 

3rd ylar 55 18 22 3 27 4 62.A 54 125 0 

mqaR 52 16 23 2 29 2 65.5 37 96 50 

J3 

3.9 16 

RAIN 

llt y.ar 69 20 

znd y.8r 34 20 

!ll6.n 52 25 

Oata for 

5ianda!d 

dlff.r!nt 

23 

23 

u,tnte!-1 st year onfy 

n 

2 67 .2 7U 

3 91 

.1 60 

u 79.1 55 

16.9 -7 

Davl,ation (SO) val,uao aro frcs the ooan ot 

ob eo r\,ratlon y rara. 

of FE b ruary. 

0 

54 19

o 

o 

o 

s 

month 

Evenin(r 

I 

orning 

Fig. 4. Trend of ej.ghtlnq of osggErs oltsido urato! 

107 

duElrq diffolent month6 at Ramatirtha. 214 e'tc. 

qorre6pond to cal€ndar nontbs Feb, tp!11 etc. 

Rr 5 lnd U, ar,6 ths €oaaooa of !sl.n, suDna! 

6riid urLnt!r, !s6prctl.ve!.y.

Fldrlttv to b"kino sitst 0n s€palats dilgrams o? 

thr brccdl,ng snclogursr ?or rach ougq!! thc aightlngs srrc 

Dlottod rc solld dotr (flgo. 5 to 10). conq€ltl'sn! ol 

dota .t pastisui.l placs3 hav! blan conEldcl6d as tha sLtr! 

o! polt1oBc of ths lncloasr! oo.t prafera.d by a ouggr!. 

{.^rther 

In rrl.tlon to thi! , .nalysl. eaa c.rti€d gut E3 st8trd 

balor undrr 't!rolJ8c! utillrrtion rnd t.rrltoriallty' . 

cooortl,bllltv rnd dorinrQE-tl Tha laqucnc. ct proclduta 

follorld te .tudy thts! asprct. of quggrt brhrvloua ralr 

rr ?ollo!!. 

(r) Thc dtrgrrr of thq .nclocur! !|ae dlvldld lnt. 

E.ctlono o? 2cr x zclr $Pra3.otl.lg tn ar!. ot applox,.lrtaly 

8. x 8i !.eh. All elghtlaga t.krn tog.thtr ?or tll Eogg!!" 

on th! notthran hrlt ol thr p.tt tto .t€'e uelc l'6ntlllrd 

rhasa .oat soncanttotlon! o? llghtlng-dots occurrrd. 

strll3llyr on tht |outhatn hrlt tno othra 'r..! !ca' 

..rt.d (ftg. f1). fndlvld$l rugg.ar uhlch rlorln'd 

togothar or ahrrrd thrac foqr idontlfild:oorr 

lrdic.tld 

thcl.r eorp.tlblllly ln t.ltc of .tflnlty or tol.!.ncr. 

(b) In osd.s to .lcartatn r dogla! ol lrhtlv! 

coeP.ttblllty lnd tha lav.ls ot doolranqr, thc !3u d.t. 

fro. th. dat! lhrlts t6!t tabulatsd io gcnrlatc n!t!.!ical 

vrluccr lrtlrd hala rr 'sontact factolt' (CF). 

(t) fn Trblo 3 th! nun.rals sho!' out of its 

totrl nulbcss ot alEhtingr, thr porc6otagr of inatanca! 

ohln a rugg.! 3a! slghlld l,n 6.ch o? tha idsntifi'd ?ou. 

praf€rrEd ton.ar n.DcJ'y 

r noaths6st (Nu), northtatt ( E)' 

southrcet (su)' rnd southorrt (sE) (Flg' 11)'

In ordls to handla tha aoor our rat dats nor! 

ct?nctlvaly, I ololEstr pcrclnlrg! ol oightlng ot 15t ln 

iho oorth pool rnd 25F ln thr !o!th pool lrcs conaldol.d 

.s thc |rinl,our noar'to tpqeat lo th. Tabl,. 3. Th. 

109 

dlfferartGc la th! linilur noDE foi ths tgo halvos of thr 

( rs7.) 

prn lFa lo vl.u of th. fact th.t tor d gr.at.r p.rtret tha 

obsrtvstl.n prslod ( ovsdbor, l96s - Jun., '1 

990) th. 

.quih pool cootaln.d 9!dt6s drpth of ratcr than thc north 

tocl (pool-A), .nd oogt .lghttngr r.a. recold.d 1n th. 

gouthr rround PqoI-C. 

(lt) Frrr T.bl.-s c.nt.ct factor. ('CF') for 

rach rsggar llth othar rlggltr tn thr pcn u.r! drt.rdln.d 

ln tba lallcli]€ !.nnar. In 2q6j-119 (frblc-3) !8 

racesd3 18.01 vrlu. rt th! lncldcnc. of a19httn9. In thr 

a.ra :ana F4 iacord! 22.3f. Tha CF val!. tos !8-F4 oas 

d!t.t!tn.d .t thc y of thetr prodaet , i.e. ) zo .o (Tabl.-4 ) . 

Stolhrly, ll 8 hsd qontrctr rith F4 1r| th! zon.llE 

(20.8tr rnd 22.3F) qnd SE (44.9f rnd 2?.oF). m,rLtfdjeA adlf 

logcth.s, th. CF valu. for ol8-lA r'as Z'l'5 (Tab1c-4). 

Sush CF vrluts to! rll Parslbh cont.ct! rmong rll st'r 

Euggtrr ara Prasantad tn trbla- . Thra. d.ts hava bcan 

ur.d to drsonrt!.ta tha Isvtls of Ptltc!anq!-coe9rtlblllty- 

dqolnancr rtc. ol Drlla rlth dltfcrcnt frmlcre lnd th! 

tEr 1619. trBl.t ulth otbrr t!. ?rsalre (R!' 11)'

110 

Rcrourc. utll,iattlon rnd trr!1toplal1tv, R6eourcc 

utilLgctlon h.v! ba.n dlacu€rad urd!r tho r.p.dt.a of (r) 

us. of lh. anlnsls st oth.a r.x lo! .rproductlon, (b) 

ugs of th. p!!lrr!€d ncctia€ r1trs, rnd (c) usq ot thq 

prcfrrlqd bteking cltcr. 

(a) Data on contact factora (rCF') froo Tabl,! 4 

r,€!c urad ta shos th. rltln1tl,a. rnd/or tolqrancc fsvols 

brtos.n mrl.r rad IrD.Ica, tnd fs611!r and fcnelor. 

ThlEr LnforlEtion havs alao d6songtratld the hlrs.rchy 

!f dooincnc! .cong any tle rlsr rnd lou! fcoalar. 

(b) 0n e di.gt.r o? thc blosding prn (Flg. 11J th! 

nrrting rpota fos rrch flcrf. qt. plcttld for rIl tho 

thrm brecdit€ a!a8ona. Thr drtra of ns€tir€ u.!! a.tch.d 

te n.atlng opots (Tqbb-5) te trcutqin It th.rr u6rr .ny 

plr?lrancr ?.! c p.rtlcuhs nc8tirE spot .nd l,l thrrr 

urtr any rlgnr of htla.tshlrl aaqulnc! ol ulc of th€ 

nratlng !pot9. 

Thc dulst1on-grp b6tur€sn flret rtrlal ncatingl 

and tho datr ol fl.rst ncstlng oerr aecertalndd iten tho 

d.ts shr€t.. This Lndlcctcd ths tina eince lhon actlv! 

dcf!ne. fo! utlll|rtlsa ol thr hrblt.t lEaourct !,lth 

lesp.ct to n€rtj.ng Eltr l.y bt ttartlng. rTrlel nrat.' 

sr! !hr!lcE 9lts dug qut at potsntlal, n$EtlDi slt6! 

on ecvotll nlghta et .ov.!tl tpott, b.fs!. actual 

ncatlqlr Thls bohavloua 1r b.lirv.td to bo rrlat6d to 

rctive Eof,€ctlon of r a€atlrq sitc and/o! . procoss 

shich 8t1tulat.r physiologlsal ploc€sscs cuLmlnatLng rn 

rctu.f nestl,B (Slngh, 1990rp401 

).

Tsbulrt€d d.ta on sighting incldencos v!lt 

al,so .rnalyard to flnd out ll tha.; lr€ft any patttt.l 

bugg€etlnq fldsllly te tho ns.t durLng tho .ntltd Po{l'rd 

of rgg l nqlbrt 1on. 

(c) froo Flg.l'l .nd T.bI!-3 d.ta !.rr 1nt.!Fr6t.d 

111 

to ehoE ths otdc! of incidlnc€ ot eightlrE (f) 1'] thc fout 

lon6r' illil 

r ;{8, 5Ur Bnd 58. luhsn r Paltlcular ron6 e!l 

u6ad by oor! than ona anLEal o? thr sang ..x, tha ordal 

ot llghting lncldrncr (!) rrl rrorlncd to rsc.ttrln thr 

blorarchy ol ua. ol tha basllng ri.tE. flgurs! 5 to 10 

sgte o.tsh.d to dstcrain€ lf th6!. sars total ovcrlaps ol 

sole dog!.!s ot Paitltlgoing of btrsklng eitoa aooog th. 

ouggrls of, the saoe g3x using th. sans zonE o? p!€fgtlnct.

TAgLL-5. Crocodvlu! palu5trlB 1n br6€ding pdn rt 

Raratirthc: 519htl,,i! lncldcncoe (f) ln 

dltfellnt zonla rbevr th! norE of 15)( 

(ltut, llE) and 25F (5rl,r sE). N, s, E, and u 

rlr notth, routh, €act, lnd 0rGst, r€gp.ctivaly. 

S.ctionst 

0ugg!8 

tir! ItE 

ShJ 

T qt.l, 

!6 

rmI 

72 

F4 

F6 

f9 

- 18.0 49.4 6? .4 

15.5 

20.6 

22.3 

17,1 

17.1 

35.? 

44.9 

25 .9 

27 ,O 

41 .5 

31 .0 

65 .7 

7e.l 

4 9.5 

5 8.5 

4 8.1

t" 

d> 

,t 

Fi9. 5. Psttern of slEhting 

dullng Feb.l 988 to 

of rlugB 

6rr mg 

June 1 990. 

113

t4 

t: 

Mra 

tlg. 5. Pattsln s? slghtfiq ol EUg96r, fil I 

durl,rE F!b. 1988 to Juno 1990.

Fls. 7. PEttean ot sl,ghtlrE of s(€get, F2 

durlDg F3b. 1989 to June 1990.

1. ,) 

i 

Ftg. 8. Pattaro ot llghtlng ot .rEgor, F4 

durlng frb. ! 988 to 5un! 1990.

fig.9. Pett€rn ot 

durtr€ Fob. 

s19bti9 of qsgg.r, f5 

1 988 to Jonc 199i1. 

tt7

J/.. . f' .xtr- 

'.1.' 

: i-'{r 

F19. 1.0. Prttlln o? 

durltg F.b. 

stght ing o? [uggsr, f9 

1 988 qnd Jun. 1990.

--: 

.tf 

I 

Ftg. 11. Prgterrsd zonoe o? baaklnl (Nllrnorth-tlBsti 

\.- 

\ 

119 

NE r north-aqst t SOtsoqth-d,sstl SElsouth-6ast) 

'rlth abovs 15F of total slqhtirE and psefErr€d 

zonos ot no!tt.€ (f 6tnal9 idsnttfication nunrberg 

2,4'6'9 olth eupgr6criptlona ol ysars ot 

ntrttngt rr1 986t b!1 9891 cr1 990)' mtmal!i 

F r f ana16. 

.l 

I 

I

tI8 

T;6Lg-4. :aocodvlr;J r,rlustrls dt Rdnatlrthdr 

fl I 19.8 

f2 42. s 

F{ 20.0 

F6 1?.5 

F9 17.5 

suc fot 

all 

lalgg - 

Coetact Fectors (GF) brecern dLllEfrnt 

ruggorr Ln tho brsadtn? lrn. 

88 tft I F2 14 

Sur for 

alI 

?aBIr! 

9?.5 115.a 

19.8 42.5 20.rJ 17.5 1?.5 

- 34.1 27.3 2s.5 26 

"5 

It4.1 - 26,4 32.7 28.3 

27.t 6,1 - 55.{ 2S.9 

25.5 32.7 53.4 - 3s.8 

26 .5 28.3 28.9 35.8 - 

- 75,6 47.3 45.0 44.0 

Sq|| lor sull foa 

t5 F9 all iaLoe al,I f€Dal.r 

{7.3 

45.0 

44.0 

9?.5 

't't6.4 

tloter m6, Elg, f2t f4, F6 and F9 qf€ ldofittflcatl,on nunb.r! 

tot leb and fo[Eb ouggar!. 

Contaet Factoa (CF) bctreen anlDsl rA. .nd anlnal rg. 

. 

u,h6ra, 1' 2r... n !!r c!!aa tn the studlod hablt6t, 

PA cnd Pg ara, tarp.ctlvely, the f ol tl,E6s 

(tror Tsbh-5) rhon cni!.t A rnd B occupl.d 

lo 6r.q oqt ol tba total nlobess of ti.6s 

..cb lat ctghtod ln th. habLtat.

9, 

pglCg_tl_i : Contact Factor 

FIg. 12. contact Factots (vs!tlcal coluon) 

oal€ (It18, fi'| 8) and fe&ele (F2r F4' 

rnd correapondlng nr.rnerals Jt the 

the bars) asEgrrg Et Rssatlrthq. 

o o1t eil en 

F6, F9 

top of 

12l

t22 

TABLE-s. lroccdvlus palusttls rn the broeding pen at 

Raoacirtha: Ths soqu€nc€s of nesti,ng and otd6r 

of use of th€ nas."Lng si.tss durlr€ Lh!se 

o6.ting s6aaons. Th6 numbsra (?r4r6,9) ghouJ 

th6 identlflcation number of ?emalss, and th€ 

lstt6re (NulrIerSu,rSE) 

shou ths zon.s of th€ 

bac!ding ps n. 

S€qucnc. gf 

n€sting. 

l 988 1989 1 990 

222,9 

5 6 6,4 

94 

49 

Ordrr of use NUJ Nll, NUI,/SE 

(2) / (s) 

of th6 

NIJ NU' NII]/SE 

nastlng sita (4 )/ (6 ) 

NE SE 

Nll, ilui

6. L 5 

AmcrE rlL al,x ruggrrr thc dlcr!.glng lrd.r o? lnctcdhcr of 

.19htlng C{) outsid! r.t!r llrol F4-F9-F6-m6-[nB-F2, urhr.cr| 

a tha lnclcasing oldar of tncldanca o? kr.plng to qratr! 

.t th6 tIE. o? rrcord (r.an valucar Trblo-1 ). Ih both 

OT(LA 

i!x.a thc ardlr ^ ?fsr! th! an ll, anleal to th! larq. 

rnloal. 

Sighting outald. !.tcr tr.. olnlruo durlng th. rltlny 

3..!6a rna qaxinut duslng thr ilntrr (Tsbl.-2). Th. 

oaxllur right,lng ostsldc !,at.s .]ro colncldad t'nr 

ts.rsn rh.n th. tllprr€tulra .nd thr B!.obo, s of roiny drrr 

5.t. th. lcurtt (Trble-2). 

Ai,l r!€galr htC novld ovar th. cntlrr br.rdlng pcn 

(.lghtltr0 dotr ln tlgr. 5 to 10). Th. t.vourlt. lpotr 

of b.rkirq !htl! qutrld! r.t6r or tuttssln8 ln shallos 

uat.! !r8r. avld.ot ttoo th! congr.g6tl.on of dotr tor .tcn 

I ni&a1 . 

sighting. el F? ucr! tho r.rt ln th6 zoncE llll, 

rori SE (Fig. 1l). In SE th. rp.s. !.. .l,ao sharrd ui,th 

tr8. zon.-E r.. rh.rrd by both 61,.! and th. r.t!6LnltE 

that! ?.oal!r. Sll, zon! rt! lhalcd by I[l I rnd rll fcnalrg. 

F2, thclofosc, h.d dorc ouabara oli prlflrlcd aloae of baakl3E 

th.n oth.r.ugqcr! (Flg. 111 TebLe-3). Cong!!qrtlons sf 

.lghtltE dot8 d F4 .nd f9 clola to s!.as 6f F2 .nd F5 

augg.rt.d talcraflcr by both th!sr latt.r f!oa1!c nhl,ch arc 

largrr (Figr. ? to t0).

Thr hlghar to looll ordar ot hirr.lc,hy of use ot th. 

.onrr by dltflrrnt lcrnalcl rrc ss folloos (TabLc-3)r 

Zonr-N!/l t2 

zonr- rrlEt F1-(f6/ti) 

Zonr-sEr F? 

Zo nc-srrt F5-F9-F4 -F2 

No lnala 

fln 8-rB 

UJhtn r paltlcular :on! rar lccupl|d by oorr than 

.nc ouggsr (f&.lt) thr lndtvldurl .sgg.r! dtd B.tntrln 

r.ps!.t. rr a rithln thr zonr (FIg.5 te l0) ruggcrtlng 

prttltl.nlng af r.!turc! to! barklng. 

Thr contsct f!cto!8 (CF) (Tab1.-4) st nB ||lth ?!aaIr. 

urr q7.5 , uhtl. th.t .f ll18 sr. t16.4 Durlng th! brrcdl.ng 

aarran! lt hra baan obarrvrd thrt f2 bccen.r nott rggrrrrlyr 

lnd plrvcnt! s.ntrctr o? rth.! ?rErlrr tlth |||8. 

recassive 

Thr gt vslu.! rl rlllfrnrlrr rlth n.L.a !.r. rlt.lt 

thr faotr rlthin . sarEc of 4r..0'47.3 Evrn though F2 uai 

t.larant to F{.nd f9 tha CF vrlua .t th. tuo r.c..!lv. 

.t6rclre rith F6 u,sra ga!.t!r than ulth F2 (Fit- la). 

Thc d.trr lhcn tlrlt tllaI nBrtlngE urslt obqorv.d ln 

th. y!ra! 1988r 'l 989 rn1 1990 t!!rr th! 25th Ftbruary' 17th 

{bash, .n4 10th f.brural. Th. c.r8.lpandlag dat!. cl 

llrat a!.ttng rt th! sa.rons |tcra th! 17tb. ttarch' 18th o.!cb, 

.nd lst}l mrrqh. Thlref.rrr, tlrrt n.ltlng osqqr!.d 20 to 

!18 

tt'l I 

25 dryr bltor. rctttt ncltlag tn 19Ba rnd 1990.

lrra-l[, Loc.ludcd thr tavoullt! rr!.s tor n.rtl]€ 

(F19r. ? to 1t) (Trb]o-5). Tho dccirnot foFaIr FZ urto th. 

tito flrst dlrLr€ .II thr... o.stLr€ eq.sonc. llc tlrs f.nrl.. 

oalt€d. ln th. 5a|' rone 1n ih. s.o. .l&ht. Ov.r thc. y..r. 

grotllng l.riollr..|ca o? t2 to F6, .nd Lt.r to F9, h.v. 

treult.d; tn. tartl,t|rl,tl ch.B.!. Thlt ls .lso avld.rlt tro! 

total trrvr$tl,on .f th. tue frdlca/ f5 .;od F9, tleF nostlng 

ln ilU. f4 brirq th! rroglllr|i oar rpparantly tolErrtld by 

f2 to n.rt lD trlll on r dlfflr.nt nlght In 1990. 

D'rtlng th. agE lncub&tton pBrLod vL8ite ta th€ n.st by 

..qh DtEgr! accurlld durlrq thc nlghtr ar usra lvld6nt fror 

rpocar !.!n 1|l th. 6ornlrE. Durlog Cry tlD! F2, F4 rod F6 

cliobad up tha brnk upt! th.l!, llspectivc no8ta Lf !,. 

.ctad ln | !|.nnar auggrrtlrg rrmcvrl of !.nd lro0r thr nrrt. 

Actlvr n.rt gurSdlng rt tho n.ltlng rlta {rca ccrn onLy 

ter f9. 

Ar tn lrpsllreotr, 1B tll,llt 1,998, a tuUy drcssod afflgy 

s.a !.d. to rtand .t th. n6tt .f t9. Th. t.!.1. idBEd1.t.ly 

125 

Lrlt itr baaking rlt! .nd c.!. clolr to thc clfigy qith oprncd 

Jrrrr but dldort rttrck untll th. lffigy ur8 put to rotl..n. 

Athck !r! rt thr IlEbr. 

In rotthaa lct of rxpqrlo!nt9 rrcordrd distre39 crll 

gl h.tchllnga ocrr playad rt rbout 2E clcy froo tho n.!t ol 

F9. lhlt drru rll frnal.r End llal,!s tourld! th6 lolrcr €? 

4u*'l 

thr strll brlt only F9 sllnbrd out (t,pto thc acurcr. |l,hon th. 

c.336tt. player- oa: ehifta{ F9 luehad upto It.

126 

O ISC USS ION 

FidaLiiy to a spot, al,60 knourn as .tsrritorisL 

baskir\Jr in cl:oDodi1lan6 ls recognieed as an aid to stusy 

and cangu9 uILC popuLtloos of ths Amsrican a11ig616", 

AIIiqatcr misslesippieosis (Thoopson and Gidd€n, 19?2), 

and the gharial, Gavialis oariqetl,cus. (Sin9h, 1905:pp 2?). 

B€qauas of suctl f1dcl1ty t9 pasticular spotg ev€n qn 

innocuous gp6cLrs likr the ghasial ooy cA.us€ qccl.dentB to 

hunanbrl,r€ (Bustard and Slngh, 1981 

). 

Such lldcltty t,t uat€r qnd basklng ettoo r!6 provcd 

rrith g:gE|y-b: palustris from tho 16sulis of th6 prgeant 

rtudy nt Renatlrthar In r ouggrr habltat, lven lf a 

clocodlLe sanctlrary 1c gazetted, it ir oftrn not poBslblc to 

c!6dlcato huocn actr,vltica und6r IndIan condlllon!. Thls 

faator, thortforo' n€6de lo bo rcAulatod ln ths Lntolset 

ot hu&.n 9af6ty. It utll be possibLe lf the nirnagenant 

4 *u'|rvi 

j.dantifiss such basking gpots(to"r!hich thsr€ is sBasorEl 

or totBl fldoLlly, snd l,npogo b3n on hurBn intruslon' 

As suggest.d from tha pr€scni gtudy ihe bgst knoun 

9€a9on for aacsltainlng tsrrltorisl 9pot3 of nuggcr i6 th€ 

u,lntrr (TablE-2). Thts acason l3 alao th6 tio! tlhich 

tboodiataly pracad6g tho onglt of ths bre€dlrrJ seaEon. 

Thslcforrr lf 16ft undlstuabod at the tetrito!iaI bBtklng 

dites, and subjoct to the avallabillty of 6u1tabl€ oostlng 

Blt.sr th6 Eugg€fs say nat Dovt auay frofil th€56 gpot! 

until ths sggs hatch around nonsoon. As a nBnagement 

oraciica undcr habitat osnipulatlon guitable n!stlng sitrE 

can br prapolad at trrfltori.I 

baaklng eit68 ulth 'n 

uttloats alo to reduco nqn-cr9codlfB ccnfllct 1n naturs'

Thi$ sLudy j,ndicdtcd th.rt 0von 1l "iro fdftrl'9 inug!o.rE 

eupear to larrra:,n ln th6 game zoos of a habl,ta+" fine! 

p.rrtltlooinq u,iLh r6spoct to ths uao of r€sourcr c.rn stl.ll 

be th6rc. In the !rild urhs!s sBvs!al aiju-Lt fsmiiL6s occuat 

and th6 Enagoment dcsir.s to devsfop ne:iting aroas urith a 

visu to lastrict movoognt, araaa of th6 crocodi.las, lt !riLl 

bc nosegsaly to d€vllop such siteg lsing oppositg banks 

sg that taklng ov€! ot ths nr!, slles 1o accornpllshad lrith 

a rtolEal manife3tatlon of thei! territolia1 btlhavlout. 

72',7 

Clocodi1laflg at9 knou,n to usa tho sams elt€ of nestlnB 

6very ycar. Th€ lnuggor srqc9dil€g comm€nce trj.al nesti.ng 

qbout 20-25 daye before astual nsating. Thorefolo, ln ! 

osggrr hatJltqt uh6ro uithqut, rosortlng to hablt.t nanlp!tl.t1on 

praotlcas lt 

o.A ' -'lt2t"ct'( 

is doEirld only io ld.ntlfy{ 

rclored EEasonl 

to roducr oan-ctocodile-sonflictr 

lt Ls lscommendod to 

gtari the clog.d gsason a nonth bsfor! actual nssting. 

Th! datcs of n99t1t€ ln mugget follaus a p!og!6s9iv6 

gtadisnt o? risa in 5umm6! t€mP€latu!6 flom gouth€ln to 

northcln Indir. In Tanilnadu th! ncstlnq eodson coon6neoE 

around f,anusry, in ollssa ,.t l! duling mld'lltslch, and ths 

Hj.oalayan totEle lgsqrd Aprll as tho ndstLng sBason' 

Lay ing Ef tuo clutchss qf eggg P6r geaaon hav6 bs'n 

leportgd sincs 19?6 tor !. gll5!g!:3 at madras (ujhitakE! 

aod uihlt.ak63, 1989). Lanco (198?) cautionod thbL ,by 

sttelptlnJ to increaea ths nuob8r of clutchgs in a year 

th€ Lncroae6d Btre.s on ths ?rnql5 urould b€ 1lkely to 

lrsuft ,.n redecsd clstch slz!, Infello! q(6llty of eggs and

128 

ultloatlly, p!!m€rturr sencsccnc!!. Thle qont6ntlon can 

tt€ oxtsndcd to rlvleu gtocklng pettsrng of aduLtr 1,t a 

btaeding proqlamm6 on th€ basi6 of data colLocted on 

mal€-fana16 contact factors in thg plosgnt study. 

Fo! a br€sding group of foul lruggers it ls consid.red 

j.ncorfact tg ka6p only One dalg bEcaug€ of ths fsar that 

tho lons nE19 mEy hqvs goms rsploductiv€ defsct. Again, 

tht dat. on eontact factolg (Tabf€-4) euggest that bocauEs 

ol tha psesosllvonssc o? ths dqninant fomsLr r..rvcr 

tho l1r!t 

mal,e, th€ Eccqnd 0a1r eontribute8 th6 most so that ths 

valuca of sontlct factor or " rr lif'i"l'"" for mats! ts 

lcsd at 44ô to 47.5. Thst neant thrt tho egcand nalr !.n 

ths llsk ol pllnaturr gensscsnc!. Th!rafo!., svrn It a 

,ruggsr nlql,a csn taproducr urith 96ve!al farml!s, for Long- 

t.ro s|anagem6nt o? E, h-Ea llh1sr.-brsedlng pr-og 

ir 

ramoe 3 malesr 

C^r;6f i^ (!rh tD ha '&; l; 2

g. ,iC KllUlJLf DGCTTEI,ITS 

ilqtin,.,j thc course of ttr is study sevtJ!.r I 

Psopla .rnd'oa,jdriLsationg have he.Lped. Son6 of 

th€ss a!el 

':Thc 3tqt,6 covt. of Crlssa, princioal Chllf 

Con6.!\rato! ol Forsats (Orlssa), Chlaf uitrlllle 

Uardan(Orlssa), Fle1d DIrEctor,:imllipal Tlasr 

t29 

Rssolvo, Ins. Se1Ly [Jalker. (loo Lutreach Urganisdtlon, 

India) Jnd tils. iusan ta!nard (Zoo Atla6g3, LJ'A) fo! 

orqan1t3tlonal facllities and fo! l"itsratu!e relatcd 

to the cours€. 

: $r. 8.C. Cha udh ury (SlB nt Ist, ,,J1l.dtif 

I Instituto 

of IodLa) and Or. S.K.Kar(tiasearch gfficsr,d!j.ssa) 

fo! inf ornat lon. 

: filr. 1.O. Ro(Itr|i].Sc.(R€search Asst.),5!1 H.C.cIri, 

B,A, (C1erk); sri covlnda T 

S!1 Savana ttarcndi and 5rl 

for hrlp at varloug stago€ 

dlscussion, analy sls and ptdsentation. 

Lf,A provided a lelloushlp t.o 

ar:-i-..rJ. o,urqg en er t 

c ol.Iede, Can-rj+e. ii:'.::, 

C;.rrse;-,rto.:. 

udu (f:lug ger Ke€par), a nd 

p.C. Goch hay at ( liugg e r Att!odarl) 

of cjata col.lsct ion, 

'. The Ccn96rvdtlon TroJtJ ,uppori. f und, ,:1-ryLdnd, 

covsr e xp €ns€,3 fol tbe 

f.crr .the ll:b"ona,l. :x --,::.,* :r1;

130 

9. R i ' E R E C E 5 

,lcharjyo, Lru. and f[.rhapatra,S(.1 

9?B)r Return of t.he 

ma!sh c!ocodils tSlg!!g4!: palustrls) 

Ind i3 n Foraster. !!!(5):385. 

Bust3rd.' H.R(1 900)! Thn L:ovt. of Indls CrocodiLe i,I.oJecr. uheetal 

33\1/2)' 11-16' 

gustald, i1.R. and SInlh, L.A.k,(198i)r Gharlal attacks on nao. 

f,. Banbav nat. Hlst- .-oc. ?S(3)r610_611 

Ch&block, R.ll.('1 965)r Thd Dov6mofit ol alllgat0t.6 jn Loul€lana. 

proc. Ano. Canf. Southeastsrn Assoc. came and FIsh ColIlB 

!9! 102-10. 

Cott, H.E.(1951)r Scicntiflc rssults of..rn inqui!y j.nto th. 

ccology,rnd ccooonlc atatus af thc lrJllo crocodll8 

Glocgsltlug nJlotlcqs) in Uganda and Northorn Bhodoelq. 

Tfansactions of th6 Zooloolcal Societv of London. 29 r 

zL | -Jao. 

F.e.0.(1 9?4,)r India. A p!6llaln.rry sulvsy of lhs ploepects for 

crocodllo falolrE. (gaeod on th€ urork of O!. H.R. 

EustaEd). F& LND/71/o33, octr 1924.1_66pp. 

Cro€obrldgs, g.(1 982)r Th€ IUCN Anphibta-ReptltIa Red Data Book 

p6rt I r TsstudlnBs CrocEdylia Rhynchocephalla. ItCN, 

Chnd, Sultzorlqnd,pp. 363-3?0. 

cupta', R.C. and SrlHarl, F(1 989)r 0n thr basking behavl.our of 

th6 dugg6! Crocodvlirs palustrls Lonon(Reptilla, 

Crocodllla) at tholsainda Clocodlle :anctuary, Halvana 

..tat!. 

ca Pt iv6 

rnti the,rrlld. 

J. nombav nat. H1!t. 5oc, 06(Z): 17O_174.

Lanco, V,rr, (1 907) r llorlnon.rl, aontrol ol IBp!oductiun in uruco 

131 

dillan6. pp 409-415. Int 'jlild.Lif s ltaoao6oent! C!ocodiles 

dnd {J.liqqto13 od. by c.J.UJsbb, :.C. li|lna}is and 

tr.J. thiteh€ad. Sutvey Ba6tty and ,;ohs plV Lloited 

1n a I s o c L a t i o n . u j. 

t h th6 C oo6s!vatj.on C omnis sj.ori of the 

I srrrLU.y. 

Langr J.'J,(1 98?)r Crocodillan Sehaviou!i Implications for 

manaq6ment. pagas 2?3-94. in ,JJildll.fs {lhndg6d|ent.1 

C!ocodIlos and AlLlgdtoBs. ed. by 6lahame J.UJ,Usbb, 

5. Cha!1i,6 manllis and Pet€r f,. Lthitehead:ulvey Beatty 

and Sone. pty lioltEd la associatlon luith tho 

Con6€rvatl.on Coo6ls6ion ol th. Nolthern Tsr!ltory. 

lnurph!, T.(1 902). C1tatl,onrp.16. In. 5lngh, L.A.K.(1905)r 

Ghqrlal populalloB. Trond in NatlonaJ' chsmbrl :,ir nct uary 

u,Ith. nots6 qo radie tlacking. Covt. of India, Croc,odllc 

Reee.rqh Cantls of UJlldlifs Instltuts of Indta. Hyd€sabad. 

PP viil + 167. 

Rao' R.J. and SirEhr L.A.K.(1 992)rCoomunal oastl,ng of the 

gharlal Eavtalis qanodticus (careltn) (Reptilia, Clocodllia) 

Ln thE Natlonal chaobal, sanct uarv.Aiggf-3gl-!'d' 

J=(i^ P"*) 

Rathr R.L.r str€h, L.A,K. sad Karr 5.(1 990): uork plan ?or 

arocodll€ managemsnt ln os1ssa.r.Indla durinq 1990-95. 

Sagur, S. and 5ir€h, L.A.K.(1 990a)3 Eaptlve Blesding and 

rehabil.it.t j.oo of ougger(Crocodvlus glg:!gi: ) in 

Slrnilipal T19rt Rcarru€' orissar India. Indian Foreater. 

Saga!, S. and Sit€h. L.A,K.(1 992 )r Notes on eurvival efficiency 

cnd grolrth of htttshung qug96!(Crocodvlus gf,f.$i!.g)' 

@:L!4l!rv'' 

(3), tYor.r tee2-

132 

,-tlr..tlr., L . . ' . ii , ( I | '/ | ) : tuoJ.ulic,rl" -Luu1r,g r..rrr l.lr,; lrrrji..l' 

thariall Javi.lig o4n.eticus (tr,relin)(neptllia) 

C!Jcodilia). tltkal Univorslty' ilr"J. Llres15. 

Singhr L.A,K.(1 9s3a)i Commuoal uss of villags ponds by the 

muss €!s ciocod i]u (S::gg34g' lg.lgll-t : ), catt 16 

and nEn. .l,Bombav nat. Hist':.:gS. !!(2)r642-645. 

SirEh' L.A.K.(1 983b)r Th€ fndian mugger,Crocodvis SLjg3.119 

Leror (ReptllialCrocodlLia) r Obsol:vJtions cn th6 

behavicur qf a feoa19 from natute. J.tomba'J nat. 

.::-]:-!-:-jt9s . jg\r)r 499-506. 

5ingh, L,A.K.(1 983c)r 0bservations on the |llovsm€nt of turo 

captiu6 rearad mugqor crocodi16sr crocodvlug 

palustlis L€sson u/h6n leturned to the '!ild. 

J, Bombilv o+li !irg! !qc] C0r,1):u6-90 

lingh, L.A.K,(1 9fJ5)i Gharlal Trsnd :n ttatiorel chi.lmbal 

Sanctualy ulth notos oo lad1otlacking. Covt. 

of India, Cro.codils Resoalch Centle of fildlif. 

IostitutE of Indi.ar Hvd€labad. pp.viii + 167. 

5inght L.A.K.('1996)lCharactet ol tbe population in Ghdrlsl. 

p.362- . 423. J!: A t6chnisal expsdltion 

uith Indlan Crocodllee. Ir'15s. 

Sirqh, L.A.K.,Chaudhury' B.C. and Kar,5.(1 990)r lndian 

ctocodil€s: option and Tasks du!ing 1990s' 

pp. 191-198. In:C!ocodiles. I !ocudln'l of tho 

9fh Uo!klng lr,€rtlng ol ths c!ocodile 

'pecislist 

C!oupr 1L[N- Th€ UJorld CooservatLon llnion' 

[land, SurltzBrland. Vo1.2.I5BN 2-0317-u009-4 

iv + 380.

-:..L, -.i.,.,;:I, 1.. 4,iu ,:1,- j.li:rtr:, .1.i.;. .' 

133 

:!o!od:1e9: .l 10-ysa! ievi.s'r of idncllsnv,.r:. p. 3a2-3?.,. 

_:l :t,Jcccilesi j.!c.oco:n!: 

trf ih,, 7:1.: i:t : ,:,,i ii, 

Df :ho i:r:)crr.lj1c puclcli:t l::u;r ,jf ' ., I -l , ir! I l:', 

:rtaqas-Venezvela, 1944. IUall pu iicJ:ieri .!,J 'd.ies 

ISB it 2-08032-3t16-1 . ro(uIlI+44J, 

-injl,' L' r,(. and liro' f.J,(1 9eb): i,iljiri:i..rncc f :-uridual 

ogg fluj.d to tTdtchfing pattsrn: irr ihc -irr:i:1 

G-!f-CU-: ,rdoaoi,icus) 'nd ernydid ftcshuJte! turtL!5 

(i.eptj.1iJ, iiocodiiia and ChsIcni{j. ]. iJ,.bn! rdl. 

llisr-. :oc- -!ll )r211-22u. 

linghr L.A.K. and Sagarr 5.(1990): The escape and captuie of 

d muggor c.rocodi.IB(Ctocod\rlul ouLustrl:r) .t (u'nrJti!tho' 

0!j.ssc. Indla n i-onester. )16(ro):8ql-S9'1 

ThompsooI R.L. and il.dden,C.9.(1 9?2J: T6rrlto!iaI 6a6kinq 

count e to s st j,oat s all ig at ol p op uLat 10 ns. -lq!!_!3-1__SI 

uJildlile lilar.3qement. 36(4) oct 1972-1081 -1088. 

Uebb' G.l.u(1 981 ): NBsting bj.olooy of Drocodvlus j$!$! n i 

in ths Northern Territory' Chap, 20. p.l0? in tlanks, 

C.B. ano,',;r. Iiartin (eds). ilocesdin(js of thc 

L,Elboucne llerp€tological'-ytlPosium. Zoolo! .cal 3oa!c 

of Victoria, RoyaI uelbouins U oolog-caI .l.tdans' 

!hitake!rn, (1 974): l,lotes on bshaviourr €co-loCr- iind preseot 

status of th6 nalsh c!ccodile(croccdvlus;l!E!!j) 

south, Indla. A giadlaa 5o€t ka Park Trust l)ubllcatLon" 

Uhi.inkorr Hdm and Zo1(1 989)t Ecology ot Lho nrtJ!!cr crocodile' 

276-296. In: C!ocodllestTh€1r fcology, [lar|agement ano 

Coneslvatlon. A :psclal liubficatlon of the Clocodil'a 

5p€clallst 6roup of the '-pec169 Sutvival toiilmis6ion 

cf ths InternatlonaL union for consB!v.rtlon of Natu!4. 

and atqral Resoulcgs. lUCt\ puolicatlon :leuJ 5cr ies. 

ISBN 2-88032-9€?-6. C l.od, Su,ltz6rldnJ. 

in

134 

Crocoalilian Conservation andl Connsrce ! 

conDon lDtereats prevail in gustal.ned uae l{allageu€Dt 

INTRODUCTION 

Uatk A. gtaton 

Uainlanal Uolalirgg Crocoalile ?arn 

P. O. Box 196 

Lae, Papua Nsr cuitea 

It is a pleasure to address this llth Working Meeting of the. 

IUCN/SSC Crocodile Specialist Group (CSG), In previous sdssions, 

we have heard from speclalists on a topic of particular interest 

to this meeting - the conservation of croco-dilians in Africa. 

Further, rderve heard reports on the status of a nunber of 

crocodilian populations around the lror1d. 

In todayrs session, we lrill hear a number of talks relatinq 

in one way or another to the utj.lization of crocodilian resourcei 

around the world. Utilization of a natural resource can of 

course nean a varj.ety of things - for exanple, sinple aesthetic 

appreciation of witdlife in natural surroundings, tourisn, or 

hunting for pleasure and trad€. For rnany large inarnmal and bird 

species, populations are nanaged to allow for -hunting - both for 

sp9f! ar-rd trade purposes. With crocoditians, resource 

utilization is primarily for trade purposes and has been 

developed to include not only hunting of vrild populations, i,e., 

I'croppingr', but also the capt.ive nanagement of-individu;ls (o; 

theLr.offspring) originating fron the;itd, i.e., ,'ranchinq" and 

ifarningtr, to enhance the yield vhich can sustainibly be obtained 

fron wild populations, Today. conmercialisn is undoubtedlv one 

of the key factors in what is the pritnary concern of this group - 

Crocodilian Conservation. The fact that a fulf day -of 

presentations on resource utilization is scheduled for todav 

bears out this view. 

IMPORTANCE OF COI'TITERCIAL FACTORS IN CONSERVATION 

wtry are cornmercial- factors so inportant at a conference oll 

crocodile conservation? At least for €wo very inportant reasons: 

(1) Past coru0ercial activities have to a l-arqe extent 

created the probLe!0s requiring conservation efforts and actiong. 

As you know, the commercial exploitation of crocodilians has qone 

on for approxittately t\ro centuries for their fat oils in -the 

early- lsth. ce-ntury, as pets and for neat in this century, but 

rost.dahagingly, of. course, for their valuable skins to rnaf.e hign 

quality leather, since the nid-1aoo's (see Joanen and McNeas;, 

1991,for a revietr). Holrever, cormercial exploitation, in and of 

itself, has -not been the problem. The prbblen has 'been that, 

until. recentLy, that €xploitation has been unregulated and, tlore 

lnportantl-y, unsustainable. This resulted in the severe 

depletion of tnany populations of most species around the lrorld 

by the 1960rs and created the need for active conservation 

meagureS.

(2t The second reason that trade issues are i-mportant here 

is that conrnercial activities, vithin a conservation-orientated 

franeworkr can represent nuch of the solution to the problerns 

created by past unregulated unsustainable trade. Further, 

connercial utilization of crocodilian natural resources around 

the lrortd can have a positive inpact on the conservation of a 

r4'ide variety of species, crocodilian and otherwise. 

The view that a positive relationship can exist betveen 

conservation activities and the rational exploitation of rrrildlife 

as a rene\^/able natural resource shouLd cone as no surprise. We 

have, as an example, a historical precedent in the United states 

of initially unrestrained exploitation of game species, followed 

by the recovery and utilization of their nanaged populations 

(Gilbert, 1964i Clepper 1966; Conalray, 1992). In the early 19th 

century there existed r4'hat appeared to be boundless natural 

resources across the United States. However, during the latter 

half of the last century, hunting of game species took place on 

a mannoth scale - culminating, for exanpLe, in the extinction of 

the passenger pigeon the decirnation of bison and pronghorn fron 

the A$erican P1ains and the slaughter of hundred of thousands of 

nesting egrets, herons, ibises and other vading birds for the 

fashion trade. This should sound faniliar to crocodili-an 

conservationists. 

By the end of the last century, conservation had becone a 

public priority. The Ne\,, York Audobon society was fortned in 

1885. Yellowstone National Park and other wildlife Refuges $rere 

established. A pro-conservation president, Theodore Roosewelt. 

was elected. Forerunners of the United states Fish and wildlife 

Service and the United States Departnent of Forestry were 

established, and professional vildlj.fe societies lrere born. 

state lar's were passed to protect local wildlife, and the first 

federal lasr dealing r4rith wild1ife, the Lacey Act, was passed in 

1900 - making a federal crine of interstate transport tildlife 

taken in violati.on of state laws. 

what followed roughly fron 1900 to 1935 has been described 

as the rrera of preservation and productiontt. During this tirne 

nany once-depl-eted populations rebounded to the extent that they 

exceeded carrying capacity and. in some cases. began to selfdestruct. 

soon, the problen was not a natter of too little, but 

instead too nuch, protection. However, the ideas of preservation 

and protection had been nsoldn so effectively that neither the 

publj-c nor official-s of wildl-ife agencies could accept anything 

contrary as being good nanagernent (Gifbert, 1964). Portunately, 

it v,ras durj-ng this period that the pioneer ecologist and wildlife 

hanager Aldo Leopold laid lhe foundation for modern lrildlife 

nanagement - stating essentially that wild populations produce 

rra generous surplus over that needed to maintain adequate stocks; 

and that this surpluE can be removed by hunters without 

endangering the species. If not used by hunters, it will die of 

other causes, some of vrhich tnay endanger the breeding stocks rnore 

seriouEly than regulated hunting. Clepper 1966). 

135

136 

Since the nid-193ors, the vildlife hanagement concepts 

pioneered by Leopold and others were lnolded into state and 

federal laws governing gahe species, but to varying alegrees. A 

recent article in National ceographic (Conaway, 1992) points out 

that in sorne cases once-depleted species such as white-tail deer, 

wild turkeys. Canada geese, black bears, and yes-even atligatorshave 

now becone public nuisances and. in some cases, public 

health threats. l,Iore inportantly, Conovray (1992) points out that 

rrhunting is an ihportant factor in the success of irildlife 

nanagenent proqrarLs. In fact, the fate of larqe aninals is 

intinately related to their status as fane..... The pittnan- 

Robertson Act levies an excise tax on arns and amnunition that 

over 50 years has raised nore than trlro bilfion doflars, nost of 

it disbursed to state ]l/ild1ife agencies for popufation studies, 

ihproving nitlions of acres of irildlife habitat'r. The articfe 

goes to decry that less than 20? of the nonies were spent on nongame 

species. However, it should be noted that (1) this is 

approxinately US$400,000,000 for species that Iack a obvious 

econo)lic value and that lrould have been very difficult to raise 

in any other way; and (2) many non-game species benefited fron 

the lrildlife habitat that was ihproved, managed and/or purchased. 

PROTECTION AND UTILIZATION OE CROCODILIAN RASOURCES 

The paralfefs $,/ith the cotnnerciaf exploitation of 

crocodilians are rather obvious. As a non-gane species, their 

unregufated exploitation continued until the 1960's. Fo1lo\\'inq 

severe depletion of crocodilian populations vorldwide, a period 

narked by lncreased public awareness of endangered species and 

other environmental issues, and legislation to protect 

crocodilians species fol lor^/ed. 

In the fate 196Ors and early 197O,s, legisfation was 

desj.gned to ban hunting of witd crocodilians and/or sate of their 

skins or finished products nade froh them. As a consequence, the 

early relationshlp betUeen conservationists and the crocodilian 

trade rvas inevitabfy an antagonistic one. Throughout the 197O's 

and 1980rs, due to the inagination and efforts of a !,ride variety 

of people with equally diverse views and interest, an evolution 

f^^L hl:-6 ih Uhi^l'. 

(1) most in trade have come to appreciate that crocodilian 

resources are finite renewable natural lesources and 

can be harvested only v/ithin bounds; 

(2) nost conservationists have shed a preservationist 

attitude and have not only approved, but have 

ernbraced, utifization of the species as a resource and 

a key to their conservation. 

A study of the Proceedings of CSG Working Meeting over the 

past twenty years rrould reveal that the CSG has served as the 

forum for this developnent.

with the recognition that goals of both conservation and 

comrnerciaf enterprise overlap, conservationists. regulators and 

industry have developed a cooperative strategy by which selected 

(recovered) populations are harvested as a rnanaged reneltabLe 

natural resource. central to this scherne. knovh as trsustained 

Use ltanagrenentlr, is the concept that this utilization be 

sustainable - i.e., within the capacity of the natural resource 

to renew itself (IUCN/UNEP/WWF, 1991). The concept is considered 

so inportant that an IUCN/SSC SpeciaList Group on Sustainable Use 

of Wild species has been forned (8. Vernon, pers. conunun.). 

Thorbjarnarson et al. (1992) offer an excellent discussion of suu 

or sustained yield utilization as applied to crocodilian 

resources. 

The new relationship between conservationists and industry 

dj-d not take place only !'ithin the crocodilian !'orld. By 1980, 

the world conservation strategy, developed by IUCN and wwF, took 

the position that rrconservation is not the opposite of 

developnent. Instead. it lras ernphasized that rrconservation 

includes both protection and the ratj.onal use of natural 

resources,, (IUCN/ITNEP/WWF, 1991). 

137 

Parallels can be found in the inplernentation of cITEs, lrhich 

took effect in the 1970rs, banning trade in some species and 

regulating international trade in other species through systems 

of tags, licenses and pernits inplenented by l"ocaL CITES 

Uanagenent Authorities. Throughout the years, CITES has been 

nodified. and changes affecting crocodilians have generally 

reflected a nore tolerant attitude tovard trade, as long as it 

lras controlled, legal and sustaj.nable. For exatnple, under Res. 

conf. 2.L2t Appendix I species which vere initially banned frorn 

trade, can be treated under the provisions of Appendix II when 

they are propagated in captivity. Further, a nunber of 

resolutions during the 1970rs and 1980rs provided a vehicle for 

the transfer of populations frorn Appendix I to Appendix II under 

ranchj.ng (Res. conf. 3.15) or quota (Res. Conf. 5.21) programs. 

CITES aras able to incorporate pro-utilization concepts .into lrhat 

was originally protective regul-ations due to the pro-utilization 

stance within CSG, the active input and support of the CSG 

lrenbership, the hard work of vildlife agencies and just as 

iuportantly, the trade nonitoring activities of TRAFFIC. At the 

recent Meeting of the Conference of CITES Parties in Kyoto Japan 

( arch 1992). a resolution, Con. 8.3 (rev. 4) that recognized the 

benefits of trade in wildlife was approved. Further, the CSG 

agenda of using sustainable use to conserve crocodilians lrith 

involvenent of the cornnercial trade sector in conservation action 

was advanced and may be a model that CITES will apply to a 

broader context (CSG Newsletter, Vol. 11 (1), pp. J,3, Li). 

CONSERVATION 

lnrrthe late 1960!s, virtually every one of the 23 specj-es 

of crocodilians iras endangered, threatened, or declining in 

numbers. Today, approxinately one-third renain critically 

endangered, but one-third have stable or increasing populations,

138 

and one-third have sufficiently large populations to support a 

rigorously managed Legal harvest. This change has corne about 

because of the econonic value of crocodilians. crocodilians are 

the best exanple of rvalue driwenr conservationl (Messel, 1991). 

Itany successful conservation prograns hawe been built around 

the economic value of crocodilians. For example, in Papua New 

cuinea, the crocodile Trade Protection Act was desiqned to not 

only to protect the crocodile resources of Papua Ner^r Guinea frorn 

over exploitation, but also to support a viable industry in vhich 

traditional landor^rners could benefit fron and control the harvest 

of eggs, live crocodiles and/or ski-ns rernoved fron their land 

(Bol.lands, 

nations, 

198?). In Papua New cuinea, as in other developing 

if people lrcan make rnoney by harvesting wild 

crocodilians nost viII do so. In subsistence econonies, making 

noney is irnportant. " 

without the econonic incentive. people are 

not wilfing to put up lrith increasingly abundant, crocodilians 

lrhich can ehdanger villages or their livestock. (Itessel, 1991). 

In venezuela, sone ranchers rrhave earned as rnuch money frorn 

harvesting capybara on their land as they do fron cattle. The 

caiman add a third species of rlivestockr. which they protect 

every bit as much as they do their cattle'r. This also gives thern 

rran econonic incentive for conserving the wetlands that support 

the caimans and nany adequate speciesrr (Messef, 1991) . 

Sinilarly, if coastal landowners of Louisiana and Florida 

are given an econornic incentive to rnaintain their property as 

wetlands, they vrill do so. They can be given this incentive by 

allo{ing them to benefit frorfl their alligator populations - 

through, for example, Ieasing their l-and for the cropping of the 

l'ild population or the collection of eggs to be used in a 

ranching progran - all under a nanagenent prograrn which is 

scientificalty, designed and rigorously enforceil (Joanen and 

llcNease, 1981; Hines and Abercronbie, 1,9e7). 

Most endangered species are endangered not because of 

hunting or conunercial exploitation, but because of habitat 

destruction and loss to an expanding hurnan population. Placing 

value on habitats leads to their rnanagement and protection for 

crocodilians and other species. The pronotion of habitat 

conservation through the econonic value of crocodilians thus 

takes on ihportance in the conservation of non-crocodilian 

species. In Florida, an integral part of the staters alliqator 

managenent program is their lvalue addedrr concept that "the 

conrnercial worth of alligators should be channelled into helping 

the conservation of both themselves and their habitats..... It 

specifies that the returns derived by the State frorn cornmercial 

alligator exploitation shall be used as a source of funding for 

the continued managenent of the \,7ild resource. This feedback can 

be direct (i.e., supporting researeh or habitat preservation and 

enhancement) or indirect (i.e., providing landor4rners with 

econonic incentives to preserve their vetland) I (Hines and 

Abercrornbie. 1987 ) .

RESEARCH PRIORITIES AND SCIENTIFIC BENEFITS OF SUM 

Control-led. legal trade r^ras thus allowed to proceed and 

expand as l-ong as vhat resulted fron SttM prograns did not darnaqe 

the natural resource. i.e., as fong as utilization lrts 

sustainable. Central to this concept is that it be dernonstrable 

that crocodilian populations are not being depleted. Thus, the 

val-ue of the monitorihg efforts cannot be overstated. It is of 

great irnportance to trade and conservation interests alike that 

monitoring methods be accurate and efforts to continually irnprove 

these rnethods should be encouraged. 

It is therefore not surprj-sing that population nonitoring 

has been a high priority for funding by the industry. 

Thorbjarnarson et a1. (1992) point out that rnuch of the fundi;g 

in recent years for crocodile conservation has been nade 

available by the reptile leather industry - and huch of this for 

surveys or to heLp irnplement SUM p1ans. 

The cornmercial iroportance of crocodilians, and the fact that 

their exploitation under suM programs is based on scientific 

principles, has lead to a remarkable expansion in the scientific 

knowledge of crocodilians. Anyone who has conducted a literature 

reviev recently viLl be struck vJith the diversity and volurne of 

knovledge on the biology of crocodilians which hls enerqed over 

the Iast 10 to 15 years - at the same tine that, and larlely are 

result of, SUI!{ prograns ra'ere being irnplemented vith recovered 

crocodilian populations around the $ror1d. A randoh perusal of 

the literature vrould show steady increases in the kn;lrledge of 

diverse areas such as: 

- endocrinology and nervous function 

- behavior and stress physiology 

- nesting ecology and vildlife nanagenent 

- rnetabolisrn and the inportance of ternperature on a1l 

aspect of developrnent 

- nutrition and feeding 

- embryology, norphology and developrnental anatomy 

- genetics and systematics 

- diseases and veterinary care 

- grovth rates and aqing techniques 

- husbandry and captive propagation techniques. 

This list is not exhaustive and could obviously be expanded. 

While it i-s true that nuch of this inforrnation has'resulteat froit 

studies on species of cohmerciaf inportance, nuch of the basic 

crocodilian biology can be related to rarer species. This 

indirect contribution to the knor!,ledge of the rarer species 

should not be rninirnized. 

TRADE ISSUES 

The track record estabLished through SUM prograrns is one 

that the csc nernbership can be proud to have toniributed to. 

However, we cannot lrrest on our laurelsr - there are norar and will 

be j-n the future new challenges to neet. one need only peruse 

't39

t4D 

the pages of the CSG neltsletter to read about sorne of these 

Lssues. The remainder of this presentation will examine sone of 

the issues relating to trade. As lre begin to focus on current 

trade issues, bear in rnind that lthat is good for legal controlled 

trade will be good for conservation, so these are issues of 

concern to conservationists as vell as to businessrnan. 

lilarkets and Prices. --- Aside fron illegal trade, which will 

be discussed below, several factors are placing great pressure 

on the prices of crocodilian skins - (1) Iimited size sel-ection 

of increased supply of skins coming fron farn production, (2) the 

ongoing stagnation in the world econony, and (3) conpetition fron 

other exotic leather industries. 

It is no secret that the volune of classical skins coning 

on to the narket is increasing. Production of classical skins 

world-lride was approximately 150,000 in 1989, 250,0oo in 1990, 

and was estimated to reach 300,ooo in 1992 (Lunnore, 1990, pers. 

contlun.; Ashley, 1990). the j.ncrease in volume of skins has 

resulted alrnost purely fron ranching and farrning prograns. while 

skins fron these sources have the advantage of represehting a 

steady suppLy of legal skins, the size selection available is 

Iinited. targe volunes of skj.ns in a linj.ted size selection has 

had a detrimental effect on prices. 

The lrorld economy for the last fe!, years has been in a 

general recession, uany, including sorne Japanese, say that the 

I'bubble has burstl on the econorny in Japan - which is the 

ultihate narket of an estimated 70* of the 6kins produced 

lrorldwide (Ishii, 1990). There are sinply fer!'er people vilting 

to pay the high price of the finished products made frorn 

crocodilj-an skins. And, sales to those people are being pursued 

aggressively by other leather industries such as fish, snake, 

lizard, shark, el-ephant, enu and oslriqh. 

The combination of these various factors has lead to a drop 

in prices over the past year or two, sone nore drastical-ly than 

otherE, but gtenerally betveen 30 - 50t for salted skins. Even 

prices for crocodylus potous skins are currently under 

considerable pressure. 

Inpact on Producers and qradj-nq standards. ---The prevailing 

conditions have created a rtbuyerrs narketrt. Not surprisingly, 

standards of qrading have becone much stricter over the last 1-2 

year6. fn sone cases, skins that would have been purchased as 

grade 1 in 1989 at high prices are today being bought as Grade 

2 skins at lower base prj.ces by the sarne buyers. This is perhaps 

natural but it is also destabilizing to such a younq j.ndustry - 

one rdhich was encouraged to grow by the leather industry. As 

part of a naturing industry, I believe that produc€rs and buyers 

of skins need to cornmunicate better on their mutual technical 

problerns and work to arrive at fair and equitable standards and 

r0ethods of grading skins - vrhere the conmon denoninator wiII be 

the quality of finished skin. Perhaps a more quantitative and 

technical approach to grading vould be appropriate.

The future: Expandinq the Market for crocodilian skins.--- 

Due to the I'down cycferr in the narket, increases in skin 

production appear to be continuinq at a nore moderate pace. 

Nevertheless, the availability of classical skins lrill no doubt 

continue to increase, Producing those skins for exPanding 

markets nill be good for both conservation and trade, but only 

if they are sold at a fair and profitabte price. 

How do rre get our rnarkets to expand? one thing r1'e can do 

is to ra'ork on the narke! at the consur0er level. The 'rpoint-ofsaLesrr 

narket.ingr research and promotion bookLet spearheaded by 

Don Ashley is an excellent exanple of the type of approach the 

industry rnust take in order to influence the market at the 

consuner level (Ashley, 1990b). 

There is an urgtent need to address and correct the 

perception that nuch of the general public - read that the 

"buyi-ng public" - still has of alligators and crocodiles. There 

are still a great nany people who believe af1 crocodilians are 

endangered. Consequently they belj.eve (1) that it is unethical 

and anti-conservation to buy an alligator or crocodi.le skin 

product, and/or (2) that it nay be illegal. to purchase all 

crocodilian skins products. 

141 

For example, in the 17 June 1992 issue of a Lafayette, 

Louisiana newspaper (Ihe Daily Advertiser, p.13), an article 

about the cuban crocodj.le stated that "v,torldwide pressure is 

being focused on cubars endangered crocodile progralr because the 

island nation has joined a treaty organization that stops 

peddling of ivory tusks, cheetah skins and crocodile productsrr. 

The article not only puts all crocodile products in the sarne 

category as ivory products - which have received nuch negative 

publicity, it implied that cITEs bans the sale of all crocodile 

products as r,retl. Irresponsible staternents and half-truths like 

these undoubtedly cost our industry sales. 

As another example, an article about a IFur Amnestyrt proqrant 

promoted by a group called "rn Defense of Anirnalsrt recently 

appeared in the tlall street Journal (9 January 1992). The 

president of the group was encouraging people to give up their 

fur coatg and stoles - by donatinq thern to the group so that they 

could rrparody those rrho think they look beautiful in fur.I This 

vould not appear to affect our industry - indeed, the text of lhe 

articfe mentj-oned not one word about crocodiles or alligators, 

and the rramnesty progranrr lras clearly aimed at the fur industry. 

However, the titl-e of the article was "Ge! Ready to send Hj-m your 

old rvory Brooches and Alligator Bagsr. The inpression left on 

the reader - by the stringing toqether of negative inpressions 

of furs, ivory and crocodilians products - undoubtedly costs our 

i.ndustry sales. 

The nessage to the public in late 1960rs and 197ors was that 

crocodilians lrere endanger€d and needed protection, and this 

loessage was appropriate at that tine. However, as lrith qane 

species in the years following recovery of depleted popuLations 

in the 1930rs, todayrs nessage about crocodilians desperately

42 

needs to be updated to ineet present-day realities. Misconceptions 

rnust be addressed with the assistance of conservationists, as the 

sane nessage corning only from the trade vtilf lack credibility. 

The csc is and should be prinarily concerneal with the 

conservation of crocodilians. However, the csc has enlisted the 

legal trade as a tool in the conservation of crocodilians. The 

csc should therefore take the lead in inforrning the public that 

only some crocodilians are endangered, tha! many crocodilianE 

populations have recovered and produce sustainable yields under 

well-managed stM prograns - in short, that buying legaI products 

supports crocodilian research, supports crocodilian conservation, 

supports habitat conservation? and supports an j'ncreasingly 

environmental Iy-f riendly industry. 

chandino structure of Industrv. ---The structure of the 

industry will undoubtedly continue to change with the increased 

proportion of skins corning fron the farning and ranchinq sectors 

- an essentially agricultural pursuit - as opposed to cropping 

prograns, vhich have dominated the supply of markets in the past. 

As ra'ith other agro-industries, it seerns likely that this 

aqricultural conponent of the industry will seek (1) to expand 

narkets for products rnade fron farmed crocodilians skins, and (2) 

to benefit fron that expanded narket, not only through the sale 

of their skins but through obtaining a portion of profits which 

nornally gto to those invotved in the processing, manufacture and 

narketing of the finished products. That can be done by 

following the exanple of other livestock industries - lrhere joint 

ventures, partnerships or single conpanies enconpass the various 

subsectors of an industry, starting, for example, !.rith breeding 

stock, producing livestock and narketable products, and retailihg 

then. In the case of the crocodilian farrling and ranch-ing 

industry, we !'ould start with breeding stock or a ranched egg and 

market handbaqs - al1 within the same conpany or group of 

cornpanies working together. This would bring a greater share of 

the profits to producers - rho suffer nost during market down 

cycles like the one we are j.n no!t. It seems likely that those 

who vrill do best in this industry over the next decade are those 

who are able to integrate the activities of skin producers and 

tanners together with those involved in the manufacture and 

rnarketing of crocodilian skin products. 

Ifleqal Trade. ---The Iegal crocodilian farming and skin 

trading industry contributes to, or accounts entirely for, the 

Livelihood of thousands of people. Landovrners, vill'age 

suppliers, egg collectors, skin hunters, farmers, wildlife 

officials, researchers, abattoir and tannery !,rorkers, leather 

goods nanufacturers, retailers, investors and others all 

aontribute to the legal industry in one way or another. As this 

legal industry vorks to produce skins and meat, and expand 

markets, it is also building a conservation base for crocodili.ans 

and their habitats. Thus illegal trade constitutes a thorn in 

the side of thousands of people involved in the trade and 

conservation of crocodilians. It is rnost unfair to industry and 

counterproductive in nore than one way to conservation efforts 

to allovr even one illegal skin to filf a sale that \irould other 

wise be filled '.rith a leqal one.

As anyone \4rho reads the CSG newsl.etter knows, il-legal trade 

continues, but great strides have been taken to curtail ifleqal 

trade in the last few year. Probably the greatest remaini.ng 

probletn is ill.egal trade in cairnan skins. For exarnple, in 1990- 

1991, at a tirne when the trade in Cairnan crocodiTus skins froh 

a1l legal sources lras approrirnately 200,000 per year, at least 

tvice that nunber were traded iIIegaIIy. A single shipnent of 

approxirnately 250,000 skins lacking legaf documehts was shipped 

fron this island in Septernber 1991. The CSG has taken steps to 

address this issue by lrriting to appropriate authorities, and 

hopefulLy this situation r,rill be resolved soon. rrThe issue with 

Cainan j-s perceived to be a question of 1egality, not one of 

conservation needs.rr (CSG Newsletter, Vol. 10(4), p. 14). 

Although by definition, illegal trade in Cairnan sklns is 

counterproductive to the conservation efforts of producer 

countries in Latin Anerica, the CSG steering conrnittee considers 

that the I'key issue is that illegal skins are unfair conpetition 

for legal skins because the cot of production is Lor," and that 

therefore illegal trade underrnines legal sustainable use 

nanagement and threatens the legal traderr (CSG Newsletter VoL 10 

(4) p. 14) . 

Il-legal trade does not take place vithout the knowledge of 

importers in the receiving nations. The actions of such 

irnporters are in turn governed by tegislation available to CITES 

lnanagenent authorities in inporting countries. Problerns emerge 

lrhere that supporting legislation does requj-re effective 

j.nplenentation of CITES. The CSG is actively involved in both 

encouraging strict CITES inplenentation and rnonitoring the action 

of governmenl in this regard. The fact that Si,ngapore has 

Iifted its reservation on inconing Cainan crocodiTus skins is 

considered a very positive developnent. Hovever, there are still 

serious concerns about exi.sting stockpiles - for which plans to 

inventory and account for these skins are stifl forthcorning. (c. 

Hinley, pers. cornmun.; CSG Newsletter, Vol. 11 (1) , pp. 5-6). 

Another serious problen has been poor irnplernentation of CITES 

by Italy (CSG Nelrsletter, Vol. 11 (1) p. 9). As a result, a 

CITES standing Conmittee has recentfy reconmended that all CITES 

parties ban vrildlife trade lrith Italy (c. Hernley, pers. cohrnun.). 

Such rneasures are both drastic and unfortunate - particulary for 

those in ltaly vrho trade le9a11y. Nevertheless, such steps are 

necessary to prornote leqal trade by ensuring cornpliance vith 

CITES by crocodilian industries throughout the world. Similar 

pressure on Thailand has recently led to serious conservation 

neasures and efforts to inprove conptiance with CITES in tha! 

country (CSG Nevsletter, Vol 11 (1), pp. 8-9). 

Universal Tadqind. ---For several year, universal tagging of 

crocodilian skins and the products rnade fron theh has been under 

serious discussion as a neasure in the regulation of trade 

crocodilians and particularly as a measure to control ilfegal 

trade. At the Santa Uarta, Colombia rneeting of the CSG Steering 

Corunittee, this group gave its approval to a proposal, which had 

been developed by the CITES Anirnals Cornrnittee, u'hj.ch called for 

a universal tagging systen for identification of crocodilian 

skins. Tagging of finished products made frorn crocodilian skins 

1,43

I44 

tras considered both inpractical and unnecessary/ a6 it was 

recoqnized that tanneries and nanufactures are suitable points 

of control-, and tagging up to these stages was recomnehded. 

At the meeting of the Conferehce of the Parties of CITES in 

Kyoto, Japan (March, 1992), a resolution (Com. 8.23) was passed 

which effectively calls for the inplernentation of the cscsupported 

proposal and which basicafly applies the tagglng system 

that has been in wide use for farmed skins to aII skins in trade, 

including cairnan skins (CSG Nevsletter, Vol L1 (1). p. 13-14. 

The resolution effectively calls for a universal aging systen for 

the identification of alf raw and processed skins and parts 

thereof, including chalecos. flanks, bellies/ taiIs, throats, 

legs and feet. These tags ar€ to be applied in the country of 

origin and naintained, even during possible re-export, through 

the point that substantial processing and rnanufacturing has taken 

place. l.{ain features of the taqs are that they be self-locking, 

nonreusabl-e, resistant to heat and to the chenicaf and mechanical 

strasses of processing and nanufacture. Information on the tag 

i6 to be perrnanently stanped and include a unique serial 

identification nunber, year of export, and encoded data on the 

species and country of origin. The resolution also calls for the 

infornation on the tags to be replicated on the appropriate 

permits, records an annual reports. Further, the resolution 

calls for registration and licensing of irirporters and exporters 

and addresses the cost of inplenentinq and adninistering the 

system (CSG Nelrsletter VoI 11 (1), pp. 10, t2-13. 

The ne!, tagging systern is to be inplenented by June of 1993. 

At the request of the CITES Anirnals Cornhittee, the CSG has 

undertaken the task of developing the new tag, presenting it to 

CITES and the rnanagternent authorities and consuner countries. 

Development of suitable tags j-s underriray, with the direct 

involvernent of several CSG nenbers, notably F. Wayne I(ing and 

John Hutton. Part of the rationale for CSG .involvenent is that 

the development of the tag by CSG can serve as vehj,cle for the 

generation of funds for crocodilian conservation is under 

continuing dj-scussion. some of the problens faced by those 

developing the tags include (1) nationaf lalrs in sone countries 

require that locally produced tags be utilized, (2) establishing 

patent rights and hanufacturing processes, and (3) developnent 

of a suj-table licensing agreement vrith a rnanufacturer or group 

of rnanufactures. obviously rnuch renains to be done in the less 

than one year renaining before inplementation (P. Ross, pers. 

collnun. ) 

The development of the universal tagging systen nay be 

vielred by some as another layer of regulation - r^rhich nany in 

trade frequently consider undesirable. However, the universal 

and standardised tagging systern should be rnore properly vier^red 

as a giant step in the control of illegal trade. This carries 

benefits for our industry which far out{eiqh any problems 

presented by this additlonal regulatory neasure. Renovingi 

illegal skins from the trade will turn over rnarkets to the legal 

trade. where it rightfully belongs. It is perhapg of even 

greater consequence that ridding our industry of illegal trade

\'iII inprove our image with an environrnental ly conscious buying 

public and increase the number of consuners who wiII purchase our 

producers. This lrill advance the cause of those involved in both 

the trade and the conservation of crocodilians. 

Farrnins Species Bevond Their Natural Ranqe ---- This issue 

tlas enrerged several tihes in recent years, and a nunber of 

objections have been raised. Objections include concerns (t) 

that escape of exotic crocodilians being farrned outside their 

natural range could have disastrous ecological inplicalionE for 

Iocal fauna, and (2) that establishnent of farninq and trade in 

a species beyond its natural range - and therefore, very probably 

beyond the jurisdiction of enforcernent agencies overseaing CITES 

inplenentation for the species - could serve ttas a conduit for 

illegal tradel (Ietter frorn prof. llessel to the United states 

Secretary of the Interior, reprinted in the CSG Newsletter, VoI. 

10 (4) , p. 13). 

Recently, l9O C. niLoticus exported fron Zanbia to Spaid 

have presented a problen. Although they vere legally inported 

into Spain, the Spanish nanagenent authority rnrithdre; approval 

because rrthey were being poorly rnaintained". possible solutions 

to the problen are euthanasia, connercial use of the animals, or 

their return to Zarnbia at the expense of the Spanish authorities 

(CSG Neersletter, Vol. 10 (4), p. 12). This iflustrates that the 

farninq of crocodiliang beyond their natural range nay not always 

go according to plans, and nay present unusual problems for local 

CITES rnanagenent authorities. Such concerns. as well as the 

potential ecological and illegal trade problens discussed above 

should not be rninimized and require contj-nued attention by the 

csG. 

SI'MMARY 

The foregoing discussion highlights sone najor issues being 

faced by the trade and crocodilian conservationists. I.tany others 

exist and are being addressed in one vay or another at ahis cse 

neeting. with the naturation of our industry and the stillgrolring 

recognition that the interests of thost involved in both 

legal, sustainable conrnercial activities and crocoditiah 

conservation coincide, it has becone possible for people of 

different and once-conflicting objectives to i/ork jointly and cooperatively 

to pronote what is in their interest - recovery of 

crocodilian populations around the worfd and cornrnercial 

expl.oj.tation of these recovered populations under sustained use 

of nanagernent plans. This approach will ensure continued 

successes in crocodil.ian conservation, continued increases rn our 

knorledge of crocodilian biology, and expansion of our industry 

and trade. As in the past, the cSG has a vital rote to play in 

the future of crocodilian coitmerce and conservation. 

ACKNOWLEDGI,{ENTS 

I gratefully ackno\rledge the conments of perran Ross, Ted 

,toanen. cinette Hi.nley, Richard Luxmore, Don Ashley, Brian Vernon 

and David Wilken in the preparation of this presantation. 

145

146 

LITERATURE CITED 

Ashley D. 1990a. Monitoring tools: how far do lre go? In 

glgggrtileE Proc. loth Working Meeting, IUCN/ssc csc 

ueeting, Gainsville, Florida, April 1990. vol. 2, pp 

3LL-3\2 . 

Ashley D. 1990b. Market production and IAcTs review, In 

glgggltlles- Proc. 10th working l,leeting, IUCN/ssc csc 

Meeting, cainsville, Florida, April l-99o. vol. 2, pp 

318-319. 

Clepper, H. 1966. or.igins of Anerican conservation. The 

Ronafd Press co,, New York. 193 pp. 

Conovray, J. 1992. Eastern uildlife: bittersvreet success. 

National Geoqraphic 181(2) : 66-89. 

Gilbert, D.L. 1964. Public relations in natural resource 

nanagernent. Burgess PubI. Co., I'linneapolis, IVIN. 227 pp. 

Hines, T. and C.L. Abercronbie. 1987. The manaqement of 

alligators in Florj.da, usA. In wildlife nanadenent : 

crocodiles and allioators. G.J.w. Webb, S.C. ltanolis, and 

P.J. Whitehead (eds). surrey, Beatty and Sons Pty. Ltd., 

chipping Norton, 2170, Nsw, Australi.a, pp. 43-47, 

Hollands, M. 1987. The managenent of crocodiles in Papua NevI 

cuinea. In wildlife nanaqenent: crocodiles and alliqators. 

c.J.w. webb, s.c. I'tanolis, and P.J. Ltd., chipping Norton, 

217o, NSW, Australia, pp.73-89. 

Ishii, N. 1990. Global rnarket perspeclives: Japanese narket 

inplications of species and size class changes in the 

crocodilian trade. fn Crocodiles, Proc. 10th Working 1990. 

vol. 2, pp. 322-326. 

IUCN/I'NEP/WWF. 1991. Carinq for the earth. A strateqy of 

sustainable living. rucN/UNDP/wwF, Gland, switzerland 228 

Joanen, T. and L. llcNease. 1991. Managernent of the alfigator 

as a renewable natural resource in Louisiana. Ga. Dept. 

Natural Res. Tech. Bufl. 5162-72. 

Joanen, T. and L. llcNease. 1991. The development of the 

American alligator industry. Proc. Intensive Tropical 

Anirnal Production seninar, Tovnsville, Qld., Australia, 

August 1991, pp.9-28. 

Luxnore, R. 1990. Internationaf crocodilian skin trade: 

trends and soulces. In crocodiles, Proc. 10th working 

Meetingi. IUCN/ssc csc I"leeting, Gainsville, Florida, April 

1990. Vol. 2, pp. 3O2-305.

Messel, H. 1991. Why sustainable use? (A letter to the 

editor of Wildlife Conservation Magazine). Reprinted in 

Proc. Synposium on conservati.on and Utiliiation of 

wildlife, part If, World Environment and Sustainable Use, 

Tokyo, Japan, 3t l,{ay, 1991, pp. 22-30. 

Thorbjarnarson, J., H. l"tesse1, F.W. King, and J.p. Ross, 1992. 

Crocodiles. An action plan for the-ir conservation. IUCN, 

GIand, Slritzerland. 136pp. 

14'7

148 

The Infllr:nce of Dietary Prawn on l-he Produ(it.iol Pe.for.oance 

of Yorng Saltwal-er Crocodiles (C|.ocodyfus I,oro.sus ) 

Mark A. Slalon, Rri?rn P. Vernorr and Bange Ilon 

l.Jeri nland Hofdings Crocodile Farm 

Lac, 

P. O. Box 196 

Papua New cui ne;r 

Three shor"t-tern (2, 5 and 6 weeks) experinenls wef(j 

conduct,ed to det.erniDe the influence of dief,ary pr:rrn orl l-he 

production per.forDance of young (&verage iniLial botly 

weigbt-s of 55, 255.and 126 grams, respectively) Saltwat-er 

Crocodiles (Crocodyfus porosusl . Marine prawn of varaous 

spe(jjes were added al- lavels of 43,23 ^ d 20X of dirlL {!!et. 

natter basis), respective-ty. In all three experirneil.s, 

crocodiles fed prawn-co'ttai n ing diets tended to consume nore 

feed. However, body eeigbt gains of crocodiles fed prawncontaining 

diets were no greater lhan, or significantly less 

than, those of cr'ocodilas fed the control diets, Dry natter 

feed conversion by crocodiles fed Lhe prawn-conlraining dieLs 

eas significanlly poorer than that of crocodi]es fed the 

control d iets.

Distlibution, population structu!6 and som€ 

ag€ects of the ecology of the estuarine 

crocodil€ 

.lCrocodylus l'o.rosus S chneider 

j'n ) 

the KIias River, Saban 

Robelt. B s.tuebing 

Shahrul Anuar Mo.trd. Sah 

Biology Depa.tnent 

Uniwe!si!i Kebanqrsaan Ma]aysia, 

Sabah Canpus 

88996 Kora KinabaLu 

The estuarine crocodile lCracodylrs porosus Schneader) as w1de1y 

distributed from rhe e.s! coas! of rndia r; rhe northern Austratia, and 

usuall.y, though not exctusivety found in rivers un.ter tidaf inrruence, 

where sal:nity ranges from abour 5 - 20 o/oo (Messet, et at., t9s1). rn 

southeast Asia, irs conselvaiion srarus is uncextain, though genexatly 

assuned to be endanqered (croonbridge, 198?). Snatt scat-e crocodlle 

surveys in areas such as the Andanan rslands (rrrhitaker anal whaEaker, 

1918), have reported iarher 1ow nurbe!s. white no recenlly published 

data are avairable from peni.sular Mat"aysia, ,thitaker (19S4j i; a;;; 

and Cox and corLbek (1985) in Sarawak repolted rha! Ctoc.dyjus porosus is 

seriously threarened. sEuebing, er al. (1990) , Iro"".... to""O u 

substantial poputation in rhe Ktias Rive! in southwest..,., S"tun, u.O 

suggested lhat poor survey lechnaques such as brief coverage of rarhe! 

extensive aleas (because of Line constrainrs), nighr have grven 

misleading resutts _ 

In depth ecotogicat research on ciocodiles in Ausrratia Deqan rn 

1973 (Webb/ 1985), and continued through lhe 1980s. DisLriburion sluaties 

showed tha! breeding poputarions of crocodiles inhabjied bor11 tadar 

raveis and freshrarer $h'anps. \tuvenite crocodites wer:e found ro feed on 

clustaceans and insects (Taytor, 1979). and nigrare upstream from their 

nest sites, thoug.h the rnovernenrs w€re nor correlarert wirh fac!o!s such 

as salinily (Maqnusson, 1979). subadult C. patosus (> 1.2 n) orsappear 

flom breeding locatities or ,'Type 

r" habi!ars, apparenrly excfuOea ty 

the assresdive behavior of tarser in.lividuar. iri".."r ;nd vorricek; 

1987). 

In Sabah, crocodiles have been lecorded mainty flom estuarlne 

areas, plancipally mangrove habirars along !idat rivers, thouqn cnere 

are repolts flon at teast 100 km jntand (T. Lamb, pers. conm.)-rhe 

eltensive surveys done in the 1980s in sararak Oy cox ina conbek (19S6) 

and in sabah by whitaker (1984) and Kusuadi (1t85) qave genexalty tow 

populalion estimares. Furrhelmore, beyonat iough app.oiimations of 

abundance, lir!1e ecotosicat infornari;n ..r."i"t"j'c. p...r". 

acquiled. stuebing.et a_t. (1990) studied rhe disrribution oi c. p,,o"," "r" 

in the Klias River in sourhwestern Sabah, and showed that lhe Klias 

possessed a clocodile popularion density comparabte to thar round in 

some northern Aust!aIian rive!s. Since this ea!tier Ktias wor:k 

distinguished only three separare clocodite size cfasses, dara on !ne 

149

150 

dislribulion of the warious size cfasses was anriguous. There was also 

no dt!emp!. nade co capcure juveniles, or inv-sLigaLe rheir diel - 

Since Lhe vdlue of lorq Lern sLrvey work has been pLoven in 

Auslralia. an effort has been made to iniriale sinilar srudies in 

Malaysia. Long-term sludies furnish a far greater depth of understanding 

than do brief, extensive surveys (S!uebing,et af-, \990). The purpose 

of Lhe ptesenL uolk is lo flovide d no!- de ailFd picLJle ot Lha.cology 

of Cracodylus porosus fron the Klias River, in order to pelhaps qain 

insighls into its ecology and behavior elsewhere in Bolneo- 

.IIE--STUDIjBEA 

The Klias River is located in lhe southwest corner of Sabah, 

becween 5o18,N - 50 25.N to 1150 23'E - 1150 55,E approxinately 80 km 

flom Kota Kinabalu (Figure 1). Mlaverses approlinatefy l0 kn havinq a 

maxinum depth of aboul 16 m, and : tidal fluclualion at km 0 (Kanpunq 

Kota Klias, about 50 km flom the south China Sea) of about 2.5 m. The 

riwer meanders Lhlough peal swarnp rorest fo! about 60? its lenqth before 

giadlnq into upper nangrove vegelalion dominated by Rhizophora apiculata 

at approxinately km 12 (downstrean from Kota KIias) changing rathe! 

quickly between km 24-2'l Lr\ta a shoreline dominated by Nipah (Mjpa 

t tucLicahs) he'e reie 'Fd Lo es \e rowe narorove lobiL4'. Drling -he 

wet seasons (Novenlcer-,ranualy and May-July), the riwer naintains a dark 

coffee color, beconing increasingly greenish with rislng salinity durinq 

the dry season (February-Apxil). 

Aquatic 

inverLeb!aLe 

]ife is typical of nanqiove, with a nultitude 

and rjsh spac-ies invao-n9 he es' ua!y du!in9 

of marine 

hign -ide. 

Marine prawns such as Peraeus and Ca.idira sp..ale nunerous duling and 

imediately following wet nonths, whrle large freshuaLe! prawns 

ltiacrabr.chiun lasenDeLgji) b,.eo .n .bJndan-p clurrng Lhe early dry 

nonths (March-April).The manqrove crab lscylla seiraca) is comlnon. In 

spite of the apparen! abundance of nunerous marine fishes/ the rnost 

coiunonly caught species is a mangrove catfish (ADus sp.). The area is 

rich in sj lo.-i er (see wel.ls, er o,,/ lot)). rne tro,L p oainerL bird 

species are s!ork-bilted kinqfishers (Podargropsjs capensjs), bulbuls 

(Pycnonotidae) and qreen inperial Pigeons (DucuIa aeneaj. The two nost 

comnton primate species are lhe long-lailect nacaque (Macaca fascicu-rarjs) 

and proboscis monkeys (Nasalis .lalvatus), though the nunnlers of the 

latler appear to have declined over the fas! few years. The Klias nay be 

classified as a Type I !iver,e.9f., possessing sui!able bieeding habiLaL 

tor crocodiles 

The (Iias 

(Messe1, et a.l. 1981; ScLrebing. eL al., I990r. 

is connected via smalle! channels to the Padas Damir 

River system to the south. The western two-thirds of lhe KIias Peninsula 

previously fotned the Klias National Palk, which was gazetled in 1978 

and degazetted in 1983 (whitaker, 19B4) . Several locations about 15 km 

downstream fxom Kampung Kota (Iias were previously inhabited, but nost 

have been abandoned since 19?5. An estimaled 500 people nod live in the 

Kota Kl ids oreo. Piver cr."ic con,-sts rdinlr or Lne snull sampans of 

elderly 

ca!lying 

people who carry out subsjstence fishing. 

flom !hree 

-o 

siy pe.>o, s e F occasionatly 

Moto!ized boats 

seen L!dveIling 

eithe! to o! from coastal fishinq orounds. 

VITFRTAT,S AND METHODS 

A tolat of 14 spotlight surveys rere nade flom June. 1991 - April, 

1992 a1on9 a 37 km stre!ch of the Kfias River west-southwes! fron 

Kanpu.ng Kota Klias (Fig.1). This sane area, bordered downstleam by the 

mouth of the Sinapokan River, was surveyed in!ensively in 1987-88 by

Stuebing, e. al. (1990) . counts eere nade once pe! nonth, except during 

DecenLer 1991 (thiee surveys) and Janua.y 1992 (two surveys). Surveys 

were carlied out ar low tide at night (1900 - 0600 hrs) fronL a 4 m long 

fibelglass boat powered by a 25 hp Evinrude outboard engine at a speed 

or approximaLeLy ls kn hr-i. Because o ne L:r;ng or lhe L-des/ surveys 

were begun from June - October at Kuala Sinapokan {km 37) a! 

approxinately 1900 hrs. while surveys fron Decernbe! through April set 

out fron (9. kota Klias (km 0) at approximalely 0200 hrs. Two obselvers 

each using o l2v, 100,000 rp ror --Jh - srLveyecl one riverbank apiece. 

The phase of lhe noon, color of the river and relative activi!y of 

aquatic olganisms such as prrwns and flsh, rere noted. Individual 

crocodiles were approached until l hey fled o! Here captured, and !heii 

size esrirn.r-d o -ordino ro o.F o evan clz6 a pqories {addpred f-on 

Messel, et a.I., 1981): Class 1 (< 0.5 n), class 2 (0.5 - 1.0 m). Class 3 

{> 1.0 - S 1-5 n). Class 4 (>1.5 S 2.0 n) , class 5 (> 2.0 - < 3.0 n), 

class 6 (> 3.0 n) and Class Eo ("eyes only,t or larqe indiwiduals, often 

exceedinq 3 n in lenqth, which submerge almost imediately upon being 

spotted (I,rebb and Messel, 1979). clocodiles conprising Class 1 and 2 

indiv-duals wcr- dp- rrecl - a' aver ro ib.6 wi h a dip net, rher 

measured (tota1 and snout-venL Iength), weighed, sexed and thei! stomach 

contents renoved by a nethod suqgesred by Taylor, et ar. (1978)f or by 

stomach pumping with uater fron a 250 n1 nalqene wash bottfe.Stomach 

contenEs were then preserved in 103 fornalin fo! subsequent 

i.lanriri.:r i.^ . .rF rl snr 

side of the .lo.sal neck scuLes (rosette) with a ye]low a se!ia1ly 

numbered floy tag 3 cn in fength. Salrnity and temperrture of the 

surface sater were measuled aith a Kahl scienrific ModeI Rs 5-3 

salinometer, and a numbered fluorescent marker was tied to the 

vegetation at the site uhele the crocodile was first seen. These narkers 

were collected the following norning, and their locations marked to an 

acculacy of approxinately 100 n onto a 1:50,000 map of rhe survey. 

RFSUI,fS 

Between June 1991 and ApriL 1992. salinities a! Kora Klias ranged 

from 0 -.. 10.2 o/oo and fxon \'1 .4 - 26.5 o/oo at Kuala Sinapokan (kn 37) . 

The rlver varied frorn a dark coffee coror during rainy intelvals ro 

qreenish blonn during dry weather. virtualLy no rain fe11 in the survey 

a.ea fron January - ApriI, 1992, and both salinity and remperature 

varied little. A toLal of 153 crocodiles from five size classes rere 

observed with a mean value of 10.9 t 8.0 sightings per survey. The 

hiqhesl number of clocodiles sighted occurred in January, 1992, durinq 

which 25 individuals wele counred in lhe survey area. None were seen in 

lhe \ovenbe,, qol surv6y. nLnerous in fecemoe., 

1991 - February,1992, folloued by June - July, 1991 (Fiq. 2). Surveys in 

March and April, 1992 were hanpered by thick snoke from blrning heath 

and sc!'rb vegetation. 

Crocodiles of all size classes except class 2 were 

frequenlly in the lose! mangrove section of rhe rive!. more rhan 24 km 

do(nstrearn fron Kola Klias. 

151

t52 

1 

2 

3 

4 

5 

6 

7 

Tabfe 1 

size In) 

< 0.5 

> 0.5 

> 1.0 

> 1.5 

> 2.0 

> 3.0 

EO 

< 1-0 

< 1.5 

< 2.4 

< 3.0 

5.3 

12 

54 

9 

0 

0 

I 

!6 

d--i - 

20.5 t 

24.Q ! 

Ir'1 .2) 

25.7 ! 9.3 

4',] 

36 

6 

0 

0 

0.6 

10.4 

1992. 

Based on a minimum nunJrer of 25 animals (seen on 1611/92), the 

esLimaled popularion of rh^

5062 

5499 

5492 

20 DEC 

2 9 JAN 

17 .tAN 

29 JAN 

29 JAN 

28 FEB 

9I 

92 

92 

92 

92 

92 

x-o 

23 

23 

28 

28 

32 

32 

5 

8 

0 

2 

TLlSV l.nl 

38/- 

4I.A/t9_1 

42.5 /24 .5 

42.1 /24 .5 

4t.r/19.3 

42.3/20_O 

rable 3. DaEa ro! r,o Ctdss I J rvenj.e .. porosus 

recaptuled belween Decenrber, r991 and 

January, 1992. 

100 

160 

140 

150 

Stomach contents consisred of prawns (A!yidae: Catjdina sp.)l 

ciabs (ocypodidae and Portunidae) and smaft fish (Hemiramphidae, 

Englaulidae and Elopidae) . Crabs (Ocypodidae) nade up the highesr 

frequency of pley ilens, while henilamphid fishes nade up rhe Iargesr 

volume of prey (Table 4). A sp.ider was founcr in one stonach. white 

numerous stomachs (11) conrained plant fibres. only one stomach was 

Ocypodidae 

(caridira sp. ) 

Empty 

(No - srdnachs ) 

13 

1 

5 

I 

\2 

3 

2 

L1 

l 

3_ 

68.4 

5.3 

26.3 

5.3 

r0.5 

57.9 

5.3 

iza-1!t!e(nd) 3 

15. 5 

0.5 

4.5 

20.0 

2 .5 

5 .5 

160 

t?0 

L.1 

9.1 

1.1 

40.8 

5.1 

TI.2 

Table 4 Prey itens fion Class I and 2 crocodites by frequency of 

encounter (per stonach), ancl roraf votume and g 

DISCUSSfON 

s!uebing, et ar. (1990) found a slightly tarqe! poputation in rhe 

same area of the Kfias in 1987-88. The previous densiry estinate was 3.6 

kn -1 compared to the plesent 1.3 km -1. Conpared to tl. fo.*.. ,r.r.r,, 

the percentase of juvenite croco.iites (< 1.0 n) n:s increasea 

1.53

154 

substantially {839) in 1991-92 conpared !o 1987-88 (63t) ' ,thile the 

numbe! of EO sightingrs has decLined flon 12.63 to 10.4t. The estinates 

for the absofute populalion of class 1 aninals in 1991-92 nay, in facL, 

be lather too conselvatj.we. Based on a juvenile lecaPcule late of only 

12t, the popul.ation of juveniles alone could be lell ove! one hundied 

individuals (assuming that their behavio! was not seriously alreled by 

captu!e). Mark lecaptuie dala were unfo!tunately insufficienl for a nore 

reliable estimate to be made. 

The plolongred dry speLl affecting rhe west coast of Sabah since 

1989 (with a severe drough! during the filst four months of 1992) nay 

have been beneficial to the Klias crocodile populatlon, since floodinq 

of nests can be a najo! sour:ce of norlalily (Felguson, 1984; Magnusson, 

1982, I,iebb et al., 1983). Dry condj"tions can also inprove sulvey lesults 

(c. webb, pers.corun.), givinq hl9her population es!inales no! 

necessa!i1y !eflectlng a population inclease. Thus, the observed 

decrease in the estimated poputation since 1988-89 is likely !o reflect 

a leal decline. 

The absence of class 4 and 5 c, porosus in lhe Klias has been 

reported flon Australian rivers (MesseI and vollicek/ 1986; Messel and 

\r^-l:-cli loq?\ r.r

juwenires (T! < 38 cm and TL > ?0 cm), diffeling in aqe by abouts srx 

months. whether the larqe! juveniles remained near their oriqinal nest 

sites or not could not be assessed. rr is hoped rhar ,ith rhe 

contanuation of surveys in rhe larLe! half of 1992. anat the rnalking of 

more juveniles, that this question can be ansrered. 

The tocation of nesring acrivily in 1991-92 has evidenrly changed 

sirce 198?-88. Stuebing, er ai. (1990) found the greatest abundance of 

a]l juveniles (Classes l and 2) cenreled berween kn 9 - 19 downscrean 

from Kota Klias. By 1991 borh Ctasses apparenlty shifred aray flom kn 15 

an uppei nanglove habirat edged by Rrjzoplrara apiculata backed by a 

swampy plain. In 1991-92t C.Lass 1 aninals wele ctusteled in the tower 

Inanqrove/nipah zone? where they had been seen onty occasionalty in 199?_ 

88. Furchermore, even lhough the 1991-92 nean fo! lhe locatio; of Class 

2 crocodiles vas nea! km 17.0, rhese ]arge! juvenites were atiscributed 

in lwo distinct subgroups cen!eied at kiloneters a2 -a.nd. 26 (Fiq.3). At 

least four nests piobably eristed in.ta!e 1991, three atong kn 24 - 31. 

one near km 37. The exisrence of a possibte fourrh is _imptieat by a 

cluster of class 2 animals flom kn 9 - 12, alrhough juvenites olcrer than 

a few months nay have already migraLed fron rhei! areas of origin. rn 

any case, virtually alI of the .est sites of 198?-88 had been abandoned 

by 19 91- 92 . 

the presen! incleased percenrase of juvenite C. porosus as de]l as 

their aI!ered distiibution coutd be related to a poaching inciclen! {hich 

occurled Marchi 19887 in t{hich 48 clocodites of valious sizes were 

either killed or removed from our survey alea. This incident rlad no 

obvious effect on the popularion in rhat year, since a foltor_up survey 

in Aprj-l, 1988 revealed compalab]e numbers of clocodites stilt present 

(Stuebing, et a-I.,1990) - In June-Jufy, 1989 however, the rive! was 

surveyed three rines, and only lwo crocodites seen. Numbers relu.Deo ro 

198? fewels by June, 1991, showing ao atmos! identical patte!n (conpaled 

to 1988) of juwenile abundance in January, 1992. 

Recaplure rate of juvenile crocodites (< 1 n) was nuch ress (12&) 

than that leported by Magnusson (21t), !hough Maqnusson incruated 

clocodiLes as large as 1.2 n io his sanpte. Slnce we obtained only 25 

juvenile C. porosus, conclusions regarding thei. ctiet are tentative at 

best. However, since infonnation of this kind is virtuatly nonexistent 

outside Austlalia. we have decided ro comenr on ir hele. 

In contlas! to the findings of Taylor (1979) in Aus!lalia, no 

insects or other insecr-like prey, aparr from a single spiate!, were 

found in rhe stomachs of juvenire c. porosus flon tht Ktia;. Atrhough 

the Austlalian aninal,s were taken from valied habirats, and were targe! 

(including animals up !o 1.2 nt), insects can be ploducts of seconoary 

digestion, and can be nis!akenty interpreted as sromach conLenLs 

{Jackson, et al.tl914). Taylor atso reported crabs as part of t'he diet 

of juvenile crocodites, an

156 

snapping wiLdly at plauns vashed uP on the ntud bank by the boq 

wave of the survey boat. The narked seasonalily and striking abundance 

of atyid plawns makes iL leasonable !r assume that reproduction in C 

porosus, aL leas! in Bolneo, could be influenced by lhe prawn cycle 

synchrony could be achieved via pho!operiodic cues, {hich though nuch 

leduced 

Class l 

near lhe equator, a!e probably stil'l detectable. Since Klias 

are already at ]easr 45 clays old (based on size; J.Jongr, pers 

conm.) when the prawns first appear. liming is ptobably nol mediated by 

nut!itional or olfac!ory cues associaled with Lhe prawns themselves. 

Another high frequency food iten, and a laxge porrion of the lotal 

volune of p!ey taken was the hemiranphid fish lprobabLy Dernogenys) 

known locally as "ikan jolong-jolonq", or halfbeaks. These are smalI (< 

100 m) surface feeders of the shallows comon to es!uarrne and manglove 

environmen!s. They are presenL throughout Lhe year' but night have peak 

..rrcr:ied with lhe only a single 

juvenile crocodile (5? of the lolal) was found tilh an enPty stomach A 

nuch highe! pe!centage (15.6') was !epoi!ed for Australian juveniles 

(Taylor, 19?9). rhe difference may have been caused by seasonal factors, 

since all of the K]ias juver,iles ercep! two wele collecced during Peak 

pley availabiliry, e. q.. Decenbe r-February . 

The three recaptuxed class 

than 300 n of their release point. 

1 tuveâLes were found Hithin fess 

This observalion collefates with lhe 

finding from sulveys (Decenber 1991- March 1992), in which the 

distribution of Class 1 aninals along the river changed little until 

Aplil, 1992. 1n April/ mo!e small crocodiles aPPealed in the upper 

nanqrove area, and relarively ferer downsLrean/ as if they had begun to 

shift away florn theii nes! si!es. In northero Aus!ralia, the tendency or 

juvenile crocodiles less than six months o1d not Lo ]eave their initial 

capture point has been re9orted by Nagnusson (1979), who also observed 

the migration of small juvenite c. porosus upsrream fron nesting aleas. 

Based on linited information fron tHo recap!ured individuals, growth 

rales of KIias juveniles are slowe! Lhan rhose reporred fo! captive 

CONSERVATION 

Surveys in the Klias River since 198? have shown its population of 

' | 1a'p. ies seen 

between years nay reflect actual increases or decreases of crocodiles 

within rhe area. Diffelences be!dee. counts over several mon!hs, 

however, are probably caused by !he novements of the crocodiLes between 

the river and adjace.,L sdamp, a.d nrt necessaril.y by morLality. Since no 

comrielcial fishi.g cakes place, nor!ality in younqer aninals is probably 

) - rr-ir . 

pelhaps only once in several years. The appatent dtop in nunbers seen in 

1989 coutd not be quaniifaecl sioce the surveys were discontinued duling 

that period, bul lhe Iarge percentage of juvenifes seen in 1992 sugqests 

that the Losses of crocodiles were real, aod tha! the population is now 

The conselvation status of CracadylDs po.osus in Sabah (and rn 

Bolneo as a whole) remains in qdestion. wfiLakei (1q84) and Cox and 

Gonbek (1985), pain!ed a rathe! bleak picture of the state of Bornean 

5 years in d r ive, noLgn o -,-. -ocodi.es imply nat Crocodylus 

1- '; '! urbance 

....r i..a - d .'.1-1rva--:r." once in 

seve!dl yed!s', I-o4e\e , Lle :nsloious eLlccLs o perslstenr Pooching

should not be discounled. Habitat disturbance in !he forn of propose.l 

marine aquaculrure projecrs (in !he Ktias, at least) atso wili pose a 

se!io!s thxeat. Neverrheless, furrhe. conctusions concern.ing rhe plesen! 

and fulule slatus of Crocadylus porosus in Borneo shoutat be based on 

intensive survey !ork in specific areas, ideatly by Iocatty based 

scientrs!s and witdlife offi.e!s. Brief, extensive surveys, even by 

expexts, usually cannor provlde rhe type of assessment required fox lhe 

Prooer mdndgerFnc oI - he .!-c:es 

ACr(NOI.iI,FDGEMENTS 

We would like to rhank the Biology Departnent and Faculty of 

science and Na!urat Resources of !he Universiri Kebangsaan MaIaysia, 

sabah canpus for assisrance and supporr_ ne woutd also tike ro ihank M!. 

Mahedi Anclau/ DirecLor of the sabah DeparLment of ,iil.ttrte tor 

pernrssron ro ca.ry out rhis project. Financial suppor:r tor rnrs 

research \^'as supplied un.ler a gralr ffon rhe John D. anA Cartrerine r. 

MacArthur Foundation for which we are grarefut. ALso, we ntuch appreciaLe 

cne assrs!ance oi Lucv KirLsui, rwaDg Lariff Mohaned, Dulait cusiri, 

Handd Ahmad, Laqani Sahid, lisa yong, t"tilun paLek, Kasa Sah of UKM5, ancr 

Mr. Tan of KoLa Klias. Tha.ks :Lso rhe Sabah Medicat Dept., especiatly 

Suai.lin and Lenan for rany kindnesses. FinaLiy, M.. Lee iryanti, Shabdin 

Long and Shahrol Hamzah deserve speciat chanks to, ,"sc.ring our outboard 

engine fron the bortorn of a crocodile infesred xiver. 

Bayliss, P., c.,J.w. !'rebb, p.J. r.rhirehead, K. Dempsey and A. Snith, 19g6. 

Estimaring !he abundance of salrwater cro"oaires. Crocodytus 

porosus Schneider, in ridat we!tands of Lhe Northern Te!!.i!ory: a 

rna!k recapture experimenr to correct spottigh! coun!s to absolute 

nunbers. and rhe catibrarion of heticoprer and spor1igh! counrs. 

Austr. wildl. Res. 13:309-320 

Cox, J. and F. combek, 1985. A prelininary survey of Lhe croco.iite 

in Sarawak, East Malaysia. rUCN/!'WF project Repor! No. 

M^t 74/85, r'roird wildlife Fund Mataysia, xuara r,unpur. 

Ferguson, M.r{.J. 1984. rhe reproducrive biology and embryotogy ot tle 

clocodilians. In: rhe Eiotogy of the R€paitla, vol. 14; cans, C. 

and F.S. Bittet (Eds.), Acactemic press, r,ondon. 

Groonlclidge, B. (compiler), 198?. The rUCN Amphibia-Reptitia Red Dara 

Book, a con!ribuLion ro rhe Giobal Environmen! Mo;iroring sysrem, 

Part I. rntelnarionat U.j.on for rhe conservarion of Na!ur;, cland. 

Jenkins. R.tr.G. and M.A. and !.orbes, 1985. seasonal va!j-arion rn lhe 

abundance and dis!riburion of crocodytrs porosus in rhe tidat Eas! 

Alliqato! Rive!. Northern Ausrr:Lia_ In: The bioLoqy of Aus!ra_Laan 

flogs and lepriles, Gri9q, c., R. shine anA H,Ehnann tros.l. 

Royal zoological society of Ne, sourh riales, sydney. 

Kushfan/ J-A. and F.J.Mazorti, 1989. poputation bioloqy of lhe Anerican 

crocodile, J- tjetpetal . 23 lt) ,.j -21 . 

Kusuadi. S., 1985. A survey of rhe starus and ecotogy of the estuarine 

crocodile in seve!ar rivers in sabah and s;;aaak (in Matay) _ 

Honors year rhesis, Deparrnent of Biotogy, Universi!i Kebanqsaan 

Malaysia. Sabah Canpus. Kora Kinabalu. 

Magnusson, w.E., 1979. Dispersat of hatchling crocodiles Craca.tyjus 

porosus (Reptilia, crocoditidae) . J. Herperot. !3:22-/_23:r. 

15',7

158 

Magnusson, w.E., 1980. Habitat required for nescing ot Crocodylus 

porosus (Reptilia, crocodiliCae) in Northe!n Aust!afia. Austr. 

wi]dl. Res. "t :I49-I55. 

Magnusson, !i.E., 1982. Mortality of eggs of the c!ocodite tCtocadyfus 

polosus) in NolLhern Australia. J. netpetal. 16:i21-130. 

Messe], H. and G.C. Vorlicek, 1986. PopuLation dynanics and the sLatus 

of Cracodyfus porosus in the tidal wate!ways of Nolthern 

Australia. Aus!r. r'rildl. Res. 13:71-111. 

Messef, H. and G.C. vorlicek, 198?. A population 

porosus j.n the t.ida1 watelways of Nolthern 

model fo! 

Australia: 

crocodylus 

Management 

inplications. In: trildlife nanagement: Crocodiles and alliqators, 

webb, G.J-, S.c. Manolis and P.J.trhitehead (Eds.). Surrey Beatly 

and sons Pty. L!d.in association silh lhe Conservation Comission 

o' Lhe NoLEnern ler riLo'y. Syon.y. 

Messel. 1,, G.C. Vorlicek. l,r.J, Greer an.l I.C. Onl"ey, 1981. Surveys of 

\F. ' ra..:. -alia anJ 

thei! crocodiLe populaLions. Monograph No.1: The Bly!h-Cade]l 

river systens study a.d Lhe .:,a!us of Crocodylus porosus in tidal 

waterways of Nor!hern Ausf ralia . Me!hods of for analysis and 

dynanics of a population of C. poro.sD.s. 

Stuebing, R., c. Isnail and K. Sallih, 1985. The ecoloqy of crococlile 

att.cks in Batanq Lupa!, Sarawak. Salarak Mus. J., 55: 189-214. 

Stuebing, R. G. rsmail and H.C. Lin9, 1990. The disLribution and 

abundance of the estuarine crocodile lCzocodylus porosDs 

Schneide!) in the Klias Pive!, 5abah. Paper presented a! the 

International conference on foresl bioloov and conselwatior in 

Borneo, Kola Kinabalu. 

raylor, ,J.A. 1979.The foods and feeding habits of subadult Crocody.tus 

porosus Schneider in llorthe!n Austlalia. Austr. wild]. Res., 

6: 34?-359. 

Taylor. J.A., G.J.w. webb, and w.E. Magnusson, 1978. Methods of 

Crocodilidae) . J. Herpetol. 12 : 4r5-417. 

tlebb, G.J.W., 1985. Saltwa!er crocodile consetvation in !he Noithe!n 

Te!ri!ory. AusLr. Ndt. H's!., 21:458-461 . 

webb, G.J.w.and H. MesseI, 19?9. wariness in Crocodylus porosus 

(Reprilia: Crocodilidae). Austr. trildl. P'es. 6.227-234. 

webb, G.J.tr., G.C. Sack, R- Buckwo!th and S.C. Manol,is, 1983. An 

examination af croca.ly.L,s porosDs nesls in two Norlhern Australia 

Ireshwa er swanps, u;Lh on onolysis or embryo norLdli!.y. Austr. 

wiIdI. Res, 10:571-605. 

welfs, D.R., A.G.Maishal] and J.B. ],orry, 1975. A surwey of rhe proposed 

l(lias Nalional Park. soulhwest Sabah. world wil-d]ife Fund 

Malaysia, Kuafa Lunpur, 

Whitaker, R. and z. whiLaker, 1978 . A prelimanary survey of the 

saltwalet crocodile (Cracodylus porosus ) in the Andaman lslands- 

J. Bombay Nat. Hist.Soc,, 75:43-54. 

whilaker, R. 1984. A prelimina!y survey of the crocodiles in Sabah, East 

Malaysia. TUCN/!lWF ProjecL Jeporr no. 3127. wo!Icl wildl.Lfe Fund 

Mafaysia, Kuata Lumpu!.

AB S T RACT 

Aprit, 

A total of 14 spotfight surveys aere carried 

1992 along a 3? kn porlion of the Ktias 

out fron 

River in 

June. 1991 - 

nortnwesEern 

Sabah, Mafaysia. surveys were done a! 1ow ride berween 1900'- 0600 hls 

from a 4 m survey boat ar 15 km hr-1 by Lwo observers. A torat of 153 

sighrings wexe made, dhich varied berween 0 - 25 per survev {mean:10.9 

I 8.0 siqhtings/suivey). rwenty-five juvenite c!;codires 

"ere capturea, 

with thlee recaplules. Calculated densiry was 0.8 - 1.3 individuats kn_ 

1, while the estinrated crocodile popularion nas 39.8 a 9.5 io! the 

survey area. Percentage sightings accordinq ro size class wele: Class 1 

(< 0.5 n): 4?t; class 2 (0.s - s 1.0 m): 369; ctass 3 (> 1.0 - 1.5 m): 

6t; Class 4 (> 1.5 S 2.0 n): 0g; Class 5 (> 2.0 < 3.0 m): 0gr Ctass 6 (> 

3.0 n) : 0.69; Class 7 (Eyes Only): 10.4:. rhe snjaltest juwenites (class 

1) were found exclusiwely in !he tower manqrove/nipah secrions of rhe 

liver. appioximately 24 - 37 km dosnsrrean from the survey srar!ing 

point, and the mean their disrribution diiferecl siqnificanrfv fron cnaL 

of larger (class 2) juveniles (t-tes! for Dnpai!et sanpres, ;

:-- 

3 

7 

6 

b 

6 

{ 

F 

D 

2 

= 

, 

"l: 

'I: 

c)l 

II 

\\ 

I 

\70 

3 

L 

D 

2 

F 

\ 

D-O 

ct|n 

FD 

at 

ir 

=D 

alE 

agl 

\t , 

o xE 

c 

-l 

-+- z 

I 

=

EI 

E 

a 

tr 

Class 3 

cl.sss ?(Eo) 

Jun Jul Aug Sept S€pl Oct 

Nov Dec Dec Dec J.n J.n Feb l.,ler Apr 

Survey montb * 

Ii$rre 2. I{um!e! oI sj.ghtirEr per montL 61ong the 

3? lm sr.rrvey area ol the Ic.ias River, 

Jurre 1991 - April, 1992.one Cl6ss 6(>3 m) 

crocoalile sas seen in October, 1991. 

*Additlontl 

survegs vere done in December 

(19, 20 & 30) 1991 ,rndJenu:rU l7 &29)1992 

to tmprov€ :5eessment ofctass 1 juvenjles

162 

w 

fft 

n 

Cl:ss 1 

Cllrs I 

Cl3rs 2 

cl:rs 7(€0) 

o 5 6 9 r?15 182l ?4 21 30 33 36 39 

Distance (km) domrstresm lrom Xota l1ies 

fj'gNre 3. nistribution oI crocodite sightj.r€s 

elonq 3? ln swvey area, I(Liss River. 

* A sjngle Clisr 6 ()3 m) crocodile v.5 

at km 23.

Crocodile Numb€rs on kke Karibq Zimbabwe and Factors 

Influencing TteE 

R.D. TAYLOR 

WWF Mdtispccics Project, P.O. Box 8437, Causeway, 

Harale, Zimbabwe 

Dj' BIAKE 

Natal Park Boar4 P.O. Box 127, St. Lucia Estuary 3936, 

South Africn 

atrd 

J}. LO1€RIDCE 

Departnent of Biological Sciences, University of Zmbabwe. 

P.O. Box MP 167, Harare, Zimbabw€ 

163 

Niie crocod e (ergsqly!]! qijglisrs klreuti) populalions in lhe middle Zambezi river s)5tem have 

recovered over the past three decades from an earller hunting pressure. Although c.ocodile numbers 

have clearly increased at Kariba, Zimbabwc, curreDt udliTatiot regimes rely on sustainable harvesting 

of crocodile eggs frod the wild and from areas where there is also considerabl€ disturbarce ielated 

to ar iEshore gilhet fishery. There is a need, therefore, to provide quantitative evidence of preseDt 

popu.iatioo abuldance oq Lake Kariba and efforts to do so are described. Frtimales of relative 

abudarce usi.g sample courts from the air, and partiatly corrected for visibilily bias witi glourd 

counts (spotlight cou{s at night), provided a population estimate of 10 02O ! 2 306 (S.E.) for fte 

crocodile population aloDg the southem zimbabwean shorelioe of lhe lake, corresPonding to a de.sity 

of 5.0 crocodiles per lm. Tte r€sults obtained were cleatly inlluenced by th€ envirotrmetrtal coiditiols 

pertainhg at the time of the survels, with lake level appea-ring to be the most important factor 

idluencing coutrts. NuEbers were sigtrificatrtly higher in protected areas (Park and Wild Life l,and) 

compared with unFotected areas (Comrnunat l$d). This is la-rgely a reflection of crocodile 

disturbance ard Eortality rclatiDg to the giUne! fEbery. Errors and lirnitalions associated {,ith tho 

c€lsus t€chdques us€d are discussed in relation to mamgement ard modtoring ne€ds for r€latively 

simple, stardardizid indices of abundance to which estimates of precision can tE attached 

Introductiod 

The Nite crocodile population od the zatDbezi river prior to 1950 was probably relatively uldisturbe4 

and of unlaown size. siEilarlx the habitat also remained undisturbed until the dammiDg of the 

zambezi at Kariba gorge in 1958 led to the fo.mation of Lal€ Kariba along the cwembe trough of 

the middle Zambezi valey. In Soutb€rn Rhodesia (now zimbabe,e) prior to 1 1, crocodiles wero not 

classfied as game aninals, aad only the landholders permission was required to hunt then (Blal€, 

19?4). Durhg the 1950s crocodiles were heavilv exploited along the Zambezi, as elsewhere i! frica 

(Cott, 1 1). For example, one hunt€r shot 2 0m crocodiies on lhe Z3mbezi above the Vicroda FaIs 

during this tin€ (G.G. Hatl, pers. comm.). A number of crocodiles were also captured on the same 

stretch of river for liie export to (he U.S-A. (Macautay, 1960). The late Prol G. Boid (Pers. comD ) 

was present when 29 crocodiles *ero shot in one night on tbe lrkola river, near Binga. He furthcr 

inform€d ooe of us (.IPL) that over 4 000 animals were shot by lwo teams of hunters on the middlc 

Zambezi in the rwo years before lale lturiba started fillins.

1,64 

It is probably safe to assume, thereforq that adult crocodile numbers on the Driddle Zambezi w€Ie 

low itr the early 196Os (Chil4 1944. ErEn in 1964, soodiles on kl(e Kariba were sti being shot 

by perso rel of th€ Department of National Park and Will Life Management (DNP&WLM) 

(Tlrodrso& 1972) because Lhey vr€re inte erbg with gilner fishing At rhe same time bowcvc!, a 

fledgling crocodile farming industry was being establish€d o[ l,ake Kariba on the initiative of a few 

pioneering itrdividuals (Blake, 19a; Chn4 1%7). This provided strong cons€rvation reasons for 

protecting wild crocodile populatiors bec.use the bult of stock held on crocodile farms was derilcd 

ftom eggs collected h the wild (Blake ad t veridgc, 195). Nercrtheless, there have been legirimate 

queries that continu€d egg collectioD (as w€ll as harcbling collectiotr in the initial few years) woutd lead 

to the de.line of the l.ake Kariba crocodile population add abandonment of tlrc for$er breeding 

gounds (Cott and Pooley, 1972). 

Furthermore, tittle is known of the adverse impacls ofbotl crocodiles and the inshore gillnet fishery 

on each other (Bourdillon, Cheater and Murphrce, 198t. Alrhowh mortaliry of c.ocodiles caught in 

fishing nets appears relatively low (Ke !uir, 1 ), there is littlc tolerance on the part of fishermeD 

towarals oocodiles because of the dam€e caBed to nets, often when crocodiles try to remove fish 

(Chimbuya and Hutton, 1988). Consequently nests and eggs are often destroyed wheD found (Hutron 

and Child, 1989). 

It was to address these concerDs and to provide a more reliable basis for the management and 

monitoring of the La-ke lQriba crocodile population rhat rhe preseot work was underlken. This 

involved the development of appropriate standardised survey and census t€chniques (Baylisi 198?; 

Graham, 1988) for estimating crocodile numbers. Use was made of sample couDts of adult crocodiles 

from the air, with partial correction factors derived usiDg spotlight counts at night Ground counts), 

made by boat along select€d lengths of shoreline. 

Study area 

The filling of l.a*e Kariba was complele by tq63. fo[owiog closure of lbe gorge ar Kariba in t958. 

Siluated ar 2O",|{) East - 29'3 Easr a 16"28 Soud - t8"6 Soulfi, rhe lake is orientaled south west - 

north east ovei a iength of some 3m km and covers a total area" comprising five mtural basinq of 5 

500 sq. km (Fi& 1). Its length along the southem Zimbabwean shorelirc is 2164 km. The lo$er 

eastem basins are characterised by a higbly denrlritic shoreline with a numb€r of large river estuaries 

whilst tow"rds the up['er western end of the lake, broketr billy couDtry of the Z^mb€zi escarpment 

borders the shoreline along much of its length. Consequently, crocodite distdbution as reflecled by 

nest sites (Fig. 1) is centred on the major ri\ers enteing lnke Karib4 with at l€ast 607, of nest sites 

occurriDg in the eastem basin between the Sengwa rfuer and Kariba itself (area A in Fig. 1). 

Whilst lnle Kariba itself is a recreational park within Parls and Wild Life Land, the only shoreline 

protected in respect of crocodil€s is some 3m km along the northern boundary of Matusadona 

National Park between the Sanlati ard Ume rivers. There is how€ver, a cohmercial iDshore fishiag 

conc€ssion bordering 30% of this Park shoreline (Fi&t). Inshore fishing els€where talcs ptace along 

much of the remahder of the shoreline witl artisanal fishermen livinq i{ Communal Land borderina 

the lake. Unlimired collecrion of crocodiie eggs preseorty latrcs ptace ;der DNp&WLM permit aloni 

the entire southem shoreline of the lake except for Matusadona National park. ell the major riveri 

which support crocodile breeding arc closed to public access from rhe lale durilg tie breediog sea.sor 

annualy b€tween 1 Septemb€r and 31 Dec€mber (Anon., 1991).

F 3 a aof 

?,-€i 5€j 

-i 

9(, 

a{t 

*il$Eq€ E 

5 *=rE ii;'! 

i,!ii+e3i 

E.=s€ 5f '-9 

E F E:i !E 1 

3ET;i=E€, 

z;:tt>;E 

tH€ii;*E: 

!-' -! S+a€ E+ 

!?r;s gg s* 

i -: E.i ei: s 

; 

3 

CD 

= 

NJ 

6 

$ 

-\' 

t 

L! 

3 

co 

E 

I\J 

s 

165 

.io

166 

Methods 

Surv€y desig! 

The southern shoreline of Lak€ lturiba was stratilied very broadly into a relatively high density stratum 

i.o the eastem basi! bet*een the Saryatr and Sengwa rivers wit-h a fifth somewhat lower deDsily 

stratuD comprising the remaining shorelhe to the west. The eutire shorelire was dividcd into 81 

sample uni6 (SU) demarc-ated by ph)sicil featur€s readily recogDizable from the air. The leqth of 

each SU varied f(om 4-48 lsn, dependirg on tlrc rature of tie shor€lire, with a mear leDgth of 17.2 

! r.05 km. withiq th€se SU, smaller sub-sample un\ represcntative of low, nedium a-od hig! 

crocodile density areas, were chos€n for spotligk counts madc by boat al night (Parker and WatsoD, 

19?0; Gralam, 1988). Surveys commenced in 19'8 ar.d lE79 along the shoreline of Matusadona 

Natioml Park. Itr 1982 ard 1983 repeated counts usiag sampliag Foc€dures covered sohe 407, of 

the southem shoreline in the eastern Kariba basir (Area A itr Fie" 1) and in 1985 the procedwe was 

e)cedded to the entfe shoreline of Lale Kariba withir zihbabwe. All coults *€re made in July, 

duriDg tle cool-dry winter period. At this timc of th€ year, visibility js edlanced as crocodiles sp€nd 

much time either oo the surface of the wat€r or basking on lar4 particularly during calE, su!!y da's. 

For each survey, prevailing weather conditions, water level, water and air teDp€ratures during dght 

counts and 24 h maximum and midmum temo€ratures were recorded, 

Crocodiles withia rardomly selected SU were counted f.orn the air using a high.ring Cassna 180 

aircraft. Flying height was maintained at about 50 n abov€ water level at speeds of 10G160 km/h. 

Suneys were flovn usually bet\reeb (Bh30 and 15h30, with a midday breat from 12h0G14h00. A 

oavigator-recorder noted all qocodrles seen by two fear seat ob'servers ard guarded against double 

counting. The tim€ lal€n to fly each sector *?s recorded and crocodrle numb€rs and distdbution 

plott€d oo a Eap of the suFey area. 

crourd counts 

It is recognised that a signific? propo*ioa of crocodiles remain uncounted from the air, especially 

animals lers $ar 2 m total lengtn (Gra.ha.g|, 1988). Counts of red/orango eye reflectioos from a 

spotlight at niglt car be used to reduce thrs soucr of error in accuracy. staDdardized night coults 

witbif sub-saople units were made from an opcn 5 Dr boat powercd by a 5 h.p. outboaid engtne. The 

crew consisted of an obB€rver in the bow ne* to. but ia froot of a recorder. and a driver in the stem, 

The obserr€r, using a had-held 12 v spotlight producing a narrow 30 watt beamJ countcd qocodil€s 

by sweepiry lie beam throrgh a 180 arc at thc surface of the water. 

The surv€y boat \vas operated about 30-50 m from, ard para.lel to the shoreline with occasronal us€ 

b€bg made of a sEall 6 v headlahp for navigational purpoGes and to avoid subnerged and protrudi.g 

trees. A fairly colstant boat sp€rd of .1 km/h was mainhhed while seatching for crocodiles. 

Rellective Earters were us€d to demarcite th€ stan a.nd finish of saEpled sub-umts, lo enable their 

accurate plotting on charts ard subsequ€nt Deasuiement of distances covered. 

GrouBd counts w€r€ undertaken corcurreotly with the ae.ial surl€)s, during periods of litde or rc 

moor! usually tretwe l9h00 and 3h00. In order to minimise crew fatigue, survey tise dur;ng both 

aerial and trisht counts did Dot exceed 2-3 hours duration.

EstimatioD of abundance 

16'7 

The est;Dation of crocodile numbers follo*ed the expressio6 and procedure described by Joly (1 9a; 

1969b) aixd Parker and Watsotr (190). Assumiry that ground c.uds reflect an improved populatioa 

count, they may be applied to aerial counts to provide a pani.l estiEate of bias with \r'hich to adjust 

the aerial counr even thowh such application degades p.ecisiod (craham, 1988). 

An estimate of bias, R, is giv€D bla 

R=Ly/Lx=y/x 

whete x = the spotlight count of animals in subsa.aple udts aDd 

y = the aerial count in subsample coun(s. 

Counts x and y come from a $na[ subsample of udt$, bur even within t-bese, night couats cortred only 

a portion of tbc subsample udt. Co""equeltly, tbes€ counts, opress€d as density p€r km of shorelile 

were extrapolated to give x valu€s equivalent to the total length of the subsample unit and the 

coresponding y value. 

Tbe eslidate of X, the adjusted number of anihals ir rhe population, is giv btr 

\rhere N = the total numb€r of saldple units in lhe survey region 

y' = the obseFed number of animals in the nain saDplc urits 

n = the number of units in the subsample ]ll€d for the bias 

estimate 

nr = the n|,.Drber of ullits itr the main samole. and where 

j' - 

v'/ o' 

Where total counts were performed, N = d Jo[y (1 9a) provides expressions for the calculatiotr of 

statrdard errors applicable to the estimates of R and X. Estiffitiotr of abudallc€ in tfis x,ay is 

analagous to Jolys m€thod 1 which ideally requires equal-siz€d sample units but which can b€ applied 

to une{ual-siz€d sampl€ units. However, a higher varianc€ associated witi the estimate ca.n be 

€xpected. Error estimates are p.eserted as standard errors (S.E.). 

Results 

Population esdmates 

x = N.y/R 

Estimates of crocodile nu-mbers obtained in repeated counts a.long th€ same l€ngth of shorelioe in 1982 

atrd 1983 were compared using the varianc€ ratio t€st (Baile, 1959) and found to be not signific-antly 

diff€rent (d = 0.33). These estimates we.e Berg€d by *eighting them brersely to thc size of their 

variances (No(on-Griffilhs, 1978) so that the nerged estimate a.Drounred to 6 427 t 2 3o2 crocodiles 

(Table l). Tbe area sampl€d li€s in the eastem K-ariba basins between the Sanyati and Sengwa rivers 

and includes the protected Matusadooa National Park (Fig.l) and can generally be considered to 

support high crocodile densities, which amounted to 7.6 adldals pei k[| of shoretne from the.esults 

obtained.

168 

Table 1. PoBulation estimates of oocodiles in L3lc IGribE 1982 & 1983. The popularion esumale 

is X and its standard error, S.E 

Year Shoreline 

s.E. s.E. 

1982 

1983 

M6rged 

length (kn) 

7m 

850 

850 

7AB 

6 182 

64n 

2121 

13'0 

1 r51 

(%) 

Density 

(uo./km) 

In 1985 when the entire sourhern shoreliDe of LaLe Kariba ,xas samDled, ao estimat€ of 10 020 + 

2 306 *rs obtained equivaletrr ro a deDsiry of 5 crocodiles per km oi shoreliDe (Table 2). hdus;o 

of tie entir€ shoreline reducrd ortrall density slightl, but rct utrery€ct€dly, which suppons the idtial 

s&atificalion based oo nest concedtrations as indicat€d by egg collectio[s (Fig. l). 

Table 2. Poputation estirbat€ of crocodiles h Lale Kariba, 1985. The populariod estimare is i nld 

its standard error, S.E. 

Shoreline 

lenel! (kn) 

30 

22 

18 

s.E. s.E. 

Eo 

8.9 

7.6 

Density 

(no./to) 

1985 2Un 10 020 2 18 

5.0 

The aerial sampling fraction fo. the two earlier counts itr 1982 and 1983 exceeded 80%, borh rn terms 

of SU counted a length of shoreline sarnpled (Table 3). Th€ sub-smptiry intensiry of rle groutrd 

couots amoudted to 147a. In 1985, ceNus of the entire shoi€line reduced sampling iDtersity to 38% 

from the air and 9% oa tb€ ground. 

Table 3. Sampling inteDsity applied to count oocodiles h 1982, 1%3 & 1985. 

1982 

1983 

1985 

Total 

SU 

81 

Estimares of bias R 

No. E" Shor€line leagth 

Total Counted 

39 

31 

85 

91 

38 

79 

850 

2 000 

There ]'as an overall dowtrward bias in excess 

of 80% which was higbly significanr (p < 0.m1; Mann- 

Whitney U = 8; n = 19; Sieg€|, 1956). How€rer, €stimates of bias between ccnsuscs over rhe diff€rctrt 

years were trot significantly diJlerent from €ach other (Table 4) although a marghal de{line in bias 

rvas correlated with fal h lake level (r = - 0.96; P < 0.05; 1 d.f.; FE. 2). 

7A 

7& 

80 

86 

38

169 

Tabtc 4. Btimates of bias @; used to adlust aeriut o{ crocodil* on lrle Kariba tocether with 

stadard enors (S.8.) andconaspoad;ng lale "ouds levetr (m asl) for rhe ycar of survey. n = su$ 

saspl€ siz€ 

Year Bias i s.E. kIe IJ\€l 

t2 

1983 

1985 

o 

E 

6. 

.g 

c) 

o 

J 

/.85 

4E4 

1E2 

180 

0.135 

0.143 

0.151 

l. = 0,996 

p

1'70 

T6 

6 fi) 

(88 500 

t86 

01 

1.0 

(8t 100 c, 

-o 

E 

s Y t'8 2 

"9 

a, 

v (0 

J IBo 

l.? I 0 

19?8 1980 1982 1991 1906 

Ycar 

200 

-9 

6 o 

o 

() 

100 

F;g. 3. Total nurnbers ol crocodilcs (closcdcirclcs) 

countod in July along lhe shorclinc of 

Ma(usadona Na(ional Park betwcctr1978 

and 1985, togcthcr with corrcsponding lake levcls 

(opc" circlcs). 

'tatrle 

5. Crocodilc nnnrbcrs and lakc level irr Matusadona Nationol Park, 1978 -1985 

tna 

197) 

1982 

1983 

1985 

(Aorial) 

134 

ll8 

395 

3t8 

248 

Dcnsity (ground @unt) 

(no./km) 

i.rs 

8.89 

7.50 

5.9 

Lake level 

(m asl) 

486.87 

4a5.37 

4€4.26 

481.61 

479.58 

Water lcvcl is an important variablc aflcclhrg crocodilo coonls (Woodwa'd and Marion, 19ti; I{utotr 

and woolhousc, 1989) and appcars lo havc s(rongly iroucnced lhcse rq\ults. Thc lake lcvelwas stablc 

during lhc 1970s (Fig. 5) whcn thc first lwo survcys wcre undcrlaken. From 1981 onwards lake lcvcls 

bcgan to fau, beforo stabilizing again in tbc nrid-1980s. Prior to 1980 the littoral and shore zoncs of 

lhe lakc were charactcriscd by rxell developcd aquatic and scmi-aquatic macrophytes (Bowmrker, 

1973) wiih liltlc barc ot cxloscd substrate, cithcr abovc or bclow thc wa(cr. Such plant covcr would 

havc rcduced the visibility o[ crocodilcs. Frrthermorq lhc lakc levcl peakcd in J nc so that (hc 

amount ol cxpos€d subslra(c in J!ly, whcn col|nk wcre nade, was minirnal.

1',71 

By 1982, Lake Kariba had fallen nearly 3 n exposing considerable stretches o[ bare subslrare. 

Established beds of aquatic macrophltes were strandcd high above water lcvel and tbe rate of lale 

level rccession precluded the establishmeot of new plant cover. This situation persisted during 1983, 

c 

J 

'c i! 

g 

-o Eco 

E o 

() 

t00 

300 

?00 

100 

Crocodila denslty (no/km grourd counb) 

Fig- 4. The relationship belween crocodile densities cnlculated from gound counts and nudbers 

counted from th€ air. 

1i 

E."- 

(, 

-9 

_1 

I 

l 

| = 0.995 

p < 0.01 

Fig 5. Moathly lhcruations in l.*e levcl ar Krriba berwe€n 1978 and 1985. t-evcls correspond to ihe 

iQriba datuE (source: Zambezi River Aulhorily)

172 

altbough there w?s some develqpncnt of aquatic \,!gatatio.. While tle 1983 meatr estimate of 

crocodile dumbers was lower th"! tf,at of 1982 thc dificrcncc wa3 not signiEcant (s€€ above). Thc 

faling late level clearlyc anced vbibilig and asritortcs ofdocodile Dutrbcrs w€re consequently high 

(Table 5). Froo 1984 oni,ards, tlc late lc'/el bcgar to stabilis€ agai!, *hich was ac.oEpanied by the 

re-establish.B€nt of aquatic wgetation. This probably rcducci visibility ajrd contributed to a lo*,cred 

coutrt of crocodile numb€rs itr 1985. 

Protcctior a.rd iEhore gilhet fishiry 

Thc 1982 survey data wcre ls€d to €xamine ciocodib truebers ard d€nsity a.lodg prot€cted (National 

Park status) and unprotected lcbgths of shorelhe (Connunal laDd status), Egg collection for 

commeicial crocodilc rearing purpo6es tates place arruely in ths latter, *hich also supports an 

anisaml ilshore gill not fishery (Bourdilotr g tL 198t. By 1985 ro egg coUection had laken place 

h Matusadona Nationa.l Parl but therc i! a co--crcid fislilg codctssiod along some 86 lm of the 

northerD shorelirc of this Part (Fig, 1). Cooparirolrs could tbcrcfo.e be 6ade betw€en protrction 

and lon-protection as c,ell as bct*ten 6shed a|rd non 66bcd s€glrclts of th€ shorelirc. The dillelence 

in crocodile rumbers betv,/eer protected and noo prolect€d areas Ctable 6) was highly sigdificant (p 

< 0.001; X'1= 49.67 wit! 2 d.f.). The mean crocodile deDsitt itr thc conBercial fishiDg ?one of 

Matusadom National Park (approxidately 30% of the shoreline length) was 0.82 t 0.14 crocodiles 

per l(E coEpar€d to 1.91 t 030 over the rest of rbe shoreliDc, a dilference which was also significa.nt 

(P < 0.05: t = 269 with 14 d.t). Thc ov€ral density *as 150 ! 0.23 crocodiles D€r km of shorelin€. 

Table 6. Coaparison of crocodile numbcrs b€twccn protected and noa-prorected lengtbs of the Lale 

Kzriba shorolinc h July 1982. The prore.ted area is Marusadona Narioml park 

Obs€rv€d lumb€rs 

Shorelire length (km) 

Deasity (no./km) 

Discus.sioo 

Abutrdance 

Protect€d Nod Protccted Tota.ls 

395 

a2 

135 

4t3 

8A 

0€3 

808 

7m 

Geaera.lly, socadile counts tend to be very impr€cbe estiDates of population size atrd at best catr 

provide oaly a.D irdex of abundarc€ (Bayliss, 198?; Grabam, 1988) unless c.Dplicated, time-consurling 

and oftetr er.p€osir€ inrrstigation is urdertalen simultaneously (Hutton and Woolhouse, 1989). 

CoDventional surve's ale usually litrl€d to maDagemeot objectives which requile trend data with which 

to Eoditor chatrg€ ir abundaacc i[ relation to the managenredt treatme . That many crocodile 

$lrvels havc rot met tlis requireEent is well appreciated. 

The preseDt work provides tbe following. 

(i) Estima(es o{ abu$&nce for crocodiles on kke Kariba that werc previously not available. 'I'hese 

estimates are likely to t€ biased dox'nvards bccaus€ not all crocodiles ar€ s€en during ground counts 

od accout of both envilo iental facrors (Woodward and Mario4 1978) and visibility bias (Bay'iss, 

tg2

198?). Hutton and Woolhouse (1989) found the mean proportiotr of their study population counted 

from the gound to be 0.36, which, when applied to the Kariba estimate of 10 O20, provides ar 

adjusted estimate of , 833 crocodiles. 

(ii) Sample counts with estimates of pr€cision, and repeatability through standardization of tech$que, 

both of which are esseDtial requirements for monitorhg treods il1 abundance. Although mriaftes ate 

high, the very simitar estimates obtaired frorn repeated counts in 1982 and 1983 support the use of 

the Eethodolog/, at least as a monitoring procedure. 

t'l3 

(iii) A starting point from which to improve and refine app.oaches to mooitoring crocodile abundanc€ 

on Lake Kariba. These should provide tread data which can be subiected to regression analysis, which 

is most usefully obtained from €stimates of relative abundance, either from the air or ground or both. 

cratran (1988) criticises th€ practice of adjusting aerial counts rdth a correction factor obtaided ftom 

ground counts, largely because precision is impaired by having to add the rtiances of the two counts. 

Nevertheless, th€ coosiderable bias evid€nt in the aerial counts $rggests such correclion has to be 

made, to at l€ast approach a realistic estimate. A total of 579 oocodiles was actually counted from 

tbe air duriDg the 1985 census yet th€re is a minimum of 800 females of breeding size on Kariba 

(DNP&WLM records). Practical considerations also suggest that on large water Mies (> 1m Lm 

shoreline tenglh) aerial c€nsus is the most cost-effective and efficient method of sure€y. It would be 

extremely tedious and lime-consuming to even sample count the entire Kariba shoreline using ground 

counts. Part of futue refinement, of course, should include better stratification which would improl€ 

sampling efficienry. 

Crahan (1988) consid€rs nest effort a sup€rior measure of indexing crocoalile abundance compar€d 

to conventional counts but this approach has ,€t to be used at Kariba. The use of nest effort merits 

attention padcularly sitrce present unlimited egg collection would greatly facilitate its application, We 

would further sugg€st however, that nest effort and counts be used in tandem as complementary 

measwes of abundance, given the practical difficdties associated with both. 

Lake lcvel 

Whilst La-ke Kariba redained relatively stable during the 1970s with atr annual lluctuation of 2-3 m, 

tbs cyclical pattem was severely disrupted during the 1980s due to b€low average rainfall over much 

of the southem African sub-region. Rainfall in the Zamb€zi catchment det€rmines both the trend and 

annual amplitude in lake level. Thus inflow to the lake has reduced considerably and lake levels have 

steadily dropp€d (Fig.s). Fluctuations in lake lev€l greater than 3.5 m per atrtrum or 0.6 m pet month 

either de,stroy or retard establishcd hydrophytes whilst re-emergence of hydrophfes is fostered by 

Ilucluatio6le$s than 2m amplitude (Bowmaker, 1973). Large fluctuations cl€arly €nhance visibility, 

atrd hence counts of crocodiles. Converselt sma nuctuations will reduce both visibility and counts. 

Silcc rainfall is a stochastic variable, predictability of lake level from year to year will remaid 

utrcertain. This in tum wil affect the repeatability of crocodile countE at le3st until a sequence of 

Dormal rainfall years occurs. Such unce(ainty needs to be taken into ac.ou in the desig! of futue 

srrveys. 

Conllicts in resource use 

Mutual conllict exists between inshore fishing and both the conservation atrd utilizatio! of crocodrles 

on Lake IGriba. lrwered densities of crocodiles are appaient where fishitrg occurs compared with 

adjacent non-fish€d arcas. In economic terms the fisherynd the ctocodrlo indusfy aPp€ar

1',74 

coftparablc witb eachnrher {Chmbuya and Hutton, 1988). Although a progressive rural economic 

relorm 

.progamme, 

Campfire (Ma(in. 1986), which places much importance on wildlifc as a 

productive ecooomic base. is being irDplenented, wry few fisherman on the Kariba .takcshorc know 

tne varue ol a \^4td crocodilc. Whilsr this is cssentially an institutional problem, oui concern is that 

will undermhe the long 

::l]111IC. T"fU" 

term sustainabitity and hence econornic viabitity of the 

crocodrle Indusrry. It was an economic hconlive that provided lhe basis for ttre conseretion of 

crocodiles in the 1960s and unless such incentives now ajso rcach fishermen, the conservation of 

crocodiles on Lake Ikriba is potenrialty threatened. 

Acknowledgements 

Much of this work was undertaken whilst rwo of us (DKB and RDT) wcre emptoyed by rhe 

Department of National Parks & Witd LiIe Managemenr, Zmbabwe anrl is pubtisUeA witt t_he 

Dire{tois prrmission. L-ogisric, supporr for the 198j survey was pa(ly funded by thc University of 

zrmoaowe lcsearch Eoard. Numerous colteagues assisted wirh the physically dcnanding task of 

coun_ting crocodiles from the air along a torturous shoreline and we arc especiaily grateful to Rupert 

and Malcoln van der Riet for rheir skilfut piloring of rhe aircrafr. 

References 

Anon., _(1991). Parks & Wild Life (Hunting of Cncodiles and Removal of Crocodile,s Eggs) Norice, 

191. Stalutory 

Insrrument No. 7 of 1991. covernment of Zimbabwe, Harare. 

Bailey, N.TJ. (1959). Staristic"l Mcthods in Biolog. English Universiries press, London. 

Bayliss, P. (1987). Survey merhods and monitoringwithin crocodile managcment programmcs. Vild!& 

Maqagess!]!_ 

_ _ : CJocodiles a!!! Allisators. (Eds.) c.J.W. Webb, S.a. Manolis a p:. Wtr;rehead, 

pp. 157-175. S. Beatty & Sons, Austratia. 

Blale, D.K._(1974). The rearing of crocodiles for commercial and conseryation purposes in Rhodesia. 

Rhodesia Science NE!! 8, 311-314. 

Blake, D.K anq higridCg, J.P. (1975). The rote of commerciat crocodile farming in crocodile 

coiservation. Bioloqical Cor'ser.?lion B, 1-z72 

Bourdi or\ M.F.C., Cheater, A.p. and Murphree, M.w. (1935). Srudies of Fishing on tnke Kariba. 

Mambo Ocaasional Papers, Socio-Economic Series tto. zO. l,tamU fr-s"Earare, 

Bo*maker, A.P. (19?3). Hydrophtte dynamics in Mwedda Bay, Iake Kariba. Kariba Studies 3,42_59. 

Trustees of the National Museums and Monuments of Rhodesia. 

Child, G.F.T- (1987). The management ofcrocodites in Zimbabwe. Witdlife Management: Crocodites 

atrd AlligatoT. @ds.) c.J.w, webb, S.C. Manolis and t:. Wtrirehead,lpllo4z s. neany & 

Sons, Austlalia. 

Chimbuya,.S. and Hutton, J.M. (1988). The conflict between crocodites and inshore fishing on Lat€ 

Kariba. 

ryggsdilgs 

of the SADCC workshoo or Crocodilc Manaeement and U-tilization. 

Kariba, Zimbabwe. 2-6 June 1987.

Cott, H.B. (1%1). Scientific rosults of aD enquiry into the ecology and economic status of the Nile 

crocod e (qg!or!!Its niloticus) in Ugarda ard Northern Rhodesra. Transactions of the 

Zooloqical SQgieltf q! lrndon 29, 211-356. 

Cott, H.B. and Pooley, A.C. (1972). Ibe {3tlD eI crocodiles !s A&!!3. IUCN publ. (N.S.) Suppl. Pap. 

No. 33, 1-98. IUCN, Gland. 

Games, I. (1990). The feeding ecolo$' of two Nile crocodile populations in the Zambezi valley. D.Phil. 

thesis, University of Zimbabwe. 

craharn, A. (1968). The l-ake Rudolf crocodile (Crocodvlus niloticus Laurenti) population. Report to 

Kenya Game Department, Nairobi. 145 pp. 

cralam, A. (1988). Methods of surveying ad monitoring crocodiles. Proceedines a! tre SADCC 

workshop g! crocodile Manaeemedt ald Utilization. Kariba, Zimbabwe. 2-6 June 1987. 

1'75 

Hutton, J.M. and Child, G.F.T. (1989). Crocodile managemenl in Zimbabwe. Crocodiles - Their 

Ecology, Management aad Conservation. IUCN publ. (N.S.) pp. 62-79. Gland. 

Hutton, J.M. and Woolhouse, M.EJ. (1989). Mark-rccapture to assess factors affecting tbo p.oportion' 

of a Nile crocodil€ population seen during spotlight counts at Ng€zi, Zimbabw€, and the use 

of spotlight counts to monitor crocodile abundanc€. JqEa! q[ Apolied Ecoloqv 25, 381-395. 

Jolly, c.M. (1%9a). sampling nethods for aerial census of wildlife populations. East African 

AEicultural ald Forestrv Journal 34, .16-49. 

Jo y, c.M. (1%9b). The treatment of errors in aedal counts of wildlife populations. Eas! African 

Agicultuml g!l! Forestfl Joumal 34, 50-55. 

Kenmuir, D. (198). A wilderness ealled {a!iba. Wilderness Publications, Salisbury. 

Macaulay, R. (1960). erceodilg Trader. The Adventurers club, lrndon. 

Martin, R.B. (1986). Communal Areas Management Programme For Indigenous Resourc€s 

(CAMPFIRE). Unpubl. Report, Branch of Terrestrial Ecology, DNP&WLM, Hara.e. 

Norton-criffiths, M. (1978). Coultinq Animals. Handbook No. 1. Handbooks on techniques cunently 

used in African wildlife ecolog. (Ed.) JJ.R. crimsdell. African Mldlife kadership 

Foundatio& Na;obi. 

Parker, I.S,C. and Watson, R.M. (r90). Crocodile distribution and status in the major waters of 

western ard central Uganda in 19,69. Eqs! Alrirlg Wildlife Joumal 8, 85-103. 

Sieg€I, S. (1956). Non-parametric Statistics &! the Behavioural Ssletee!. Mccraw-Hill, New York. 

Thonson, w.R. (1q72). A field guide for estimating the overall length of tho crocodile. lg!!ga! e! &Q 

Southern African wildlife Manaeement l\segbfe! 2, 27. 

Woodward, A.R. and Ma.ion, W.R. (1978). An evaluation of the factors affecting night-light counts 

of alligators. EIgsEEIlilgs of the southeastern Association of Ebh aagl !U!!U!fg Aeencies 32, 

291-T2.

l't6 

Ultrasound I Evaluation ol the Fotlicle Developm€nt in Adult Femde 

Broad-nosed Caiman (Caiman lati rostris) 

Miriam H. Vac. L.M. Verdade:. C F. Meirelles. R.E. Larsen. F. Michelotti. 

M.C Ranget. C Z Salem & .A.. Lavorenti 

CIZBAS / ESALQ 

University ot Sdo Pa'rlo 

Caixa Postal O9 

Piracicaba 134OO 5P BRAZIL 

1 Ulhasound machine: Aloka No. 210 - DXZ t3.F Mhrl 

? Authol to +vhom 

correspondence 

should be sent

L77 

Ultrcroundl cvrlultaon ot tho lollicle dcvalopmcnt in adulr lcmalc broad' 

nosed caimans lCaiman.lElitoslthl 

Miriam H. Vac. L.M. Verdadc?. C.F. Mchc$as. Ft.E. Lllsen. F. Michclotti. M.C. 

Flangcl. C.Z- Salem & A. Lovorcnti 

CTZBAS / ESALQ / Universi$ ol 56o Paulo 

Cx. P.09 Pkacicaba 13400 SP SRAZIL 

I ntroduction 

The reptoductive cycle of crocodilians has been shown to bc more complex 

and evolved than that of other reptiles. Their sexual matutity is size and age 

dependent. and normally- malcs grow up fastet and g€t largcr than lemales whan 

adults. Generally. caimans. alligatots and smallcrocodiles reach iexual mahnity at 

a relativcly smaller size than gha als and the lalgcr crocodilcs [Mcgnusson ct al'. 

19891. According to these authors the r€ptoduetive clEb ol crocodlians can ba 

distdbuted all ycar lonq. like faioln eigqqdihrt Ellcqdi[u in $-|E Amazon bashi 

in two distinct Feriods. like Nilc crocodile h Uganda and Kcnya wharc some 

lcmales nest in August 6nd othcrs in Dcc"mbcl; or iust in a rcstrictcd pctiod of thc 

year. like the other species. 

The Arne can alligator. which occupies the North limits d dl crocodilbns 

distribution. has ! vEry delimitcd rtploductive cyclc. lt stltts h Malch with the 

beginning of gonadal dcvclopment through hormonal aclion. whcn Eit arid wrttl 

temperature rises. Copulation occuts from lateAprilto ea y May. ?Yith the egglaying 

peak occu irtq in a two week period inJunc [hot ycarsJ orJuly (cold yearsl. 

Eccording to Jorhan & McNeasa [1979J. Tharc is a rapid &cline of tha adult 

female ovaries and adult malc tasticles soon after eggiaying and duing thc 

incubation pe od [Lance. 1989). 

I (Ita.ound mtctrin.: Alokr No. 21OO)

178 

There ir too little iniorrrration on the broad-nosed caiman reFroductive cycle. 

The first captive breedinq result. may elu*idaie some important aspects such as: 

nestinq. incubalion and hatching Feriod- clutch ei:e- etc. f,rerdade et a1..19321. 

However. Er.3zilian captirre colonies of the lFecies har.e a lor.v level of hatching 

success possibly due tB rnanagernenl mistalies ,3nd,ror high eninrals infertility rate 

perdede & 5antiago. 19521 The folla,.+ing factors.dn nlfect the snimals fertilitv: 

genetica. age [si:e], illnesses. and niarra1:ternerrt practices such as. sF8 ratia. 

stocking density, breeding pen de;ign. ,.tress- and feed m6nngen-'ent 

[L:ardeilhdc. 

1 SS9l. 

Ultrasound erral"ration of tl're fullicle de'reloprr'ient may indicate the st.ge of a 

female in e certain moment of its repraductive cycle. lt can also be used to 

evolu€te the inlluence c,f erogenous hormones ond the possible correct time t'l the 

,rrtificial insemindtiar' as described by Lersen et al. [19S8]. 

Materials & Methods 

We evdluated the follicle develooment of 1l adult females lrorrr November 

l9g0 to January 'l 991 . and of three adult fernales hom Augusl 1 331 to January 

1992. We tested bath '..entrtsl and l€teral aFpro.rches '/+iih the rdt.aeound 

transducer. 

PMSG ,ruas tested to induce ,rvulation in five females, The mean dose of 

'17.53 

lu/kq ranqing from 13.43 tD 20.0O lU/kq was di\.ided into sir! or seven 

applications lrom early November through the middle of Becember or Januor_t'. 

Flesults & Discussion 

t 

BEth ventral and lateral ultrasound transducer approaches rlrorked well in 

medium fernales ismaller than 90 - 95 cm in sncrut-vent lenght) but the lateral 

approach worked better in larger ones because of the osteoderms c'f the belly skin.

119 

During the first leal lust t'.+r, lemales leid eggs and arrother one ovulated but 

did not lay eggs. The othets showed a sholt develrpment followed by a tegtesstcrn 

of the follicles. 

Duting the second period iust one female ovulated and laid eggs. InAugust 

the lemales had follicles of 1.0 to 1.5 cm diameter, arrd ovulation occulred about 

'14 

weeks latet, when the follicles reached 3.0 to 3-B cm diarrreter [Figures 1 and 

21. 

The tested PMSG doses did not produce follicular development with 

ovulation [Figure 3]. Three possible teasons ate: 

At The dose of FMSG was insufficietrt to induce ovul.:tion: 

E] PMSG was used l€tel than ihe best period for its action. SeFtertrbel - 

Dctober mdl be bettel than No'/erBber " DecemFer.: 

Cl Periodic handling lor administration of drugs could have produced a level 

of stress incomDatible with nolmdl ovarian lesponse t.r exogenous hormones. 

Female reproductive activity occurred over a much btoader time Period thart 

observed in the alligator. \,vell-developed shelled eggs. ovulating eggs' and 

enlerging ovarian ova +!ete EbselVed during the sarrre day in difletent females 

within the colony. This may make it more dilficult lor 'l regimen of hormorrdl 

stimulation to produce synchrotrised ovulation in capti'/e colonies 

Acknowledgements: 

Fundo Mundial oara a Natuteea " \.aA{F, Pt':'cesr No. 664D"03?. 

FundagSo de Ampato i Pesquisa no Estado de 56o Paulo-FAPESF. 

Process No. 50/2832-0 

Institulo de Pesquisas e Estudos Flotestais'IPEF 

Fundag6o de Estudos AgI6lios "Luiz de Queiroz" ' FEALQ

Litarsture Cited 

Cardoflhac. P. 1989. Husbandy and prev€ntaliva medicine practicac th€t inctease 

reproductive cfliciency of breeding colonies of a$igators. Aqurcultula Mnlket 

Development Aid Program. Flodda Depa ment of Ag culture and Consumer 

Services. Tallahasse. Florida. 25 p. 

Joanen. T. & McNcasa. L. 1379. Time of cgg deposition for thc American alligotor. 

Proc. Ann. Conf. 5.E- Assoe. Fish & Wildl. Agencies 33:15-19. 

Lance. V. | 989. Fteprod,rctivc cycle of the Amcrican alligator. Amer. Zool. 

29[3J: 999-1 01 8. 

Larsen, Fl.E.; Cardeilhac. P. & Godwin- F. 1988. Atilicialinsemination in the 

Amcrban alligato. Proc. Ann. Mcct. Soc. Thciogcnoloqy- Orlando. p. 285-292. 

Magnusson. WE.; Vliet. K.A.: Pooley. A.C. & Whitaker. Fl. 1989. Flep*oduelion p. 

118-135. ln: Floss, C.A. [Ed.]. Crocoddes and alligators. Eoldem Press. Sdverwaler. 

Aushalir. 240 p. 

Verdade. L.M. & Santiago. M.E. lgt|2. Status of captive population of broad-nosed 

caiman lCaiman !1ig]1igl in Brazil. Proc. Xl Wolk. Mcet. Croc. Spec. Group. 

IUCN ' Tha worH Con*crvation Unbr. 2 - 7 A€ust 1992. victoria Falls, 

Zimbabwe- 

: Lavorcnti. A.; Michelotti. F; Flangel. M.C. & Cullen. L. 1992. 

Captiv. bleedng of hoadnoscd caiman [CliE{ 

lati]ortrid in 55o Par,rlo. Btazil. 

1992. Proc. }(| Wo&. Maet. C.oc. Spec. Group. IUCN - The Wodd Cs$effdtion 

Union 2 - 7 Ar,rgust 1 St|2, Mctoda Falh. Zimbabwe.

o 

U' 

o. 

E 

= 

' 

It 

I 6 

E 

o 

c 

o 

-9 qtE 

EO 

.9o 

,9 

'o 

de 

EO 

CIE 

= 

o 

: 

Eo 

€c E 

-e8 g 

.9> S 

=+. O 

eg E 

Fe 

..o 

o 

t 

.9 

lr 

at! 

*i 

pi 

c.: 

ct: 

F iC, 

rt isr 

oic 

o i.9' 

tr!c 

r\ !3 

| \ io 

I ll 

II 

It 

| '- 

.ix 

i 

I 

lo(troNrO.FloO 

c)(\to 

o 

uJ 

l! 

b 

Z. ri 

1l 

f 

@ 

:* 

+ 

181 

i 

+^ 

lo 

s T* 

6E o.p 

r|.-' 

+ 

Orr 

zl 

F 

(, 

o 

T 

rt 

I

182 

o 

o- 

E, 

= 

3 

E o(! 

o 

o 

o 

I (! 

E 

o 

I 

c 

o 

E 

o. 

o 

o 

o^ 

lt)o 

=> 

=o 

'i sy 

oi 

o 

l 

.9 

l! 

E 

(, 

6 o) 

o 

o 

(|) 

G 

o 

o 

E 

(! 

d 

o 

E 

ol 

rt 

o 

(9 

o 

uJ 

-i--'- ^ * I 

l 

tl 

I 

-t llJ 

ll! 

o 

o 

IrJ 

o 

o z 

F 

o 

ol,r,J 

./t 

a f 

J 

f 

- 

(Y' 

rt 

I 

)ts 

I 

qt 

NO 

*E 

'E 

lo 

+ 

I I

o 

o c 

: 

= 

o o(! 

|D 

o 

-g 

(tt 

E 

I 

o 

E 

o 

I o 

o 

o 

.9 

o 

l! 

(f) 

o 

.9 

tJ_ 

E 

() 

o 

q, 

() 

q, 

c 

o 

E qt 

!l 

(5 

0, 

E 

u, 

C{ 

-,t-. 

rt? 

@ 

l llj 

l* 

I 

I 

I 

zl 

- 

ro 

+t 

{ 

x 

{ 

rt 

IL! 

I 

a, 

c)o 

il *E 

orE +o 

,| |ts 

o z 

-._ _r lr 

o 

oo 

$l 

lt 

l 

{t 

I 

I 

18i 

o 

0 

.l 

{r 

p 

o 

o 

z 

o 

z

184 

F,i]p!..lt,Ar IaN i l-'ftri o' t!-{E gFt:IA-L=D 

II{ IHg !.]F|JEZUELAN FLAIN 

VELAZCO, A. (*) anci J. AYa\ZAUi.JENA 

.]AIIlAN 

* Servi€io AL{tc,nomo PROFAUNAT Hdf. Camejt}; OeltLe, m(r.:;rr.rr|]iir(, 

Cara€as 1010 Ven€,ir: Ltf- I a 

" 

IntroduEtion 

Sin{:r: lrrirlll, f trn r:fifimf,)rni,ir.l !,rf-,irtl,_rl:i.lrrr r:il f il.:: r-L.rr LFr 

tr.rha (liI(nr l:.'iIlfl(l rr j.rnar] ' 

[B_r_1]!:,1, 'rri r'r,,!l: 1', h,i:: be.:+rr ':1i;vi',1r] 

irr..r ,rt: I .,Ir!i,. 

Th,:l 1,!!r{ I j r!, t,11. I pi: r- lr.iI : N:ir , 1 , 

$f {r ,rririf:frlJ rrIfr'l:r:,] 

' J_rr,rw 

' 

,,. , i. , 

i:intv ;,,r. i ;:,. l. : ,,,r 'il,i, , i,:., l' 

'rh.rf' 1.fli.i iri. i,. ,ii i, ,, +rfr', .,r',, ii] !, rl 

]t ;.i:, fir.t ;.t:l rirr" L f:r :ri lr , I '.i, 

IV uri lf ir , ,ir,:,r. 

i, 

I rrr. 

, r-q(i i.;,tr(i l,i.i! i-! I rtrrjr |rl 

,ri 1.! a,l 

: i;ir,' . :ii:r l ,i r'i , i l'il 

r,j i:,;trrr r irr:rt i rr- 1r t:rr i: r.r ii !i, i: : r j 

']]/gi]lr]]if'|l|;,];.;.:,.'.il;]l]1,' 

rriii)rr-nl lji! llll]l|i ,:,. r:,!,ri i,,, .r,, I irL l. l..rii 

'i: :i 

" , ii:"1':|rl lr 

I t. ,,r I : :r,r : ;,1::r rr,i. ., f,,,.,i t rLi,.r't,ri |i,:"i1jrt.. 

,i , L ,/ , i 

i,.:jL. 

lrl ,. 

rl ,r,!il 

'., 

lrl I 

i'',.: r,:i 

f:i Iir,i.,l. 

ri, j; ii.r.l ,.i irr,.r 

..r.:.r lrf'!-'r':jlri: lrJ 

" i ir:i;rli 

ir,i,; :;llrii': i!i,, ;1. 

rl,i ii.;::, i , r,:f ..: :lt:Lrr 1..,1 :"r I : .tirL.!i,,,r, .iiitr,:::!

HatFrials a.ld HethodotEqY 

f'liLlhtI/ r €:fl!,'i.rti tn{rf: 

qonsllc:i-r Li!'fi yder:!: il Fr:l 

185 

1ac:e dLrr:rnrl tfr€e rJry !ru.r!i.r$.r'1 r!.rtr 

1 tr Ay 1r?91 anrj j anlrar'/ 1i'| :lr.lci' 

lii, ,:1,i,,,i;11:i1r' ,:t!::rll!,ri li, ia":,r: rtturr:i.trn iry $ai,t,r.'' rta 

i,irrng riLrrr.rrq Ilrilhl.I; f:rlfiiit,r$' ih!. ";inr: liîl-i-!!Fl rlr i:r '!ii,. 

il;r! iritrrl nirJhl, A' r:i]rrl:,iii: r.r itr]l:l |",;1,.;'i d'i'iit:rj.he.J f,-v 

.1,ri,:t !'=ri:. I Ir?ll:li) 

" 

r_iy.rr 

Results 

6lrarico Reg ion 

i.r:' frrr|liiirr:rl ,' -.-, .:i:'rlillf r,liiii, /iri:l ,il:l :l;r! |]r: fri ]!.:ii 6!r,:;lrli: 

ii.:.].rr..]ll|i,.:'.']:i"'r|:]i[l1I+1]pi-esfl',r]|E':]"l'|].!;1|r.iii:iri1!'Ilii1r,.]r. 

ri,:,:,! tt,i 

fr r 

.r .r1: !r:rj,!i r'{Hir,: r':riifi'llllrl {'i ir r'.,ri i ,l 

- 

r;rIj 'ri,,,.:r illill.:!!1r- ll.. {; l'art \ir 1: 

ii'r(:r {iri.j;,r ::il:irri t!!, F .ri ,rlr,ri i i/rl .":' ':i r, ':i lj'- ir,.l 

lrri: ,rl,a$,r, L.l .:;:lr lrir\' r' :r:l i:,;1r, i: :lir,ri"r IIt iii 4 i' r:)i; Lr+ 

i | 1 , I i !/ i ' I i I ir I ,,t fi(1in lllsq1 r: \.' r.:.''ii:rt1"r_y. l_rii{ !,i;iq- ii 'l_'r,rr"!r, lL?:l r,i 

l:]t.i\irc:irl.r j];lr;rt){.! ,..,l ,t; 'i ir!1i:i. ,:r:ri:r:lerii(?ci lri!!r,,lar:1,r,'l 

':,,i Er l, ,,' L 

Lower AFLrre Reqianr 

t,i i i lr 

'-,ii ii:rir r,_. r,i: 1]i;l.r 

l I1r ,i i :i , r:11:: 

i trfl i v ., i:,,,,.l q.,: 

j ;r! e4. 

_/fi,1/:l 

lr.r i'!F:v Lr r.,i:t rii'.?:.| 

;,\:;ilr r',1 :,rl ,jf .n"1! :1,:i,l-'7:r ':t]1? l-,r'rlr:(l {::ri{inrr,t HPi'r-) 

. 

1.i 

tllr:i; l; 

i i ir$.l 

{r:i /i:rs. 

lrll] :;l I 

.! rr!!1 ji:rnirl! il-ri'rir',' r}i il :rir) 

lr:t: r,i : rr l, ':. ;ri,, i'ii! iiii :i!Lr|*r r:i,r-rr'.: l irii.rl,lre: Fllll il:!nd {:11,'i" L 

l.l{l .:i I linr'l,! r! !., i r:, t i l t . i. , i i '' !:h.!irr.,, ,.ri.trlr &?"::i .tl irrfl:ivli:irrill: lrr,rii 

tT r-,3r n,ii r, l:lrf ti'/ 

fron i li:t:. l{I .'irir 1llli,:jil L::i: 

for i idr.: l: ': lr:1li' l"i':': .r{ ': lr,'rFnr l:, ri:vl)ri1:,11 l{ 

fi :ir!,:" .:,i!.;\h!l.] ,lr)1tJ].i.i:i tal:ir:)Lr f I'i::1.':i: fr! vo {r_iiF:r. 

Hiqh ApurP Req ton r 

!i'i:' f'lri..i1r lli)r!r€i hl.'lii rl t:r(:rlrFr i riir'lii i"l ' j..1,1:' lilrid rri, 'r'l 

"r'r'i- I 

:rrill;r,'?lii: :'.:t r;r::rl-! |:l]!r1i]ai{l! ilrr a !','rl4:{ flF tfi i:.': I ,:--ir'riiiiiJ ,;1t , '" 

i:i!,tlrilrlrifin t a-il?.4r?!l :i.!]{ jivirltt,ilL':' titr!'! er::il.].fllii lr!:ri ]:rJi- 1l},:il:;i 

i rdi."i.*ri,ni:i, I)!rr hi! dr'lrlij:i Lt fr.v l-hl+ rrjllliorr i llar lr fi-r-' :ll . liiil 

$.i;e ,:ilr/r.r{: i:rrr'{: Ancl hief.lrqr*irr (f:lr.rrt" Nl? 2 rrrii +:l1rrrr:' N1 ?J nre 

.._. j lni-:lr! r tcr f ho!;e IE,prr'[r,'cl h/' A!,rr;:":!Jlitrr!.:r (1q$j) Rnd :]t:;ja1! 

.: lQili'l., rh,-rr,r( l+:r:i.:.r,rl hy |rL ij,'r .rm-i.r1a:l qhnirF:,

186 

Southern Apure Reqion: 

I t cor,rrrtses 

r.:6:..)7e l;' ra"-J -r.,* ,n*',,;i.1, ';;r;' :t i".,.\ .,r,,) 

.,n*sr :;q.r:z 

"1""t"rtro/r l:rirr: !rr1' r-rnrn rr)ii lat*r 

equivalflnt- o". tha? 

t,, rs.s=2 

{:r+riciLr!i' 

,,+'ti.l"T:-jo 

t'riri(h -ie 

o+ thr:: reqicjnAl t"t-*r, ;ri.'i^jl'i'a.rrn/Jer FhF l'rn'j.ou- rnrl 7,1i:'t 

rFsion;r a""*itv,,i"r,. ri' ;;;:'";;.1.]il,ll:J,,1 ;,,i::;,i:j,,,1,:,, " 

The .iize 

. 

s Ir_Lrc +-Ltr_H inrj, h:st{]qrcr} 

snipe wrth 

:ihi:l4 the 

a grf!;itEr 

pyramjddrl 

I,rc liirrr 

'ch.rrL 

ri r+ i:.tits-: 

N!.1.1 

. 

inrt r 

t,rriii: II 

iqlrr I. 

tnjrv:.rtLrate 

Ncr- ",\ 

lloody Plains Region I 

thF r€rgj.trn {::c}ver.ri tlfl 

cover!.:rl 19::..A7A fia t:.,lx\ 

I ndrvj clua16 +.1r r rr. rrjn-L 

( c hdrt N.::.1I . 

.'.-:' ,'l -.,r'r,fJ4 

h thE. , 

'r{ 

-n-+u," 

1l,F rr,hl ,rLL..i, Fi ,rrng ..,U.r,r:r,. 

rJF:rreri ty rj+ al" 1- jnrj-ivj.ctrai:: 

per rra 

. -ThF, {+i.qr!r.er Nn ji: and r:harr. 

46,:7 i.n{J i. vi.rJLla I !: {ron 

III end 1g.tZ rf th$ 

rr 'o h,. tr.rr.l.r,n ,.r,t ..1.,r. t r.l: 

D :f"- rr', r.i, ., . :,, ..., ,.,..,, 

clc.:q 

.t:1.,, ,.I-ti\.,,L..,|.- 

.lT, 

,r .. j | ,, 

p(:)pLrlatiofl {rl:}a th{: . l*'q.ii 1,, (.:.rr-1.!(:j(::r y" 

floye de Arisftenc,i Region; 

*;;:,*;,^;i.fl.,ij]i 

.-".,',, 

ro'f r:: :r,-i,ii i,i 

:l:;".:iil 

;lji,,1I,,, jll;. -,ii..,11, 

l. ",.,, ^ l;":il l:,",i,t f l:f 

-IIiii:l]i 

^,^ _,-n: 

r;.r.q 5t|,,.t.rr,, n+ h.r::ro.J. al .r lr,.L" L 

ll?,;,, :!.':.rvpj{.:r 

F'}r,rn;d..r ..,.,p,. -r 

wr-th_*a 4.',:17 ,,f w-l 

rn(trvr.rr.(alr. ,, . L.,; ,larrd 

?:1,O 

::r: 

Z o+ individlrtsls .From.it"i!;s 

1V" 

COt tCluSfOr.t5 

i,t,::.:- 

2 ar,,::i 

8'ti Fr{Jtn I 

.. ll l). :i4:l 

!i ir tc h 

t i fjt, r i,: 

1.1$r.i lI 1l li 

Guarico Regionr Thi*i regjon repftfrFr.r 

very !!rrri:i-riIri 

low valLre rri1,,r.J*! 

+or- iir 

crasBFq rri anr: rv. 

II i r_, ,,.,-,t-...lii 

E hrqher L..,, 

valLrpsj, ,.r*,u,,, 

Edr(sed by thfl overr..€ixtr:.1t1+-iirtj.t.i.r 

re$ource, 

ciJ ttre; 

The regi.rrnal densiLy vetrrirjr 11:i;rllii!:r :tflrr. ,:r!||!f]€rrr,"d wrrn

pr€vicJlrsly r€,!portr:|d vRlLle!: frr:,fl! r:or!on{Iritiier::' j.! llrF' r.:.'!lri:rl 

nclt und€,r the Explotati-{:}n Frrgraff { l'lrc'rl'.j ar n.1r-'i{:tr_I. li:r)rli'r ) . 

187 

1t i5 r€c om€n'nen rl ecl . l_Jirsed fln ttr{r rFrqtrlf!} o{: i:J-r! :r'r?'i{:rfrr: 

study, 

+ollow 

to ban 

up stLtdv 

thi 

' 

Fl.frlort,rLrior'1 t1f t-hr .r*--,i:rl i . :!rr1: rrrifrl 

'i .. 'n-)' .r{ 'ttrci!]:r llril: t'ri)i:tr,llii{t 

j;1:, 

Low Apure Reg.on' fl,+ re{:ir:,nAl !:le}fr:.j ty vrlLr(: {,.r:1.1.r. ,ailhirr 

the interval reporlli:rJ t,]/ Aiar;;rUi.r(]n":r I l'till::: ,':L11rl llrr1.i.'r:rt { 1.'?llll) 

for lncalitieE |,?ithin th4 a\Ilr!r'e qLr]:F., 1'::.r, ir !+l 

structure o{ t-he Fopq:laLi,L}F shoers ij!!r!r {:f +hi:, ,::ri:,1,:!italit1n 

t^rhich it has hepn und-ir lllqr Fiigr li l t_r i'+,ilr'r,i. 

Hiqh ApuFe Region: ilerrsi il:,' 1!.11.t t|.i +$r 

5:imi I ar- +n FhnEb FErinr t,,,t i ,.. 

198;i) Lle{ere the beqt jninq sFeciP. 

o{ ::!r! |::r,f ll ;,:i:irjri 

'| h' I iji nlr, ,af ii 

{ i-\,/.r r i: iiijr llrfri:i , 

a,r r! | ":(!n i (]r the 

ThB Eire 

comparatlle to 

EtrLr{::trrr*: in tht| sir,rFe rJ: a ir.;:r.rnji]t' i:; 

the orlp pr_l?v:cjl-l!sly rarFLrrl.Erlr srhj!r:!r 5h,;z': f.h,r fr 

the reglon is (rne? rr{ the! he},,r i n?1iilr4r!. 

Southern APure Region: li" r4,!iflf!!:!l 

"i:.i,:rl.1.r v*lL{|j lcJwest o+ alI 

jii 

the reqin.r r:nviirrli!{J tr.: Ih!: -i.,re!..nt.ih dy. 

tili., 

Th1]l 

extrlan;rti$n +or tfris re'.tli L :j.* 1-tr{"- ijt!.rl j l:' ,:if L t_'{ii fr.]bj h;rt j. 

th.r rBgiorl. !^rjth lnw 

q.F.rF ir r 1t,. ..nr-.r r. 

[rtritlrll 

.-, il 

laaler 

. 

vr.ri .i:; :in tlhnt fo.]d ir: 

The si:p Etrl'rcf,,rrE! qh!,-:. srJr!i:l.rr v,1 r-rL,. {!:!r iIa,niir:,- .tI 

and IIl ,reinq hiqher tlrn !..a:lre". l$r r:.1.n$!! lV, Nlli.rh !n.1y inr:!;rn 

ad t.-++eEt of t"he [:rplc] j.l,,itrrj-c]n FrLritr.i:!n ,:iyrI lh'lr p.rpLrI,rtirfr" 

The Fr$qr.im has ttl he ril-ju$LFd ilrli]f riri,rq lc! i:hr. rE,;irrlt$ ${: 

the presenl w(]rlr so t$ avc.i!:l .r de-rnr[]'*$4:r {r Lh..' nrrml-rFri_ {:}+ lh!! 

individ AlE (]{ c l.:r*!: IV. 

Wc,ody Plains Region: Tlri.Fi r(?qi1,n ril!fl|:q l,L,: l:hri ,.d I-,r::irt 

density valLru dLlt? to a i;troru lr.nLri!)u.irr.:,::::rrrl3i t:liii.l '::.:ir h(.,l 

v€:ri{y I:rbsf:rvrfig I,ht-r v;:\l r.rn,€i .jfrri l::1i !:fi,:ii:,r: i.i+ ft,ir :.tr::r} 

strLrEtlrr{: typr{a1 ili thr} ;ifing?ri r"rhof ,:.' lir!nLjrrrJ r,ir iri::j nnr i:rf ;.! f {j.rr 

than al:Lr7{4Pr,, Y€it. inl}r:l'r ;rJ t I ir'..j r. {:,r1ii1':!r. r r:!1 ri?iiiairi.i:' 

Fxploiterl 

percentajFr 

lindFr rrr:!,r v;r11!ei:r i{ L:hr? iillriii!r'ri:1ir, i:ii thr: 

r)+ !?)jfiIr:!j iiable j | | i I i v i ni r ! A 1 -. .t.i:rr rl.i:i,rl :rV l,:ir, r!! ije 

Hoya de Arismendi ReqicJn: Thr! ,rl,l;::ii..rl '1,'eLj,:iri ty vallre 

the second l"riqhelrt .r'f .11. 1 1;tl.rd:i{:cl ri::r'l j.*rij,' i r'r!rir:l: ,-nh.Jer:i .ii r!ond 

poF'-'ldt.ion ,,{ i. r {.I. LF.ri j..-,1rt.' 

Thr: si ire st r(rf: tll r.,," i!i tyI,i{ra.l. r-i :rlr i;i :! rr rlitr i ,:,,., a|i,i'-

188 

bl{: r:xt:f ij t:.rt:)-nrr ! fjr:r:.i [.i rtJ laf ge: nLrmher$ 1'{ individ al,'5 f rf:]m 

Finat 

rAim;rn 

EOncl Biansr I hE Foprri ai:i ort alr ncl;rnce tr{ itFsirtRc I a:ld 

tn:ri-r .l]Atilrl hy flr*,r11,r r-J ( Ltrr| rlrrnhr:r' nf jr!!J:llv j'Jrtlrl.i; 

Fer li'rL 

(r.f tsrf itri;, ifli\,. indrir:il1,r, lh,r ".lat|]": 

a qlrairti l.il !:/". tr l jrrL []: ,ri i:"tl 

.r{ li:hF: pfipL.L1.1i:ri.on lLnrler 

[:lr.i! '!{],"t ,,iL iirL. !'i:'f,' qi:ritrrlr,rf:; !!rl!:if' tir rll.r,:\lj.lrt :,!: rl'!r:l 

s l-Lrllie,:i tri:)rrriir:i{rir!r .rIJ/ lrtJlt i j 

f rlllolfii:iinrr iir,:rilr_ani h;rri 

.r++t:|! L.nr 1 I i,i' rJr ' 

ii,:i:r'r. r', !iti I i i'l!r!)' rii: i:l'.,i iri:!r!:!iLi'fiii ii, il: i:h4: a:l jr"1:i r'rr! hrl 

{r.:r !:'r r}r l$rLleld, l,iirh !lr p:r:nt f .:- or1al rit. ll{:r+lrririi. ;'l' i 1'j jtr''! 

r:./r:r: ;i|,rl rt,t,irl ,r::i1l{1.i lfi ir::i::Jn :'r'f rrf,F! 

Lr ::: r,r:!r'i,i,:.,ry f I'rt:I j '. :,,:.ll,rl lr,Ii::;.,r1 i:f] ri rtiq r'.:ijilr' 

,,!j r .!('rl 

.,: 

ili:ri,,-,: 

rr{1lif !t;,1. rr!fl i(:r (rrii r,:rL.r l'irta ir-:,:i: ri jr jr r::t)if 

i,ri!al1r! l,i i,:i..,r: ., i'1i'i! fllei l:', {:rqt,rni, 

ii,,r riirir:L".ir !:!f lt:i,":f r1.;il.{:l I ii: iri,rir!_, flrf rr i}r,::1 .i!!,:fj!r 

rir r jrlf;1 ir r;)rj F{}r t hF L,:r]r:,il F.lajfi 

,::,ii.;. i !r!.rit;ridlr trrrr 

lr'i::ll i.ofr ijrii Fr.lrri' :iti i)rlir L:1] 

.Jflinf 

FIELID6RAFIA 

AYalitrlrii:irlr r,rt'," ,1.::i i::!:nioti,i"r .i, !:it:ir,n, rlrr ,irrri i'r|-: l!:i {} b":rlrA 

i lli:rlinr:\i.r- ', -!:i- l,li.l.i !.1.','1 l.' r e:r: 1'':r l'll triirr:i ':i:' 

t:i:ri:.;rir:r t:: r:rr',i. ijfj, ;1 -t :rri 

'r:lr:r|ii {Vl}rf]l;i:'!ela) ' 

lrl l.l/lr:i. A,r:, i::.-:|:i 8r4r i.(:jtrr:ii:' Ilrl,i'(r itrdi+i: llr lr.:! |"lq { (:l!i 

Ulijf:] 

{: tijt"irjtiJ..il. L:,j,ji.-: -!fl lios L.lan{:ri! i.l,:!:ir:lii'fltrl1'!:L d. L/ 1, r l:'r, rp li ,i, Vi(ii 

fii ivr,r,.+tr r: fl:jt,l:rrrrl fal l. 11.r :",ilr;,: ir,r: 

l,i illr 

!:i'iJ\ii!fL. ti"A, dnd,l , A. O:lXflN, lilhlrr1;e:i dfv !]t-.$]3r)fr l]r.{:)]. 'l,' ',i 

f:t:.!lnl ,,:1!;!, .],-l!l:l !.i.r'L.q!l-!L-||! lrn{ [fia:: !.r8]ia::.r!!r!lArr i i'r:,':: I'i:'ir' 

$ir . i:r,.r1. t\irt .:5 1,:71-i) irj,. l:lr:i/ ;lrii 

.|'J'l]:|ii]l\jA|]||\.i|'].1i]li]ri'Li,'li'';]:l:j:L:]qy.rd|ii]i.it.:;.],!| 

ll.ri$:!, i!:'lIlllrl!:i f,-ll .!lii:Jl.il..i-i,l-:i 

' -i!1 'lrri! 1:ir1r"il t'|!141r::Lri": i;trr l-i.rrl': ' 

i\f1i::!:.:i.i.i...}].:]l:irf'0j!rilnti.'{|1:|!ri:ll{:,:!.i|^d11Athi|ii(i!ir::.Lr1+illl(:;ji]] 

v#rsl.i; 1rf !:r: r' jil;i rlr f .rrl-:.:1 li: , r I I, i- I rniiir l. {;f l:11|] rirlilliiil::!r,+fr'11 

'I'i,r ri.rqr:!,r.,'1 ir.,1 r,., r:. fr'!i:i !r!.{rt)l!y, llrl./!'!r!irLy n{ f 1fl'-ri ;r.

1. -Guarico 

2.-Baio Apu& 

3.-Apuje MeridiDnEl 

4.-Alto Alue 

5.-Ho]'a de Arj.smendi 

6.-Lliro3 boscogog 

?.-AJEa dc irdluencia del Orircco 

Alto Apure 

Bajo Apur€ 

Apure Merid. 

Gu6rico 

H. Arizmeodi 

Llanos Bosc. 

Fe3b de los Llanog 

Fig. 1,- Los Llanos Inundables y su divisi6n 

Superlicie Total (ha) 

2.662.296 

571.389 

1.262.M9 

784,475 

615,342 

3.114.384 

Superficie Censada(ha) 

25t.95626 

78.t74 

234.126,51 

69,297 

95.r54 

r93.873,50 

9,46 

13,86 

18,55 

8,83 

15,46 

6,23

U) 

UJ 

F 

() 

I 

E. 

z 

E, 

o 

F 

O 

ul 

o 

E 

(L 

a 

o 5 

:f 

a' 

[rJ 

E 

o 

5f a 

# E 3 

c] 

z 

o 

;i 

(\l 

Xeb 

;n- '= o 

oC') 

(L 

uJdF- 

(f, -r 

[rJ 

2J(r) 

C)or 

ul 

26_ 

t=lir 

5(e 

F- 

trl o 

u)or 

1=oi 

5'f 

z 

o 

o 

ul 

E 

ot ot 

Ol rco 

@o 

Or() 

lFig. Z. Hirtogru*"t d. ..t.*tur", du r"rn"n", p* R.st6;l 

Regidn Alto Apure Regi6n Bajo Apure 

191 

a:ra* ltl clrse Iv Clase 11 Clase lll Dlosr lV 

Regi6n Apure Melidional 

Ilegi6n Guirico 

Cl.$r Ill cln!.lV ClEse ll Cl6ee lll C)ase lv 

Regi6n Llrrnos Boscosos Regi6n Hoya de Arismendi

192 

STATUIS DB ILAS POBLAGICINES 

DE BABA 

{edma wffitu} SOMETIDAS A 

APR@VBGHANfiNENT@" 

AlvrrD rtrbillo* & Jora Avsnrgl*u. 

* $nriqiD A!li*}Do FR+IAUHA, Edf. Crnrio Orrt., M.zruilr! C *:$ 1010, V.!r .tr. 

A$!a ErFiola ia C0o!*nri6[ Eema.ric*ra, CdL titr]hirro, Qti.l+ l0r Lr C$t.lt tr, Crrrrr, \L!.zudr_ 

lNTRODUCCION: 

Desde I.!81 :e h;r 

"'enid+ 

desarrrll.udt, en lrr Llan+s lrrundaHes de Verurr:ela 

el "Fr+grama de Apr,:','erlnmienia f,omercial de la Especie Baba [C--z,lmn 

i;'r;rr.diri"tJ". ei_.Llrr^d esta regdado por la F.e;o1rni;.rn N! l.?,9 de fecha 13/ l2/g l, 

pruhhtarla en la Sai_=eta Oficral Ns .14.l![ del 33i lJ/! I d: la F.epirblira de 

'{ernzuela. 

_ EntJE la-i hnses miis lr$orlarrt'rs que ngEn el mencior.ado Ptograma, podemos 

cli,, 1,.1s si.qrxerrtr-,s: 

- !rni'. :rE FErrril€ Lr{rsF:tiar m mdsrno del 5,e?d de la p,ltrlaDidn censada. 

- :rl,r ::e cossrlu a la rlase IV, irrt€grdda prr mar:hos mayores a l, gB mt ,le 

hqqrtud l.,rlal 

- nn.r8 Fe-r'rutr rtosechal enaqr_ull3s gn quellas loca.lidades que reporleD porcentajes 

de ':1a::,: IY irrfen,-rres al 15?.i 

Enjt Eslrlr crilErlos se lta regl.dnd':) la co:echa en los ullimos diez aflss. rr,n urn 

paLi-"a en 1.986, en la cual s* erralu+ la: cosucl.ns otorgad.as hcta El molrunt3, 

prl|luclenrli:r:e comr resuitadr_i drl misnrt rura redu:cidn en laq tasas de extxacclon de 

la p'rblaci6n 

. - El+trjeiivi..r !'rlrDipa.l dEl presenlE B:ludi+ es detern:rnar el ei'ecl,o que a temdo 

el Frr-rgr'tura :i,tre lar poblmr+n* nalrrnlEs de la esDecre que se han ,,€nido 

lplo'"P|hindn, l esd+ ru punlo rjp r,tsla c,rlllahvo y cudnhtattvo. 

AREA DE ESTUDIO- 

En la fig. I se identifican hs sei: regrorns naturales estudiadas en los Llanos 

Inundables, en las cuales se des rolla el Pr+grama de Aprol,eclurrner$o de la espeue. 

. 

Las cararteristims que defirun rada regron vienen dadas por la preserun o no 

d.e garceros, dellas rnternos, mlidad de nutrienres, grado de inLuria*i6n de las tierras y 

tipr-: de srrelo, tldar ellas r:arart€risticas que se eltima que [enen relari6n con la

densidad de las poblaciones de baba (tabla I ). 

MATERIALES Y METODOS- 

193 

Se realizaron censos endos tempordas correspondientes a los mese de sequia. 

La primera deabnlamayode 1.941y, la obade ernro a lrio de 1.992. 

La derridd de la poblci6n se midi6 con certsos nocturnos, contardo tdos los 

individuos observados por nEdio de faros pilotos y linlernas de frentE. l.a estructua 

de larnafros e realiz6 tffto de dia como de rnche, utilizado el rftndo dscriio por 

AFrzagrnna (1.983). 

RESULTADOS. 

Regril4lto-t\pue. 

La regi6n Alto Apure abarca un suprficie de 2.ffiZ2% ha, de las cuales 

freron cerxadas runs 251.956 ha, lo que repr€senta el 9,467o del area l,otal, 

estitniindose una poblaciin fu

194 

poco desvida beia la cl6e II (tabla 2). 

Reei6n Grffco: 

La regr6n Guiirico abarca rrn sqerficie de 784-t75 ba, de lr cules se 

cerraron 69.296 ha, lo qtc representa el 8,83% del area total, estirnrdose rm lolal de 

8.792 idividuos, para run densidad de 0, l3 itd/14 (tabla 2). 

La eshutrra de tarnaflos mr:estra ur 70,47o de individuos clase ll, 2,6% de la 

clase III y un 7,0% para la clase IY. El histograma presenta u:a fornn de escalera, 

lipica de zoras sobre e:Elotadc (fig. 2 y tabla 2). 

Reoon Uanos Boscosos 

Bta regi6n cubre urn superficie de 3. t 14.384 ha, de las cmles se censaron 

unas 193.873 ha, lo qrn rcpresenta el 6p57o del arm t/otal de la regr6n. Fwron 

estrmadas unas 28.886 babas para urn dersidad de 0, l5 ird/ha. 

El histcgrama y es|Juctula de tanufios {fig. 2 y tabla 2) presenta rma fornn de 

escalera, conun 46,3% de irdidduos de la clase Il, 35,6% paralaclase lll y un 18, I % 

de la poblmi6n en la clase IV. 

Reet0LttsE-de 

- AagrnErdr: 

La iegi6n Hop de Arisnerd.i abarca una superficie de 6 I 5. 342 ln, censardose 

unas 95 154 ha lo que equrvale a un 15,46% del area tolal, estrnmndose ura poblaci6n 

de 32.856 babas, equi\ralente a una densldad de 0,35 ind/ha. 

La stxuchrae hislogranra de tamaflos (tabla 2 y fig. 2) presenta una forura de 

pirdmide lipica de zonas bien manejdas , con tm 48,27o de individuos de clase II, 

:6, 8fo para la clase I I I y 2 3, B7o de indivtdllos clde IV. 

RESUI=T*EoS - (rNcLur\c sE:, 

BeciesAlslp.$e: 

La demidad de la regtdn es ser@Fnle a la reportada en la literatura pa? la 

zona {Ayarz4grrrm, 1.983), antes de' implenenlarse el Programa de 

Aprormhamiento de la espcie. 

La estnEtura de tannios en forma de piriilrrrde tarnbrdn coirnide con lo 

antEnorfi€nte reporlado, demoshanlo qr.E es um de la mejores zonas para el 

aprovechamienio del recurso. 

Regi6n - Bap Ap1rg: 

La iterridd regroml obtenida se erruentra dentro del interrnlo repoddo por

195 

SeiJ6 (l.gEd) en localiddes del estado Aprre. Sin embargo la estructra mrstra 

sintornas del aprolechamienio al cual a estado sonEtida en los iltirnos di€z afios. 

ReslgaApge Mendignal: 

La derridd regio:ral es la rns baja de todas las reglores estr.diadas. La rZz6n 

qrn explica esb lncho as la calidad del hibital dorde las agrm sou pobres en 

nutnentes y por lo tanio la disponibilidad de alirEnlo para la eslecie es baj4 lo cual 

deternum la abundaruia de la misna 

La estructura de taffaffos presenti lorus senEjantEs enlre la c16e ll y la 

clase III, sierdo mayores qrc la de la clme IV, lo que.podria significar un efecto del 

Progratra de Aprornchamiento de la poblaci6n, el cual debe ajuslarse a loli dabs 

obtenidos en el preseutE estudio para no prodrnir urn disnunrui6n de los indtvtduos 

que integrana laclase IV: 

Region ,Suilrjlqg: 

La eslructura que sE r€poria presenla un muy bajo ',ralor para la clase IV 1' la 

clase IIl, en contraste con rm alto ralor para la clast II, prodruto de una sotre 

explotacr6u del recurso. 

La dersidad regrornl tarnbidn muestra un bap val+r, en compamcton con lc 

reportado por Thorbjanranson {1.990) en localidades no sometidas a el Frograma de 

Aprorecbamienlo de la especre. 

BasaDlonos en estos resultados se recomienda vedar el recurss haita qw ur 

trabap sinular demueske que la poblaci6n se ha recuprdo. 

Refl pn_Llgnos-EgEqgssr, 

Esla re$on presenta el lercer lalor mits bap de densidad, produto de urn 

frnrte presron de cazr, qw se corrobora al ohseruar la forma de escalera y los 

valores que se obtiercn en la esaucbra de larxaflo, lipica de zonas donde la crceria ha 

sido nayor de la permitid4 aunqw todada queda recurso para aprowchar bap ua 

nuera politim, basado ;n una disn]lnrridn del porcentale de irdividuos clase IV a 

cosechar. 

RegionHoE! 54wsL: 

La derurdad obieruda es la segrurda mas alta de lo'das las regrones esfidiada, 

demostrardo que e)flste urn hrcnn poblacidn de babas. 

La eJtnEfura de tamafios e6 caracteristica de zooas sorEttdas a un marcJo 

sosterudo, existiendo importantes canlidades de idivrdltr clase IV.

196 

,:4rnhsi4nes Finalesl 

La abundarura de la poblaciin de 1a baba estinmda como ntnuro de tnlividuos 

For heclirea de terreno, solamenle indica Bl sl.atrrs de la poblaci6n desde un punto de 

\,"ista cmnhtaLr!'o. 

En canbro la esl.rmtura de tatniriio: indrca la ',-alidal de lm !',:blarl'rnes 

estrdiadm y tomo hm srdo alectads por el Fru,qr:rma de ,..lI i t;t,ll-r3nrentd 

Ct'nrer[ial a] [rra1 eslan snirEtadaj 

En el Lla:l: rlurdn hsh.ffE }Er:lrsn qu8 Fr:rdt'in atrfnvEc}lnr'se, prrselimrrdo 

grander diferencr*: p.tr reglin, 1t que al,g.uras harr stdi; inlrr apri'nrlrrda: 7 oins 

iobre npror.Etl]nd;D. 

Es wcesan." irazar p{rlitrEs de aF}'1:r'lEchrTfietrt:' Fart cada regt,rn }. i:':, ,-l.e 

nrarnra global, sretrdo el cruo de 1a P,eglon iit.r;ri 11r.: rirle deh* .,'El1;1rse 

El niurer.i r-1: hahe-q eli li L13n]:: Filra tma e::!1,1iffi,:,1-r ra[16nd] Fldriil llsllf' eri 

el ,rrd r:n ,1e 5 0 LlLl tl .r 7 0. ll Ll ll q Emnialss/;lfi ,, 

BIBLIOCRAFIA- 

Ayarabrnn4 J.S. 1983. hologta del Cairnamde anteops o bba ltiainza tnwdix 

L. ) En lo,s Lleo6 de Apurt. (Verczrnla) Dofuna t 0: 7- 136. 

Seip, A.E. 1986. Estinncior*s poblaionales de babm I Cenatu cr1rr.rlillx) Lnltr. 

Uano6 ocridentales de Verczrnla. Vida silvestre reotropical. (l): 24-30. 

Slalon, M. A. ad i.A, Dxon. 1975. Strdies on tlz dry s€ason biology of c€ra?EE 

rctz;rdttw az:|?'dzhr from tln Vernzrrlan Llaos. Mern Soc. Cierc. Nat. 35:237ffi. 

Th,:rtlunarso4 ,i. B. l?gtl. E,:nliBl' and beln'ri,,r oi lhe specemled lniftilri lf--i/ir,t*r 

;'arr-/-d;e.'J i}] tlE ,]srtr.d Ye r:r,Elatr Llarros. A dts.rerlatir.:n presentrd hi a grixlrratr 

scll",.iil .,i '']re ljm 

"'ersil]' 

tf Fl'rrrda rn partial frrlsillneni. cf the rgquerimenLc thr ihe 

,ieeree ,ri D'lior ,.,i Plui ,saf?. Llru',iprsd'f of Flortda.

l. -Guirico 

?.-Bajo ApurE 

3. -Apure l"teridional 

4 . -Alto Alure 

5.-Hoya de ArbrErdi 

6.-Llanos boscosos 

?. -Aiee de hlhrncia del Oril|oco 

Alto Apur€ 

Bajo Apure 

Apure Medd. 

Gufrico 

H. Arizmendi 

Llanos Bosc, 

Resb de los LlorLog 

Fig, 1.- Los Llanos Inundables y su divisi6n 

Superficie Total (ha) Superffcie Censada(ha) 

2.662.296 

571.389 

t.262.079 

744W5 

615.342 

3.114.384 

TOTAL 

LLANOS INUNDA. 9.010.365 

2s1.9s626 

78.174 

234,126,5r 

69.297 

95.r54 

193.873,50 

922.581,27 

9,46 

13,86 

r8,55 

8,83 

t5,46 

6,23

U) 

lu 

F 

() 

I 

E. 

z E 

o 

F- 

O I,U 

o E 

(L 

U) 

o 

c] 

4 

5 

:f 

U) 

trJ 

E 

o 

6f o, 

A E 3 

() 

z 

o 

ôr 

B =3 

(L 

uJdF- 

[r'r 

2 JC) 

()AI 

ut 

26_ 

r=V 

6(9 

F. 

tJJ O 

(DGr 

1=oi 

6* 

z 

I 

(, 

t"u 

(r 

(\t ot 

or 

oo 

(no 

or() 

.d' a 

c! F.. 

r0 c{ 

(O F- 

ro 

O)r- 

ro 

(\t 

!f 

(f, 

or ot 

oo 

oo) 

n' 

c\ At 

oo 

o_ o^ 

oa 

Fis. 2.- Histoeramas de estructuras de tamanos n 

Regidn Alto Apure 

Regi6n Apure Meridional 

Regi6n Bajo Apure 

199 

c1€se ll Cl6se lll Clase lv 

Regi6n Guirico 

Clase lll Clase lV 

Regi6n Llanos Boscosos Regi6n Hoya de Arismendi

2N 

Agonistic Social Behavior of Broad-nosed Caiman (Qaiman 

lati rostris) in Captivity: lm pl ications to Reproduetirre Managemenl 

Luciano M. V€rdad€ 

CIZBAS / ESALA 

University of Sao Paulo 

Caixa Postal Og 

Piracicaba 134OO SP BRAZIL

Agonastic social behaviot of broad-nosed caiman lf-aiman laklikiS] in 

captivity: implications to reptoductive management 

Lu':iano M. verdade 

CIZBs\5 / ESALQ 

Urrivetsity of 5 3':' Faul.' 

Cai:+a Pr,rstal ll9 

1-a4DO Pirar:icaba 5P 

E F.i;llL 

20t 

l.,lanagernent Frogfarornes ol clocrrddi3ns in captivity may implv in keeping 

adults ior reproductilln ond / or rearin,l lqunq* t"ith lhe nim oi economlc use. 

.onser\r.itinri E f the .,:Fe,lies and educ.stiDr' [Bustard, .t 571 and Lanq. I 587] 

The !,r.,,ill beha'.,rot af a sFecies, desptte the differencas betr'"{een wild and 

capta\.e-born .rninr3lg. alfe*ls direcllg its cD'sptsc,ifir-, tolerance level and *s 

aggres"-iue beha'ior. Theteiore it ie decisi'e for the success of keeFing D€Ftive 

u:c'lonies. ilrdependentlv sf the Frogram obiecti"ec lLang. 1 987J. 

The study of rtoc,odili.rn soEial behaviDr irl the +'rild has beerr generally € 

diflicrdt u-rr rrearly impossihle tasl'. ber:arrse rrrost nf its artivity is Ferformed ']t or 

below the suti.:ce of the tlaler. Hotevet, progtess ha: been made thtough studies 

in cdFtivity, berlelited by the latqe numbet crf ,:aptive breeding programs which 

have been established duririg the last lv+,:' decader The':a studies all,lw ihe 

ei€ftination. dt close tarrge. of certairr behaviors exhibited by animals accustomed 

to the Dresence of humans. r+hich could hardly be documented in the wild Ctespite 

trigh anirodl densities in caFli'/it-v lead to an irrcrease Lrf sEcidl encowlets r.rany of 

the obsen ed intera,:liann are usually :.Fec'ifiD dnd Feculiai to tha social behavior of 

n Fartic,r ar speeies fLang. 1 989] 

Most ol these -rh-rdies in caFtivdy have teveaied delaile of mating. leedino 

teDhniques. rate of youngs. atrd :+onre social behaviots more similar ttr that af birds 

and mammals ll'ran that o[ othsr reptiles [Vliet- 19F2 and 1586] 

Ganick et ot. fl378l describe,J lS diflerent k'inds of socidl communacat,ons 

lor Amedaan alliqa|:t. eight visual. six vocal .rnd four non-vocal acoustic eigns. 

rnr-'st Dl them dscrete and non-gtadual. that is- being demonstrated irr a corrtplete 

,aay or not being demonsttated et all. Ayarzaquena [l383] described for Cainen 

crocodilus crocodilus in Verrezuela 13 visr-ral and I sound kinds of social 

.otnmunieatio.', iix vocal and three non-vocal. Vtiet (1989) includes not only visual 

arrd sourrd signols but also corrrplex sound and possibly tdctile iorrmurlcohon 

channels among adult animtsls oi both sexes. Lazell & Spitzer [19771 described a

202 

possiblB Fl€y behaviot shotaed b-u lrne ],oung Ameri(:an dllitratDr, which t\,ould be 

new amEng other reptiles. 

The dispotilion of the communictstiolr char*rels trelween visual and:ound 

$ystem:6nlang thE several species of crocDdilians seems to sulle. sEle':ti'Je 

Ftessure lr'trm their habitats. Visual siqne seem tD be mfrr€ efticier't in oper' 

envitonments. .such as those ocEupied by CrcCgdylqg aqutus and f, njlqtiplC. 

sounds +eeft tB be mc're efficiei't in dErr!:e vegetated s{..'amps. ru6h.is ttrol'e 

occuFied by Ametican alligator [Gorrick B, Lang. l977]. Tlre.:dult ar'imal dens,it! ir' 

a patticular atea is also related to the e8istence and inten'rit-u $f cert6ir-r behaviors 

or social Eommunicati'rn signals lv.-liet. 1983]. 

Aggressive beh.ivior among territorial males during the reFroducti.re rt.rtion in 

Nile croc,rdile qrouFs was observed by Cott n961l. Adults can alsD thre€iEn ur 

sccasionalb attack youngs. mdinls tr'hen the1, get clc,'re tcr hatchlinq'.r. as noted by 

Hunl [1971J in CrqEslflUs E{uslElli in cdFtiriity. F.n American alligalor adult 

female may also ati€ck sub-adults in the wild ra+hen they get Elqser l[.r,in I 5 meters 

of her nest [Hunt. 199OJ. Ttre aggre:sive behevi']r ol adult flgqgdyfuS Do.rgsus 

ton'€rd sub-adults over 90 to 120 cBntimeters long in certain places in /rustrnli.t is 

lhe main cause fst their elimination ol place: oc,:upied bg adulte lhlesrel i" 

!'Drlicek. ! 9871. Even yor:ng Ametir:an alligator.l r.r.:J, hE a!!reslLre Enicirrg 

theriselve$ in captivity if placed in high arrirrral derrsity enclosures, despite rrf beinq 

c,r.!e Df the most socidl sFeeies of the Drder Crocodllia paanen & Mcl.lea:re. 1387J 

Accotding to Lanq [13871, infornration rel.lted lo lhe :ac'i€l ,]r!tsr iatr,ln oi .r 

spe*ies in the +vild can pro'ride qorrd directions for the plarrning.,i r-rocodiliat-r: 

c.:ptive breeding. Territoriil :Felries tend to be less so,:ial ,:nd can ber:r-,me 

.rgglessilie towcrd allies. These species require nrore area in their reF,roduEtive 

pens and / Dr must be keFt i*''f,laled, irr pairs. or in small grFups itf orre nrale with 

sonte fernalBs. lln the othet hand. specier rnrhich forrr'r large:az,:n.:l graups ior 

reFrcduction tend to be more sDcial and permit d larqer populBtiFn densitu rrr 

caPtivity. 5Fecies like Americen alligator nnd the e.tuarine c-,r,-,codile [f- g.{|[ ga$J 

,tan be Gorsideted the oppasite extrernes in relation t.J the fealure abc'.re. 

However. there is no s.rfe end fir'al inform€tion dbolrt some specie.s of c,ro*odili.:r'ir 

CgiEcD clacadfus is still found in large groups fAyar=aguena. I 583 and L]or;ul.:. 

19701. but ttre same is no lclnger lrue for the brodd-r'osed csimon [Flontes. 1383, 

Laniera. I 990; Verdade & Lavorenti. 1 930 and Yanaski. l35Dl. althrrr-rgli it i.: 

unknown if this sFecies originalll'used to 'orrn large s':cial gri:ups. 

Materials and Methods 

Cases of agonistic interacti,lns.. which resullEd in h.3rms lD at len.Jt Ene ':,i the 

involued animels, rnrere reported from Augu-it l5B7 t'r DecembBr.l39l dt the 

lacililies of the Captive Breeding Progrom of the broad-nosed cairrran ol ESALQ / 

University ol 55o Paulo. PiraciDaba, Brazil. 

Hatms were identified at typical skin FerfDr€tions cauied b_9 bites.

203 

Durin-q this period, a tatal of 188 animals wete splead in 34 enclosutes.. 

divided into 'frouFs with two to thity animals, witlr a petmdnence time per animal 

Fer enElosure rdnging fiom one month to fout years, in order to meet the Pt,>gram 

techrrc€l-otreraliondl needs. 

Results and Discussion 

The number of ngonistie inlerdctions reparted during the study period c€n be 

considered small. H,rrnrever, tlley replesented almost l5Z af the global mottality 

rate of the Prr:gtarrr, with almost B0ia of the cases repor[ed hd?ing lesulted in death 

ot one of the involved aninrals. ll seems to be related to bicterial infections 

relulled fr,rm the harms. as destrihed by Farnos et al. fin press] andZwart [1578]' 

l"lo,:t of ttre attaL:|..,,i 'rccured taon in the first day of the gtoup assembly or 

the ne,,^r individual inhoduction itltr-l the gro,rp. Howevet- sometimes the €nimals 

rFEnt nirre ('f even len rrontirs livtng apparently peocefulllt togelher before fiqhtin-q 

iFiq. 1i. This s,:mpli|rg does not petmii a concluaion about the tequired period lo 

thJ seitlenerrt ol a new lrieratc:frical :ttuctute into a grl.luF- like a "pecking ordel' 

ol domestic fol\,|s. but Fossibly the filst-dag agottistic interactions must have distinct 

ceuses of those occuted monlhs later. A first-d€y fight seems obviously to be 

resulted of the introductian sf a nE+,t individudl in a stable gloup or of the group 

assemhly iteelf through fomerly isolated animals. On the olhe. h€nd, sometimes the 

apparent social balance af a grr-rup may be btoken up by something new. like the 

approach of the reploduclive petiod. ,r sudden we€ther change, or any othel 

stressing fa':,tor such as Dapturing hy humans. etc. 

The high freqr"rence of lights itrvolving iust t$ro animals lalmost 352] ean be 

due to tr.ao tactors: samplinq etror. since the gtoups assemblages did nol follow a 

research design but the immBdiate opelational needs of the Program; or the gratel 

lendence ol rsolated animals fight r'{llerr suddenlv put in touch with co-specifics. 

This would be similar to wlrat Magnus=on [1986] desctibed for,rverhunted wild 

populations, where the rernaining individuals may become more tellitorials The 

most frequent fights in two-€ninrsl groups [Fig. 2l in relation to latqer etisting groups 

may - be lelated to the faclots abc,ve. 

The enclosure animdl density itltetleres ternatkably in the aqressi'reness of 

indi'riduals into a gaup. In qenetal en increase itr the animal density tesults in the 

increase of the social meeting frequence. and consequently in the agressiveness 

of the animals lLanq. l3B7]. Ho+veve,. the occulence of agonistic interactions 

nror'? fiequently in the density enclosures of 0.0? to 0.01 animal Fer square metel in 

felation to othets up to 0.1 animal per square meter shows that passibly animal 

density v.,as not the main cautie fot agonistic intetactians in this case [Fig 3]. 

The se8 of involved animals- conttary lo what could be suFpDsed" did not 

inlerlere in the occulence of agonistic inte.actiole. In other words: the frequence 

of tights imong animals of the same ser w€s the same ol amotrg animals of the

204 

opFo:rite sEh iFiq. 41. lf the sEnle occ r h,ith the rqild FBFul.ftitrni- i.lrp can infEr thnl 

the species Fossibly {:nnntri stnnd Isrge rs.-rrrr.rl gtr-ruF,:; altl-'Duqh :.om':tir'ie; it i; 

corrsidered ns sDcial as Caiqag cr11cgtlills [Lang. 13S7]. 

The oriqin of the anirnals 14.'a$.in imporlant factor. tut not decisi'/e. to the 

o6rur+n.e ol agor')isli'.,- internctions. *'rc,ur.rd 85t:,:. rt tlie lights rtrvoh,ed anirnale hon-r 

diflerent otigiti [Fig. 51. Howevet. !tressinq siluatians ,:,r-ich es c,aFture, 

imflr:,bili:aticn and clrange ol encloirure .iar] Lrredl. uF the sc'ci.3l rlnr':ture of a 

grouF even terrrF,:rarily. resullirrg in fights. 

The ag'rr.ristic intBroctrons inrrolved Fredorninantlf the biggest anin.rah of the 

c.rl,rr,y [Fig. lj]. ',,{} rat is tompatible lo the r_,9;s1,.';1|o.is ai.5.yar:;guena [1583J for 

Caiman cleqqdilg* craaqdilu$ durirE the summer time rn the Venezuelan 

"llanor" Ihere r"+as no srqrriii*arrt difference L'etrq,eerr ar'irrals of ihe sarire sr?e 

[agtessc,r and aggreijsed srrout'?errt length ratic, ftorn 0.8 tc' 1.2J ,:nd anirrrals of 

dilferent riza [aggrel:or and aggre:;sed 5n,:,ut-vartt lEr'oth ratio honr LJ l+ 1 6j. in 

relstic,n ln t["ie occ,.]rBncE af fiqhtr lFig. 7i. Ho,fle'rer, lhe.rggre:-rrat r eqgres-ted 

v+eighl ratio seenr.t tr' be. deci:i're. h4'rst ol the fiqhis involved individu,:ls +&ich the 

+rerqht ratio 'r.ra+ up to 1.i lFirr. Bj. Thie diii*rence between eize and ',vaight retios 

;: a predeternrirrir''g laclrrr fr:r liglrl car' be r*latid lo il-,e !r.!,etl-r ,:ur'.re of 

crocodilian;. r"',here fr':,rn rertarn,:,ize ot'i;rnell lengll-i r-rcrea;eJ are hllowed t'9 

relatively bigqer weiqlrt geins [i,lcllhenn-y. 1335, Cr'ul.orl et ,31 ] 97il: ,loarr*n L 

h.lcl.,lease. l97li and l$i!. Hational Eesearch llouncil. l9E3; \'"r*bh et al.- 1983 

arrd Etisbit-r. 19901. 

The peal,. of aqanishD iriler.-ctioni alonq ihe year ccrin':ide:. 'J,rith lhe 

beltn'rninq f,,1 thE rFFrr,'du-tr'/F ,r,-:tivitie:r [Fig 9] There i:: r'ro !.,E!eciiic inlorrr,sti,--ir' fBr 

broad'nosed cdinr r about the trme peflod bet,,.reetl E:c,p(lEtisn ,3nd egq'ln-ytl1:t- 

Lsrseir *t al. ll gllBl Dite: a g*riod of :pprr-,xirnat*lly E l\'eel-.: b*t{a,Eer, o\jr.ilatiL-ln 

[ar'd probably *rrpr-rlatiorrJ arrd egg-layirrltr lor lhe ArnerEan alftgator. lf this frottern j3 

lhe !ame f 'lr broad-n,:red 6aiman. lhe Fenh ,tri occ urencE Dl iightt corncide r''rith 

lhe copulation periad. This ,,i'auld ,rlres3 the role ul :e;{ual h'lrmones,rn the 

aggresive behavic'r ol the anirnal,. ir-r cc,n:rnan.-,e t.-, tijiilerrberqer [1381J, Eihnt] 

Wilson [19f51. Leshner [ 378]. ond Frain [1!7311. There wos ir,] report Df tir:ihts 

hom Aptil lo May. This i: proL'ably d,re lrr lhe end of reproducti're cyele arrd lhe 

reduciion of qener3l a':tF/it-! c'f the tsnim,3lr bv the auh-mn [Lang. 13871. 

IWilsoh,EO. 1975. Soclobiologv: the n€'./ st/rilhesis CJmbricigo, Mass.:B€lknsF Press 

L€shner. A 1978. An inlroduLlion lo behavioral endocrindlosv. NewYorl.r L)xord Univ. 

Brain, P.F- 1979. Elecls otthe t,ormones ollhe pnuitary gonadalaxis on b€'haviour. p.155- 

329 In: Ctromical influ6noes on behav,6ur. K Brown o S J Cooper lEdr l. New York. 

Acad€nric Pregs

Conclusions 

205 

AJ Alth*ugfr agonrrhc rt'rtetaLrtrr:,r'ri Inny nrJt IEprB::ent the rrrain ':ause of 

rnortalit!t rn c.iptitirt!. they enrr significantll,r rBduce a.nptrve col,rnv of braad-nDsed 

caiman. 

El l',{o.:t,ri iha.lgBni,:lic int,"I-ttiDn,i ott:ur by the introdu.tiBn ol arr animal 

into =n en*l,:i:ure fqtrrret!t orcuF,ied b-r' = lorrel-v ttrd*iidt.t:l ThBIefore. the 

Fe.tnanence cf knlated atrirrr'eh iot lorrq p-:ri'.'d:, :houlci be a'.,oided- 

t:] |'l':':! ':i tl're ag!-rn!ltii- rnte!n'rtinno- .t'.ut durirrg ihe fifs! dai,' c'i Lhe !I,lr-lF 

aslernblv ,:r the nelv in,jiridual intr.ducli.rtl inlo tlrE SrL-ruF. Ti'retef c,re- thi'; thor-"rld 

be c,r-,n:rrdered the nrinirrurr pariod,:,1 E net"r qt.rLrF Fbsel'i-liqr' ih order to isolate 

rnd rerrrr-rve if'6 rndt'/idunl whir,h t.,, :rrt.rEotrtued. 

tr I .rirrirrral',. L'f the :.ame res CD rrot pre.Enl ; different tendency to fight than 

atirnal.: oi diflerent ser:. Therei':te- rer seemE nDl tD be deciei+e in rel.rtion to 

eor:i.:i aqtes:.ive bef':viot,,3t len;t in caFtivity 

Eibic,;t of the,rqtrnislrc rnletdction! o'r,:ur amlllg ddult$ with differetrt oriqin 

Thereff,re. rotl3iderinq the geneti.- manngefirent of the aLrlDnt. rrel4 teprodt-lctF/e 

qroups should F,,a arserntled t5. -f.-'rlrrgs ar lrb-adultJ. 

Fl Fept':durtive gro,-rFi sft.ruld F ltferabll' be .ersernbled by animals whicfr 

tl'e $,"itlht t,Jhu dc, rlnl erceed Li. 

Gi The no:t adeqr-rnlF. perioll to ieprc,ducti'Je gloup ntsenrtrly in 5Eo Faula 

State- Erazii tt lerms Lrf ngqtt:Eive social behaviot, seeris til be the autun-,n' Irorrr 

Aoril 1o,,1|Jne 


f'I,r.664tr-032 

Fr,indo h,iut-,di.:l pern 3 Natultzd - t'v WF. f'tor:ess 

Inrtiirt,r de P*sqr-risas e E:tndar F[:re':tais - IFEF 

Frrnda;.Jr-r de E studo;.5.gririos "Lui: de Queire=" . FEALQ

206 

Liter6ture Cited 

Ayar:agu€na. J. 1S3, Ecologia del caiman de arrt€oio. o baba ((:tim_an c.oc-odilus L ) en 

los llar|os d6 Apur€ (V€nszuela). Dofrana Acla Vedebrata tqg) 9135. 

B||sbin. 1.L.. Jr. 199O. Growih cuN€ ahalyses and lheir application to thc cons6ru:rti()n anij 

oaplivo mabagoment of crooodilians. o 1'16-145.ln Proc.glhWolk Meret Croc. Sp6c croup 

Vol. 1. IUCN - Thc Wodd Cons€rvalion Uniorl. clan SwiE€rlahd. F. l-393. 

Bu3iard, H. 1971. The scop6 of the discrtssion; lh€ worldwade situalion ol cr

Lang.,J. 1989. Socialbehavior p. 102.1 17.Inr Roe3. CA [Edt.]. Crocodtl6s and alllg.lort. 

Geldom prr.ss Silvorwatdt. Arslalra p | 2,4O 

20'7 

Larri€ra. A. 1990. A program ot moniloring and recov€ring ol caiman'3 population in Arg€ntirta 

wilh rh€ arm ol manage.nenl p 1-5.|h Pro.. lOh Work Meet. Croc Sp€c. Groqp. Vol. 2, 

IUCN - Tf'., World Conso'vatron Union Gla'r..|. 9wiEerland. p 1345. 

Larsen, R.E.r Cardeilhac, F. & Godwin. F 1988. Arlillcial il|seminaiion in lhe Amsrican 

alligalor. Proc Ann. M€61. Soc l-h€riogonolo€ry. p.284-292. 

La:oll. .J.D & st,it .r. N C 19?7 Appar.nl play traha\r'ror in an Atnodcan alligalor. Capeia 

Magnur.oh, W.E. 1986. The poculiarilio3 ot crocoditran populalioh dynamics lnd th+ir 

po3srbb imponancolor managemer etraiogr6i. p.434442.lhr Proc. ?th Wotk. M€cl. Croc. 

Spec. Group. IUCN - Th€ Wortd C.)nseNation Urlion (:land, Switzerlahd. p. 1-446. 

Mollhcnny, 6.n. 1935. Th+ allignler's lilr hielory Chiislophor Publ. Housc. Bostoh. MaJt- p. l- 

117 

M€ssel H & Vr,rlicok. G C 19a7. A r,optrtalron mod€llor c.ocodvlur F-gta!!A in *r€ Tidal 

Watorwayr ol Norlhern Aulualia: minagemenl implicalions p. l8!1.1S In: W.'bb, C.J.W.I 

Manoli$. S (; & Whrl.he.d P.J [Ed:r ] Sultey Beatt Chippho Norlon. Auslralia. p 1-562 

Morneg, G. [Ed.l. 1983 Falna arg6htina el yacare 6ato Cenlr€ Edilor do Amerrca Lallna. 

Bu{,ho. Airee. p. l-3? 

N^li,rnrlResearch Council 1983. Croc(Jdile3 a3 a rasourc€ lor th., troFrca. NanoâlAcadomy 

p|d5i Was{rington, D C. p. 1.62 

r:laftros MCC.:Malushrn..F: H.. Veldads. LM iCarvall)o.V.M & Sahoh€3, F. In pr.ss. 

tridrof'iola t,a..!6r;rna ;!(!l6hi.ra .ral dc ia.,116s-cle-paFojtm^reht {Ctiman ltliraslti3): 

rmpitcagao no man€lo €m caaiv€rro lOp in Veldadc,L.M & Lavorentt A [Ed$l Anaisdoll 

workshop robro coh$$rvasAo e Man€io do Jacar6-do-Pdpo-Anrar€lo (Caimlft lalirgrkl$ 

i:SAL(J (rfiiver*itv ol Sli$ Fatllo, piracjeaba, Braril. 

Verdad6. L M. & Lavor€ntr. A. 1990 f'reliminary noles on lhs stalus ahd cons€rualion ol 

caiman laliio.tras in the State ol Sao Pa(,1o. Brazil. diraclions o, tho caPlivc brlgdang. 

reantrociuclioh arld manag.rment prcgram. F 231-237. In: Proc 1olh Wo.k. Me€i. Croc. Sp€c. 

croup. Vol. 2. IUCN - Th€ Wortd Corrserualion Union. Gland. SwiEsrland. P. 1_345. 

Vli.t, K.A. t98? Socral and r?llro(tu4livn behavior rtl $1€ slligalor F 32-3iJ.lhr Ctr{Jnilhtc, P; 

Lrn€.T.&Larse .R.H.[Fdx] Proc znd Ann. Alligalor Frod. Conl. Univor$rv ol Florida, 

Gainesvills e 1-52. 

1986. Social behtvior ot tho Ama'rrcan alligatot f, ?4a211. Ini Proc. 7h Work Meel 

Croc SD€c. Giouo. IUCN - Thc World Corserualion Unioh, (iland. Swiaerland. p 1-446.

208 

Vliet K A. 1S9. 56cial display$ ol lhe American aria{Jtor. Am6r. .zool. 29(3}:101+.1{]31 

W€bb. G..j.W.: Buokwo|ih. Fl, & [4.hotis, S.C. 1983a C]ocodylus iqbnlaoi tn a controllcd 

gnvironmerrl chamber: a raiiing trail. Au.lralian Wil.ll. Fl€s. tO(2t 421.a32 

Wiienberger, J.F. Animal soclal b6havior. Duxbur/ Presr, Boalor| 198l 721F. 

Yanoslry. A A 199O. Hisloite naturolla du caiman.rnu3dau larg6 (Caim:rn |rtlrortti.). url 

Alligaiorin6 mai connu. R€vue lr. Aquariol. 111):lgiio 

Zwan. P. | 978. lhl.cliol.l' di.€as6s ol reptiles p 155-162- In Fowl€r, M E. [Ed I 7oo & wilri 

anamalmedici'l€. W.B. Saund€ri. P'lriladclphia IJSA r, l -?ils

c 

.9 o6 

o 

.= 

.9 

.9, 

c 

o 

CD 

(t 

a 

q, 

] 

o 

o 

E 

.g oo 

c, 

= 

a 

'6 

CL 

a 

o 

o AI 

o 

.9 

TL 

o 

o 

a qt 

q, 

o 

o 

o ED 

6 

o 

o 

z 

o 

o 

o 

o 

'-c 

o 

.5 

I qt 

E 

E (! 

('o L 

o 

lt 

E 

= 

c.

2lr 

ci 

i 

-(l) 

oq) 

d{e 

9cr 

a)L (tr 

o 

at, 

o 

..{ cf 

9a 

9tu 

+F 

-fit 

q 

o 

o 

o 

o 

(! 

o 

at 

tt) 

(! 

.i 

z 

.9 

(, 

(! 

o 

:0 

.9 

o 

o, 

d 

q, 

(U 

3 

o 

o 

E 

'6 

o 

- 

.: (t, 

c 

o 

E 

(o 

.E 

(! 

ot- 

o 

o 

o 

ul 

(Y) 

q, 

Lr-

212 

o c. 

.o 

o o0) 

.E 

.c 

!2 Coot 

G 

o o 

6 

.E oo 

.E c(l, 

o x 

o rf 

E 

.9 

lr 

o o 

(u 

E o 

l!= :i< 

x+ (\l 

O-, 

I (uEo 

II 

\ \: 

o (, 

(0 

=^ 

-s 

x@ 

osy 

-9 

(u 

c. 

(\, 

(\^ 

vi3 

o (g 

E 

0) 

lJ- 

I 

o 

ct 

E 

o 

l!- 

Xi 

g's 

o 

6 

o 

o 

o 

{, 

0 

o 

c 

z

o c 

.9 o(It 

o 

:0 

,9 

o 

(t 

6 

.E 

oo 

: 

o 

.; 

d 

.E 

c 

cl 

o 

E 

o 

c. 

o 

J 

lct 

o = 

.9 

lt 

@rt$lO 

@@ 

!tato 

o 

ol 

o oAI 

I 

ct 

o d, 

I 

@= 

213 

=+. 

.!9 

Jb 

(, 

og 

s.o 

ir 

N 

o 

ol 

I 

o 

o o

2r4 

g, 

.9 C) 

ct 

o 

:e 

.2 

o 

o, 

(6 

; 

o 

.; 

o 

E 

.E 

o 

o 

c 

.9 o 

@ 

o a 

.9 

lJ- 

a, 

() 

(5 

{l) 

o 

o 

([ 

o 

^ 

z 

o 

lo 

ro 

o 

'+ 

O^ 

!t o) 

Y,Y 

ov 

"o 

E c 

6(g *E 

oo) 

:.- o 

9ts 

o 

u)

ao 

C 

.9 c) 

(d 

o 

.g 

.9 

I coCD 

(tt 

.= 

E o 

: 

o 

.c 

(, 

c 

.E 

c 

(t 

CD 

C 

o 

E 

6 

.9 6 

c (' 

c 

o 

J 

T\ 

= 

.9 

lJ- 

6 

.9 

() 

(! 

o 

,; 

:2 

o ol 

6 

o 

ct 

z 

-c 

ctt 

ttc 

ci9 

O-l 

--o 

I 

J 

o 

c 

o 

û 

'-: c) 

ol oD 

,a .r, 

=o ot 

o, 

(u 

ot 

6C 

=o 

Crl +. 

Fc 

o 

I 

f 

o 

o 

..: o 

5U, 

@o 

o 

.9 oct 

o 

.g 

.9 

.9 coo, 

(! 

; 

o 

o 

n(I' 

E c(E 

Ot 

o 

E 

$ 

.9 

(! 

.c 

,9 o 

di 

o 

.9 

lJ- 

.D 

o 

o 6 

o 

o 

o 0o 

o 

z 

(! 

f 

.c. 

.9' 

o3 

o (l) 

o o 

ol 

^. o, 

'-r (d 

6\ 

qo 

.9 o= 

o 

o, 

o, 

(u 

ot

; 

0) 

q) 

o) 

@ 

.9 C) 

(U 

o 

,c o 

o 

o o) 

(t' 

o 

.9 

"o 

(r, 

o 

o, 

o 

.9 

lr 

v, 

() 

(d 

o 

o 

o 

(tt 

o 

z 

l'1 

z I 

a f 

J 

D.) 

I 

(EX 

(L5 

q, 

-o 

{) 

c, 

o 

l\- 

rr ot 

ll 

()o 

= 

t 

; 

!, , 

o 

o 

1' 

.9 

tu

218 

Status of Captive Population of Broad-nosed Caiman (C.atmao 

lqluos&id in Brazil 

Luciano M. Verdad€* & M.E.B. Santiago*" 

' Studbook-keeper of the Broad-nosed Caiman Regional Studbook 


University of Sao Paulo 

Caixa Postal 09 

Piracicaba | 34OO SP BRAZIL 

** Parque Zool6qico Municipal d€ Bauru 

Pg. das Cerej€iras. 1- 59 

Caixa Postal 271 

Bauru 1 7'l OO SP BRAZIL

219 

Stdtus ot captiye population of broad-nosed caiman lCnimnn laUlqsldsJ in 

Erazil 

Luciano M. Verdade["] & M.E.B. Santiago[."] 

["] Studbook-keeper Df the broad-nosed caiman Regional Studbook 

CIZBAS / ESALQ / University of 56o Paulo 

Cx. P. 05 13400 Piracicaba SP BFIAZIL 

[*"J Parq']e Zool6qico h,lunicipal de B autu 

Pq. das Cereleiras. 1 -59 

Cx.P.2?1 17100 Bauru 5F BllAZlL 

The broad-nosed caiman is an endanqered Erazilian crocodilian. lts skin is 

considered bettet fot manufacturing goods th€n that ot glin4 crocodilus 

becar.rse it has le:s osteoderms in the belly skin. This is causing an increase in the 

level of inlerest in its fatming itr southetn and southeastern Btazil. 

The remnant populations are possibly depleted and fragmented by habitEt 

deekuction. The State of S5o Paulo had only 8.62 of its original native 

ecossystems until 1973, and will possibly have around 3.02 until the year 2080 

f/lCTOFl.1S75l, There are some preliminaty observations on the apparent 

colonization of broad-nosed caiman in environments such as small dams and 

decanting ponds of indushial ot human drainage IVERDADE & LAVORENTI, 

19901. There ate also some reports about the appearance of animals in suburban 

areas. even in big cities like Sdo Paulo end Fio de Janeito, 

The lack of information about the actual dishibution and possible nesting 

sites of these remnant tropulations maRes it diflicult to start a progtam on 

populational self reeovering based on the collection of eggs in the wild. ot 

ranching- like is being carryed out with success by Laniera [1990 and l991] in 

Santa Fe. Arqehtina. On the othe. hdnd. broad-nosed caiman has been a very 

common native strecies in Braailian zoos. although fiequently not consideted of 

greal importance. Nevettheless, trocradays. any plogrom of recovering. 

reintroducing and farminq. should start with a captiva propdgation ptogtam based 

on the real existing eaptive colony inZoos, research cenlers and other institutions.

220 

Materials t Methods 

We based our study on the Feptile Censuses of Etaziliatr Society of Zoos 

from 1984 to 1 991 , the Flegional Suldbook ol the hroad-nr-lsed caimon / 1 991 . and 

on direct consultalion lo lhe Erazilian Zaos staff. 

Resulls & Discussions 

The Fleptilian Census / 1991 by Bra:ilian 5 ociety oi Zoos reported 331 

broad-nosed caimans distributed in Zoos, research cerrters nnd othel ilstilutions. 

The captive colony hos been incteaging in the last yeat! [Fig. ll. Hoh,et/er, thls 

expdnsion is basically drre lo wild-caught animalx instead ol qoFtive'barn DnEs. 

The Flegional 5tudbook of this species repotted 183 animals spread in 19 

instituti€n$ in 1391- Around 40?; Df lhese animals were captive born, althouglr the 

r:olony of flZBAS .,r ESALQ .,'Univereity ol 55o Faulo. the bigge:.t in BtEail, 

FrEsenled a rdte ol 902. 

The sex r€lio of the Studbook colont'is apptoxrmatellg 6 moles,' 3lemales / 

2 indetermined. The teal numbets ate: 93 males.47 femeles and 37 itrdetermined. 

Some seriing mistakes moy happen, althaugh thE Z€'os staffs do not ccnsider 

sexing ':rocodilians a difficult tdsk. T raretrtg-two 

[44.7?] of the females are 

apparently adults. but just thtee bred suecesfully in the reproduclive perio'J of 139D 

i 13Sl and pnssibly iust one in the last tepraduElive treriod. Ies'rlting in 36 

hair-hlings in .l931 snd lusl 13 in 1992. 

9BvBn institutic,ns crf nineteen included in the 9tudbook [36.821 have 

reported nestinq al least once in itre la$t yeds, but iust 57.12 of the reForted trests 

were suceeifull, witlr a low nrean of 7 hatchlings per nBst. Ianging flom 1 to 31 in a 

medr, flulch :ize of 33 eggs Per nest. 

Only five institutions [28.3i;l sy:tematically m:rk l]reir arrimals individuallvand 

eight [42.lZl present some difiiculty in identilyinq Btazili€n cloDodilians. 

Age-pyramid of the Sludboak calonJr is completely btoken-r.tp- Thete is a 

great demand al youngs to enlarge lhe age-trtramid base [Fiq. :1.

221 

taplive ptopagation of br.-rdd-nosed caiman in Bt:iil nray be cun:idered 

insipient, altt'rough it is a relatively cornn otr :pecies in Btazilian Zoos Horryever a 

fe,ar zoas have alread-f' reported suocesfull reproduDtic'ns. Eqg incubalic,n seems to 

be the mort urgenl techniqu,e lo be managed to aviid loss of embryos or even 

v,'flsle ':iuh:l'res drrtin,f irrcubation Fretiod inta lhr, rresl 

The rnstitutions should n-|ark animals individual!' and certify tl'remsel'res 

6baut lhe sEeEies taxrrnorrri': identiiicat|on to al'oid l'-res ol data ahout tlietr 

ciJlLlnies. 

The rnarnten;..r-,i:e trl Fraziftau F'apulntion: af btoadlo:'ed cairnan in A'tex I 

of IITES is ulrri,::t importent beoause oi the lollc,wirrg reasons. poor captive 

FroEaqatir,n, deslruction of habitai!- illegnl l-'untinq FrBssule- and the lack !f 

irriormaliorr r-rn {.+ild pop'rlations. 

lBAh4A - Erazitiarr rlrildlife Aqericy is starting tn liberatF troad-nosed *ainran 

farms ior commetcial Furpr,-;e: lt miqht hove beneficial con*equences fc't the 

rFeDiFs r:.rn:retvalion. Ne\/erthelee!, lhe incleaslug interest of potencial fatmers 

and the FrEsant impo:,sibility af tanching srrcces: rn y resull in arl immBdi€te 

depletion .-,f the .emnarit Fr-rpulatiorr* lhreugh the captule af '.Îild .snarnals ta 

assembly captive breedir-rg qroups in tl're fatrns. To avoid.luch pressure on r"rlld 

pc'puldtiens, captive-horn anin.rals should he u-',Ed instead c,f ','.tild-born onas. T he 

latter 'rould only be captured dnd tlansferted to fetms when they ore in ptoblematic 

situ.rtiBn whi'rh mag represent tiskt tc, thts survival of the.inimal$. lo l]umarrs or 

tivestock (VEFDADE & SAI'ITlAGO. 1 5Slil. 


Furrdo Murrdral para a Natr-rle?i 'WV/F. Proeess No. E64ll-032. 

FundagE:' de Estudas AgrErios "Luiz de Oueitoz" - FEALQ 

Instituto de Fe,;quiras e Estudas Fl':restais - IFEF

. 

222 

Literdture Cited 

ilenso de animais- 1385. Sociedade de Zool6gicos do Erasil. Ssrocaba. Brazil. No 

pagandted. 

Censo de oninrais. 1 386/1 987. Sociedade de Zorrldgrcos do Brasil- 5 orocsba. 

Erazil. Nr: paginated. 

[enso de Feptais. 1 9l]S Sociedade di ZoolAgicos do Braril. Sorocaba- Era:il. 

65o. 

fenso de €nimais. 1 990. Sociedade de Zool6gicos dr: Brasil. Sorocaba. Erazil. 

94p. 

Censo de Animais. 1 991. Sociedade de Zool6gicos do Frasil. Sorocaba. Brazil. 

93o. 

Laniera.A. 1990. A program af rnonitoring and re+overing of caiman's populatior in 

A,rgentints with the airn o[ management. p.l-5. In: Proc. 1oth Wo4,:. Meet. Croc. 

Spec. 6roup. lUtrN'The\dorld Conservation Union. Gland. Switzerland. Vr:|. 2. 

345o. 

. 1931. A program of manitoring ar'd recovering of wild rrr*,puloatiDns ol 

c€imane in Ar:lantin,: r"+ith the aim of manalement. Fragress report 1:t Beg. Wr:rk. 

ldeet. Crou:. Spec. Group. Santa h4arta. Colombia, T-1 1 November'139'1. 7p. 

Fegional Studbook of the broad-nosed caiman lCaiman latirqstrisl. 19S1 . ESALQ 

/ Unrversrty ol SEo Paulo. Pitacicaba. Btazil. 33p. 

Verdade. L.M. & Santiaqo. M.E.B [Eds.]. 193ff. .Anais do I Workshop sobre 

ConservagHo e M aneio do iacare.de-papo-amarelo lCaimin lrtircrlr$]. ESALQ / 

University ol SEo Paulo, Firacicaba. Erazil. 34p.

223 

Verdade. L t*l & Lavorenti. A. 1 990. Preliminary note$ Dn the status and 

conservation of ttimtg blitO$rlf in the State of 56o Paulo. Brazil directions of 

.iaFtive breeding. reintroduction and management ptollram. p.231-237. lrr: Ptoc. 

1Oth Work. l.,leet. Crurr. Spec. Group, IUCN - TheWorld Conservation Union. 

Gland. 5wileerland Vsl. 2 345F. 

Victor. M A,M. 1375. A devastagEo 

llotestal soc. Bras. Silviculiura. 

55o Patdo, 

BrE:il 4Bo

(tt 

-o) 

He 

6g 

c(' 

>rF 

6t 

8s 

9,3 

o, 0) 

Gto 

oo 

c9 

Efi 

.=,* 

cto 

') o 

6H g 

gtx tt 

= .r, 

ic E 

c 

ct= 

Od 

9! 

E 

oI c; 

oq = 

3e 5 

9o ; 

8sB 

r- 

o 

.9 

lJ- 

o- 

o(t 

C' 

o () 

o 

() 

N 

o AI 

o 

ro 

o 

q) 

o 

o 

g) 

gr 

o 

@ 

o) 

o 

o' 

F.P 

coY 

o) rl 

rvo 

q, 

o! 

a0 

a 

o 

(tt 

lI)c 

o.9 

or= E 

o 

{,= 

co 

.9 oe 

F 

..:

Figqre 2: Ag6.pyramid ol b.oad-noe€d c.iman captiv€ colo.iy in Brazil 

(knovfi aged animats) 

As" 

4 

3 

1 

0 

F6rndei 

?::: 

7::t:!t.1r,: 

N=21 

PS: Exlractod fom the broad-nos6d caiman Rsgional Studbook,/ 1991 

225

226 

Prelimina.y Not€s on N€sting Biology oI the Broad-nosed Caiman 

(Caiman hlilgtlrrt) in Seo Paulo. Bra-zil 

l-uciano M. Verdade. A. Lavor€nri. F. Michelotti, M.C. Rangel. L- Cullen & 

M M. L.rnandes 


U nivLlfsity ol S5o Paulo 

Caixa Postal Og 

Piracrcaba 134OO SP BRAZIL

227 

Preliminary notes on nesting Eiolog_v of ihe broad-nosed caiman [Laie0a0 

iilitr*tnrl in S5o Paulo, Brazil 

Luciarro f.4. Verdede. A. Lavorenti. F Miche!:tli, l'4.C. Fanqel. L fullen & M.M. 

Ern.:nder 

l.lzF.qi /' F5AL[ ,' lJrri'retgty of !5,: Paulc, 

llr. P t-l:l ! ll40D Firacicaba :lP FFAZIL 

lnlroductiqn 

Tl'lere arE iiar19 !eFrrft! ,ll rucc,estrill cror:odilian,: cap,tirre F opsgahon 

Eroed'nored caiman specifically has also been reporied to have been succesfull,|, 

reprodu*ed in coplivitj,r {Ractra e I il" a & Zuquim Antas, I901 ; Arronimous. | 988; 

Widhoher et al.. 1S8E: L.arriera. 1 938 end t/erdndE i', Lav'rrenli. 1 99L1J However. 

its large dlstrihution zDne dFmand! rr,lre Infornr.iticn on its nesling BiolLrgf to 

inDrEsse ils iapli\.e prapeg3tinr'. 

l'{aterials & Methods 

l,rje reported 17 nest.: ,-rf hruad-r-r'.,secl cainran in Laptivity an SaLr PnrdB Sl€t* 

lrorir 19EF; !o 1ils?. Nine r-,f there nesls t.,ere located ir' the facilities oi ESALQ / 

Unilersity ol S5o Par-rlo, six inioc,s. ond trnr':, in other irrstilutinrts.

228 

Besults & Discussion 

The nunrber of rep,rrted nells can be considered s.ndll Dompared to studies 

conducted r,rith Fther crocodilians [r't/ilkirrssn. 1 984 and Cattroneau & Chabteck. 

19901. However. this paper represents thr maiDr repnrt for this speries in Erazil. 

Generally, the nest materials followed ttre mound-nest pattean desDribed ir.) 

the literdture fGreer" 1970; Martin. 1977 and Ferguson, |985]. The nest sizes 

presented in Table- 1shor"" thdt there is no signiiicant diftptence belween nests 

that ha\ne soil ac a content, and thase tlrat do not. As a result, t^,e cnn infer lhat 

nests are built up nith a rel€tively c'trnst€nt size. 5o . at least in captivity.. can te 

used ordy lo complete the "normal" nest size. The fact that soil as a content wa$ 

found only where there wos apparently not enough amounl of lear/es and debris 

reems to corrobcrate this ided. Laniera [personal communication] has been linding 

two basic nesting sites in the Argentinean "pampds": savanna-nest and fotestnBSt. 

The latter ulually presents soil Es one of the maiil contents. ptobably also due 

lo the smoller otler of leaves and debris on the forest oround lhdn on lhe savannd 

ground- 

Table 2 shows sonre other reeults on nesting Biology. The nests wete 

located around 2 meters far fiom the wdter pond in average. ranging lrom 0 to 7 

meters. The incubation period ranged from 73 to 33 da_vs [77.5 in average). The 

clutch size ranged fronr 1S to 49 [33 in average] with a relativelg low rate ol alive 

hatehlings per rrest: 7 33 ranging from 0 io 31. The mean egg weight was 70.89 q 

each. ranging fiom 60 to 82.2 q. The eggs maior diameier measured 6.73 cn'r. 

ranging fiom 6 to 7.5 cm, u+hile the minar diameter measured 4-28 cm. ranging frcm 

3.4 to 4.5 cm. The hatchlings weiqhted 47.61 g in average, rangir'g fiom 3S to 63q 

each, and measured 24.65 cm total length" rarrqing from 21.3 to 27 cm. The dams 

weiqhted ?9.52 kq in average- ranging from 15 to 59.7 kg. ar'd measured 88.83cm 

mB.rn snout-vent length, ranging lrom 7tl to 110 cm. The sires weighted 37.95 kg 

in auerage. ranging irom 30 to 64 kg and measured 95.04 cff. rfiean snout-vent 

length- ranging from 90 to 109 cm.

229 

The nesting Feriod slarted in late flctober and linished in mid Febru€ry,,ith d 

pick in Jarruaru. while the hotchinq period :torted in eady Febnrary and ended in 

middle.April. with a peak in March [Fig. .l l. 

Almost all of the femeles i94.4?jl esibited maternal behavior durng 

incubalion period. bul contr€ry to the observations ,rf \,r/idholeer et al. [j986l. no 

m.:le had teen seen to e:

230 

Litetatute Cited 

Anonrmous. 19€6. Nasoeu a Fnmoi.t nirthada d€ iacare do CIZBAS' Jornal

i act€ I N€:t sEes 

Heighl (cm) 

Longlh (cm) 

Widlh (cm) 

Chi-rquar6 Test: 

Heiehr 

Longth 

\A,id|}r 

(samples A & B) 

49_2 

134.2 

103.4 

2 

)< 

1.541 

2.94S 

415.18 

30.56: 

42,55 

Nests wilh loil 

(sa.nple A) 

-m)a 

> 2t)'" 

> 5.1. 

42 

1tg 

104 

10.65.1 

34.63:i 

17.41: 

'rabb 2: Nestihg behavior ol broad-nosod caiman in captMiy in Sao Paulo State, Brazil 

(P€.riod l9a5 - 199a1 

Distanc€ kom th6 wale. (m) 

Incubalioh p€riod (daF) 

No. ol69gs p€r nest 

Siza ol €ggs - lsnglh (cm) 

- width (crn) 

\,v€ighl ol 6qgs (g) 

No. ol hatchling3 p6r nest 

Sk€ ol halchlings 

Worght ot hatchlings (g) 

Wgighl ol dams (kg) 

Woight ol sires (kg) 

Snoutvenl l6hg h ol dams (crn) 

Qno!!y9ll|lP!9th 9!_s'I93 G!!L I 

N: Sample siz6 

sd: Standard davialion 

CV : Coslid€nl ol varielion 

231 

I N6sta wilhoul 3oil 

:r (samPle B) 

s4.3 

145.7 

102.9 

cv% m4or N 

39.59 

27,41 

56,Oi 

7 | 16 n6sts 

77,5 3.Ol I 3.Aa 

9:] | 90 eggs 

3:| 10.63 | 3?.2 1a 49 | 12 ê3t3 

4,?A o.2 | 4,54 3.4 4,5 | 123 6gss 

6.73 o.3 4.59 6 7,s l 123 osgc 

7(),49 5,64 7.95 60 42.2 | 156 69gs 

7,33 1l 14S.$) I 31 | 12 nesis 

2{,5s I 1,15 '1.66 21.S 27 | 50 hatch. 

47.6r I Lr8 17.14 36 63 | 50 hatch. 

29.52 | 10.61 35.92 1s I 59,7 | 15 damg 

37.S{' I I o.o4 26.44 sol 64 | 15 dam6 

80.33 | e,32 11,52 701 110lt3.ires 

t__s.7s I_ 9,05 |_.sO l_ _.-l_q I 13 3ir€s 

_._ _gs:::q!_

o 

6 

o 

.E =qt 

';o) trol 

ii o, 

Ee 

8o 

eo 

IP 

(n .. 

o>\ 

EE 

Eu' 

gE 

EE 

o.'f 

s3 

ON 

EE 

so 

Eo 

(UE 

?6 

Eo 

at, = 

2E 

t'j 

E 

a 

.9 

lI- 

o o 

t! 

9.- 

:o 

ri 

E! 

:9 

:? 

.tz 

oz 

() 

o 

ct 

.ll o 

t! 

(p 

I 

!r o- 

(r 

@ 

lrJ 

tt 

z 

o ut 

o 

F 

o 

o 

ttJ 

CD 

E 

o G 

I 

f I 

E' 

F oo 

z 

o 

o 

at 

c 

F- 

,i.l 

q 

o 

E E 

c 

o

CROCODILE MANAGEMENT AND RESEARCII 

IN THE NORTHERN TERRITORY: 1990-92. 

Grahame J.W. Webb, S. Charlie Mruolis, Breta Otlef 

and Andrew Heywardl 

G. Webb hy. Limiled, P.O. Box 38151, Winnellie, N.T.0821; 

Conservation Commission of the Northem Territory, P.O. Box 496, 

Palmersron, N.T. 0831; and, *Modical School, University of Adelaide, G.P.O. Box 

498, Adclaidc, S.A. 5001, Australia 

The central a;m of this paper is to summarise thc progrcss that has becn 

made with crocodilo research and managcment in the Northern Terrir.ory, in 

the last 2 years (April 1990 to July 1992). [n this regard, it complcmcnls the 

previous three updates presentcd at successive Crocodilc Specialist Croup 

(CSG) meetings t1986, 1988, 1990 (Manolis and Wcbb 1990; Webb 1989a: Wcbb 

et al. l990a\1. As before, it also includcs morc dctailcd results oI somc studrcs 

considered significant to CSG mcmbcrs. 

MANAGEMENT PROGRAMS 

Both spccies of crocodilian (Crocodltlus porosus and C. johnstoni) ir the 

Northem Territory are on Appendix Il of CITES. Croco.ltlus johnstoni has 

always becn on Appendix II, whereas C.porosus was lransfcrred from 

Appendix I to Appendix II, for the purposes of ranchhg, in l9tl5 (Webb e, al. 

1984). 

Within Australia, wildlife conservation and managcment is a 

State,/Torritory responsibiliry, bu! the export and import of wildlife and 

products derived from thcm, into or out of Australia, is a Commonwealth 

responsibility. It is controlled by lhe Australian Customs Sgrvice and lhe 

Australian National Parks and Wildlifc Service (ANPWS), according to rhe 

provisions of the Wildlife Protection (Regulation of Exports and Imnorls) Act 

l9]la. This Act makes export and imporl of species listed in CITES appcndiccs 

subjcct to the Fcderal Minister approving Managemen! Programs for thosc 

specics. 

The currcni Norlhcrn Tcritory Crocodile Management Program, approved 

in January 1990 (CCNT 1989), addresses the management of both spccies of 

crocodile and is currenl lor 5 years. h describes the ranching program for C. 

polosri, which involves a widespread egg harvest and the limited taking of 

older stock for farming purposcs. It also describes the program lor C. 

johnstoni, which involvcs bolh cgg and hatchling harvcsts. I1 details 

maximum levels of harvest from the wild of all stock, for all purposes, 

including animals ronrovcd as "problem" crocodilcs and animals usod for 

rcscarch. It also contains a protocol for altering those limits from year to 

year. Currcnl (1992) annual harvcsl limits are: 

Viable Eggs 

Hatchlings 

Juvcnilcs 

Adults 

C. porosus 

15,000 

400 

500 

250 

C . johnstoni 

4000 

6000 

1000 

200

234 

The Managemcnt Program also details thc moniloring programs caricd 

out on the wild populations, and the manner in which captive stocks on thc 

six registercd crocodile farms are bo[h regulatcd and monirorcd. Under thc 

auspices of tho Managoment Program, consideration has now bccn given rc a 

"Crocodilc Industry Strategy". It will lead to increased involvement in 

crocodile farming by both thc Dcparrment of Primary Indusrry and Fishcrics 

and the Dcpartment of Industrics and Devclopmcnt. 

MONITORING . PROBLEM CROCODILES 

Since April 1990, there has been onc fatal attack (on Groo!€ Eylandt) a d 

one serious but non-fatal attack in thc Daly Rivcr (Fig. 1; a C. porosts entcred 

a tcnt at night and atlacked a woman). A number of minor incidenls havc 

bccn reportcd, particularly with fishermen, and somc have received mcdia 

attention. Ovcrall, the rcsponse from rhe public has bcen objective and 

rational, allhough calls for culling continue. Thc cconomic valuc of 

crocodiles in the Norlhcrn Territory is thc single most importanr inccntivc 

Ior the public to accept the ncgative side of having largc wild populations oI 

C.porosus throughout thc coastal wctlands. 

As pan of the public safcty campaign within thc Northem Territory, 

"problem" crocodiles are removed from the wild and assigncd to crocodilc 

farms. Such animals are broadly defined as "those wilhin scttled areas or 

areas of intcnse recreational use wherg public safety is a prirne 

considcration and those individuals which affect a land-use activity (c.a. 

takinS stock on pastoral land). In intensive conlact arcas such as Darwin 

Harbour and Cove recreational bcaches, any crocodilc, rcgardless of speeics 

or size, constitutes a 'problcm"' (CCNT 1989). 

During 1990 and 1991,457 problcm C.2orosas were deatr wilh by thc 

Conscrvation Commission (Tablc 1). Of these, 431 (94.3Eo) were distributed to 

crocodile farms, 19 (4.2o/a) wcrc rclocared in rhc wild, 6 (1.370) dicd al capturc 

^nd 1

S- - ^r\^ 

A "L

236 

MONITORING - HARVESTS 

Crocotl!lus johnsrori Harvests 

Egg and hatchling harvesls for 1990 and 1991 are summariscd in Table 2. 

Altogether, 3390 eggs wcre collected, of which 3024 conraincd live embryos 

and were considered viable (89.2o/a\: the remainder were either infertile 

(4.2Vo) ot dead prior to collection (6.67o). A proportion of the viable cggs 

Ioc^red

disturbancc to all unwary crocodiles: thc pcrccntage of the total populalron 

sighted afte( thc harvcsr may wcll have becn lowcr than rhe percenlagc 

sishtcd beforc lhe harvest. 

Crocodtlus polrrxr Dgg Harvest 

Thc resulls of C. porosus egg harvesting are on Tablc 4. Crocodylus porosus 

have a prolonged ncsting pcriod (Novembcr to May) that coincides with thc 

wel season. Largc numbers of cggs arc flooded before collection, and in somc 

locations where nesls are conslructcd in the open, the eggs overheat (Wcbb 

and Cooper-Preston 1989). Thcrc is also a significant relationship bctwecn 

rhe exlent of mo(ality in rhe ficld and thc cxlent of morrality after collcction 

lduring arlificjal incubarion;Wcbb (1989b)1. Thus allhough our assessmcnls 

of "viablc" eggs are based on live embryos at the timc of collccrion, many of 

those embryos arc alrcady compromised. Variation in thc numbcrs of cggs 

harvcslcd each ycar (Table 4) rellects annual vadation in ncsting cfforl 

(webb et al. 1990a). and also variation in ha est areas. Annual variation rn 

nesting effort for some areas is summariscd on Tablc 5. 

Tablc 4. Numben of C. porosus eggs haryestcd lrom the wild with an 

asscssment of viabilily (containinS live embryos at the time of 

collection), and lhe percentage of viable eggs. thal produccd viablc 

hatchlinss. 

Scason Total Eggs 

Col lccred 

r98618'1 

1987/8 8 

198 8/89 

1989t90 

1990/91 

4401 

5300 

649',7 

12,010 

9212 

Vo Yiable 

Egg s 

62.7 

64.3 

67.2 

't 4.5 

59.6 

'/o Viablc 

Halchlings 

80.1 

82.7 

u4.5 

85.5 

'77.4 

Table 5. Numbers of C. porosus nesls localcd (cxcluding false nests) and total 

cggs collccted, in threc areas where collcclion elfort has bcen nore 

or less constanl In mosl ycars. * indicare where effort was rcduccd. 

Season Adclaidc River 

(mainslream) 

Nests Eggs 

1983t84 

1984185 

1985/86 

r986/8'7 

l9 87/8 8 

1988/89 

1989190 

199019r 

t99t 192 

2l 

37 

39 

56 

27 

45 

1025 

695 

859 

1272 

1'756 

2250 

tt71 

| 547 

Adelaide River 

(Mclacca Swamp) 

Nests Eggs 

28 

22 

22 

I2 

27 

ll 

618 

959 

934 

1002 

581 

1189 

1560 

622 

1327 

Finniss 

River 

Nests Eggs 

20 

23 

36 

4l 

4l 

-)l 

64 

960 

105't 

tl72 

r443 

t936 

1U48 

3179 

237

238 

Tolal Ilarvest Limits 

Total harvests of both C. johnstoni and C. porosus, for all purposes, during 

the tenure of the current Management Program (CCNT 1989) arc sunlmariscd 

in Table 6. 

Tablc 6. Numbers of C. johnstoni atrd C. porosus c8gs, harchlings, juvcnitcs 

and adults taken from the wild during the last two years, with 

harvest limits applicable in thosc years. 

Species Limit Harvestcd 

C. johnstoni 

C. johnstoni 

C. johnstoni 

C. porosus 

C. porosus 

C. porosus 

C. porosus 

1990 

t991 

1990 

1991 

1990 

1991 

1990 

199r 

1990 

1991 

1990 

1991 

r990 

1991 

1990 

t99r 

Viablc Eggs 

Viablc Eggs 

Harchlings 

Halchlings 

Juvcnilcs 

Juvcnilcs 

Adults 

Adults 

Viablc ESgs 

Viable EgSs 

Hatchlings 

Hatchlings 

Juvcniles 

Juvenilcs 

Adu I ts 

A du l1s 

4000 

4000 

6000 

6000 

1000 

1000 

200 

200 

10,000 

10,000 

400 

400 

400 

400 

200 

200 

MONITORING . WILD POPULATIONS 

C rocod!lus johns totti 

207 | 

953 

1621 

45't9 

2t) 

187 

0 

2 

{i 953 

5491 

l3 

l0 

120 

t62 

Annual spotlighr and helicoplcr survcys arc conductcd in rcprcscnrarivc 

samples of C.johnstoni habiaat as pan of a lon8-lcrrn moniroring progranr. 

The Daly River (Fig. l) is suneycd annually, and is one of thc maiD rivcrs 

from which C.johnstoni harchlings arc harvested. It provides a good sysrcm 

lor cvaluating tho gencral impact of harvcsting. For survcying, ihc river is 

subdivided into 9 segmcnts scparated by rockbars and waterfalls (total 

distance = 196.3 km). Hatchling and egg harvests are restricted to lhc 

upslream 91.9 km and the downstream 6{1.5 km; the ccntral area of 35.9 km 

has been surveycd but not harvested. 

70 

63

E 

3400 

32 00 

3000 

2800 

.s, 

'6 

6 

F 220 

24 

2000 

1800 

1600 

1400 

1982 1983 1984 1985 1S86 1987 1S88 1S89 1990 1991 1992 

Year 

Figurc 2. Toaal numbcrsof 

C. john.rtori counled by spollight in thc annual 

survcys of thc Daly River betwecn 1983 and 1991. 

Thc population of C.johnstoni in thc Daly Rivcr has continued to incrcasc 

(Fig. 2) regardless of thc harvcst of 866 eggs and 15,655 ha!chlings betwccn 

1982 and 1991 (Table 7). The natural logarithm of numbcft sighlcd in ihc 

spotlight survcys was rcgrcsscd against ycar to estimate r, the exponential 

rate of population incrcasc (thc rcgrcssion line slope)(Caughley 1980). To 

express r as a mcan pcrccnlaSe changc, the exponent of r is uscd 

lpcrcenlage cbange = fer - l).1001. 

Tablc 7. Numbcrs of C.johnstoni hatchlings and eggs harvcstcd from rhe 

Daly Rivcr bcrwccn 1982 and 1991. 

t982 

198 3 

19 84 

19 85 

1986 

r98'.1 

1988 

19 89 

1990 

199 r 

Tolal 

Hatchlings Eggs 

1299 

825 

13t7 

0 

928 

229'/ 

15 60 

2'.700 

t223 

35 06 

15,655 

548 

318 

0 

0 

0 

0 

0 

866 

239

uo 

The cxponential rate of population increasc for all sightings in all areas 

of the Daly River (Tablo 8) was 0.056 :r 0.020 (p = 0.024), indicaring an avcragc 

increase of 5.8qa per ycar ovcr the period 1983 to 1991. 

Within thc 9 individual survey scctions (2 non-harvested and 7 

harvested) r rcached significance in only two (l non-harvestcd and l 

harvested)(Table 8). In both cascs the change was positive, indicarinS 

annual average incrcases of 9.37, (Section 2; non-harvested) and 2'l.IVo 

(Section 3; harvested). There is almost cenainly interchangg of animals 

betwecn the harvestcd and non-harvested populations, which confounds 

any dclailcd analysis. 

Table 8. Annual spotlighl counts in 7 harveslcd and 2 non-harvcslcd 

scctions of the Daly River. r = tho exponential ratc of increasc; SE= 

standard error; P = the probability that r is duo to chance. Totals lbr 

1983 and 1984 arc based on cslimatcs for the 3 sc[mcnls not 

su rv cycd. 

Section 

km 

198 3 

1984 

l9 85 

19 86 

r987 

r988 

l9 89 

r990 

1991 

r 

SE 

P 

Non-harvested 

t23 

14.3 2r.6 31.0 

I7I 

240 197 

292 24'7 

203 346 

220 331 

303 470 

195 380 

196 313 

201 442 

-0.01 0.09 

0.03 0.03 

0.82 0.03 

- 216 

70 233 

109 r9'7 

r12 199 

229 303 

3 83 422 

266 275 

398 262 

312 276 

0.2 4 0.0 5 

0.0-5 0.03 

per ycar) was posilive and higher than the ratc from rhc non_harvcsted 

rivers (-0.011 ! O.041: -1.1o/a 

pcr year) which was irself highly variabtc. 

Tablc 9. Thc si/e struclurc ol C. johnstoni si*htcd in sDotli{hrsurvcys 

in lhe 

Daly Rivcr bcrwccn t98J and t9vl. Fcrccnragci rcfir only to non, 

hatchlings whose size could bc estimated. Haivests in any onc ycar 

(Table 8) arc conducrcd afrer thc survcvs. 

Year ToIal 

Count 

1983 

1984 

r985 

19 86 

1987 

1988 

198 9 

1990 

1991 

1433 

1682 

1843 

2125 

2364 

318ri 

2350 

2228 

2485 

Eyes >2' 4-6' 6-8' >8' 

Only (E" ) (E" \ (v") 

706 

889 

1495 

t402 

1510 

185 8 

1512 

143 8 

1448 

105 

91 

64 

183 

50 

'71 

8't 

83 

99 

81.0 

82.5 

45.4 

69.3 

dJ.) 

75.0 

92.4 

7',7 .8 

'79.7 

t 6.4 

r J.5 

43.0 

26.9 

14.3 

21 .8 

7.1 

l9.t 

t7.6 

1.8 

2.0 

3.7 

2.2 

3.1 

0.5 

3.0 

(../a ) 

0.8 

0.0 

0.4 

0.2 

0.0 

tJ.2 

0.0 

0.1 

0.1 

Table 10. Exponcntial ratcs of incrcase (r) lor C. johnstoni in arcas surueycd 

by helicoptcr annually. In survcys wherc no crocodilcs wcr, 

spotred in a parlicular arcr. in any onc yerr, t sighling has bccn 

added so rhar a log (ln) value could bc compurcd. *-inOiiates :, 

signilicant rcgrcssion relationship. 

Rivcr Survcy Area N Years r 

Dal y 

Daly 

Daly 

Daly 

Daly 

Daly 

Daly 

D aly 

Baincs 

Baines 

Baines 

Baines 

Baines 

Baincs 

Bainss 

Baincs 

Wickham 

Wickham 

Wickhan1 

Wickham 

Downstrcam tidal 

Crossing-Isl 

and 

Fish-Witch Wa; 

Wilch Wai-Bccboom 

Bceboom-Rookbar 

Rockbar-Oolloo 

Oolloo-us rapids 

Bullira 

ds East Baincs Pool 

East Baines Pool 

Homesread Pool 

TH Holc 

us East Baincs Pool A 

us East Baines Pool B 

us East Baincs Pool C 

Homcstcad Holc 

Humbcrt Rivcr Pool 

Humbcrt Slation 

lrrigalion Holc 

7 

'1 

7 

'l 

7 

'7 

7 

't 

7 

7 

6 

7 

5 

7 

,7 

1 

7 

7 

,7 

1985 91 

1985-91 

1985 91 

l9lr 5 -9 I 

l9 85,91 

1985-91 

1985,9 r 

198 5-9 I 

19 8 7,91 

1985-91 

1985 -91 

198 5-9 1 

l985-9r 

1985-91 

l9 8-5 -91 

1985-91 

r985-91 

1985-91 

1985-91 

1985 9l 

0.2 6l 

0.250 

0.288 

o.23'I 

0.252 

0.369 

0.390 

0.405 

0.3 l1l 

0.196 

0.t25 

o.126 

0.154 

0.450 

o.044 

0.t61 

0.5 3l.l 

0.339 

0.251 

0.4 18 

0.03 * 

0.06 

0.2 8 

0.26 

0.50 

0.20 

0.25 

0.0 u 

0.81 

0.47 

(J.03 * 

0.10 

0.05 x 

0.01 

o.02 

0.00 

0.15 

0.04 

0.06 

0.01 * 

241

Tablc 10 continucd. 

River Survey Area N 

Wickham 

Wickham 

Wickham 

Victoria 

Victoria 

Victoria 

Victoria 

V icto ri a 

Victoria 

Victoria 

Victori a 

Mean all areas 

Stoncy's Crossing 

Vicroria/wickham Jn. 

Yarralin 

ds bridgc 

Jasper A 

Jasper B 

Old Vic. R. Crossing 

Pigeon Holc 

Policeman's Point 

Rockhole 

us bridgc 

7 

7 

7 

'l 

'l 

'l 

'7 

7 

7 

7 

7 

1985-91 

1985-91 

1985-91 

1985-91 

l9 85 -91 

r 9 85,91 

l9 85 -91 

1985-91 

1985-91 

1985-91 

1985,91 

0.257 0.3l 

0.503 0.0r 

0.491 0.04 

0.415 0.12 

0.202 0.16 

0.040 0.47 

0.551 0.03 

0.r99 0.13 

0.049 0.60 

0.162 0.10 

0.313 0.02 

0.282i 

0.026 

Tablc 11. Exponcrtial ratcs of incrcasc (r) for C. johnstoni in river syslcms 

spotlight survcyed rcgularly in the Norlhern Tcrrilory. 

a significant rcgression relalionship. 

surveyed; P= the ProbabilitY thal r 

significanl aI thc 5% level. 

* indicatcs 

N = number oI ycars 

is due 1o chancc; * = a result 

River Survey Arca N Years 

P 

Baines 

Kathcrine 

Mary 

Moyle 

Finniss 

Reynold s 

Mean Non-harvcslod 

West Baincs 

Dal y 

Finniss 

Mary 

Reynolds 

Reynolds 

Victoria 

Victoria 

Victoria 

Victoria 

Wickham 

Mean harvested 

Mcan All rivcrs 

East Baines Rivcr 

Katherine Gorge 

Downstream 

Moyle River 

Buffalo Holc 

Walcrholc 

TH Hole 

Daly Rivcr 

Finniss mainstream 

Ups tream 

Rcynolds mainstrcam 

Fish Canrp 

Downstrcam 

Mid dl c 

Upstream 

Pigcon Hole 

wickham 

3 

9 

5 

7 ,7 

6 

7 

9 

9 

6 

9 

8 

5 

7 

3 

J 

l1 

t7 

1982-86 -0.002 

1980-88 -0.084 

1984-88 -0.014 

1984-88 -0.025 

19tt4-90 0.176 

1984-90 -0.115 

,0.011 i 0.041 

o.97 

0.0 6 

0.8 8 

0.91 

0.02 

0.3 5 

1883-91 -0.01? 0.72 

1983-91 0.056 0.02 

1983-91 0.008 0.84 

l s84-89 0.048 0.40 

1983-91 0.041 0.59 

1984-91 0.016 0.77 

19112,86 0.154 0.1'l 

19{J2-88 0.094 0.15 

1983-86 0.159 0.i 6 

1982-91 0.041 0.12 

1982-87 0.070 0.36 

0.061 i 0.017 

0.036 t 0.019

The disparity bcrween lhc ratcs of increase indicatcd by helicooter and 

spotlight counts rcflccts in part the limitalions of hellcopicr couniing with 

C. johnstoni. A small proportion of thc total population is sighrcd, and in ftis 

case, it could be reflecting changes in thc largcr animals. Al!hough the 

dispariry is undcr investigation, ir is significant that both survey mcthods 

indicatc a positivc ratc of incrcase despite harvcsling. 

C rocod!Ius poro sus 

AswithC. johnstoni, monitoring of lhe C. porosus population involvcs 

surveys at two lcvels of rcsolution. Firstly, spotlight counts in selccted rivcrs 

aro car.ied out annually to monitor thc biological aspecls of continuing 

recovery (see 'Recovcry Trends in the Blyth-Cadcll Rivor System', berowl. 

Helicoptcr counts arc the method used to monitor the populalion as a wholc. 

Wilhin individual rivcrs subjccied to intcnse harvcsting of eggs, rhc 

population has conlinucd to increase dcspite harvcsring (Fig. 3). Significanl 

numbers of nests arc not detcctcd and local recruitnrsnr srill occurs (Fig. 4). 

The population size slructutc does not reflcc! a "missinq" cohort !hat could be 

expccted to inllucncc adulL numbcrs in thc futurc (Table l2). 

(, 

z 

- 

F 

r 

z 

o 

o 

c! 

f 

2 

900 

800 

7AO 

600 

500 

400 

300 

200 

1976 1978 1980 1982 1984 1986 1988 1990 1 992 1994 

YEAFI 

Figure 3. Annual spotlighi counts of non-hatchling C. porosus \n thc 

mainstream of the Adclaide Rivcr, Northern Territory (60 km east 

of Darwin). Numbers of cggs harvcsred from 1984/85 to t99llg2 Ne 

in Table 5; in 1983/84 525 cggs wcrc collectcd from thc mainsrrcam. 

"fo dale, 19,942 eggs havc been harvcslcd {rom the sysrcm since 

19 83. 

243

244 

o 

z 

- 

r 

E 

l 

z 

350 

300 

250 

200 

150 

100 

50 

0 

1976 1978 1980 1982 1 S84 1986 1 988 1 990 1 992 1 994 

YEAR 

Figure 4. Numbers of hatchlings sightcd during spotlight survcys ol lhc 

Adclaide River mainstreaDr (117.0 km). The line indicates thc pcriod 

in which cSgs have bccn harvcstcd (1983/84 to 1991192 wet 

scasons). 

Table 12. Size structurc of C. porosus sighted in spotlighr surveys in rhc 

Adelaidc River bctween 1977 and 1992. Percentagcs refcr only to 

non-hatchlings whose sizc could be estimated. Suftey results arc 

those nearcs! June in each ycar. * indicatcs years in which eggs 

were collected in the wcl scason bcforc a survey; between 1977 and 

1979 aninals grcatcr than 7'in length wcre recordod as ">?". 

t9'7',| 

19't8 

r9'79 

* 1984 

+1985 

*r986 

*1987 

*1988 

,N 19 89 

*1990 

*1991 

*t992 

Total Eyes 

Count On ly 

388 

387 

618 

582 

5'72 

?85 

151 

709 

936 

8'/ 6 

1082 

36 

33 

36 

144 

13't 

112 

130 

161 

168 

161 

4' 2-4'. 4-6' 6-8' 8-r0' >10' 

(E") (E > (q") (E") (8") 

48 

62 

80 

r37 

99 

2s9 

'76 

350 

85 

403 

36.1 

23.1 

36.5 

31.5 

40.1 

46.',7 

41 .8 

55.3 

43.9 

52.6 

51.0 

56.8 

28.9 

32.1 

30.5 

26.8 

22.0 

22.6 

16.1 

18.0 

2t.l 

-------- 11.3 ,----- 

_---____ 12.6 -,-,-- 

--,-,-,- 20.1 ------ 

21.8 10.4 2.3 

20.8 

r7.5 

r9.'7 

15.0 

9.7 

8.9 

5. {i 

1t.5 

5.8 

2.5 

1.0 

4.3 

17.8 

22.6 

14.0 

l1.0 

16.0 

'7.2 

3.5 

3.0 

5.4 

23.8 9.2 2.0 

Annual spotlight counl survcys wcrc carricd out in 8 rivcrs in both 1990 

and l99l (Table 13), the majority of which had cggs harvcstcd lrom them. 

The exponenlial ralc of incrcasc (r) was calculatcd for each major river 

scction. Thosc wilh a significant change in population size ovcr thc study

period had all incrcascd. Thc mcan r valuc lor all survcy scctions was 0.053 l- 

0.015, indicating a Dean annual rate of incrcase ot 5.48a per ycar ovcr thc 

period of study. The rale of increase in the haryesled scclions (0.051 ! 0.012; 

5.2Ea pe( yeat) was slightly lcss than the mean rate in the three nonharvestcd 

sections (0.070 i 0.086; 7.3qo per yca(), although lhcy werc highly 

variablc. 

Tablc 13. Exponcntial ratcs of increasc (r) [or C. porosus in rivcr syslcms 

surveyed by spotlight. In lhe 4 inslances where no crocodiles wcre 

spottcd in a particular crcck, in any onc ycar, I sighting has bccn 

addcd so that a log (ln) vaiuc could bc computed. + indicatcs a 

significant regrcssion relationship; 'H' indicates areas lrom which 

eggs are harvesred each year. "Last NH-D" = lhe non-hatchling 

densily rccorded during lhc last survcy. 

Survey Arca N Ycars Last 

NH,D 

P 

Adelaidc - downslrcam 

Adelaide - upslrcam 

Adclaidc - sidccrceks 

Blyth - mainstream 

Blyth - sidecrecks 

Cadcll - mainslroam 

Finniss - Bullcoin 

Finniss - Palj Patj 

Liverpool - Gudjcrama Ck 

Liverpool - mainstrcam 

Liverpool - Atlas Ck 

Livcrpool - Maragulidban Ck 

Livcrpool - Morngarrie Ck 

Liverpool - MunSardobolo Ck 

Livcrpool - Tom's Ck 

Reynolds - McEddy's 

Rcynolds - Noaklies 

Rcynolds - Wclltrce 

Tomkinson - mainstrcam 

Daly - mainstrcam 

Reynolds - Dccp Hole 

Rcynolds - Horscshoc 

Harveslcd 

Non-harvcslcd 

Total 

8 

11 

t'7 

15 

't7 

8 

8 

14 

t5 

l3 

l5 

l5 

15 

t0 

8 

8 

l) 

9 

8 

19 

3 

22 

r9'/7 -9r 4.36 

1977-91 6.34 

19'7'7 -91 1.57 

t9'15-91 6.17 

1975-91 0.69 

r975-9r 4.46 

1984,91 20.00 

0.03? 

0.068 

0.034 

0.029 

-0.034 

0.003 

0.092 

0.01*ll 

246 

I 

E' 

9. 

>'6 

o. 

I 

a 

a 10 12 14 

Years Since Protection 

Figurc 5. The rclalionship betwcsn lhe mean dcnsily of non-hatchling C_ 

polasrr (helicoptcr count/count equivalents) and ycars since 

protection (1971). Valucs for ycars 4-17 (1975-1988) are correcrcd 

spotlight counts. Thc last 4 values arc mean helicopter counts. 

Over the last four years, thc hclicopter counts have demonstralcd mean 

values and Ievels of varialion consisfcnl with those prcdicted {rom spollight 

counts, This tcnds to support our contention that tho correclions used ro 

derive hclicopter count equivalents from spotlight counls wcre realistic. It 

also supports the hyporhcsis thal a largc proportion oI the variation rn 

numbcrs of C. porosus sccn in tidal rivers from year to ycar reflccts variation 

in thc extent of the populalion found in such rivcrs; rcal riscs and falls in thc 

lotal population arc much nlore sub(lc. 

Thc rcgression line relating helicoprcr count densiry (HD) to ycars sincc 

prolcction (Y)(Fig.5) dcscribes the mgan increase in thc dcnsitv of animals 

sighted with time sincc proteclion: 

HD=0.12 +00286Yr0.003 (R2=0.86; 

P=0.0001) 

When used to calculate r, thc helicopler counts give an cstimate of 0.063 :l 

0.007 (R2= 0.84; P = 0.0001), indicaring a mean rare o{ incrcasc of 6.5% pcr ycar 

ovcr the period 19'15 to 1992. This cstimatc is consistent wilh thc mean valuc 

derived from spotlight counts within 8 rivers (0.053 :L 0.015; 5.4o/o per ycar\ 

discussed above. The two methods are rhus giving comparablc rcsults for C. 

polosi./s, whereas thcy are widely divcrgent with C. johnstoni (see abovc). 

The size distribulion of C. parosus sighlcd in the helicoprcr survcys (Tablc 

14) has shown no significanr changc over rhc four years rhat thc mcrhod has 

bccn used,

Table 14. Size dislribution of C. 

Nunrbcrs ;n bmckcls Zdrorrs sighted in bclicoptcr survcys. 

arc pcrccnragcs. 

Ycar Total Small Medium Large Extra-large 

1989 

1990 

1991 

1992 

461 

454 

407 

53s 

41 

( 8.9) 

48 

(10.6) 

38 

(e.3) 

49 

(9.2) 

ll5 

(24.9\ 

116 

r22 

(3 0.0 

) 

196 

( 3 6.6) 

224 

(48.6) 

236 

(5 2.0) 

184 

227 

(42.4) 

81 

(r'7 

.6) 

54 

(11.9) 

63 

( 1s.5 

) 

(l1.8) 

241 

In 1984, the lotal wild C. Pororrs populalion (hatchlings and nonhatchlings) 

was estimalcd to be at lcast 40,000 individuals (Webb ?t al. 1984). 

As mean density derivcd from thc rcgrcssion line on Fig.5 has increascd from 

0.50 km-l to 0.?2 km-l betwcen 1984 and 1992 (a 447o increasc), thc lotal 

population in 1992 is now estimatcd to bc at lcast 57,600 C. porosus. 

MONITORING . CROCODILE FARMS 

Thcre are currently six crocodile Iarms in thc No hem Terrilory. Total 

captivc stocks havc bcen incrcasing sleadily (Tablc 15)' as has the 

producrion of C. potosus through caplive brceding (Table 16). Culling for 

skins and mcat was initiatcd in 198?, and sincc that time lhere has bccn a 

stcady incrcasc in produclion (Tablc 17). 

Table 15. Increascs in lhe caplive population of crocodilcs hcld on Norlhem 

Territory crocodile farms- Stocks are at 31 Decembcr cach year. as 

rcported in the monthly stock retums. Culling and exPon of skins 

slarted in 1987. 

Year Numbcr of 

Farms 

198 7 

1988 

t989 

1990 

1991 

4 

4 

4 

6 

C. porosus C. johnstoni Tolil 

5711 

't172 

9183 

12,986 

14,40',7 

10,543 

12,267 

r 5,601 

15,450 

1'7 ,83'.7 

16,254 

19,439 

24,7',7 4 

28,436

248 

Table 16. Numbers of hatchlings produccd through 

Northern Territory crocodilc farms. * this 

ncsting season, 

Ycar No. of 

Farms 

19 83 

1984 

1985 

1986 

1987 

r988 

19 89 

1990 

l99l 

1992 

3 

3 

3 

3 

3 

3 

3 

4 

6 

C. porosus C jnhnstoni Tolal 

99 

362 

6'7 5 

614 

444 

922 

I t2o 

t5'7 6 

2436 

26 

105 

95 

t67 

116 

90 

164 

91 

captivc brecding on 

asscssment 

donc bcfoac 

125 

467 

55li 

842 

730 

534 

l0u6 

12t 1 

1634 

2436 

Tablc 17. Numbers of skins produccd in thc Northcrn Terrilory sincc 19g7. 

1987 

1988 

198 9 

1990 

1991 

No. of 

Firms 

4 

4 

4 

6 

C. porosus L. lohnsront t ntal 

251 

962 

1402 

1954 

2381 

1020 

923 

t3'13 

908 

574 

1982 

2325 

3327 

3289 

Given thai mortalifics on farms arc usually highesr during the firsa ycar 

of life, thc moniforing program is bascd largciy on inu"rrto.i-"* of l-vcar_ 

olds. There is significant varialjon between farms, and wiLhin thc one farm 

from ycar to year, in bolh growlh and morlalily ralcs. Mean mortalirics aDd 

srzes al one year ol agc, arc summarised on Tablcs 18 and 19 respectivcly. 

Table 18. Mean perccnlage mo alily bctwecn hatching and onc ycar of 

on Nonhcm Territory crocodile farms. N = number of firms. * 

two farms had C. johnstoni, but invcntories at one wcre at l8 

monlhs (data not inc lud e( 

Ye ar C. porosus 

Mcan 

i SE Min. Max. 

1986 

r987 

198 8 

r 989 

1990 

1991 

62.5 a I {J.0 

24.6 t 6.5 

29.9 t 2.5 

31.2 r 3.9 

26.3 r 10.1 

36.3 t 11.-l 

28.1 89.0 

18.0 31.1 

25.7 34.3 

24.6 38.1 

10.9 45.3 

7.2 63.9 

age 

C. johnstoni 

N Mean ! SE Min. Max. N 

3 

2 

3 

3 

3 

4 

1'7 .0 ! - 17.0 17.0 

15.2 i 10.6 4.5 25.8 

9.8 L 5.2 4.6 15.0 

16.4! 

13.4! 

6.1 4.5 

- 13.4 

24.5 

13.4 

I 

2 

2 

3 

l*

Table 19. McaD roral longlh of one-yclr,old crocodilcs on Norrhcrn Territory 

crocodilc 1arms, for ycars in which thcrc are comparablc data. N = 

nunbcr of farms. * = lwo farms had C. johnstoni, bur inventorics ar 

onc wcre at 18 months (data not includcd). 

Ycar C. porosus 

Mcan i SE Min. Max. N 

198'7 

1988 

r989 

1990 

199 | 

696.4 ! 

689.7 t 

675.8 r 

687.5 r 

3.3 

3.2 

2.'7 

313 

340 

307 

304 

1075 3 

1262 3 

1279 3 

13'14 4 

RESEARCII 

l. Homing 

C. johnstoni 

Mean i SE Min. Max. N 

t)n I + 

569.2 t 

561.'7 ! 

573.1 ! 

541.1 i 

- 408 811 

t.2 407 791 

t.2 347 820 

1.1 354 1198 

1.9 359 635 

Thc rcsul!s of rclocating problcm C. porosus ,m Covc, on tbc norlh-cast 

corncr of the Nortbcrn Tcrritory (Fig. 1), wcrc rcccntly analyscd by Walsh 

and Whilchead (1992). Govc is a largc area of Aboriginal Land, whcrc 

crocodilcs arc of totcmic significance to the local pcople. Thcy objccted to 

crocodiles bcing killcd and/or g;vcn to thc crocodilc fanrs. Accord;ngly, of 

52 problcn crocodifcs caught bctwccn 1986 and 1991, 48 (92o/a\ wctc rclocdLcd 

in the wild bclween 1? and 282 km away lrom their capturc sitc. A 

significant proportion (487o) were recaughr at lhe samc caplurc locirtions al 

Ieast once. The probabilily of rccapturc could not bc a(ribuled stalistically to 

sizc, scx, season, distance or dircction of rclcaso. 

2. Recovery Trends in tlre Blyth-Ccdell River System 

The survcy program in rhc Blyrh-Cadell River systcm, started by Harry 

Messcl (Messcl ct al. l98l), has bcen conlinucd by the Conscrvation 

Commission. An analysis of 17 years dat^ (19'74-1990\ has now becn 

undertaken (Wcbb and Manolis 1992), and thc rcsults arc summarised rcrc. 

spotlight coonts wcrc converted to estimatcs of total population size, ano 

thcn sizc classes of juvcniles werc converted !o age classcs as dcscribcd 

prcviously (Wcbb et aI. 1984), 

Thc total population was rclalivcly slable betwccn 3 and 14 ycars aftcr 

protection (Fi8. 6), but thcn increascd significantly. This incrcase was 

comprised maiDly of increased numbcrs of hatchlings (Fig. 7), but it was no1 

rcflected in thc 1-ycar,olds, rhe following ycar (Fi8.8). The numbcr of lycar-olds 

in thc populalion has steadily declined since protection (mcan = 

to3.2 ! 7.6). 

249 

I 

2 

2 

3 

l*

250 

E] 

N 

z 

z- 

I 

F.l 

J 

F 

,t 

F 

F 

900 

800 

700 

600 

500 

400 

a 

300 

2 6 8 10 

a 

12 t4 t6 18 20 

YEARS SINCE PROTECTION 

Figure 6. Estimaled total populalion of C. poros s in the Blyth-Cadell River 

system between 1974 and 1990. 

500 

450 

400 

350 

300 

250 

200 

150 

100 

50 2 

Figure 7. Estimated tolal 

6 8 l0 t2 14 16 18 20 

\TARS SINCE PROTECTION 

popufation of hatchlings between 1974 and 1990. 

a

tt 

F] 

F 

F 

160 

140 

120 

100 

80 

60 

40 2 6 8 l0 t2 t4 16 


18 20 

Figure 8. Estimated total population of 1-year-olds between 1974 and 1990. 

In contrast, the numbers of 2-year-olds (Fig. 9) declined precipirously 

throughout the posFprotection period, and the impact of that decline was 

clearly carried on to the 3-year-olds (Fig. 10). 

../) 

,..1 

c.l 

! 

140 

120 

100 

80 

60 

40 

20 

a 

a 

a 

a 

a' 

a 

a a 

a 

to 

a 

a 

a a 

a 

a 

a a a 

a 

0 2 6 8 l0 12 t4 16 I 


Figure 9. Estimalcd toral populalion of 2-year-olds bclwcen 1974 and 1990. 

a 

a 

a 

a 

ao 

20 

251,

252 

v) 

t-.1 

'J 

F 

F 

90 

80 

70 

60 

50 

40 

30 

20 

a 

!.' 

aa 

10 

2 6 8 l0 12 t4 16 

\€ARS SINCE PROTECNON 

a 

a 

a 

a 

O 

18 20 

Figurc 10. Estimarcd 

rclal population 3-ycar,olds betwecn 1974 and 1990. 

Numbcrs of 4,yeaFolds (pig. tl) increased slightty in the jmmediarc posr_ 

protection period, buI dcclined aftcr abouL l0 ycais. Similarly, 5_ycar-otds 

(Fig. 12), showed a sharp incrcasc during rhe first I0 ycrrs. aftcr which 

numbers stabilised. 

,-.1 

J 

F 

F 

50 

4l 

40 

35 

30 

25 

20 

l5 

a 

a 

l0 z 6 8 10 12 t4 16 


Figure 11. Estimated 

total populalion 4-ycar,olds bctwccn 1974 and 199U. 

a 

20

Numbers of oldcr, larScr animals in thc population (6.3+ ycarsiFig. 

l3) 

incrcased slowly during thc first l0 ycars, thcn sharply lo aboul 15 ycars, 

when thcy appeared 1o slabilisc. 

J 

gt 

J 

F 

F 

35 

30 

25 

20 

l5 

l0 

5 

4 6 8 l0 t2 t4 16 

YEARS S]NCE PROTECNON 

zo 

Figure 12. Estimated total population 5-year-olds between 1974 

and 1990. 

J 

.t 

J 

3 

250 

225 

200 

t'7 5 

150 

I 25 

100 

75 

50 

i.' 

a 

25 

2 6 8 10 12 14 16 18 


Figure J3. Estimated roralpopulalion 6+ year-dds betwecn 1974 and 1990. 

a 

a 

a 

a 

a 

a 

z0 

253

_Generally, 

ir appears that as the number of older, larger crocodiles (6+ 

year-olds) increased, numbers of 2-year-olds, 3-year-olds and cventually 4_ 

year-oldt and 5-year-olds were affecled. Further insighrs can be sained 

from "retenrion rates" - the ratio of the number of a given year ciass sighted 

in a river in any one year, versus the number of the -next yiar class sightcd 

the next year (Table 20). 

Table 20. Retcntion rates of C. porosus year classes in consecutive years. 

Values greater than 1.0 reflect a net gain, which can bc ;ttributed 

to many causes including survey biases. p = probabili!v associated 

with a regression line relating relcnrion rate io years'since 

protection: "Trend" indicates whether the ratio increascd (+) or 

clecreased (-). 

Ycars 0.3 - 1.3 1.3-2.3 2.3-3.3 3.3-4.3 

197 4-7 5 

1915-7 6 

1976-'17 

1977 -78 

r97 8-79 

1979- 80 

1980- 8 r 

l9 81 -82 

1982-83 

1983-84 

19 84-85 

19 85- 86 

198 6- 87 

r987-88 

1988-89 

19 89-90 

P 

Trend 

Mean 

|.17 

1.13 

0.80 

0.59 

0.56 

0.71 

0.68 

0.59 

0.7 6 

0.84 

0.90 

0.94 

0.36 

1.51 

0.3 6 

0. l4 

0.23 

0.7 5 

0.61 

0.47 

l.l8 

0.95 

0.93 

0.50 

0.53 

0.50 

0.95 

0.27 

0.15 

0.5 8 

0.62 

0.34 

0.25 

0.09 

0.01 

0.56 

0.61 

0.66 

1.04 

0.7 4 

r.o2 

0.69 

o.79 

0.87 

0.9 8 

0.59 

0.68 

t.72 

1.06 

0.84 

0.45 

0.82 

0.63 

0-85 

0.51 

0.26 

0.65 

0.50 

0.64 

0.46 

0.52 

0.77 

0.66 

0.59 

0.64 

|.24 

0.79 

0.7 4 

0.3 8 

1.13 

0.03 

0.65 

Hatchlings and l-year-olds do not disperse greally from their nest sitos 

(Webb and Melsel l9?8) and the RR0-t should be a ieasonable index of 

hatchling mofialily Iactually mortalily belween 0.3 and 1_3 years of ags 

(mean = 0.75), becausc surveys are conducred mid-year, abour 0.3 vcars aftcr 

peak hatching). Thc RRo.l declined as a function of thc number oi 

hatchlings in the river (Fig. 14; R2= 0.68 p = 0.0001). This rclalionshiD was 

not improved by enlering, in various ways, rhe numbcrs of older or largcr 

crocodiles inlo the analysis. The rcsult suggests that harchling survival may 

be density-dependcnt, and thar largcr crocodiles are lgl the main Dredator 

involved. Howevcr, it docs not constirure proof ot dcnsity-depcndenc;, as 

lhere is a negativc covariance involved with counts of succe:sive year 

classcs, A tendency lo ovcr. or undcrestimatc hatchl;ngs in any onc year, is 

nol necessadly followcd by thc same bias wilh l-yoar:olds rtre ncxr year. 

Thc RR1-2 dcclined as a function of thc number of older 0areer) 

crocodrles jn thc poput ion, and this rclarionship rc:rihed ma,

significance with the number of 6+ ycar-olds (N6+)(R'?= 0.34; P = 0.018); i.e., 

not just non-hatchlings. However, as with the RR0-1, it also declined as a 

function ol the numbers of l-year-olds (Nl: R2= 0.33; P = 0.019). which could 

reflect negative covadance. Multiple regression analysis, with both 

variables, accounted Ior 76Vo of the variation in RRI-2 (RRl-2= 1.57 - 

0.0028N6+ - 0.0066Nr; R2 = 0.76; P = 0.0004). when corected for mean 

variation aitributable to Nl, the general trend in the relationship between 

RRr-2 and N6+ is shown on Figure l5 (RRt-2 = 0,876 - 0.00275N6+; R2 = 0.63; P 

= 0.0003). It suggests that the incrcasing losses of l-year-olds may be due to 

predation, specifically by the larger crocodiles. 

The RR2-3 declined as a function of lhe lotal population of non-hatchlings 

(Nt-0i total population minus hatchlings)(Fig. l6) and the relationship was 

best modelled by a polynomial regression (RR2-3 = 5.875 - 0.0242N1-6 + 

0.0000282Nr-02; R2 = 0.6?; P = 0.0007). The RR3-4 declined as a funclion of the 

numbcr of 3-year-olds (R, = 0.49; P = 0.0007; Fig. 17) and the RR4-5 as a 

function of the number of 4-ycar-olds, again being better modelled by a 

polynomial regression (RR4,5 = 3.2675 - 0.123Na +0.0014Na2: R2= 0.?5: P = 

0.0001; Fig. 18): in both cases negative covariance could be involved. 

1.6 

t.4 

> .8 

&.o 

.2 

a 

a 

a 

a a 

a 

0 5 0 r00 r50 200 250 300 350 400 450 500 

TOTAL HATCHLINGS 

Figure 14. Retcntion rate (hatchlings to l-year-olds) as a function of the 

numberc of halchlinss in the river. 

a 

255

256 

F 

a 

p 

l.l 

I 

.9 

.8 

.'7 

.6 

.5 

,4 

.3 

.2 

aa 

.1 

2 50 7 5 l 00 r25 | 50 1'1 5 200 225 250 

TOTAL 6+ YEAR-OLDS 

Figurc 15.Rclention rafc (1, to 2-ycar-olds) as a function of 6+ ycar_olds in 

thc rivor. Values have been standardiscd significanl variation 

attributablc to (hc nun)ber of l-year{lds lsce tcxq. 

ca 

c.l 

1.8 

1.6 

1.4 

1.2 

I 

.8 

.6 

a 

a 

a 

a 

a 

a 

a 

a 

25027 5 300 325 350 37 5 400 425 450 47 5 500 

TOTAL NON-HATCHLINGS 

Figure 16. Retcntion rate (2- to 3-year-olds) as a lunction of the nunlbcrs of 

2-ycar-olds in thc rivc r. 

a 

a 

a 

a 

a

A1 

).n 

1.4 

t.2 

Figure 17. Retention ra!e 

3-year-olds in 

A 

.2 I 20 30 40 50 60 70 

TOTAL 3-YEAR-OLDS 

z.? 

2 

1.8 

1.6 

1.4 

1.2 

I 

.8 

.6 

.4 

a 

a 

a a 

a a a 

a 

80 90 

(3- 1o 4-year-olds) as a function of the numbcrs 

lhe dvcr. 

.2 I 20 25 30 35 40 

TOTAL 4-YEAR-OLDS 

45 50 

Figure 18. Rctcntion rale (4- to 5-year-olds) 

as a lunction oI the numbcrs of 

4-year-olds in the river. 

Taken 

_ _ 

togclher, thc rcsults soggcst, but do not provide uncquivoca. 

cvidence of, a density-dcpcndent clemcnt in thc probability of particular 

juvcnile ycar classcs being rcrained in the rivcr. .ihe largeit croiodilcs (6+ 

a 

a 

a 

a 

of 

2s7

258 

year-olds) do not appear to be a major predator on hatchlings, but are 

probably the major predator on l-year-olds. In - contrast, 2-year-olds are 

sensitive to the total numbers of non-hatchlings - as against the largest 

animals (6+ year-olds) - in the river: perhaps reflecting a spacing need as 

proposed by Messel and Vorlicek (1986, 198?) and Messel et rl. (1986). Il so, 

emigration would be a likely cause. With 3-year-olds and 4-year-olds, 

dcnsity'dependent relationships may exist, but movement rather than 

predation is the likely cause of losses. 

3. Life History Strategies ol C. johnstoni 

Harvey Cooper-Preston's PhD thesis (University of New England) is 

undergoing linal revision. She has compared life history lrails and various 

aspects of the population dynamics of three distinct populations of C. 

johnstoni. The results indicale that life history traits and thus population 

dynamics within a species such as C. johnstoni can be highly variable 

between arcas. 

4. Sex Delermination 

The relationship between incubation lemperalurc and sex in embryonic C. 

johnstoni is differcnt from that in most crocodilians: no constant incubadon 

temperature produces 1007o males (Webb et aI. 198'l), even though 1007, 

males are produced in some wild nests (Smith f98?). An obvious hypothcsis 

which could explain this result, is that the mechanism of temperaturedependent 

sex determination is sensitive 1o daily fluctuations in temperature 

as well as to the mean temperature. This possiblity was tested in 1989, using 

temperatur€s in th€ range (32"C) that produce lhe highest proportions of 

males. No significanr variation in offspring sex ratio was detected between 

mildly fluctuating (31-33"C; 0.4f propo(ion of males) and constanr (32oC; 

0.39) temperature, and the sex ratios (0.41 and 0.39) were well short of 1007, 

males (Webb et al. l990a\. 

Clearly, wider fluctuations in temporature may bc nceded to ex€rt an 

influence (Georges 1989). However, we decided to pursue a diflerent 

approach. Another feature of C. johttstoni incubation in the ficld (which can 

produce 100% males), which is not duplicated with constant tempe(aturc, rs 

increasing rnean n€st temperatures throughout the incubation period (Webb 

et ol. 1983i Snith 1987). 

In 1990, this influence was simulated by increasing incubalion 

temperatures in 1oC incremcnls throughout ihe incubalion poriod (Table 21). 

Depending on the desired star! and finish tempemtures, and thc tcmperature 

range, the increments were evenly spaced with development at 30oC. They 

were then scaled to other temperatures using temperature dependent 

development rate coefficients (Webb et 4l- 1987). For example, 30-35oC and 28- 

33'C both involved 5 increments. The first one occurred a! 16 days for the 

30.C eggs ^nd. at 22 days for the 28oC eggs (i.e. ir was prolonged so rhat the 

increment occurred at the same embryological stage of development). The 

second increment was calculaled on the basis of develoDment rate at 3loc and 

29oC respeclively, and so on. The eggs uscd for rhis exptriment were 4.7 ! 0.3 

days old (N = 314; range 0'19.7 d), when introduced inlo rhe incubators, and 

developmenl in rhe field was taken into account when timing the 

inctements.

Table 21. Results of incubating C. johnstoni egls 

in loc increments throughout incubation 

expressed as the proportion of males. N 

Treatment 

ec) 

28-3 | 

28-32 

29-32 

29,33 

29 -34 

30-33 

30-34 

30-3 5 

3r-34 

Sex Ralio 

(N) 

0.03 (34) 

0.00(2s) 

0.00 (2'7) 

0.04 (2't) 

0.14(36) 

0.53(19) 

0.72 (47) 

o.72 (18) 

0.80 (20) 

0.56 (36) 

0.36 (25) 

at temperatures increased 

(1990). Sex ratio is 

= number of hatchlings. 

Dead during 

Incubation (7o) 

29.5 

t'|.9 

40.3 

20.8 

8.3 

9.3 

20.3 

39.1 

_ 

Some escalating lemperalures clearly gave a much higher proponion of 

malgs (

260 

Table 22. Rcsults of incubaling C. johnstoni eggs in 1991. Scx ratio is 

expressed as the proporrion of males. 'Esc. 30-35'= tempcfaturcs 

increasgd gradually throughout incubation from 30oC to 35oC: 

'Switch 31-32'= eggs began incubation at 3loc and afler 22 days 

were switched to 32oC (see Webb e/ dl. 1987). N = number of 

hatchlings. 

Treatment 

(oc) 

Sex Ratio 

(N) 

Ago at Collection: 0-5 days 

Constant 32 

Switch 3l-32 

Esc.30-35 

Age at Collection: 0-10 days 

Constant 32 

Switch 3l-32 

Esc.30-35 

0.2'7 (tt) 

0.78 ( 9) 

1.00 ( 9) 

0.30 (20) 

0.61 (28) 

0.88 (17) 

Dead during 

Incubation (%) 

5 6.0 

56.'7 

52.8 

52.0 

44.8 

56.7 

5. Scrling of An:rerobic Muscle Work in C. porosus 

John Baldwin (Monash University) and Bill Runciman (Royal Adclaide 

Hospiral) joined Rogcr Seymour (Univcrsity ol Adclaidc) in anolher round of 

experiments on thc physiological cffccts of capture on C. 2orosas. As bclorc 

(Bennett et dl. 1985; Scymour et al. 7985, 1987), blood samplcs (and this timc 

muscle samples) were laken from crocodiles !hat had strugglcd to exhauslron 

during capture. 

LarSe crocodiles struggled for longer periods bcforc bcinS fatigucd and 

produced more lactic acid lhan smaller animals. Howevcr, smallcr aninals 

produced lactic acid faster. bul for a shorter period. Thc ratc of lactate 

production correlates with the higher aclivitics of ratc limiting glycolytic 

cnzymcs in thc muscles. Small crocodilcs becomcd exhaustcd when all thcir 

musclc glycogen is used up, whilo Iarge animals rctain around 257o of their 

inilial muscle glycogen slorcs following exercise. Although thc results are 

still bging analysed, the results may provide new insights into why large 

crocodiles sometimes die during capture. Smallcr crocodiles, with higher 

mass spccific aerobic metabolism, nray b€ able 10 rccovcr acrobically using 

lipid fucls. Largcr onos, with lower mass spccific acrobic mctabolism, miry 

require a glycogcn buflcr to allow some anaerobic melabolism during thc 

initial recovcry phase. If all the musclc glycogen was used up (during 

extrcmo struggling of largc crocodiles), thcy may noi be ablc to fucl this 

initial recovery phase. 

It was suggestcd previously (Scymour et aL. 198'7) that artificial 

respiration could bc an effcctive method for enhxncing thc rccovery of 

large crocodiles with mctabolic acidosis. This was testcd via an cndotrachcal 

tube using both an oxygen jet and I slandard human resuscitalion apparatus 

consisting of a large rubbcr bulb pump and a one,way valve. Both 

tcchniques provcd elfectivc. Blood samples indicated an immediate incrcasc 

in blood pH, due lo thc blowing off of CO2, and a drop in btood lacrare levcts ar

about twice the rate oI unvcntilated animals. 

Animals wcre immobilised wirh gallamine rriethiodidc (,,Flaxcdil"), bur a 

short'term musclc rclaxant, Atricurium, was tested. lntramuscular injcctions 

resulted in paralysis for l5 minutes !o scveral hours, wirh spontaneous 

recovery without an antidote. Atricurium is used as a reDlaccment for 

Flaxedil in hospirals and is pracrical for use wirh crocodiiians, allhoush ir is 

expcnsive and rcquircs refrigcrar ion. 

6. E{rly Embryonic Stages of C. johnstoni 

The ea y devclopment of crocodilian embryos occurs while the eggs arc 

in the oviducls, and they have rarcly been retricved and studied. Ruth 

Bellairs (University ol London) has starled a research projcct on this pcriod 

of development, with parlicular referencc to the devclopment oI thc 

primitive slreak. 

Soft-shelled oviducal eggs were rcmovcd from gravid lemale C. johnstoni. 

Thc eggs were maintained in an incubalor and cxamined in a scies as 

developmcnt procceded. Two females were sacrificed for the eggs, after 

attempls to induce oviposilion wirh oxyrocin (Carmel l99l) failcd. Alrhough 

some eggs were laid with the oxytocin trealment, we could not gct thc 

completc clutch to be voidcd. Cloarly, we wcrc trying to induce laying somc 

2-3 weeks bcforc nalural oviposition, and thus thc uterine sections of the 

oviduct may not havc been particularly rcccptivc. We were also 

administering the oxytocin in single intramuscular injcclions which may 

not have bccn idcal. Oxytocin may wcll {unction eflicienlly at or ncar thc 

time of natural oviDosition. 

7. Captive Husbandry of C. porosus 

Gregor Riese [Crocodilc Farms (N.T.) Pty. Limited] is invcstigating various 

aspocts of thc captivc husbandry of hatchling C. poroJts. Trials in l99l 

(Riese l99l) found large clulch spccific varialion, and a signilicant 

relationship betwoen growrh rare (g d_1) and initial s;ze (snout-vcnt 

length). The filming of halchlings revealcd Ircquenr aggrcssive 

interactions: aggression and dominance behaviour appear to influencc 

grcwth rates cvcn in thc immediatc posFhatching period. 

Trials in 1992 confirmed that dcnsity effccts are of primary influencc ln 

the first 6 weeks of growth, allhough they can be mcdiated !o somo exlenr by 

pen design- Light conditions (low,wattage fluorcsconl globes: l2 h on, 12 h 

off) gave supcrior growth to dark conditions. Hatchling bchaviour is 

considered 10 be the key proximate variable affecting halchling growth. 

8. Densily versus Spac€ \yith I{atchling C. porosus. 

The success with which C. porosut can bc farmcd is partly dcpendent on 

tho timc takcn for ncw halchlinSs !o sct|le and begin fccdinS. previous 

oxperimcnts havc examincd thc cffccls of a ranqc oI diffcrent variabtcs 

within thc lirst month, particularly lood (wcl)b ei at. 1990a). In t99t, etlccrs 

of density and maximum space were examincd. The differcnce belwccn 

density and maximum spacc is bcst oxplaincd by example. If two adjaccnt, 

identical pens had !he samc numbers of animals (samc dcnsity), and thc 

partition separating rhcm was lified, thc dcnsity would be lhe samc, but 

26'l

2A 

maximum space would double. 

The experiments were conducted in large fibreglass tanks subdivided wift 

partitions ilrto 4 pens of 1.7 m2, etith 44% l^nd ^nd 54% warer (maximum 

depth l0 cm) maintained ar 32oC. For all treatments the dier consisred of a 

minced mixture of potk (75%) and chicken heads (25Vo\, with dicalcium 

phospato and vilamin premix ("Petvite") added at rates of 2Eo and l% 

respectively. Hatchlings were placed in tho pens within 2 days of hatching, 

and were fed 7 days per week. Food was presented in the evening (1630-l?30 

h) and the waste removed the following morning before draining, cleaning 

and refilling (0830-1000h). All crocodiles had their head lengrhs (HL) and 

total lenghs (TL) measured at introduction and after l month. 

Because grcwth irr C. pororus hatchlings is subject to pronounced clutch 

effects, three clutches were divided evenly amongst the four density 

trcalments. The results, in terms of percentage change in HL and TL, are 

summarised in Table 23. As expected, dramatic clutch e{fects occurred, and 

they were highly significant (ANOVA qoHL a[td Eo"fL vs CLUTCH; P

The maximum size and the minimum size, for borh %HL and TL, are also 

indices of perfonnance. When ranked from 4 (best growtb) to I (worst 

growth) (Table 24), some interesting lrends are apparent. Firstly, lho 

distribution of total scores is significantly different betwocn minimum and 

maximum values (Chi-square = 8.49; DF = 3; P = 0.037). SecoDdly, rhe highesr 

densily trealment (l?.6 m_r) gave the poorest perfonnance in terms oi both 

maximlm and minimum sizes: this density, evcn within the firsl month, is 

probably too high for C. polorlr harchlings. Thirdly, maximum and 

miDimum size lendcd to be negatively correlated. At low densities (7.1 m-: 

and 10.6 m-2) lhe minimlm sizes wcre larger, whereas the opposite trend 

occurred at higher densities. 

Table 24. Ranking of the maximum size (4 = highesri I = lowcst) and minimum 

growth (4 = highest: I = lowest) of head length (%HL) and total 

lengrh (z,TL) for rhe individual clutches used in rhe densiry 

cxperimenl. Totals = percenrage of maximum possible scorc (iZ C = 

24) for both minimum and maximum values. 

" 

Density Clulch M7 

(m-2) VoHL lo"fL 

Mi. Mx. Mi, Mx. 

1.1 

10.6 

l4.l 

17.6 

263 

Clutch Al8 Clutch D24 Totals 

%HL %"IL %HL 

Mi. Mx. Mi. Mx. Mi. Mx. 

%TL 

Mi. Mx. Mi. Mx. (N) 

83% 587o 

83% 63Ea 

42% 7 5Eo 

42% 54% 

The four experiments on maximum space involved animals from various 

clutches, divided between two pens (in one tank) of unequal size (1.7 m2and 

5.1 m2). Because each of the iour experiments was carried out in differenl 

lanks, with slight variation in therII|al characteristics, precise comparisons of 

densily between tanks may be compromised. 

Mortality was a variable of significance (Table 25), in that pens with large 

numbers of harchlings resulted in losses due to piling. Our results suggest no 

more lhan 35-40 hatchlings should be kept together in any conventional pen 

conducive to piling. 

The growth rcsuhs from the maximum space experimenls are in Table 26. In 

the first experiment, density was held conslant at 7.7 m-x. The results indicated 

that clutch exerted a significant effcct on growth (ANOVA %HL, %TL vs CLUTCH; 

P = 0.004, 0.007 respecrively), but there was no effect from the treatmcnl, nor any 

interaction between treatment and clutch. 

In the second experiment, density was held constant at 10.6 m'2. The only 

sigtrificanl eflect on growrh was again clulch (ANOVA %HL, %TL vs CLUTCH; 

P = 0.01,0.02 respecrively). In the rhird experimenl, densiry was increased to 

14.1 m-2. The only significanr cffecr on growth was clurch, bur only with %TL 

(not HL) (ANOVA %TL vs CLUTCH; P = 0.03). I lhd fourth experimenr, 

densily was increased to 17.6 m'2. The only silnificant effect o; growth was 

34 

28

264 

clutch (ANOVA o/oHL, qoTL vs CLUTCHi p = 0.0001). Taken rogcthcr, rherc was 

no significant effect ol treatment, nor any interaction bctween treatment 

and clutch, in any of the expciments. Clutch effects were highly 

srgnrtrcant. 

Table 25. Percentage mortalitics lor C. porosus hatchlings maintained at 

different densitics and amounts of available space for the first 

month after hatchins. 

Density Space N 

(m-2) (rn2) 

7.L 

10.6 

t4.l 

7.1 

10.6 

t4.l 

r7.6 

t.7 

1.'7 

l.'l 

1.7 

J_ I 

).1 

).1 

5.1 

t2 

18 

24 

30 

54 

72 

90 

Mortality 

(c" 

) 

0.0 

0.0 

0.0 

0.0 

0.0 

1.9 

9.7 

Table 26. Percenragc increase in hcad lengrh (E|HL) a\d total lcnglh (Z,TL) 

Iot C. porosus hatchlings from diflerent clutches maintiined aa 

different densities and amounts o{ maximum space for the ftrst 

month after hatchin[. 

Clutch N Density Space 

(m-,) (m2) 

F24 

F24 

A3 

A3 

ALL 

ALL 

D26 

D26 

L4 

L4 

All 

All 

6 

1E 

6 

18 

t2 

36 

4 

12 

ll 

5 

7.1 

7.1 

7.r 

7.r 

't .1 

7.1 

10.6 

10.6 

10.6 

10.6 

10.6 

10.6 

1.7 

).1 

t,7 

).1 

1.7 

)_ I 

1.7 

5.1 

1.7 

5.1 

1.7 

5.1 

%HL SE Ran ge %TL SE Rangc 

18.6 1.30 

r9.'7 r.16 

2t.6 1.29 

25.t 0.94 

14.6-23.0 16.r 

I 1.6-30.8 14.6 

t9 .2-25 .8 t8 .7 

t8.8-32.8 22.0 

20.1 0.99 t4.6-25.8 t'7.4 

22.4 0.87l1.6-32.8 

18.3 

16.6 t.04 

18.8 | .45 

21.6 1.47 

21.0 1.02 

14.'7-18.5 12.t r.2r 

r0.7-26.5 13.3 1.15 

t8.7 2.t0 13.7 -23.9 12.6 1.52 

22.2 1.50r2.6-30.5 

15.5 1.37 

1.37 12.I-20.3 

r.46 6.6-29.0 

t.l9 11.9-21.7 

1.22 15.5-34.5 

o.95 12.r-21.7 

1.r2 6.6-34.5 

8.7,14.0 

6.t -20.0 

16.3-24.9 13.0 r.16 8.9- 15.7 

15.5-27.8 12.2 0.7'7 7.6- 18.5 

8.1-14.4 

8.3-23.1

Tablc 26 continued. 

Clutch N 

F18 5 

F18 15 

ALL 18 

ALL 53 

T2 

18 

F2r 6 

F2r 15 

M56 

M5 t7 

Ft 6 

F7 15 

ALL 24 

ALL 65 

MRI 6 

MRI I8 

R1l 6 

Rll r8 

D23 9 

D23 25 

829 

B2 26 

ALL 30 

ALL 87 

D cnsi ty 

( m-2) 

10.6 

r 0.6 

10.6 

10.6 

t4.l 

t4.r 

t4.l 

t4.l 

t4.l 

t4.t 

14.1 

t4.l 

14.1 

t4.l 

17.6 

17.6 

r7.6 

17.6 

r7.6 

17.6 

17.6 

r7.6 

17.6 

t'7 _6 

Space 

(m2) 

t.'7 

J.l 

t.'7 

5.1 

1.7 

t.'7 

5.1 

t.7 

). t 

t.7 

5.1 

1.7 

5.1 

1.7 

1.7 

5.1 

t.'7 

).1 

r.7 

5.1 

t.'l 

5.1 

loHL Range Range 

23.2 r.97 20.3-30.8 

t1.2 

23.3 0.96 r7.9-29.0 15.6 

0 14.8-23.0 

9.1-20.2 

20.3 0.99 13.'t-30.8 13.9 0.79 8.1_23.0 

21.4 0.63 10.7-30_5 

14.1 0.54 6.1-23.r 

18.8 0.97 

18.2 0.88 

16.5 1.07 

18.8 0.94 

19.2 1.37 

18.6 0.73 

16.7 1.53 

16.7 1.02 

r7.8 0.64 

18.1 0.45 

14.7-20.8 t4.'l 

9.6-23.4 14.1 

12.2-20.2 14.0 

13.0-27.0 15.1 

15.5-24.4 18.1 

13.9-24.7 16.3 

lr.6-22.5 12.7 

9.'t-25.1 12.9 

r1.6-24.4 14.9 

9.6-2't.0 14.6 

t6.2 2.13 9.4-24.3 10.5 

17.4 1.10 10.2-26.6 10.6 

28.2 2.6r 

25.6 1.49 

16.6 0.95 

19.3 0.94 

18.5 1.12 

20.5 0.64 

19.4 t.l2 

20.6 0.58 

23 .2-39 .0 25 .2 

t3.4,34.6 20.0 

10.8-20.1 11.0 

10.6-30.4 r 3.8 

13 .2-23 .2 12 .0 

12.'7 -26.6 14.6 

9.4-39.O 14.0 

10.2-34.6 14.7 

0.95 1r -6- 17.9 

0.73 10.2-20.3 

r.40 10.2-r9.4 

| .46 5 .3 -25 .6 

2.19 9.8-24.5 

r.t0 7.6-24.2 

2.07 7.4-20.9 

0.90 6.6-18.8 

0.90 '1.4-24.5 

0.54 5.3-25.6 

2.68 3.t-20.6 

r.o7 |.6-r'7.3 

3.45 16.4-39.0 

r.42 8.6-31.6 

t.L9 4.6-t5.1 

r.05 1.8,23.8 

1.22 7 .'1-t7 .r 

1.00 4.3-27.r 

1.41 3.1-39.0 

0.64 r.6-31 

.6 

As with the density experiments, minimum and maximum sizes were used 

as indices of performance. As cach clutch was uscd in only two lreatments 

(11 m2and 5.1 m2), thc highesr maximum and highcsr minlmum ZoHL,s and 

TrTL's were coded as "1", and thg lowest as '0", for each clutch. Thcre was thus 

a maximum value of 4 that could be allocated to any clulch on Table 

qaHL 

26; 2 for 

and 2 for 7oTL. When summed, .he rcsutts in;icated a marked bia; (Table 

27)(contingency. lable, Chi-square = 61.2; DF = 1; p

266 

The negalive corrclation can also bc dcnonstralcd by cxamining thc mcan 

differences in thc growlh mcasurcs ('/,HL, q.HLf;.;\, q.HLnax, qoTL, %TL11i11. 

ToTLmax) belwccn ihc rwo nraximun spaccs tcstcd (1.7 m2 and 5.1 m2)(Tabtc 

28). This differcncc in cach oI thc six columns dccrcascd wilh incrcasing 

dcnsity (lincar rcgrcssion), but in none was the decrease statistically 

significan!; lhus mean valucs werc cilculated. With EaHL and Ea"fL, thc mc^n 

differences (1.01 !0.48 and 0.18 40.63) wcrc close to zcro, as expcctcd from 

the ANOVA'S above. However both minimum measures (ToHLmin and %Tl-nin) 

showed negative valucs (-2.26 t 0.71 and -2.'72 !0.68> and both miximum 

values (%Hl-nax and o/aTLm^) showcd posilivc vilucs (3.89 !1.10 and 3.63 ! 

1 .62). 

Table 27. Asscssmcnt oI thc rangcs ol valucs rccordcd on Tablc 25 (mcximum 

and minimum loHL's and TaTL's) Ranks of 1 and 0 wcrc allocated to 

thc highcsl and lowcst rcspectively for cach clutch. N = thc 

number of "highest" values in each maximum space category. (N) = 

marimum possiblc scorc for cach ranEc c\tremc, 

Space 

(m'?) 

1.',l 

5.1 

N 

RANCE 

Minimum Maximum 

Value 

32 894/o 

ll9o 

(28) 

25Eo 

7 5Vc' 

(28) 

Tablc 28. Relative advantagesand 

disadvantages of small (1.7 m2) and large 

(5.1 m2) maximumspacc 

as indicaled by the differcncc (5.1'1.7 m,) 

in mean, minimum and maximum growlh. 

Clutch Density 

(m 'z) 

F24 

A3 

D26 

Atl 

F18 

't2 

F2l 

M5 

F7 

MRI 

R11 

7.1 

7.1 

10.6 

10.6 

10.6 

10.6 

l4.l 

t4.l 

14.l 

t'7 .6 

r7.6 

Mean 

t.l 

2.2 

-0.6 

3.5 

0.1 

,0.6 

2.3 

-0.6 

0.0 

1.2 

%HL 

Min. Max. 

- 3.0 

-0.4 

-4.O 

-0.8 

1.1 

-2.4 

,5. 1 

0.2 

- 1.6 

- 1.9 

- 1.0 

-9.8 

?.8 

7 .{) 

8.0 

2.9 

6.6 

- 1.8 

2.6 

6.8 

0.3 

2.3 

-4.4 

/o'lL 

Mcan Min. Max. 

- 1.5 

3.3 

t.2 

-0.8 

2.9 

- 1.6 

-0.6 

1.1 

- 1.8 

0.2 

-0.1 

-5.5 8.7 

1.6 

-2.6 

- 1.3 

12.8 

7.0 

2.8 

0.2 

-5.',t 

-t.4 

-4.9 

,2.2 

-0.8 

8.7 

-2.8 

2.4 

6.2 

,0.3 

-2,1 

- 1.5 

-7.8 

-3.3 

-7,4

Tablc 28 continucd. 

Clulch Dcnsiry 

(m') 

D23 

B2 

Mcan 

SE 

Mi n. 

Max. 

17.6 

r7.6 

O/AHL 

Mcan Min. 

2.'7 

2.0 

1.01 

0.48 

-2.6 

3.5 

-0.5 

-2.26 

0.7 | 

- 9.8 

0.2 

Max. 

10.3 

3.89 

1. 10 

10.3 

a/oTL 

Mean Min. Max. 

2.8 

2.6 

-2.8 8.1 

-3.4 10.0 

0.r8 -2.'t2 3.63 

0.63 0.68 1.62 

,5.2 -7.8 -7.4 

3.3 l.6 r2.8 

26'1 

Tikcn logclhcr, thc rcsuhs of the maximum spacc cxperimenls arc 

consislent with thosc fronl thc dcDsily cxpcrimcnls. Thcre was little variation 

in the mcan values, but significant variation in thc cffccts of maximum sprce 

on thc range of values, The trcatnrcnts thal gavc thc highest maximum sizes 

(5.1 m'?) Savc !hc lowcs! minimum sizes (cncouraging "runting"), and vicc- 

One plausible explanalion Ior thcsc rcsults is tha[ "cffcctivc" dcnsity is 

sonewhat independent ol thc measurcd density and thc maximum space. In 

esscncc, thc tcndcncy of hatchlings to pile or huddle, could mcan that ihc 

key variable is the lotal numbcr of halchlings logcthcr in a pcn, 

independent of its sizc. Il also secmed possjblc (givcn cxlrcmc clutch eflccts). 

lhal thc numbcr of arrinrrls from thc one clutch, in a pa(icular pcn, could bc 

significant. 

To exaninc thcsc hypothcscs, the clulch specilic inlormalion in Tablcs 23 

and 26 wcrc combincd (N = 40), lnd allempls werc nladc to prcdicl growth, xs 

indicated by thc six indicss (o/atlLrl'can, a/aHLmjtu q.HLmax, VoTL6g2n, o/oTLr..|., 

ToTLnax) from density (D), maximuD spacc (S). rotal nunbcrs (N1), and rhe 

number of animals from a clulch in a pcn (Ns). Simplc linear rcgressrons 

were followcd by nrultiplc rcgrcssions sceking thc best prcdiclivc models. 

Thcse analyscs indicalcd: 

1. lt was not possiblc 10 prcdict ToHlmcan or o/a'lLmcatl from any of thc 

var;ablcs, singularly or in combinatior). 

2. II was possiblc 10 prcdic! %HLmin rnd /"TLmin from all four variablcs, but 

mullipic rcgrcssion analysis indicalcd that it was largcly sharcd varialion; 

N1 gave the highcsl R'? and rcndcrcd lhc contribulion of othcr variablcs 

insignificant. This suggcsts thal thc c[[ccts of dcnsity and maximum spacc 

are simply cxprcssions oI thc 1o1al numbers of animals in a pcn. Thc 

regression slopes indicalc that on avcragc, %HLmjrr and ToTLmin dccreasc 

by 0.068% ^ d 0.091"/. Ior cvcry addilional animal in a pcn, rcgardless of 

actual dcns;tv or availablc soacc, 

%HLn\n\ = 16.95 - 0.068Nt:L 3.35 (R2 = 0.19; P = 0.005) 

o/oTLî" = )2.34 - 0.091Nr ! 3.59 (R, = 0.26; P = 0.0007)

268 

3- With thc exceprion of D and ToTLmax, ir was possible ro predicr ZoHLmax ano 

Eo"fLmax lrom all variables, but muttiple regression analysis indicated that 

it was largcly shared varialion. Surprisingty, Ng gavc the highesi R2 and 

rendered lhe contribution of other variables, including N1, insignificant. 

This suggests that the altainment of maximum size is rclated to thJ srze ol 

panicular clutch groups within each pen,. wilh the regression slopcs 

indicating that or average, a/aELmax ^nd ZoTL.u^ increaie by O.2.tEo and 

0.36% for every additional animal in a clutch group within a pen, 

regardless of actual density or available space. 

EaHLmax = 23.09 + 0.272N ! 4.07 (R, = 0. 1 4; p = 0.02) 

VoTLû* = 17.35 + 0.367N t 4.97 (R, = 0.16; p = 0.009) 

If this rcsult is an anefact due io the large amoun! of variation 

unexplained (much of it duc to clutch effects), lhen Nl would bc the next 

most significant factor, rendering borh marimum space and density 

insignificanl: the slope would remsin posirive tinireasing growrh with 

incrcasing total numbers in a pen). previous unpublish;d lnformauon 

suggests that clutch rccognjtion within pens of miicd clurches is a reat 

phenomenon, and thus we are nol prepared lo discounl it. 

A number of conclusions and hypolhcses can be drawn from the 

experrments: 

1. High effective densities in the lir$ month may be stimulating somc 

individuals to become dominant, and they achicve high growti rates as a 

consequence. However, it is at the expense of the poor;r performers, 

whose low growth rates are rotarded even further. 

2. Assessments 

based on mean valucs and an asumption of normal 

distributions may be misleading. 

3. Where a large disparity between maximum and minimum sizes develops, 

assessmenls 

. based on body weight trarhcr lhan lentLh r could wciAht 

. 

rhe 

maxlmum srzed animats significantl), causing a shift in mean valuis rhat 

lgnoreJ Lhc effecrs on the min;mum siTed animals. 

4. In'pens where halchlings congrcgare or pilc, ellective density telares 

more to the rotal numbers lhan lo \tandard measures of density or 

maximum space. 

5. The attainmen! of maximum size may be related to the size of a clutch 

specific group in a pen. 

6. The best strategy for rcducing "runts', in C. porosus within the first monul 

would seem to be !o maintain small groups of animals, quite possible n 

small pens. A cosr, if nor rccrified by griding, may be ieduced numbers of 

very rapidl) growing indiv id uals. 

10. Stress in Hatchling C. porosus 

Jenny Tunon (James Cook Univcrsiry of Nonh eue€nsland) is engaged in a 

scries of,rrials .aimed ar. improvinB our understandiig of rne retati;nllip 

ocrween husbandry pract'ces. srress, immunity and disease susceptibility in 

C. porosus hatchlings. The research ro dale has involved rcDealed blood

sampling of hatchlings mainlaincd in pens with waler at 320C, but then 

switched for va.ying periods inro pens with water at 28oC and 36oC. Blood 

samples are being analysed for conicosteronc levels, which indicate srress, 

and both leucocyte counts and immunoglobulin levels, which indicate 

immune funcIioD. 

11. Growth Hormone 

In 1990, three clutches of C. porosus hatchlings were used for preliminary 

experiments evaluating the effects of recombinant growth hormone. 

Animals from each clutch were dividcd among 4 pens within the one tank, 

and subjected to thc following treatments, which were allocatcd randomly 10 

the pens: 

l. Injected wift growth hormone and measured every 2 weeks 

2. Injected with saline and mcasured every 2 weeks (sham) 

3. Handled and measurcd every two weeks (Conlrol 1) 

4. Measurcd at beginning, and at end only (Control 2) 

Recombinant porcine (pig) growth hormone was injected every 2 weeks 

for 12 weeks (i.e. 6 injeclions), at a rate of 2 p"g per g of body weighr. Animals 

in the saline treatmenr were injected wi|h an equivalent volume of saline. 

They were injccrcd through thc axillary region into the body cavity, using 

fine gauge ncedles. 

The results (Table 29) indicale obvious clutch effects on growth, which 

were highly significant (ANOVA; P = 0.0001). There was no effec! of 

treatment between hoamone and salinc. nor between the two controls 

However, thc conlrols wcre significantly different (reduced growth) from 

both hormone and saline treatmcnls (ANOVA; p = 0.02). The reasons why the 

controls showed reduced growth relative to the saline treatment are unclear. 

Although no significanr difference bctween means was apparent (Table 29), 

minimum growth rates were consistently larger with thc hormone trealment 

than with the saline lreatment; maximum growth rates were not. Amongsl 

the iwo controls, rhose with thc least handling (Conrrol 2) gave consist;nlly 

better growth in terms of means, minimums and maximums, although the 

variation was such Ihat ir did not reach significance. 

In 1991, mini-osmotic pumps wcre implanted into two groups of 

hatchlings to provide a continuous output of solution. These pumps released 

recombinant porcine growlh hormone (0.1 pg t!l-l) into one group, at a rate 

of 0.39 pl h_1, and saline into rhe other. The toral dosage was approximalcry 

llo/a of the lotal dosage in 1990. The pumps used were cylindricat (? mm 

diameter), rounded at the ends, 30 mm long and weighed 1.1 g. To implant thc 

pumps, a small incision was made in the animals' sido, towards .rhe back legs, 

and the pumps inserted under the skin; the incision was then stirched. A 

control group werc nor ireated in any way. All animals wcre weighed at 3 

and 6 wceks of age (Table 30). By approximarcly 20 days thc homone willin 

thc pumps would have been depleted. 

The pumps remained in place until lhe 4th week, when some staned to fall 

ou1. This was allowed to continue until after the measurement at 6 weeks, 

when.any remaining pumps were removed, No infection was noted on any 

hatchlings as a resul! of thg insenion of the pumps at any slage of lhe 

experimcnt, or aler rhe experimcnts. Thc study indicated that osmotic purrps 

can be uscd in crocodilians, allhough smaller pumps (now available) would 

269

270 

have been preferable for hatchlings. 

Tablc 29. Pcrccntagc increasc in hcad lcngth ('/.HL) lor C. porosus 

hatchlings lrom dilTcrcnl clulchcs injcclcd with growth hormone 

cvcry two wccks, ovcr a 12 wcck pcriod, aflcr halching. 'Control l'= 

hatchlings mcasurcd every 2 weeks; 'Control 2'= hatchlings 

measur€d at bcginning and end of experimeDts only. 

Treatment Clutch N ToHL SE Rangc 

Hormone 

Saline 

Control 1 

Control 2 

Hormone 

Saline 

Conlrol I 

Control 2 

Hormonc 

Saline 

Control I 

Control 2 

Hormonc 

Salinc 

Control I 

Control 2 

F40 

F40 

F40 

F40 

45l 

A5l 

A5l 

A51 

M4{) 

M40 

M40 

M40 

ALL 

ALL 

ALL 

ALL 

6 

6 

6 

tt 

6 

6 

6 

6 

6 

t2i 

18 

Itt 

l8 

3 3.8 

27.9 

30.4 

49.3 

48.4 

41.3 

45.3 

52.0 

43.0 

40.1 

42.1 

45.0 

42.3 

36.6 

39.4 

3.30 

2.69 

7 .91 

2.61 

4.21 

4.33 

2.45 

4.04 

2.02 

4.54 

3.05 

3.60 

2.65 

2.49 

2. 18 

2.45 

26.t-47.4 

23.9-4r.1 

18.7-38.9 

19.9-38.4 

36.4-60.6 

36.1-62.6 

33.0-51.1 

33..+-57.0 

44.5-56.6 

33.4,64.4 

30.3-52.3 

32.9-58.2 

26.1-60.6 

23.9-64.4 

18.',7 -52.3 

19.9-5 8.2 

The rcsulls showcd no signilicant diffcrcnces berween trcatmcnts, nor 

between clulches. The hormone consistcntly rcsultcd in larger minimum 

sizcs than !he saline lrcatnlent. Tn contrasl. thc maximum sizes were 

gcncrally largcr with thc salinc trcatmcnl than wilh thc hormonc 

lrcatment. The reasonably good performancc of controls in expcrinent 2, 

relative to both hormone and saljnc trcatmcnts, probably indicates advcrsc 

cffccts on growth rcsulting from the surgcry and handling of animals in 

both hornlone and salinc trcalmcnts- 

Overall, thc rcsults of our expcriments do not show thc dcfinitive growlh 

advantagc rcporlcd by Andcrsen ct al. (1990) for C. ,il.rrlcrs juvcniles 

injected with recombinant human growth hormone. However, diffcrcnccs in 

dosage (they used ?.5 t;mes thc dosc) and frcqucncy of injection (twicc - 

week vcrsus oncc each two weeks) may be involvcd. Our rcsults did suggesl 

that the hormonc lreatmcnt may bc posilively affccting rhc animals wirh low 

growth rates. In this rcgard, lhey suppofl Andcrscn et dl. (1990), who 

suggcstcd thal stunlcd individuais may sulfcr from low cndongenous growth 

hormone levcls. Clcarly, changcs in thc dosagc and frcqucncy of injeution 

may aller the general rcsponse of C. porosus hatchlings 1o thc hormonc 

lrcalmenr, and expcrimcnrrri,rn is (onrinuinE.

Table 30. Pcrccnlage increase in head lenglh (SaHL) lot C. porosus 

halchlings from diffcrenl clutchcs implanlcd with osmolic pumps 

(releasing growth hormonc or saline). Animals wcrc mcasurcd al 

halchinp and afler 3 and 6 wccks. 

Trcatment Clutch N Agc a/"HL 

(wccks) 

Hormone 

Saline 

Control 

Hormone 

Saline 

Control 

Hormonc 

Saline 

Control 

Hormone 

Saline 

Control 

Hormone 

Saline 

Control 

Hormone 

Saline 

Control 

R14 

R14 

R14 

M4 

M4 

M4 

ALL 

ALL 

ALL 

R14 

R14 

Rt4 

M4 

M4 

M4 

ALL 

ALL 

ALL 

7 

'1 

1 

6 

o 

l3 

13 

l3 

'7 

7 

7 

6 

6 

6 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

6 

6 

6 

6 

6 

6 

6 

6.J 

7.3 

8.1 

9.0 

7.6 

8.8 

8.8 

7.4 

a.) 

13.4 

13.7 

14.6 

13.3 

16.0 

14.0 

14.8 

SE Range 

0.60 

0.84 

0.45 

o.44 

1.07 

0.43 

0.37 

0.64 

0.32 

1.09 

1.69 

0.98 

0.63 

0.91 

0.65 

ACKNOWLEDGEMENTS 

6.2-t1.1 

3.9,10.3 

6.2 9.8 

7.8 - r 0.9 

3.5-l 1.5 

7. I - 10.0 

6.2-11.1 

3.5-11.5 

6.2 - 10.0 

8.2-1"/.3 

6.2-18.2 

9.2-16.',t 

0.51 12.2-15.8 

0.57 11.4-14.7 

0.54 14.9-17.9 

8.2-17.3 

6.2-r8.2 

9.2-17.9 

Many individuals have contributed directly to thc rcsearch discussed 

here, particularly David Ottway, Sharn Daly, Stuart Barker, Rebecca Bakcr, 

Akira Matsuda, Mario Orjucla Castro, David Clark and Boyd Simpson. We would 

like to thank rhc following people for providing summaries of their 

findings: Roger Scymour, John Bald)vin, Bill Runciman, Ruth Bcllairs, Jenny 

Tunon, Pctcr whitehcad and Gregor Riese. Funding of our research was 

provided primarity by lhc Conscrvation Commission of the Northcrn 

Territory and G. webb Pty. Limilcd. A variely of olher Universities and 

establishments funded collcagucs aDd other research summa scd here. Matti 

Ufictt and Craeme Davis have been instrumcntal in maintaining the 

Conservation Commission's intcrcst in crocodile research. 

211

2't2 

BIBLIOGRAPHY 

. Wift the exception of p.pers and reports markcd (*), which are retcrred 

lo rn the rext, lhe following publications (1990 to mid_1992) arc based on 

work carried out in rhe Northcrn Territory, mosrly with CbNT assistanse. 

*Andersen, O., Kimwele, C., Amfin, A. and Kanui, T. (1990). Effecrs of 

recombinant human growth hormone in juvenile Nile Crocodiles 

(Crocodylut niloticus). Comp. Biochem. physiol. 97 At 60'l -g. 

*Bennett, A.F., Seymour, R.S., Bradford, D.F. and Wobb, G.J.W. (19g5). Mass_ 

dependence of anaerobic metabolism and acid-base disturbance dunng 

aclivity in the saltwater crocodile, Crocodylus porosls. J. Exp. Biol. llgi 16?- 

*Carmel, B.P. (1221). U_se 

of oxyrocin r(j inducc oviposition in a dysrocic 

saltwater crocodilc - Crocotlrlus porosus. ADst. Vet. J. 6g(6): 216_17. 

*Caughlry G. (1980). Analysis oI Venebrare populalions. John Wilcy and 

Sons: New York. 

*CCNT j1989). A m,anagrmcnt prog'am fot Crocodrlus porosus andCrocod!tus 

Johnstoni in the Nonhern Tcnitory of Australia. Conserv. Comm. N.T.: 

D arwi n. 

*Georges, A. (1989). Female turllcs from hot nests: is ir duration of incubation 

or proportion of developmen[ that matlers? Oecologia gl: 323_2g. 

Ilutton, J.M. and Webb, C.J.W. (1992). An inrroduction to the farmins of 

crocodilians. /n A Directory of Crocodilian Farrning Operations, c-d, by R. 

Luxmoorc. IUCN Publ.: Cambridge (in press). 

*Manolis, S.C. and Webb, c.J.W. (1990). Crocodile management and rcsearch in 

llr9^-rygryA Terrirory: 198?-88. pp.38-53 iz proc.96 Working Meering 

Iy^C-N-!Sq Crocodite Specialisr Group. Lae, papua New Guinea, t9l2i Ocrober 

1988. IUCN Publ.; cland, Swirzertand. 

Manolis. S.C. and Webb. C.J.W. (t99t). Incubarion of crocodile eggs _ hygicne 

and managemcnt. Pp. 249-5'l /, proc. lnrensive Troplcal Aniil-al 

Producrion Seminar. Townsvillo, 7-8 August 1991. Depr. prim_ Ind.: 

Townsville. 

Manolis, S.C-, Webb, c.J.W., pinch, D., Melvilte, L. and Ho[is, G. (1991). 

Salmonella in captive crocodites (Crocodylus johnstoni ani C. p"lror"O. 

Aust. Vct. J. 68: 102-5. 

*Messel, H., and Vodicek. C.C. {1986). popularion dynamics and slatus of 

Lrocodytus porosus in the ridal waterways of northern Australia. ,4/lsr. 

WiAl. Res. 13: 7l-111. 

*Messel, H. and Vorlicck, C.C. (1987). A populadon modcl for Crocodylus 

porosus in thc lidal walerways ol nonhern Australia: 

jmplications. 

manaeemcnt 

Pp. 189-a8 in Witdlife Management: Crocodilcs ind 

Alligarors. ed. by C.J.W. Webb, S.C. Manolis and p.J. Whirehead, Surcy 

Beatty and Sons: Sydney.

*Messcl, H., Vorlicek, G.C., Creen, W.J. and Ontey, I.C. (1986). Crocod.tlus 

porotus - A ten year overvicw: The population model and imporiance of 

1]ry wet' scason and stalus, managemcnt and recovery. pp. 23i-306 an 

P-roc. 7rh w-orking Mccring IUCN_SSC Crocodite SpeJialisi Croupi-curu"u", 

Venezuela, Octobcr 1o84. IUCN puhl.: ' 

Cland, Swirzerlana- 

*Messel, H., Vorlicek, G.C., We s, A.c. and Green, W.J. (l9Sl). Surveys 

River 

of Tidal 

Systcms in rhe Northern Territory of eu*t.uti" _i rfreli'i.ocoOifc 

Popularions. Monograph No. l. Thc Blyih__Cadell niver Systemi-Siuoy 

lhe.Sratus 

anO 

of_ Crocodylus porosus in Tidal Warerways of'Noiit"_' nu.rruf,u. 

A4ernoos tor Anatysrs. and Dynamics of a population ol C. porosus. 

Pergamon Press: Sydney. 

*Riese, G. (1991). Facrors influencinS rhc survival and growrh oI harchling 

Crocod!lus porosus in commcrciai crocodile farming. 

-Unpulfisr,"j r.,rS" 

(Qualifying) Thcsis, Univcrsiry of euccnsland. gris6ane- 

' 

*Seymour, R.S., Bennctt, A.F. and Bradford, D.F. (1985). Blood sas rensions and 

acid-base regularion in lhe salFwarer crccodite Crocodyln, |iriii", o, ,.", 

and aflcr cxhausrive cxcrcisc. J. E\p Bto!. lIIj 143-5g. 

*Seymour, R.S., Webb, G.J.W., Bcnrctr, A.F. and Bradford, D.F. (1987). Effect of 

caplure on rhe^ physiotoBy of CrccodJtus potosus. pp.253_57 in *ikJtife 

vrana.ge,menr: Urococtrles and AIIigators, ed. by C.J.W. Webb, S.C. Manolis and 

r.r. wn eneact. Surrcy Bcatly and sons: sydncy. 

*Srnith, A.M.A. 198?. The sex and..survivorship of embryos and hatchlings of 

the Australian freshwaier crocodile, C r o c o r1y I us j o hni to ni. UnouUf i.f,"a 

Ph.D. Thesis. Australian National Univcrsity, Cirnbcrra. 

Walsh,-.8._ and Whitchead, p.J. (t992). problem crocodiles (Crocodylus -retocatron porosus) 

at Nhulunbuy, Northern Tcrritory, Australia. As assessmeni- ii 

as a management strategy. Aust. Wildl. Res. (in press). 

*W^9bbr GJjW (1989a). Crocodilian research in rhe Norrhem Territory, 1984- 

86. pp. t6-21 in proc. -!"oi"i 

sth working Meering IUCN_SSC ii."oJ 

ur 

Group. Quito, Ecuador, t3-18 Ocrober 1986.- IUCN putf., Ciun{--S*]ir".runa. 

" "" 

*Webb, c.J.W. (19tt9b). Thc crocodile as a producrion unit. ,L proc. Inrensive 

Tropical Animal producrion Scminar. Towniville, July 19g9. qfO.-b"pt. f,irn. 

Ind.: Townsville. 

Webb, G.J.W. (1990). Urilising wildtifc- the cconomic incenrive for 

conservation. 1, Proc. "Environmcnt '90" Conference. Darwin, Marcl t990. 

Conservation Commission N.T.: Darwin. 

Webb, G.J.W. (1991). The influence of season on Auslralian crocodiles.pp. 

125l3l 

irt Monsoonal Auslralia - Landscapc, Ecology and rrau"'ln'li,J- lonh".n 

Lowlands, ed. by M.C. Ridpalh, C.D. Haynes ana jra.a.f. Wiiff"r"". a.e. 

Balkema: Rotterdam 

*Webb, C.J.W., Beal, A.M., Manolis, S.C. and Dcmpsey, K.E. (198?). The 

rcmperaturc 

ellecrs of 

on sex determination and embryonii develoDment rate 

Ctocodylus johnst.oni 

rn 

ard C potosus. pp. 507:31 ; t;ilii:i. ;"na.e;*"rr,, 

lrocoo es and Altlgators, cd. by C.J.W. Wcbb. S.C. Manolis and p.J. 

wnrrcneao. Jurrcy tscally and Sonst Sydney.

ai1 

'r'rr'rnb. 

al i.'! . il,rc.woiL!,. ,l 

rirr r,lcKln{Nv iiivc: rr:f 

' 

.,,r iriis. S.C. !\t:ta):. Cro.odt'in.i john.\to/ti ;t 

' :'1rr!r Sioiog)/. r\{rs1. !]/i1C!. P..i l0: 607-37. 

..!.'r.bb. {l.r ,! ;ir(t a,1iuoc..rr",_.. :iir rr irir). ef]ccLs oi rncubiii,,r, 

I :'ncf:irrrc lrir ,rir|t)nrir! ;:'r 

ci aai:llia! 1r"!airiiv t\m. 

",),.rlic1r 

,i,'.;. :,. !,il-rr. 

:'!-!î-rb. ;: J.!\i.. ]';illon. i .-. i. ci-.:i r.i;.. ,-artoirs. !.C. ii,,!1 ll.r,c,. i. r. il;:,Ob.). 

,'1-rllioring ilir :r:ilviucf I rr'._ri rr'. -':)ro?!lus ro.a!t4s)'roDuialion rr hc 

'i,iilhern :irririory lf : iistriiiii. 

',i- -: '!-ilo ia :-'r'oc 

"1'r worklng ./lcelrns 

l!,N-SSL' Crcc.dile .l'.cc:iriisis a: ioritr r-;r!, ::TDua .'jc.v ,.ruinca ::.1':r :.l.l1rrf" 

illlill. :!CN PND!.: : l-r :r', .. - rrr. 

,:,i1.t0. ii.r."/ . .lclll!. .l... 

r,f ..r. ri ... ,..a, i',1.;.' I 

,r:r, r,-f::1.ir ;r'ilis r,i 

't),"a!t:t,t 

i l. :..:.ttt:l.i): . ':,a ,\i.: ' ' 

ijjt. 

.r,ri;:. ,: .\r',i! ..n,, li.(io 

.'.1:i-r.,,. : ;s .' 

a/ r ir!.,ir,.n, _l |..,,j,;,i1]]i. 

..!i r:.,r , r :r,lr ,r'rr- 

rV!lc. aj.j.li. aiLi ,'lijirolir, :1.4. tlr":) a:',Jeoelli ';iirr:i! - f.:eri!i: ir:rr,r1rti,. 

Pp. 256')65 ln P.o!. lr1,:r)ti'!: 'iro.,.ill Afiirf' P.fd!,.riorr 5'rrrilr.r1. 

l'ownrv;i1., 7li A!!,rst 19t,. :lqri F'lJr, lrd.r 'i.!,:s/l:i.. 

Wcob. C.J.W. and Marolr. :j.{1. ili(,:1. Ir:crirrrirr! s1i1\rirlcr !rorodilcs 

lCrocodylus /,..)/ririr) ;n ri,; li.rlli.rir Tcrfilor) oi Auslraiia. -/, Pro'- 

"Wildiitu 2001 ' Confcrcncc. O.i.i(l.r1r{rs. California" 29-31 July 1991. lin 

\"v'cbb, c.J.lV., M!nolis. s.C. ard Cooncr Frcston, ]1. (ltti)!). Crocodilc .escarch 

end nranagcncnl in 1hc Northcrn Tcrrilory: l9Bll-90- Pp. 253 73 tn Proc. 

10th Working Mceting IUCN-SSC Crocodile Spccialisls Group. Cttincsvillc, 

irlorida, 2,:-2? ,^pril 1990. IUCN Pubi.: 6lano, Swilzeriand. 

tWcbb, C.i.W., Itanoirs. S.C.. \'./lrrcncaa, P. and Lcrls. i;.,1954). L proposJr ;or 

ric rransfcr of thc Australill populalion oi C/ocodtLus porosur Schncidcr 

il80l), arorn Appcnsix t to /\Dpcnoix 1l of C.I.T.E.S. Cons. Comm. N.T. Tcch. 

Rcp. No.21. 

*Wcbb. G.J.w. and Mcsscl, H. (19711). Movemcnl and dispcrsal pattcrns of 

Crocodllus porosus in somc rivers of Amhcm Land, norlhern Australla. 

Ausl. wildl. Rcs. 5: 263-83. 

wcbb, C.J.w. and vcrnon, B. (1992). Crocodilian managcmcnt in thc Pcoplc s 

Republic of Chinll - a rcview wilh rccommendelions. Rcportro 

IUCN-SSC 

Crocodilc Spccialist Croup. 

whitchcad, P.J. (1990). Yolk deplclion and melabol;c rate oI 

Crocodtlus johnstoni. Copcia 1990: 871 5. 

halchling 

whilchcad, P.J. and Scymour, R.S. (1990). Paltems of metabolic rate in 

embryonic crocodilcs. CrocodJLus iohnstoni and C. /o/ojtJ. Physiol. Zool. 

631 334-52.

Whitehcad, P.j., Wcbb, C.J.w. iind Scymour. R.S. (1990). Ellccls ol tncubrtion 

lcmpcrafurc on Srowlh and dcveiopncnt |ar.!t of Ctocodtlus johnsttni 

embryos. Plrysiol. Zool. 63(5), 94941. 

whilehcad, P.J-, Wcbb, C.J.w. and Scynrcur, R.S. (1992). Encrgelics ol 

embryonic dcveloprncnt in Crocod!lus johnstonit rslalion 1() duralion of 

incubalion. Physiol. Zool. 65: 360 78. 

z'7 5

2',16 

Artificial Incubation of saltwater Crocodile (Crocodylus 

porosus) Eggs 

D.w. tlilken, H.A. Staton, B,P. vernon, and B. Bon 

Mainland Holdings crocodi le Farm 

P.o. Box 19{; 

Lae, Papua New Gu i nea 

Three experiments were conducted to detormine the influence 

of incubation parameters on hatching success and the 

unifornity and pErformance of hatchling saltwater crocodile 

(Croaodylus parosus). In experiment f, eggs from 17 nests 

were incubated in a walk-in. commercial incubator at 3l ,7oC- 

Eggs from each nest were divided ihto tlto or more groups of 

12 or more eggs, and these groups tere randoml y allocated to 

one of four treatment groups (either "wood wool" or natural 

nest material as Lhe incubation substate; vrith e99s either 

covered or Lrn( overed dur i ng incubat ion ) . Between-nest 

differences in hatchability were statistically significant, 

However, even with this variabi I ity accounted for, 

differences in hatchabiliLy due to treatment (75.6-82,9x) 

were not significant. fn experiments II and III, 105 e99s 

from three nests were incubated at 31.O. 3l.7 or 32.4oC. 

Incubation pe|iod ranged from 78-79 days for eggs incubated 

al 32.4oC to 85-92 days for eggs incubated at 31.OoC. 

Hatchability averaged 90.5* over the two experiments, and 

was not 6ignificantly different between treatment groups. 

At higher incubaLion temperatures a greater percentage of 

eggs hatched naturally (e.9,, wjthout assistance). Over the 

range of incubation temperatures in the6e trials, posthatching 

growth rate was greatest for hatchlings from e99s 

incubated at the higher incubation temperature.

'rrfr 

EFFtcls 0F cRoppllrc o AxERlcA ALttGAr0R popurAiIof{s 

It{ rLoRt0A, u.s.A. I 

by Al 'an P. lrscdyard, Cljrtrn T. tioofe, Uichaol nelarJT, 

anC Trony C. Hj ne:: 

Flarida Ga$e and fresh Water Fish Co|nnisston 

4005 South i3rn $treet 

Geinesvilje, tiorlda,J.S.A. 

27',1 

Abstrait'-Arr rxperim€ntil harvest cf conmercjal-sjze (:11?-cm) An€rican 

8lligato.9 {.4iligntor rissis,"ippigrsis) has conduateC on t.eatrlent areas. 

Lochlcosa,orarge, and ewn!fts lal*s in northcentral Florida dtri|1g 19Bl-90 3nd 

response to h6!'vust v,as conFared ivith ccnt!"o] afeas pnynes p!"airi9 and Lake 

*oodrrff. An ovefall oeal) of 13yr \{as harve:ited nnrLtally but thjs vdiied i;lightly 

Dy area. Ihe fiBijj an total iength (-IL) of harve$ted all igatcrs ,a.ied by a!.€a and 

gnal14r alljgators congtit te$ an increaslngiy greater p.opofticn of th; harve$ts 

c';er yetrs. Ihe horvest bras p.eCoDrjnartiy (69.gjl) male. incieased huntsr etfort 

i'las tece953t'y over yeaas tc nai tain slccess fates beca!se of Dn l'lcrease tn 

!.Jtri ness of laager alljgdtors. 

lJo changes rvere C€terted in the physjcil cooditi0n of ha.vegted alligators, 

Njght-'!ight cou.Jts of r,arvestable alligators .eirained stable on alj harvest and 

control aress, but sone evidence of derlining counts of adult ().!93 cn) 

alliSntors was dete.ted cn lakes ofa'.'gp {-45'bj, Lochloosa (,6:JS), and *oodrlff 

(-lB%), Declines rsre attribut-ad prjma.ily lo r]arjness from h(]l!ting and livecaptor€. 

Colrts ol juveilile alligetors increased otr Crange and Lochlocsa lakes, 

Nest prodrction was lllostly jr,fluenced hy May and Septefiber water ?evels aod 

re,nained stable oir all areas except orange ,-ake ar,d Lake Wocd.uff whefe nesi.ing 

jncreased. Hest sl-rrvival ircreas€d d0ring the study, prioari 1y due to decreasing 

jncidence of flocalin0. ,,lest p.edaticn iras attriblted tr raccoans and !/as 

g:"eatest 6n o.ar$e t.ake i51%). 

Clqt0h si?e Cistrjbutjons varied aftono areas rjirrpled (0range L.ak€, paynes 

Prairie, and Lake $crdr!ff' and medr! c?utch $i.e on Lake Woodrxfi f42,9) lvas 

greaier than thaie ot Crra^ge i-axe {32.8} and PeynEs prairie 

{33.8i_ Clutch size 

drd,rot chante ovor years Or eithe. treatrlani or contfol a.ea5, lri,1idum siie at 

oaturrty i{as J80.5 r& for an orange Lake fesale but only 64!t, of >J83 cdt feF,iles 

were liat{lre, PrOpO.liDns of;ratur€ fe'n3les ai ., tiven s.jre class v;ried by aaea 

'.rith flewnarG ia'(e lenales aat!ring at a greater siie, paopDrtion of nature 

fenal-As ovulating did not change cver years but d6s less on Newnans {15,9S) than 

eiiher j-ochloosa {38-srv") or o.aoge Lake (3$.8%j. 

The langest al'ligator recordrd cn study lakes f!.on 1gBl,g0, an Orange Lake 

nale, wag 423 crn TL and 473 kg. The largest fenale, taken on O.ange Lake, was 

297 ch and 115.5 kg. Skbad!]t (122-19, crn) all igators 0rew t,rster on t.ochloosa 

atd flervoafls than they did on drange and yloo,-jruff lakeo, Fsti ated years fcr 

f-6rhales to,-eath ri'|,in m rEprodrcl.i ve sire (180 cft for Lochlcosa anC O.ange, and 

21 I cin for Nelvnans) ranged f.o'! 8.9 on Lochloosa to 12.4 on Ot.ange_ Markrecapture 

data and feaur annr)i analyses indicated that grolrtl, .ates cf females 

j 

Presentedat 

the 11th Worki|19 MeEting of the Croccdile Specialist Group, 

Vi ctori a Fal i., ;iqbabwe, 2-7 August, 199?. 

2 Presefit Address: 

ficlte J, 8ox 509, Newberry, Flo.jda, U.S,A

278 

did not chnnge tufi09 ths hrt"Je:!r- but tirat grotri h rate-< c{ thE Frbai{r'lt r'ale:l 

1t;.e.!5ed. 

]4e fclid nO evjceqae tjlat 3lj,igatcrs frarveFts afigcled fish Foprlaticrs or 

n!trten: levels ir iares. Lra!i ight risjht lit!. af rlligatcr"s dr!i-';'.d j4t,i9di119l! 

afte,- hlnts bllt reccvered f!jli.by the follcwing yearj siJggestjri'iiit hiryests 

htd rrnly a tedporar!, effrcl rr daylj.Jht vjeirrn! ci alligatcrg. 

A s!slsrneil 13ql proportr.rnnl ha!_',9st cf ao*inarcial -ci:e nlliSatorr haC rlu 

fieas{Jrable negative a{feats on elligntor populatjons. Diffp!.ence! aocr!1 gtuly 

areas in resporsg 9t deilDgriphir ira.am|)ters to hafvest tndilate that ,etlaFds 

with dissiniiar denogfapl-"r.s ftay respond differently io harvr5ts.

...: .. 

''rli i.. :l:i:r_ri-1 

I ,r ,.,.:.,ri ,:j rj.r,;,, 1 

a:r. r' il,:l : :!. 

.,r:li:ll,nf: i 

! 0 ii!:\ i - f :r.-'' 

'Iil. 

i,lir.:s*,e 

i r:.rl!a l|] / 

f:A 

.ABEflCRONI6iO A' 

ltofroni Colleg.€ 

jpaitanDury 

South Camlins 29303 

{JSA 

BARRETT J 

c/oPOBox636 

CsDberra 

ACT 2601 

Austmlia 

BEHRA O 

Biod€v 

Irt VX lE Andr€frndrova 

Anta nana rivo 

MadlgFsctr 

r! ir".); .; ::: 

:':.':,:.:, 

inlrrf 

:ii:lrrrdrlr 

;iiiibai)*e 

:IROWN K 

Z;mbrow€ 

CALLOW R 

P O Box 191 

Har:tre, Zimbahw€ 

( \wooD B 

Private Bag 5730 

B€it Bridge 

Zimbabwe 

cocK E v 

15 Knowetop Drive 

Grc€ndale 

Ha*rre 

Zimbabwe 

cll-ql]HouN I 

F D 8ox i30 

iriorton 

Zlmbabld€ 

:,1'rj 

'TILISES P 

? 0 Aox 39E6 

Pi€t€rsburg 

lepublic of South Africa 

c'J;:i ti 

? I) .3r,;t 53i0 

,.1.r:"rs 

'at'a!irr:r5ran! 

,'rtli:!rll.r ,18 il 

aati ; 

rr 6l\0 

? C llor 2-333 

./ricrrld 

:lrdonesia 

CRA1G C 

62,4 Nilpier AY€nue 

HiUs;de 

Sulawayo 

Zimbabwe 

DACEY T 

P O Box 40617 

Crsuarina 

No hcrn T€rritories 

Australia 0811 

DA\'ID D 

716 NW 97 Tierr 

GaiDesville 

FL 32607 

USA 

DAVIS G 

P O Box 42092 

Casuarira 

Northern Ter tories 

Australia

280 

DENLE"T M 

Coixs Postal 239 Cep 

9 Osodo RS Brazit 

DORE M 

PMB 21198 

Ikeja, Irgos 

Nigeria 

DRYDEN D C 

P O Box 191 

Ilarrrt 

Zimb.bwe 

EDWARDS S 

IUCN 14m l6rh St Nw 

WsshiDgton 

DC 20036 USA 

EII)BEID A M 

Wildlife Cons€rvation 

P O Box 336 

Khartoum 

Sudan 

ELSEY R 

Rouie 1, Box 20D 

Grard CheDier 

Iruisiarna 70613 

USA 

ERIKSON A 

P O Box 559 

Oudtshoorn 

Cspe Province 6620 

Republic of Soutl Aftica 

EVANS P 

P O Bor 3214 

Quito 

Ecuador 

FERGUSON M W J 

Dcpt Cell & Structural 

Biolo$/ 

Univerfity of Monchesacr 

Stopford Building 

Oxford Roed 

MaDchester M13 9PT UK 

FERGUSSON R A 

CFAZPOBox55 

lGriba 

ZiEbabwe 

FERNANDEZ E 

Finca Chojoja 

Mszatetrsngo 

Suchitpeques 

Guatemala 

FINCHAM J R 

Archosaurir Crocodile Farm 

P O Box 260 

RaDsgate 4285 

Rcpublic of South Africa 

FOOT C 

P O Box EH29 

Ernerald Hill 

Harare 

Zimbabwe 

FTILLER M 

P O Box 6870 

Tallahassee 

Florida 32314, USA 

GAMES I 

P.O. Box U.A. 296 

Harare 

zimbabwe 

GENOI,AGANI J 

Natiorlal Crocodile 

MaDagemena Uria 

D€partmena oi Envimnment 

& Consenation 

P O Box 6601 

Bomko NCD 

Papua New Guinea 

GIBSON D 

624 Napier Avenue 

Hillside 

Bulawayo 

Zimbebwe 

}IALLDR R D 

Baobab Farm Ltd 

P O Box 90202 

Mombase 

KeDya 

HALLER D T 

Baobab Form Lid 

P O Box 90202 

Mombasa Kcnya 

HEMLEY G 

Traltrc USA 

1250 24th Sa Washington DC 

20037 USA 

HEONC Koh Chootr 

50 Detu Lane 7 

Singapore 1953 

HIBBERD E M A 

Biolo$/ Depsrtment 

University of CeDta I 

Queensland 

Rockhampton 4700 

Australia 

HINES T 

Route 3 Box 509 

Newberry 

Florida 32669 USA 

HOQUE E 

155 Ho$l€y Road 

Panania NSW 2213 

Australia 

HOOGMOED M 

Nationaal Natuuftisaorisch 

Museurn 

Postbus 9517 

2300 RA Leidcn 

Netherbnds 

HOPE C 

Dept of Sociolos/ 

C.oll€ge of Charl€ston 

Charleston 

South Carolina USA 

HUCHZERMEYER F W 

P O Box lA99 

Ond€rstepoort 0ll0 

Republic of South Ahica 

HUNT H 

Atlafis 7ô 

800 Chemkee AveDuc SE 

Atlanta GA 30315 

USA 

HUNTER I 

P O Box 417 

Mamndera 

Zimbabwe

HUTION J 

CFM 

POBoxHGll 

Highlands 

Harare 

Zirnb{bwe 

IMWUTIKUN W 

Wesao Crocodile Farm 

121 Mou 3 

Malsm Tao 

w't Singh 

Chsinart 

Thailand 

ISHII N 

4"7.10, Nihonbashi Honcho, 

Chuol 

Tolryo 

Japrn 

JELDEN D 

Mallwiazstr, 1-3 

531X) Bonn 2 

Germany 

JENKINS R 

ANFWLS 

P O Box 636 

Csnberra 

acr 2fi1 

AUSTRALIA 

JOANEN T 

Rorrae 1 Box 20-B 

Grand Chenier 

I,A 70643 USA 

JOUBERT J 

P vste Ba8 3 

Buhrmannsdrif 2867 

Republic of South Africa 

JOUBDRT B 

Priv.te BAg 3 



KELLY H R 

Rive$end Crocodile Farm 

PO Box 2"45 

Ramsgete 4285 

Republic of South Africs 

KELLY T J 

Riveniew Crocodile Fa.m 

POBox 

Wartburg 3450 


KENNERLEY D 

Dwangws Sugar Corporation 

POBox46 

Dwengwa 

Malawi 

KOCHEN R 

Guadrh 5 Casa 15 ' Jardim 

Petmpolic - Cuiaba . Malo 

620550 

Brazil 

LANCE V 

9925 Mozelle l,ene 

L Mesa 

California 91941 

USA 

I,ANDREY 

P O Bor 87416 

Houghton 

Johannesburg 

R€public of South Africa 

I"ARRIEM A 

Bu. Pell€gdni 3700 

3000 . Santa Fe 

Argentina 

I"ARSEN M 

Crookes Brothers Ltd 

P O Renishaw 4181 

Republic of South Africt 

LELLO J 

P O ReDishrw 4181 


LEON A 

P O Box 240956 

Bogota, Colombis 

South America 

LEVER J 

Koor€na Crocmdile Fsrm 

MS 76 Rockhampton 

Queenslrnd 4702 

Austnalia 

LOKJH 

P O Box 420 

Bulawsyo 

Zimbabwe 

287 

LOVERIDGE J P 

Univc$i1y of Zimbabwe 

P O Box MPl67 

Harare Zimbabve 

LOWE C 

c/oPOBox185 

Victorie Falls 

Zimbabwe 

MARAIS J 

Pdvaae Bag 3 


Republic of South Afri:, 

MENGHI O 

CITES 

6 Rue Du Maupas 

1000 I-ausanne 9 

Swiazerland 

MDSSEL H 

CIIAIRMAN CSG 

l2AC Hope$ood Gdn 

13 Tholnton St 

Darling PT 

NSW 2027, Australia 

MILLIKEN T 

P O Box 30131 

Lilongwe 3 

Malawi 

MOLER P 

Florida Geme & Fish 

Commissioo 

4005 S. Main Str€et 

Gainesvillc 

FL 32601 USA 

MPIIANDE J 

P O Box 498 

Mzuzu, Malswi 

MUSOKOTWANE I 

IUCN 

P O Box 7.15 

Harare 

Zimbabwe

282 

NIGIITINGALE S 

P O Box 630825 

Choma, Zambia 

ONIONS Y 

P O Box 669 

Crims 

Queensland ,|t70 

Austnlia 

ORTIZ B 

Cslle 91-13A-45 apt 303 

Bogota 

Colo|Dbia 

South Americs 

PAT.ACIOS I 

Carrcra 35 No 1lX-65 

Ssnts Fe de Bogote 

Colombia 

South Anrerica 

PANI M 

TRAFFIC (Iaaly) 

via Selamis 290 

fi)199 Roms 

It8ly 

PASCAL D 

P O Box 130 

Norton 

Zimbabw€ 

PENTOLFE N 

P O BOx 389 

Chiledzi 

Zimbabwe 

PENZHORN H 

201 Medical Cenare 

Jakantrdr Hospital 

MuckleDeur 

PrctoriN mO2 

Republic of South Africsn 

MTANAKORN P 

Crocoilile Ms trrgement 

Associstion of Thailand 

Faculty of Science 

Kasetssrt Uhive$ity 

P O Box 9-10900 

Bengkok 10900 

Thailand 

RAIIARJO Y 

P O Box 123 

Bogor 16001 

Indorcsia 

RANOT S 

32 Rewtzki Streea 

Rssnana, Isr|el 

RDVOL B 

P O Box HGll 

Highbnds Herare 

Zimbabwe 

RICE K 

2508 Southwesa 35 Plsce 55 

Gainsville 

Florida UsA 

ROSS J P 

CSG, Florido Muscum of 

Neturel History 

Gainesville 

FlJ2611 

USA 

RULE I 

P O Box 241 

Chirudzi 

Zimbabwe 

SCHOEMAN P 

POBoxl 

Malelane 

Republic of South Africl 

SEVERRE E 

Ministry of Tourism, Natural 

Resources & Envimnment 

Wildlife Divisio[ 

P O Box 1994 

Dar-es-Saltem 

Tenzania 

SHIELD J 

P O Box 652 

Cairns ,18?0 

Australia 

SMITH G 

Posbus ,180 

ftcne 1675 

ftepublic of South Africa 

SOMMER H 

P O Box 1105 

Bulewayo 

Zimbsbwe 

STAMBULIE M 

F-d. Banco Popular # 1207 

Cartsgena 

Colombia 

Souah America 

STATON M A 

P O Box 30985 

Lafayette 

Louisians 70593 USA 

STEYN G 

89 Oosa Sl 

Piete$burg 0700 

Republic of South Africs 

SIJMMERS R 

P O Box HG 300 

Highlands 

Harare 

Zimbab\ve 

SWALES K W 

POBox33 

Darwendale 

Zimbabwe 

TAMARACK J 

Wildlife Survivol Center 

Rt. I Box 207-2 

Midway 

Ga 31320 USA 

TANGARWATCIIANAKARN 

Chamwit 

Spirachatarm Co Ltd 

POBox16 

Srimcha 

Cholburi 20110 

Thailand 

TAYLOR P 

P O Box 191 

Harsre, Zimbabwe 

TAYLOR R 

P O Box 8,137 

Causeway 

Harare 

Zirnbabwe

TEMSIRIPHONG M 

Sfirachatarm Co Ltd 

POBox16 

Sriracha 

Cholburi 20110 

Thailand 

THOMAS J 

P O Box 30131 

Lusaka 

Zambit 

TIFFIN J 

P O Box 8067 

Causeway 

Harare 

Zimb$bwe 

van der RIET R T 

P O Box 191 

Harare 

Zimbsbwe 

vsn der RIET M R 

P O Box 191 

Harare 

Zimbabw€ 

vsn JAARSVELDT J 

POBox16 

Binga 

Zimbabwe 

vsn JAARSVELDT K 

414a Sabi Drive 

Chiredzi 

Zimbabwe 

VERDADE L M 

Cizbas / Esila / University of 

Seo Paulo 

Caixs Postal 09 

Piracicsbs 13400 SP 

Brazil 

\tsLASCO A 

Seraicio Autonomo Pmfavns 

Edp. Crmejo, Mezzsnina 

Oeste, CSB Cerecas l0l0 

Venezuela 

WEBB G 

P O Box 3E151 

Winnellie NT 0E2l 

AustnElie 

WILKIN D H 

Mairland Holdings 

P,O, Box 196 Lae 

Papu, N€e Guinea 

WILKINSON P 

407 M€eaing St 

G€orgetown 

SC 29,140 

USA 

WOODWARD A 

Wildlife Research Laboralory 

4005 Soulh Main Street 

Gainesville 

FL 32601-9099 

USA 

YOUNG R 

POBox5 

Sherwood 

Bolswane 

YOUNG E & R 

P O Box 522 

Thonotosrssa 

FL 33592 

USA 

YOUNGPRAPAKORN 

Chamon 

Samutprakarn Crocodile 

Farm & Z,oo 

555 Taiban Rd 

Semutprakorn 

Thailand

Crocodile Specialist Group

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?