Bird Species and Climate Change: The Global Status Report - WWF

Climate Risk Pty Limited (Australia)Level 1, 36 Lauderdale AvenueFairlight, NSW 2094Tel: + 61 2 8003 4514Brisbane: + 61 7 3102 4513www.climaterisk.netClimate Risk Europe LimitedLondon: + 44 20 8144 4510Manchester: + 44 16 1273 2474This report was prepared by:Janice Wormworth BSc MAjanice@climaterisk.com.auDr Karl Mallon BSc PhDTel: + 61 412 257 521karl@climaterisk.com.auBird Species and Climate Change: TheGlobal Status Report version 1.0A report to: World Wide Fund for NatureThe authors of this report would like tothank our peer reviewers, including Dr.Lara Hansen and Prof. Rik Leemans.We would also like to thank CorinMillais, Paul Toni and Gareth Johnstonfor their input.ISBN: 0-646-46827-8Designed by Digital Eskimowww.digitaleskimo.netDisclaimerWhile every effort has been made to ensure that this document andthe sources of information used here are free of error, the authors:Are not responsible, or liable for, the accuracy, currency and reliabilityof any information provided in this publication; Make no express orimplied representation of warranty that any estimate of forecast willbe achieved or that any statement as to the future matters containedin this publication will prove correct; Expressly disclaim any and allliability arising from the information contained in this report including,without limitation, errors in, or omissions contained in the information;Except so far as liability under any statute cannot be excluded, acceptno responsibility arising in any way from errors in, or omissionscontained in the information; Do not represent that they apply anyexpertise on behalf of the reader or any other interested party; Acceptno liability for any loss or damage suffered by any person as a result ofthat person, of any other person, placing any reliance on the contentsof this publication; Assume no duty of disclosure or fiduciary duty toany interested party.

ContentsConclusive Summary 51. Introduction 111.1 Aims and methods 111.2 How the climate is changing 111.3 How climate change is already affecting biodiversity 121.3.1 Rate of warming a crucial factor 121.4 The current conservation status of birds 132. The ways in which climate change acts on birds 132.1 Changes in temperature 142.2 Changes in precipitation 142.3 Greater climatic extremes 152.4 Indirect effects of climate change 163. How climate change pushes birds out of ecological synchrony 173.1 Birds’ seasonal responses are shifting: Phenology 173.1.1 Egg laying dates 183.1.2 Migration timing 193.2 Climate change causes mismatch between behaviour and the environment 213.2.1 The vulnerability of long-distance migrants 224. How climate change shifts ranges and disrupt communities 254.1 Climatically forced shifts in distribution 254.1.1 Human barriers to migration 254.1.2 Changes could undermine current conservation efforts 264.1.3 Distributional shifts already underway 274.1.4 Forecasts of distribution changes 294.2 How climate change will disrupt communities and ecosystems 334.2.1 How birds are already affected by disrupted communities 355. How climate change affects population dynamics 365.1 Climate change and birds’ reproductive success 375.1.1 A note about climate extremes 425.2 The effects of climate change on adult survival 42Bird Species and Climate Change: The Global Status ReportClimate Risk

6 Climate change and bird extinction 436.1 The scale of risk climate change poses to general biodiversity 446.1.1 Additional reasons for concern 466.2 Estimating the scale of extinction risk to birds 466.2.1 Regional case study: Extinction risk for European birds 476.2.2 Regional case study: Extinction risk for Mexican birds 516.2.3 Regional case study: Extinction risk for Australian birds 526.2.4 Regional case study: Extinction risk for South African birds 546.3 Bird groups most at risk of extinction from climate change 566.3.1 Migratory birds 566.3.2 Wetland birds 586.3.3 Coastal birds and seabirds 606.3.4. Mountain and island species 616.3.5 Antarctic birds 636.3.6 Arctic birds 657. References 68Appendix A 74Bird Species and Climate Change: The Global Status ReportClimate Risk

Conclusive Summary1.0 Introduction“Climate change is emerging as the greatest threat tonatural communities in many, if not most, of the world’secosystems in coming decades, with mid-range climatechange scenarios expected to produce greater extinctionrates than habitat loss, currently deemed the top threat tobiodiversity” (Thomas et al., 2004; Malcolm et al., 2006).More is known about birds’ response toclimate change to date than for any otheranimal group, mostly as a result of manyspecies- and location-specific analyses.Yet of the global or international-scaleanalyses of biodiversity and climatechange, very few concentrate on birds inparticular. This review seeks to providea global survey of the climate threatto birds by compiling hundreds ofindividual studies to resolve the largerpicture of impacts.This analysis finds compelling evidencethat, with 0.8 °C (Hansen et al., 2005) ofwarming having occurred over the pastcentury, strong negative impacts onbirds are already taking place. Climatechange is affecting birds’ behaviour,distribution and population dynamics,and is implicated in complete breedingfailure in some populations. Themajority of evidence indicates thatcontinuing and expected changes tothe climate of 1.4 to 5.8°C by 2100 (IPCC,2001a; a projection expected to berevised to 2.0 to 4.5°C under a scenarioof a doubling of CO 2in the UnitedNations’ upcoming Fourth AssessmentReport [Giles, 2006]) will have veryserious effects on birds, including hugeshifts in distributions, major populationdeclines and high levels of extinction.At high risk from climate change: the red-breasted goose2 How climate change canact on birdsHighly sensitive to climate and weather,birds are pioneer indicators of climatechange (Berthold et al., 2004), thequintessential “canaries in the coalmine.” As global warming bringschanges in temperature, alteredmoisture and precipitation, moreextreme weather and a generally morevariable climate, birds from the Arctic toAntarctic are already responding.In future, global warming will also affectbirds indirectly through sea level rise,changes in fire regimes, vegetationchanges and land use change. With adoubling of atmospheric CO 2, climatechange could eventually destroy orfundamentally alter 35 per cent ofthe world’s existing land habitats(WWF, 2000).Photo: Chris Martin Bahr, © WWF CanonBird Species and Climate Change: The Global Status ReportClimate Risk

In the Arctic, where several hundredmillion migratory birds breed, adoubling of CO 2suggests the lossof almost half the breeding groundsof 10.4 million geese and 14.5 millionwaders by 2080-2099. Some Arcticbirds will lose more than 90 per cent oftheir habitat at higher levels of warming(Zöckler and Lysenko, 2000). 1 In Europe,Mediterranean coastal wetlands, whichare critical habitat for migratory birds,could be completely destroyed with1.5 to 4.2°C of warming by the 2080s(IPCC 2001b).Climate change will also cause some ofits most serious but least predictableimpacts by shifting the timing ofnatural events and by shifting species’geographical distributions. This will rearrangeplant and animal communitiesand ecosystems, and disruptbirds’ relationships with predators,competitors, prey and parasites. Thesechanges are expected to alter themakeup and functioning of most, if notall, the world’s ecosystems (Root andHughes, 2005). Evidence suggests manybird species will not be able to adapt.3 The effects of climatechange on birds3.1 Shifts in timingThe early warning signs of climatechange can be seen in shifts in timingof important seasonal events for birds,such as egg laying and migration. Theseshifts have been documented in NorthAmerica, Australia and Europe. Somebirds in Europe have even stoppedmigrating altogether with climatewarming (Lehikoinen et al., 2004).These timing shifts are a threat whenthey force birds’ life cycles out ofsynchrony with plants and insectsupon which they depend. In Europe,some populations of pied flycatchers,which are long-distance migratorybirds, have suffered a 90 per centdecline in numbers over the past twodecades, an effect strongly linked totheir failure to keep pace with climatechange. With their insect prey numberspeaking earlier due to warming, but theirmigration timing unchanged, they nolonger arrive at their breeding groundsin time to match peak food supplywith peak nestling demands(Both et al., 2006).Thus climatically-forced shifts canharm birds’ reproductive success andsurvival, and could even contribute tothe collapse of breeding populationsover the long term (Sanz et al., 2003).The mismatch puts serious additionalpressure on long-distance migrant birds,which are vulnerable to the summedclimatic risk for each habitat used alongtheir migration path (Huntley et al.,2006). Of 119 long-distance migrantsstudied in Europe, 54 per cent havealready shown a sustained, oftensevere, decline from 1970 to 2000,with climate change implicated as amajor contributing factor (Sandersonet al., 2006).3.2 Shifting and shrinking rangesThere is compelling evidence that birds,along with other animals and plants, arealready shifting their ranges in responseto climate change (Parmesan and Yohe,2003). Importantly, although rangechanges will vary for different species,1. UKMO climate model; a rise of 5°C at the time of a doubling of CO 2by the period 2070-2099.Bird Species and Climate Change: The Global Status ReportClimate Risk

ange contractions are expected to bemore frequent than range expansions(Huntley et al. 2006; Böhning-Gaese andLemoine, 2004; Erasmus et al., 2002).Range shifts pose major threats to birds,both directly and indirectly.3.2.1 Direct effects of altered rangesBird species are already shifting theirrange boundaries pole-ward (IPCC,2001b; Pounds et al., 1999) and sometropical mountain birds are shifting tohigher altitudes in response to climatechange (Pounds et al., 1999).Future range shifts and contractionswill occur as vast areas of bird habitatare lost or altered due to climatechange, with bird population declines orextinctions inevitable. In North America,approximately 2.5°C of warming wouldreduce the world’s most productivewaterfowl habitat by two thirds(Sorenson et al., 1998), cutting thiszone’s duck numbers by almost threequarters. In Europe, the boundaries ofmany birds’ ranges would be requiredto shift 1,000 km or more under midlevelglobal warming of 2.5°C by 2100(Huntley et al., 2006).Global warming of 3-4°C could eliminate85 per cent of remaining wetlandsworldwide, critical habitat for migratorybirds (UNEP, 2005). Looking at threatsto individual species, the Spanishimperial eagle and Marmora’s warbler(both found only in Europe) will entirelylose their current range under futurewarming scenarios, putting them at highrisk of extinction (Thomas et al., 2004b;Birdlife 2004a). The outlook is bleak forthe Scottish capercaillie, the highlandhabitat of which could shrink 99 percent. This bird could disappear fromthe United Kingdom by 2050 (Berryet al., 2001).Rate of change too rapid: Humaninducedclimate change could causehistorically unprecedented rates ofchange (Huntley et al., 2006), withspecies forced to shift 10 times fasterthan during any climatic change seen atleast since the last ice age (WWF, 2002).This will exceed the ability of manyplants and animals to migrate or adapt,causing extinctions.Barriers will prevent migration: Asbirds’ climate space is altered withglobal warming, species may be unableto shift in tandem if their new potentialhabitat is rendered unsuitable by humandevelopment. Their current habitat mayalso be fragmented by human land useand disconnected from potential new,climatically suitable areas (Hannahet al., 2005). Physical barriers such asmountains and large bodies of waterpresent further obstacles to migration.The prospect of such range shiftsis of great concern to managers ofconservation assets because manycentres of species richness for birdsare currently located in protected areas-- from which they will be forced byclimatic changes into unprotected zones(Böhning-Gaese and Lemoine, 2004).3.2.2 Indirect effects: Birds’ naturalcommunities disruptedAlso of highlighted concern is thethreat range shifts caused by climatechange will easily disrupt, or as someBird Species and Climate Change: The Global Status ReportClimate Risk

scientists describe it, “tear apart”ecological communities of birds andother interdependent plants andanimals (Peterson et al., 2002; Root etal., 2003; Root and Hughes, 2005). Thiswill occur because birds and the keyspecies they interact with are unlikely toshift as intact communities. Birds will bebrought into contact with different preyspecies, parasites, predatorsand competitors, as their habitatschange or they are forced into areasless suited to them.Seabirds are early responders to theseshifts and illustrate the magnitude ofthreat. Warming ocean waters havecaused key prey species underpinningthe North Sea food web to shift(Lanchbery, 2005). In 2004 majordeclines in a small fish species knownas sand eels caused complete andunprecedented breeding failure inseabirds on the North Sea coastof Britain, events linked to climatechange (Lanchbery, 2005).Thus shifts that re-organise naturalcommunities are expected to producefurther, still stronger, changes (Petersonet al., 2002) as bird populationsrespond to new levels of prey,predation and disease.4 The scale of climatechange impactsClimate change will have seriousnegative consequences for many birdpopulations (Berry et al., 2001; Zöcklerand Lysencko, 2000; DEFRA, 2005;Both et al., 2006) and has already beenlinked to population declines and majorreproductive declines. Looking to thefuture, the most serious of possibleimpacts - extinctions of entire birdspecies - are predicted.4.1 Climate change affectsbird populationsStudies are already linking climatechange to declines in population andbreeding success in bird populationsaround the globe. For some groups ofbirds, the effects are drastic.Extreme weather events, a feature ofglobal warming, appear to be increasingin frequency and magnitude (Parmesan,2005). The radical 97 per cent breedingdecline of California arid-land birdsduring a record 2002 drought potentlyillustrates the highly destructive anddisproportionate effect of climateextremes on birds (Bolger et al., 2005).Island birds, as well as seabirds, are alsohighly vulnerable to climate change.Endangered Galápagos penguinpopulations have halved since theearly 1970s because the adult penguinsbecome emaciated and fail to reproduceduring severe El Niño years (Boersma,1998). Because climate models predictEl Niños to become more frequent in thefuture (Timmerman et al., 1999), climatechange is expected to further reducethese small, restricted populations ofGalápagos penguins and threaten themwith extinction (Boersma, 1998).4.2 Climate change will causebird extinctionsClimate change puts many bird speciesat risk of extinction, even those currentlyconsidered safe (Birdlife, 2004a); andthe stronger the climate change theBird Species and Climate Change: The Global Status ReportClimate Risk

stronger the risk. With a global meansurface temperature increase of 1-2°Cabove pre-industrial levels, manyunique and threatened ecologicalsystems will be at risk and numerousspecies will face extinction (Noble et al.,2005; van Vliet and Leemans, 2006).Risk is dependent on the species. Thegolden bowerbird, like many otherbird species in the Wet Tropics ofAustralia’s northeast, is particularlyvulnerable. Its suitable habitat woulddecrease 63 per cent with less than 1°Cof future warming (Hilbert et al., 2004),illustrating why this zone’s climatescenario has been called “an impendingenvironmental catastrophe” by Williamset al. (2003).Among particularly vulnerable groups-- migratory, Arctic, Antarctic, island,wetland, mountain and seabirds --heightened impacts are expected. Thethreat of climate change to migratorybirds is equal to the sum of all otherhuman-caused threats combined(DEFRA, 2005) with 84 per cent ofmigratory bird species 2 facing sometype of climate change threat. Forexample, the Arctic-breeding redbreastedgoose, already globallyvulnerable, is expected to lose 99 percent of its tundra breeding habitat dueto climate change (Zöckler and Lysenko,2000). Birds that are habitat specialistsare at higher risk than generalists(Huntley et al., 2006; RSPB/WWF 2003).Birds breeding in arid environments(Bolger et al., 2005) and those with lowpopulation numbers, poor dispersalability, already poor conservationstatus, and restricted or patchy habitatsor limited climatic ranges are also atelevated risk from climate change (Reidet al., 2005; Huntley et al, 2006).The overall extinction risk of climatechange to birds is still being quantified.However, first-cut estimates present thepossibility of the extinction of more thana third of European bird species undera maximum (>2.0°C) climate changescenario, if birds cannot shift to newclimatically suitable ranges (Thomas etal., 2004). Indeed their capacity to shiftis subject to considerable uncertaintygiven Europe’s heavily modifiedlandscape (Huntley et al., 2006). Onecandidate for extinction is the Scottishcrossbill, expected to lose 100 per centof its current habitat (Thomas et al.,2004b).In the Australian Wet Tropics bioregion,mid-range climate change is predictedto threaten almost three quarters ofrainforest birds there with extinction inthe next 100 years (Shoo et al., 2005a).Table 1 provides estimates of birdextinction rates in four regions aroundthe world, from Thomas et al. (2004).However, many current projectionsof climate impacts, including thoseof the Intergovernmental Panel onClimate Change (IPCC), are likely to beunderestimates (van Vliet and Leemans,2006; Pounds and Puschendorf, 2004;Thomas et al., 2004). Most researchconsiders only the direct effectstemperature or precipitation will havein shifting or contracting climaticallysuitableranges. Limiting the numberof climate variables used potentiallyunderestimates the risk of key climatic2 Those birds listed with the Convention on the Conservation of Migratory Species (CMS).Bird Species and Climate Change: The Global Status ReportClimate Risk

Population sizeremaining (%)Figure 11201008060402000 1 2 3 4 5 6 7Temperature increase (ºc)Figure 1: Populationdecline of 55 Australianrainforest bird specieswith climatic warmingfor the year 2100, if nomigration is possible(Shoo et al., 2005a).These Wet Tropicsbioregion species arefound in habitats ofvarying altitudes: filledtriangles = speciesinhabiting 0-299 m;open circles = 300-599m; filled squares = 600-899 m; open squares900-1199 m; filledcircles = 1200-1499m. (See section 6 forfurther information.)in climate (Berthold et al., 2004).Compelling evidence shows that birdsare responding to climate change,which makes them ”pioneer indicators”for changes related to globalwarming (Berthold et al., 2004) --the quintessential “canaries in thecoal mine”.2.1 Changes in temperatureTemperature affects birds both directlyand indirectly. Birds are warm-blooded(endothermic) animals and mustmaintain constant body temperature.The response of birds to climate changewill vary from species to species,depending on how strongly theirmetabolism reacts to new temperaturelevels (Root and Hughes, 2005).Climate change will affect temperaturesin regions around the globe differently.Higher latitudes (i.e. regions closer tothe poles) are generally undergoingmore intense changes in temperature,with the Arctic warming almost twotimes the global average rate over thepast few decades (ACIA, 2004), thushabitat loss is expected to be mostmarked toward the poles (WWF, 2000)as species respond to this change.Where local and regional climates warmdue to climate change, bird speciesare expected to shift their distributionseither pole-ward or upward in elevation(in mountainous zones) to maintaintheir optimum temperatures. Becausesome species are adversely affected bytemperature increases as small as 1°C(Hilbert et al., 2004; Shoo et al., 2005a),they face an uncertain future if theycannot shift their distribution to tracktheir optimum climate envelope.2.2 Changes in precipitationPrecipitation and moisture are criticallyimportant climate variables to birds,and changes are expected to affectbirds both directly and indirectly. Somespecies, including inland water birdssuch as ducks, are highly dependent onBird Species and Climate Change: The Global Status Report14Climate Risk

precipitation to sustain their wetlandhabitats. Consequently, precipitationreductions have major implications forthese species.And although warming is likely to be themore critical climatic variable for birdspecies at higher latitudes, at the tropicsprecipitation timing and intensity maybe more critical (Root and Hughes,2005). Periods of low or zero rainfall tendto be linked to reduced bird populationsbecause these dry spells reduce birdfood sources, such as insects and fruit(Williams et al., 2003).Precipitation, along with temperature,is also especially likely to influencethe behaviour of migratory birds. Itis expected to affect their decisionto depart for migration indirectly byacting on food availability and birds’consequent ability to build up energyreserves. Drought in critical stopoverareas for migratory birds affects theirability to refuel on water and preybefore crossing barriers such as deserts(Bairlein and Hüppop, 2004).Changes in snowfall will also affect birdsin mountain habitats if these speciesdepend on areas of freshly melted snowto keep the ground wet and rich in insectlife (Inouye et al., 2000).2.3 Greater Climatic ExtremesScientists believe that global warming iscontributing to more extreme weatherevents, with heat waves, droughts(IPCC, 2001c) and tropical stormintensity (Webster et al., 2005) expectedto escalate in the future. More frequentoccurrence of these extremes, includingtemperature and precipitation extremes,will affect the survival of birds and otherwildlife. Upper and lower precipitationand temperature limits play anespecially important role in determiningthe distributions of birds and otherwildlife (Parmesan, 2005).Extreme weather can affect survival,especially of young birds but alsoadults (Crick, 2004; Stokke et al., 2005;RSPB, 2004b), particularly in thehighly variable Arctic climate where asummer storm can eliminate an entiregeneration of young birds (ACIA, 2004).European birds and their young are alsovulnerable to extreme events and morenegative impacts can be expected in thefuture (Stokke et al., 2005).Because some migratory birds arepushed to their limits of enduranceduring migration, increased frequencyof storms reduces some species’ability to reach breeding grounds(DEFRA, 2005).Increased extreme weather events suchas storms will also harm birds’ habitatsby eroding mudflats of estuaries thatare important feeding sites for birds(DEFRA, 2005). Along with sea level rise,storms will inundate low-lying islandsand seabird nesting colonies on themwill be lost (UNEP, 2005).Climate change is also expected to makeweather more variable (IPCC 2002).This is significant because birds expendmore energy after sudden temperaturechanges and if temperatures aremore varied. If energy is not abundantBird Species and Climate Change: The Global Status Report15Climate Risk

to compensate for such additionalexpenditure, birds may lay smaller eggs,for example (Pendlebury et al., 2004) .We can also expect bird species to beaffected by more intense and prolongedEl Niño events, another feature of globalwarming (DEFRA, 2005). Researchershave linked El Niño years with death ofadult birds and reduced production ofyoung (Mazerolle et al., 2005).2.4 Indirect effects ofclimate change“Climate change will oftenact in combination with majorthreats such as habitat lossand alien invasive species,making their impactsconsiderably worse…”Birdlife, 2004aHabitat changes: With a doubling ofCO 2, climate change could eventuallydestroy 35 per cent of the world’sexisting terrestrial habitats (WWF,2000). Birds’ habitats will be alteredthrough changes in sea level, fireregimes, vegetation and land use(Böhning-Gaese and Lemoine, 2004;IPCC, 2001b).Photo:Olivier Langrand, © WWF CanonOver the last 100 years, the globalsea level has risen by about 10-25 cm,depending on location. As noted above,rising sea levels can combine withincreased wave activity during stormsto inundate, erode or alter importantbird habitat.Sea level rise is expected to inundatelowland coastal bird habitats aroundthe world, including marshes. Oneimportant effect will be “coastalsqueeze”. As rising sea levels inundateexisting estuaries and deltas, hard seadefences and agricultural or urban landwill effectively form barriers against thenatural retreat of these habitats up theshore (i.e., further inland; UNEP, 2005).This combination of rising sea level andcoastal squeeze could permanentlyinundate mudflats, severely impactingwildfowl and wader species (DEFRA,2005). As noted above, rising sealevels will combine with tidal surges tothreaten the nests and young of birds onlow-lying islands or near the shore.By increasing the length and intensityof summer drought in many parts of theworld, climate change has increased thesusceptibility of ecosystems to fires.Fire, and fire frequency has increased(IPCC 2001b), destroying forest birdhabitat. Climate change is also expectedto cause major shifts in vegetation,further reducing bird habitat. Climatechange could also prompt shifts in landuse by humans, such as agriculturechange, which will also impact on birds.Shifts in communities: Because climatechange is also expected to shift thedistribution of plant and animal speciespole-ward or upwards in altitude withwarming, the overall indication is thatWarming will reduce tundra breeding groundsfor Arctic terns and other migratory birdsBird Species and Climate Change: The Global Status Report16Climate Risk

Figure 2: Current and projected vegetation shifts in the Arctic with climate change.Figure 2: Current andprojected vegetationshifts in the Arctic withclimate change. Notethat vegetation typesmove pole-ward andupward in elevation(ACIA, 2004).many bird species will have to competewith, or be displaced by, invadingspecies. Bird food species may also beaffected by changes in temperature(Both et al., 2006), wind patterns oraltered ocean currents (Peterson,2005). Climate change can also affectthe incidence of disease in birds(Epstein, 2001).This potential for climate change to“re-shuffle” ecological communities isdiscussed in greater detail below.3Howclimate changepushes birds out ofecological synchronyThis section examines how climatechange is forcing a shift in the key lifecycle events of birds, such as nestingand migration. It will show how birds’behaviour, in many cases, is shifting inresponse to climate change at a differentrate from that of key species (e.g. preyand parasites) and natural eventsupon which birds depend to completetheir life cycles. It demonstrates howthese differential shifts threaten birds’breeding success and survival.3.1 Birds’ seasonal responsesare shifting: Phenology“It’s when the canary keelsover that you know you’re introuble–and these changes inphenology are the canary.”Ecologist Alastair Fitter, York University,UK (from Jensen, 2004)Birds’ life cycles and behaviourare closely tied to the changingseasons. Seasonal variables includingtemperature and precipitation alsoaffect the availability of flowers, seeds,insects and other food sources for birds(NWF/ABC, 2002). The study of thetiming of recurring natural phenomenasuch as migration, nest building and egglaying, especially in relation to climate,is known as phenology.The effects of climate change on theseimportant behavioural or biologicalevents is already well documented,with robust studies showing a strongresponse to climate change in birds. Thechanges are of concern because theycan force a given bird species’ lifecycleout of synchrony with the ecosystemsand communities of which it is a part, aneffect discussed further below.Bird Species and Climate Change: The Global Status Report17Climate Risk

Figure 3765Days Advanced432Combined Trees Non-trees Birds Amphibians InvertebratesFigure 3:Analysis of oversixty studies revealsthat birds aroundthe world haveadvanced the timingof spring phenologicalphenomenon, suchas migration and egglaying,at a rate of 6.6days per decade onaverage. “Non-trees”refers to plants otherthan trees (Root andHughes, 2005).Taxa (group)We know with certainty that birdsare already responding to climatechange. One analysis of more thansixty phenology studies worldwide(Root et al., 2003) found birds hadadvanced timing for spring phenologicalphenomenon at an average rate of 6.6days per decade. Furthermore, theseshifts were in the direction consistentwith climate change (see Figure 3; Rootand Hughes, 2005).Large numbers of studies in Europehave also documented shifts inmigration, timing of mating, nestbuilding,egg-laying and clutch size inresponse to climate change. The smallcross section of research presented herereveals the types and extent of change.3.1.1 Egg laying dates:Strong evidence documents earlier egglayingby birds in response to climatechange. Approximately 60 per cent ofstudies on egg-laying show long-termadvances in laying date consistentwith patterns of global warming(Dunn, 2004).In Europe:■■A 25-year study of UK birds found that 20out of the 65 species studied were layingeggs 8.8 days earlier on average (Crick etal., 1997). Another study found a strong(statistically significant) correlationbetween laying date and climate change(Crick and Sparks, 1999).Analysis of 23 long-term studies ofEuropean flycatchers using datafrom 40,000 nests shows laying datesadvanced significantly in nine out of 25populations; furthermore, the more thetemperature increased at the site, themore the laying date advanced (Bothet al., 2004). Laying dates advancedsignificantly over the years in nine out of25 populations. Furthermore, “20 out of25 populations show a significant effectof local spring temperature on layingdate,” that is, the more temperaturesincreased at a site, the more the layingdate advanced.In North America:■New research using 50 years of datademonstrated that four ecologicallyBird Species and Climate Change: The Global Status Report18Climate Risk

■■diverse species are laying eggs earlier inconjunction with warming local climates(Torti et al., 2005).The North American common murre(also known as the common guillemot)has advanced its breeding date 24 daysper decade (Root et al., 2003).The mean laying date for Mexicanjays’ first clutch of eggs advancedby 10.1 days over a 1971-1998 studyperiod. Noting that initiation of layingis sensitive to warmer springtimeminimum temperatures, Brown et al.(1999) reported that “changes wereassociated with significant trendstoward increased monthly minimumtemperatures on the study area, traitsthat are associated with the onset ofbreeding in this population.”3.1.2 Migration timingSpring migration of birds is generallyconsidered more important thanautumn migration because it determinestheir arrival timing at breeding grounds,which is in turn crucial for matingand territory choice. The number ofsuccessful spring migrants also directlyaffects breeding population size(DEFRA, 2005).3.1.2.1 Spring migration advancesIn general, research indicates birds aremigrating earlier in spring in conjunctionwith warming climates. However, longdistancemigrants seem to be laggingbehind short-distance migrants in termsof their response, an effect discussedfurther in this section.The evidence for earlier springmigration is powerful, as the examplesbelow indicate. The linkage betweenearlier arrival dates and climate changeis strengthened by data showingarrival dates are unchanged where no(significant) local temperature changehas been observed, and arrival datesare later where local temperatures haveactually become cooler (DEFRA, 2005).In Europe:■■In the UK, where decades of extensiverecords exist, three studies have foundthat between 26 per cent and 72per cent of recorded migrant birdspecies have earlier spring arrival, witharrival date advances of up to two weeksover the past two to three decades(DEFRA, 2005).Analysis of more than two dozen studiesthroughout Eurasia shows first arrivaldate for migrants in spring advanced anaverage of 0.373 days/year (3.73 daysper decade) towards the end of the 20thcentury in conjunction with climatewarming. This includes birds in Norway,Russia, Finland, Estonia, Denmark,Lithuania, France, Poland, Germany andGreat Britain (Lehikoinen et al., 2004).In North America:■A 63-year data set on first springsightings for 96 species of migrantbirds in Canada revealed that, as meanmonthly spring temperatures increased(by 0.6 - 3.8°C), 27 species altered theirarrival dates significantly, most arrivingearlier. Only two species arrived later,“evidence that climate warming hasinfluenced spring migration arrivaldates of several species in Manitoba”(Murphy-Klassen and Heather, 2005).Bird Species and Climate Change: The Global Status Report19Climate Risk

In Australia:■Arrival dates for 24 species anddeparture dates for 12 species of birdswere analysed using data spanningthe past 40 years. On average, birdsare arriving 3.5 days earlier per decadesince 1960, with half the speciesshowing significantly earlier arrival.These results, reported by Beaumontet al. (2006), “add further evidencethat the modest warming experiencedover the past few decades has alreadyhad significant biological impacts on aglobal scale.”In Antarctica:■East Antarctic seabirds, including Adéliepenguins and six species of petrel, arearriving at their colonies an average of9.1 days later and laying eggs 2.1 dayslater than in the early 1950s. Some birdsare arriving as much as 30 days laterthan in the 1950s. The findings havebeen linked to global climate changewhich has decreased sea ice extent inthis region overall, but caused the seaiceseason to increase by more than 40days due to localised cooling since the1970s. These changes are associatedwith declines in krill, a key prey species.The birds’ delayed arrival and layingdates may reflect the longer feedingtime to build up the energy reservesrequired to breed (Barbraud andWeimerskirch, 2006).3.1.2.2 Autumn departure shiftsBirds’ autumn departure dates alsoappear to be changing, however thiseffect is more difficult to monitor(Crick, 2004). This response to climatechange also appears more variable withsome species advancing and otherspostponing their autumn migration.These differences appear to reflect therelative importance of summer andwinter seasons in completing birds’ lifecycles (Lehikoinen et al., 2004).In Europe:■Birds that winter south of the Saharahave advanced autumn migration anaverage of 2.5 days in the last 40 years,possibly so they can cross the Sahelbefore the seasonal dry period. Bycontrast, migrants wintering north of theSahara have delayed autumn passageby 3.4 days on average over the sameperiod (Jenni and Kery, 2003).In North America:■Of 13 North American passerine birdspecies, six were found to delay theirmigration dates in conjunction withglobal warming (Mills, 2005).3.1.2.3 Failure to migrateIn Europe it appears that climate changeis causing individuals of some birdspecies (which normally migrate) to failto migrate at all.This includes greenfinches, which haveseen a six-fold increase in their winterpopulations in Finland in the last 40years, as fewer individuals migrateto Northern Germany (Lehikoinenet al., 2004).Bird Species and Climate Change: The Global Status Report20Climate Risk

3.2 Climate change causes mismatchbetween behaviour andenvironment“Global warming may causemigration and nesting to get outof step with food supplies. As aresult, the ‘early birds’ may notget the worm”NWF/ABC, 2002As demonstrated above, many birdspecies’ migratory and reproductivebehaviour is shifting with climatechange. But there is concern some birdspecies may not be able to alter theirbehaviour sufficiently to match shiftsin the availability of important foodsources such as insects, flowersand berries.invertebrate phenology (six days per1°C; DEFRA, 2005). Such animals couldbe caught in a race against time as theyevolve to adjust to shifts in the seasonalavailability of food sources triggered byclimate change (Pennisi, 2001; Thomaset al., 2001). Some bird populations arealready in major decline due to climatechange-induced mismatch (Both etal., 2006) and there are indications thismismatch could also hasten the declineof species that are already endangered(Scheigg et al., 2002).Given the enormous complexity of foodwebs, the balance of evidence indicatesthat more such problems are very likelyto occur. However, the current lack ofdata on this subject makes it difficultto quantify the level of risk to birds(Leemans and van Vliet, 2004).A timing mismatch between predatorand prey could cause major speciesdeclines if birds are unable to completetheir life cycles (Both et al., 2006). Forexample, migrant birds may be unableto breed successfully because theirarrival time no longer coincides withpeak food availability. Biologists refer tothis as “phenological mismatch”. It mayoccur because birds, and the specieson which they depend, are drivenby different cues. For example, oneanimal’s behaviour may be cued by daylength, the other by temperature (Pew,2004; Visser et al., 2004).Research shows the extent of themismatch already underway today.Advancement in the laying date ofBritish migratory birds (typically twodays per 1°C) appears to be laggingbehind advances in vegetation andIn Europe:■■In Spain, leaves on trees are unfolding16 days earlier and plants floweringsix days earlier than in 1952; fruiting isnine days earlier than 1974. Yet springmigratory birds are arriving 15 days laterthan in 1952; researchers speculate thiseffect is due to climatic changes in theirwintering area (Penuelas et al., 2002).In France, blue tits in Montpellier areexerting themselves at almost doublethe normal metabolic rate as they forageto feed their young. Climatic warminghas meant the birds are failing to breedwhen and where their food is in peakabundance, forcing them to exert extraenergy to forage. According to Pennisi(2001), “These parents’ overall survivalsuffered because they had to workharder to feed their young.”Bird Species and Climate Change: The Global Status Report21Climate Risk

In North America:■Research on endangered red-cockadedwoodpeckers in North Carolina over twodecades shows that while normal birdswere laying eggs earlier in response toa warming climate, pairs that includedan inbred partner were not (Scheigg etal., 2002). Since endangered speciesare often reduced to small, isolatedpopulations that become inbred,“climate change poses a previouslyunknown threat that may hastenthe decline of endangered species,”according to Karin Schiegg. 43.2.1 The vulnerability of longdistancemigrants“Long distance migrantshave an extra handicap toadjust their breeding date toclimate change, because onthe wintering grounds itis often impossible to predictchanges in the onset ofoptimal conditions in thebreeding grounds.”Visser et al., 2004Long-distance migratory birds do notappear to be responding to climatechange (by shifting their migrationtiming) as rapidly as short-distancemigrants, according to several piecesof research (Crick, 2004; Mills, 2005;Tryjanowski, 2002). The differentresponses are believed to stem fromdifferent underlying processes thatdetermine migration timing of thesetwo bird groups. It suggests that longdistancemigrants are more likely tosuffer from of climate change-inducedmismatch with their environment(Coppack and Both, 2002; Visser et al.,2004). As a result, they may bemore likely to suffer as a result ofclimate change.For species that do not migrate, localweather and vegetation act as reliablecues to start breeding. However,migrating birds, and especially longdistancemigrants, are removedfrom the food sources at the otherparts of their migratory path. Insteadthey respond to “internal clocks”,environmental stimuli unrelated totemperature (Coppack and Both, 2002;Barlein and Huppop, 2004) or weathercircumstances along the migrationroute (Gwinner, 1996). Climate changemay advance events such as insectemergence in the migrants’ breedingareas; but if a given species’ springmigration does not advance in keepingwith their prey, they are at a greater riskof being out of synchrony (Both andVisser, 2001; Visser et al., 2004)Some researchers argue that pastselection pressure could have promoteda very stable timing of migration due tothe severe reproductive consequencesof arriving either too early or too latein spring breeding grounds (Coppackand Both, 2002). Genetically speaking,this means that long-distance migrantscould lack the ability to change thetiming of migration (Coppack andBoth, 2002; Pullido and Widmar, 2005).According to Pullido & Widmar (2005),“If this were true, the adaptability oflong-distance migratory birds wouldbe limited, which would explain thevulnerability of this group of birds toenvironmental changes.”4 Quote from NWF (undated).Bird Species and Climate Change: The Global Status Report22Climate Risk

This is of special concern given anoverall trend of strong decline forlong-distance migrants in NorthAmerica and across Europe, with longdistancemigrants doing significantlyworse than short-distance migrantsor resident birds (Sanderson et al.,2006; Both et al., 2006; Birdlife, 2004b).Climate change-induced mismatch isprobably a widespread phenomenonand strong evidence already ties it tomajor population declines in some longdistancemigrant bird populations (seecase study 1; Both et al., 2006). There isconcern it could cause further collapsein breeding populations of such birds inthe future (Sanz et al., 2003).Other climate change related risks facedby long-distance migrants and othermigratory birds are detailed in section 6.■■on food availability and the build up ofenergy reserves required for the birds tomigrate, illustrating the complex effectsof climate change on the birds’ lifecycles (Gordo et al., 2005).Changes in timing of vegetation growthcould lead to a mismatch betweenmigration time and optimum vegetationconditions at stopover sites for longdistancemigratory geese, and otherplant-eating migrant birds that dependon high-quality forage plants at a smallnumber of staging sites (Bairlein andHüppop, 2004).New research reveals 54 per cent of 121long-distance migrants studied haveshown sustained, often severe, declineor even become extinct in many parts ofEurope since 1970, with climate changeimplicated as a major contributing factor(Sanderson et al., 2006).African -- not European -- conditions more stronglyinfluence the hoopoe’s spring arrival in EuropeIn Europe:■Fifty years of data revealed that for sixtrans-Saharan migrant bird species,conditions in the birds’ African winteringquarters had a stronger influence onfirst spring arrival dates than theirEuropean (western Mediterranean)breeding grounds. Temperature andespecially precipitation affecteddeparture decisions indirectly by actingPhoto: Fred F. Hazelhoff, © WWF CanonIn North America:■■Short-distance migrants in the UnitedStates arrived an average of 13 daysearlier in their summer grounds in NewYork and Massachusetts during theperiod 1951-1993 than in the first halfof the century; yet long-distancemigrants arrived just four days earlier(Butler, 2003).Wood warblers showed no significanttendency to migrate earlier from theirneotropical wintering grounds, despiteearlier springs in their northern USbreeding range. According to Strode(2003), “These results suggest thatclimate change may force many speciesof long-distance migratory songbirds tobecome uncoupled in the spring fromtheir food resources that are drivenby temperature.”Bird Species and Climate Change: The Global Status Report23Climate Risk

CASE STUDY 1: EUROPEPied flycatchers fail to keep up withclimate changeThe pied flycatcher is a small, insecteating,long-distance migratory birdwith relatively fixed migration timing.It winters in West Africa and migratesthousands of kilometres to breed inthe spring in the UK, northwest Europeand Poland and Russia. Thoughnot currently threatened, recentevidence reveals some pied flycatcherpopulations are declining in the faceof existing rates of climatic change intheir European breeding grounds.The birds appear to be nesting morequickly after their arrival in spring,which helps compensate for earlieremergence of their caterpillar prey,which also grow and pupate faster inresponse to warming (Both and Visser,2001; Both et al., 2006). However, thebirds do not appear to be shiftingtheir spring arrival time. If caterpillarpopulations peak too early, piedflycatchers are simply unableto nest, lay eggs and producehatchlings in time to capitalise on peakprey availability.New research on nine pied flycatcherpopulations in the Netherlands from1987 to 2003 reveals a 90 per centdecline in the birds’ numbers in areaswith the earliest food peaks, and muchlesser declines of about 10 per centin areas with the latest food peaks.Furthermore the populations thatshow the least adaptation to theirchanging environment -- those thatadvanced their laying date least - showthe greatest population decline (Bothet al., 2006).In a Mediterranean population ofpied flycatchers this mismatch hasalso been linked to reduced nestlinggrowth and a 15 per cent reductionin nestling survival (see figure 4).According to Sanz et al. (2003) “thebreeding season has not shiftedand it is the environment that hasshifted away from the timing of thepied flycatcher breeding season”.These authors state that if climatechange and effects such as this aresustained in the long term, “it mayimply a further collapse of breedingpopulations of long-distance migrantsin the Mediterranean region”.1009080Breedingsuccess (%)70Figure 4Figure 4: The breeding successof Mediterranean populationsof pied flycatchers declinedby approximately 15 per centbetween 1984 and 2001. Thislong-distance migrant did notarrive in its breeding groundsearly enough to breed andmatch its nestling demandwith peak food supply. Insectsnow emerge and peak earlier inkeeping with global warming(Sanz et al., 2003).60501985 1990 1995 2000Solid dots represent the LaHiruela study area, hollow dotsthe Valsain study area.Bird Species and Climate Change: The Global Status Report24Climate Risk

4Howclimate changeshifts ranges & disruptscommunities“Rapid movement of climaticzones is going to be anotherstress on wildlife ... In effectwe are pushing them offthe planet.”James Hansen, NASA Goddard Institutefor Space Studies (from Hansen, 2006)This section discusses how climatechange causes spatial shifts inpopulations. This can directly affectbirds by causing major populationreductions, or in future, could result intheir complete collapse. We will furtherdiscuss indirect effects of such shiftsthat arise because different specieswill shift at different rates as theyrespond to climate change, forcingbirds into new and “reshuffled” habitatsand communities. This effect bringsadditional, possibly greater, threatsof its own.4.1 Climatically forced shiftsin distribution“How species will find andmove to suitable new locations,and what other elements oftheir habitat they will find there,are difficult questions thatscientists and governmentsare still exploring.”RSPB, 2004aThe strong relationship between birddistribution and climate (Root, 1988)means that when climatic boundarieschange, bird distributions are expectedto shift too (DEFRA, 2005). In thenorthern hemisphere the northernboundaries of bird distributions arelimited by cold temperatures, while thesouthern boundaries tend to be limitedby heat or water scarcity in arid regions,and competition between species,predation and parasitism in humid zones(Böhning-Gaese and Lemoine, 2004).If local and regional climates followglobal averages by warming, birdspecies could be expected to shifteither upward in elevation, or poleward,(although exceptions exist) totrack their optimum temperatures. Inaddition to temperature, moisture,precipitation and invasion by competingspecies are other direct and indirectclimate-mediated factors that can beexpected to affect distributions of birdpopulations(DEFRA, 2005).4.1.1 Human barriers to migrationOf course distributional shifts ofspecies have occurred across timein conjunction with climate change.However, a threat today, in addition tothe rate of climate change (see section1), is that habitats are increasinglyfragmented by human development.Consequently climatically-inducedmigrations will be checked by cities,highways, farms and other humanbarriers (Hannah et al., 2005; Parmesan,2005), in addition to natural geologicalbarriers, such as mountain ranges orlarge bodies of water.Bird Species and Climate Change: The Global Status Report25Climate Risk

Habitat fragmentation reduces theability of birds to disperse into newareas and causes lags in distributionalshifts (RSPB/WWF, 2003; NWF/ABC,2002). According to the IPCC (2001b),fragmentation can also facilitatethe introduction of invasive speciesinto an area “leading to potentialpopulation declines through predation,competition, or transmission ofdisease.” Fragmentation will be a keyfactor affecting species’ response toclimate change (RSPB/WWF, 2003).4.1.2 Changes undermine currentconservation efforts“Conservationists are enteringa new era of conservation,one in which last-ditch standsto save species where theycurrently exist may notbe enough.”Hannah et al., 2005Distributional shifts are of great concernfor international bird conservationefforts, which focus on areas with highnumbers of endemic and threatenedspecies. Many centres of speciesrichness for birds are in protected areas.As climate change progresses, manypopulations of bird species’ will beforced to shift out of protected areasand possibly into areas with humandevelopment or conflicting land use.If birds cannot move and are forcedto remain in areas that have becomeinhospitable, birds and other groupscould see their range and populationsize decrease until they eventuallybecome extinct (IPCC, 2001b). AsWalther (2002) puts it, “species withlow adaptability and/or dispersalcapability will be caught by the dilemmaof climate-forced range change and lowlikelihood of finding distant habitatsto colonize, ultimately resulting inincreased extinction rates.”In North America:■New findings conservatively projectspecies losses of up to 20 per cent fromUS national parks (under a doublingof CO 2), potently illustrating how themandate of such parks to protectbiodiversity would be compromisedwith climate change (Burns et al., 2006).A stark summation is provided by thePew Centre: “Species that are notadapted to urban and agriculturalenvironments are likely to be confinedto smaller total geographic areas asclimate causes them to contract fromtheir southern 5 and lower boundaries.Already rare or endangered species,or those living only on high mountaintops, are likely to have the highest risk ofextinction” (Pew, 2004).This is of special concern toconservationists and agenciesresponsible for protecting birds’survival in future. According to theRoyal Society for the Protection of Birds(RSPB, 2004c), “It seems that despitethe work of conservation organisationslike the RSPB, much of the hard workto preserve habitats and ensure thesuccess and survival of our wildlifemay be compromised by the effects5 Explanatory note: refers to northern hemisphere species.Bird Species and Climate Change: The Global Status Report26Climate Risk

of climate change”. Thus we findthat climate change has the potentialto seriously undermine existingconservation efforts (Böhning-Gaeseand Lemoine, 2004), which may beinappropriately configured for a world inwhich the climate is changing.Despite the seriousness of these effects,very few studies document climatechange effects on birds’ ranges andcommunities (Böhning-Gaese andLemoine, 2004). A review of someavailable studies below summarisesthe findings.4.1.3 Distributional shiftsalready underway“There is some chance thatclimate change will inducemajor ecosystem shifts insome areas that would resultin radical changes in speciescomposition and unknownconsequences.”ACIA, 2004As expected, bird species are alreadyshifting their distributions in responseto climate change, with species inAntarctica, North America, Europe andAustralia moving pole-ward (IPCC,2001b), and tropical species moving upslope. Overall declines in the proportionof migratory species to residentspecies have also been observed withincreasing winter temperature, as milderwinters allow resident birds to outcompetemigrants (Böhning-Gaese andLemoine, 2004).Strong evidence ties such responsesby birds and other groups to climatechange. An analysis of 434 rangeshiftingplant and animals species,including birds, from around the worldrevealed that 80 per cent of range shiftswere in the direction expected fromclimate change, providing a high degreeof confidence that natural communitiesare responding to climate change(Parmesan and Yohe, 2003).In Europe:■■Climate change has forced changes inthe wintering areas of the white-frontedgoose, whooper swan and Berwick’sswan. The birds’ migration routes haveshifted eastward and northward, andthe birds are using new staging areas inthe eastern Baltic (the Lithuanian coastalregion) as a result. This has promptedurgent calls for new protected areas(Žalakevicius and Švažas, 2005).A large-scale survey shows UK birdspecies’ ranges are shifting in responseto a warming climate by extendingnorthward, with northern margins ofmany species’ distributions moving anaverage of 18.9 km further north overtwo decades. However, no consistentchange was detected in the southernboundary of bird species’ ranges.Climate change was “themost parsimonious explanation” forthe observed changes (Thomas andLennon, 1999).Bird Species and Climate Change: The Global Status Report27Climate Risk

In Central America:■In Costa Rica, keel-billed toucanswhich previously bred only in lowlandsand foothills are nesting alongsideresplendent quetzals, birds whichsymbolise the Middle American “cloudforests” -- evergreen mountain forestsshrouded in cloud or mist. This tendencyof birds normally intolerant of cloudforest to colonise higher ground hasbeen positively correlated with raisingof the cloud bank and drier seasonalweather conditions, linked to climatechange. Between 1979 and 1998, 15such species both colonised the cloudforest habitat and established breedingpopulations there (Pounds et al., 1999).Moving on up: the keel-billed toucanPhoto: Anthony B. Rath, © WWF CanonCASE STUDY 2: NORTH AMERICAnutrients for plankton and prey.Seabird population declines 90 percent with changing oceanic climateThe sooty shearwater is an abundantseabird thought to number 20 millionindividuals globally, and known to behighly sensitive to water temperature.It migrates from its southernhemisphere breeding grounds tospend the boreal (northern) summeron the west coasts of both Europeand North America to feed on fish andsquid larvae.It is still not known whether thepopulation truly declined, or redistributedto the North and CentralPacific where food may have beenmore abundant. However, accordingto Viet et al. (1997), “If the observedwarming of the waters of the CaliforniaCurrent System is an irreversiblemanifestation of a changing globalclimate, then the impact upon SootyShearwater populations seems likelyto be profound.”An important sooty shearwaterpopulation in the California Current offNorth America’s west coast declined90 per cent through to the mid-90s,from a starting population of fivemillion (Viet et al. 1996) . This occurredin conjunction with a rise in sea-surfacetemperatures consistent with globalwarming, and a reduction of availableIn recent years a slow and partialrecovery has been observed inthis California Current population(Sydeman, 2005) consistent with thisspecies’ low reproductive rate. Thiscould also reflect re-distribution backinto the area; however, the balance ofevidence suggests a slow recoveryfrom a population decline.Bird Species and Climate Change: The Global Status Report28Climate Risk

Range shift(overlap offuture projectedrange as % ofcurrent range)Figure 56050403020100Crested TitRed - legged PartridgeCollared FlycatcherCitril FinchAzure - winged MagpieMarmora’s Warbler Spanish Imperial EagleRock PartridgeItalian SparrowScottish Crossbill50 100 150 200 250 300 350Range size change(future projected range size as % of current range size)Figure 5: Overlap ofcurrent ranges of 10endemic European birdsand future ranges at theend of the 21st century,according to a climatemodel. 6 The Y axisshows range overlap,the X axis future rangeextent. The citril finch’srange, for example, willshrink by half, and itsfuture climate space willoverlap with its currentrange by only 10 percent. Of serious concernare those species withzero projected overlapbetween present andfuture range (Birdlife,2004a).4.1.4 Forecasts of distributionchanges“The most frightening resultof all approaches to modelrange changes are the largemovements of ranges expectedto occur within the next50-100 years.”Böhning -Gaese and Lemoine, 2004Climate change is expected to causesignificant range contractions inpopulations of many bird species,as the area of climatically suitablehabitat available to them shrinks oralmost disappears. Some bird species’distributions may expand or remainunaffected by climate change (DEFRA,2005) but, importantly, indicationsare that range contractions will bemore frequent than range expansions(Huntley et al., 2006; Böhning-Gaeseand Lemoine, 2004; Erasmus et al.,2003). Research on European birdsindicates substantial shifts of 1000km ormore for many bird species under midlevelglobal warming of 2.5ºC by 2100(Huntley et al., 2006).Even if a species’ theoretical climatespace does not shrink, that species willbe threatened if its “climate space”shifts to an area where it is unableto follow, or that is fundamentallyunsuitable for other reasons, asdiscussed above.Species with ranges that both contractand shift are expected to be mostthreatened by climate change andin some cases this threat could besevere enough to cause extinction(Birdlife, 2004a).In Europe:■Mapping the future climatically suitablearea for 10 land birds endemic to Europe6 The model is from Gordon et al., 2000Bird Species and Climate Change: The Global Status Report29Climate Risk

Photo: Martin Harvey, © WWF CanonEighty four per cent of migratory bird species, including the Siberian crane, face some type of climate change threat■revealed that for six species, suitableclimate space will decrease. However,even when it does not decrease there islittle overlap between future and currentmodelled ranges. For eight species,20 per cent overlap or less is predictedbetween present and future ranges, andfor three species no overlap is predictedat all (Birdlife, 2004a). Furthermore,even if overall climate space remainsthe same or expands, birds may still beforced to shift to unsuitable areas.See figure 5.The future distributions of 10 BritishIsles bird species were mapped usingsix climate variables. While somedistributions are expected to remainunchanged or even expand, themodel revealed: “serious negativeconsequences” for UK populations ofwillow tits; a “bleak” outlook for theUK populations of capercaillie with areduction of 99 per cent of its currentdistribution; the loss of the south eastEngland population of the nuthatch;decline of the red-throated diver; andpossible disappearance of breedingsnow buntings from Scotland’sGrampians due to loss of suitablehabitat (Berry et al., 2001).In the Pacific:■In Hawaii, pastureland above a protectedarea (Hakalau Refuge) is expected toprevent the retreat of honeycreeper birdspecies upward in elevation to coolerBird Species and Climate Change: The Global Status Report30Climate Risk

Table 6: Gross and net loss of neotropical migrant birds in the USANeotropical Migrants Gross loss % Net loss %California -29 -6Eastern Midwest -57 -30Great Lakes -53 -29Great Plains - Central -44 -8Great Plains - Northern -44 -10Great Plains - Southern -32 -14New England -44 -15Pacific Northwest -32 -16Rocky Mountains -39 -10Southeast -37 -22Southwest -29 -4Mid-Atlantic -45 -23Table 6: Gross and netloss of neotropicalmigrant birds in theUSA under a scenariowith a doubling ofCO 2. “Gross” changesdepict the overall loss ofspecies currently foundin areas, while “net”changes depict speciesloss from an area offsetby species moving intothe area from an outsideregion (from NWF/ABC2002).Based on U.S National Assessment Region modelling results from Canadian ClimateCenter’s General Circulation Model (CCV-GCM2) climate data.areas as their current forest habitatbecomes unsuitable due to invasionby mosquitoes carrying avian malariadeadly to the honeycreepers (Benning etal., 2002; see case study 4).In North America■In the USA, climate models suggest thatunabated global warming will cause anet decrease in neotropical 7 migrantbirds in every region. In the GreatLakes region, for example, although a53 per cent loss of species is predictedto be somewhat offset by new speciesshifting into the region, a 29 per cent netdecrease in neotropical bird species isexpected (NWF/ABC, 2002).In Africa:■The cape longclaw is a fairly commonendemic southern African bird foundin grassland habitats from the coast tothe highlands. Climate envelope modelsused moisture and temperature to mapits future distribution, revealing thespecies would retreat southward as itsrange contracts considerably. It wouldbe confined to higher ground in SouthAfrica and would become locally extinctin Botswana (Birdlife, 2004a).7 Species which breed in North America but migrate south to the neotropics of Central and South America, southern USA and Mexico.Bird Species and Climate Change: The Global Status Report31Climate Risk

CASE STUDY 3: NORTH AMERICAShrinking, shifting wetlands willreduce crucial duck habitatThe Prairie Pothole Region of theNorthern Great Plains of NorthAmerica is the most importantbreeding area for the continent’swater birds, providing breedinghabitat for between 50-80 per centof the continent’s ducks. It is also themost productive duck habitat in theworld. Research on this area furtherillustrates the risk posed by humaninducedclimate change to wetlands.Based on a doubling of CO 2by 2060,a 2.5 ºC temperature increase and nochange in precipitation, researcherspredict the number of ponds in thiszone will be cut by two thirds (67 percent), from the present 1.3 millionponds, depending on the climatescenario used (Sorenson et al.,1998). As a result, duck numbers innorth-central USA are expected to bereduced by almost three quarters (72per cent), from the present five million.These findings have been backedup by new research, which foundthat suitable waterfowl habitat inthis region would be halved as earlyas 2050, and would shift to wettereastern and northern fringes -- areasthat are less productive or wheremost wetlands have been drained.According to Johnson et al. (2005),“Unless these wetlands are protectedand restored, there is little insurancefor waterfowl against future climatewarming.”This work incisively demonstratesthat “static” bird conservation effortsbased on current protected areas willbe undermined by climate change, andinstead a dynamic approach will berequired that incorporates protectionand preparation of new climaticallysuitablehabitat.Breedingpopulation(millions)Figure 787654321+15% precip.+7% precip.No precip. change.-10% precip.Figure 7: Projectedduck breedingpopulation sizes inthe Northern GreatPlains of the USA, asa function of climatewarming.Baseline populationis five million(from Sorensonet al., 1998).00.0 +1.5 +2.5 +4.0Temperature Change (˚C)Bird Species and Climate Change: The Global Status Report32Climate Risk

4.2 How climate change willdisrupt communities andecosystems“… well-balanced birdcommunities as we knowthem will likely be torn apart.As species move, they mayhave to deal with different prey,predators and competitorsas well as habitats that areless than ideal.”Terry Root, Stanford University Centerfor Environmental Science and Policy(NWF, undated)When groups of plants and animals thatmake up an ecological “community” (aset of populations that inhabit a specificarea) respond to climate changes byshifting their ranges, they do not shiftintact. Rather the speed and distanceeach species shifts depends on itssensitivity to climate change, as well asits mobility, lifespan, and the availabilityof moisture and other needs (Hannahet al., 2005; Root and Hughes, 2005;ACIA, 2004).Thus with climate change, the makeupof communities will change as speciestrack their climate space by shiftingto new areas (Hannah et al., 2005). Asa result, the type and abundance ofspecies upon which birds depend --food sources such seeds, fruits, insects,as well as nesting materials -- maydecline, affecting birds’ health (NWF/ABC, 2002). These disrupted ecologicalcommunities mean birds may also facenew competitors, predators, prey andMore frequent El Niños, a feature of climate change,make ocean prey unavailable to Galápagos penguinsparasites to which they are not adapted,and that “optimal” habitats for manyspecies may disappear, at least for theshort term (NWF/ABC, 2002; Benning etal., 2002). As old ecosystems disappearand are replaced by new ones, theconsequences are unknown andlargely unpredictable.This explains why changes indistribution caused directly by climatechange, described in the previoussection, appear to be just the start ofa chain of effects. The resulting reorganisedcommunities will in turnproduce further distribution changesof their own, changes that are likely tobe even more extreme (Peterson et al.,2002; Davis et al., 1998; Pounds andPuschendorf, 2004).Photo:Y.-J. Rey-Millet, © WWF CanonBird Species and Climate Change: The Global Status Report33Climate Risk

CASE STUDY 4: The pacificWarming islands bring malaria toHawaiian honeycreepersHawaiian honeycreepers, a type offinch, once numbered at least 29species but are now down to 19 withpast extinctions driven by habitat loss,introduced predators and disease(Benning et al., 2002).Research by Benning et al. (2002)shows that with 2ºC of regionalwarming, a level in keeping withclimate model predictions for theregion, optimal habitat for the birds’three forest refuges would be reducedby half in the first refuge (HanawiForest), 96 per cent in a second(Hakalua), and completely eliminatedin the third (Alakai Swamp).Introduced avian malaria playeda large role in the decline of thebirds, which are susceptible to thedisease. The birds’ current habitatis now mainly restricted to higheraltitudes where malaria-transmittingmosquitoes are few or non-existent.These high elevation forests forma refuge for eight endangeredhoneycreeper species.14,00012,00010,0008,0006,0004,0002,000Furthermore, the area aboveHakalau Wildlife Low Refuge is used asMediumHighpasture land, and this would preventmovement of forested honeycreeperhabitat upslope. Under this climatescenario several of the remaining 19honeycreeper species are expected tobecome extinct.0Current+2˚CHakalau National Wildlife refugeLowArea(ha)3,5003,0002,5002,0001,5001,000500Figure 814,00012,00010,0008,0006,0004,0002,000Malaria risk to birds LowMediumLowHighMediumHighFigure 8: Invasion by malaria-carrying16,000mosquitoes with climate warming 14,00012,000will radically reduce the forest refuge10,000of Hawaii’s honeycreepers, and is8,000expected to result in extinction of6,000several species (Benning et al., 2002).4,0002,0000MediumHighCurrent+2˚CAlakai Swamp (Kauai)00Current+2˚CCurrent+2˚CHakalau National Wildlife refugeHanawi Forest (Maui)gure 814,000Malaria risk to birds12,000LowMedium 10,000High8,000LowMediumHigh16,00014,00012,00010,0008,000LowMediumHigh6,0006,0004,0004,0002,0002,0000Current+2˚CHakalau National Wildlife refuge0Current+2˚CAlakai Swamp (Kauai)Current+2˚CHanawi Forest (Maui)Malaria risk to birdsLowMediumHighClimate Risk16,00014,00012,000Bird Species and Climate Change: The Global Status Report10,0008,000LowMediumHigh34

The movement of communities dueto climate change must be consideredwithin the context that the requiredmigration rates for plant species due toglobal warming appear to be historicallyunprecedented (WWF, 2002) and are10 times greater than those recordedfrom the last glacial retreat. New datashows European birds will be subjectto climatic changes of this magnitude,and that “boundary shifts are likely tobe faster than many species are ableto realize such boundary changes,”according to Huntley et al. (2006). Ratesof change of this magnitude will likelyresult in extensive species extinctionand local extirpations of both plantand animal species (van Vliet andLeemans, 2006).This risk to biodiversity must also beconsidered in light of the extent to whichclimate change will alter birds’ habitats(see also section 2). In Eurasia alone,more than half of the existing habitatin Russia, Sweden, Finland, Estonia,Latvia, Iceland, Kyrgyzstan, Tajikistanand Georgia will be at risk from globalwarming, through outright loss ofhabitat or change into other types ofhabitat. “There is no certainty thatsimilar or equally diverse ecosystemswill establish themselves elsewhere”(WWF, 2000).Climate change can also affect theincidence of disease in birds, by shiftingthe rate at which pathogens reproduceor affecting the distributions of theanimals that carry disease. Reducedprecipitation and greater drought isexpected in some regions, and thiscould cause birds to accumulate aroundlimited water resources, potentiallyincreasing disease transmission andreducing their survival (BTO, 2002).Thus climatically-induced shifts couldeasily “tear apart” communities ofinterdependent plants and animals(Root and Hughes, 2005). Therelationships between predator andprey could become disconnected,and competition for survival betweenspecies could be pushed to new anddifferent equilibrium points. Theseclimatic changes in turn “would likelyalter the structure and functioningof most, if not all, of the world’secosystems,” according to Root andHughes (2005).4.2.1 How birds are already affectedby disrupted communitiesThis section shows how climate changeis already affecting the interactionbetween bird species, theircompetitors, prey and parasites, usingexisting examples. Some examplesalso indicate the scale of future impacts,such as an expected 40 per cent speciesturnover for an entire ecologicalcommunity in Mexico.In Europe:■In Germany, the number and proportionof long-distance migrants decreasedand the number and proportion ofshort-distance migrants and residentbirds increased between 1980 and1992. Research suggests the effectscould be explained by observed climatechange, with the trend of warmer wintertemperatures in this zone benefitingresident birds and increasing theBird Species and Climate Change: The Global Status Report35Climate Risk

competitive pressure they imposeon long-distance migrants. Thus,“increasingly warmer winters pose amore severe threat to long-distancemigratory species than to other birdgroups,“ according to Lemoine andBöhning-Gaese (2003).In North America:■■The first study to examine the effectof future climate change on a wholecommunity in detail (including 1,179bird species, 63 per cent of the totalinvestigated) in Mexico predicted 8 thatturnover among the species in somelocal communities would exceed 40per cent by 2055 as dozens of speciesdisappear or are displaced by invaders,suggesting that severe disturbance ofecological communities may result,according to Peterson et al. (2002).Brunnich’s guillemots in Canada’snorthern Hudson Bay had greater eggloss and adult mortality during hot dayswhen high numbers of mosquitoeswere in the area. Mortality was worst atthe edge of the colony where mosquitoattacks were also worst. The dates offirst appearance and peak abundanceof mosquitoes have advanced since themid-1980s, in conjunction with ongoingclimate change, but the breedingseabirds have not yet adjusted theirbehaviour to adapt to this change inpeak mosquito parasitism (Gastonet al., 2002).In Antarctica:■At the Antarctic Peninsula, temperaturesare rising relatively rapidly, a changeresearchers believe is due to global5Howwarming (Turner et al., 2006; Cook etal., 2005). This warming is thoughtto be shifting the makeup of thephytoplankton in the Antarctic foodchain as glacial melt-water runoffincreases and surface water salinity isreduced (Moline et al., 2004), a trendexpected to increase with furtherwarming. This shift is causing aproliferation of salps, transparent jellylikecreatures that are not a preferredpenguin food, and a reduction in krill,a keystone prey species of Antarcticanimals including penguin species.Negative impacts on these birds areexpected as a result.climate change affectspopulation dynamics“… the low end of theprecipitation range brings thepopulation near reproductivefailure. Any change inclimate that would increasethe frequency of extremedry conditions would likelyendanger populations ofthese species.”Bolger et al., 2005Climate change is already affectingthe dynamics of bird populations.This occurs because local weatherand regional climate patterns have astrong influence on bird behaviourin both breeding and non-breedingseasons (Crick, 2004; Saether et al.,2004). Because the size of a populationdepends on both survival through the8 With 1.5 - 2.5°C of warming and a 70-130 mm decrease in precipitation.Bird Species and Climate Change: The Global Status Report36Climate Risk

non-breeding season and on breedingperformance, the ultimate effect ofclimate change will depend on therelative impact upon of these twofactors (DEFRA, 2005). How climatechange effects interact with populationdensity 9 will also be important (Saetheret al., 2004).Taken as a whole, the vulnerabilityof birds in this respect is becomingclear. Research so far indicates that forbirds whose offspring are born highlydependent (so-called altricial species 10 ),climate change effects in the nonbreedingseason will be most important.For birds with precocious young (socallednidifugous species 11 ) and thosebreeding in arid environments, climatechange effects during the breedingseason will be more important (Saetheret al., 2004; Bolger et al., 2005).5.1 Climate change and thereproductive success of birds“The 2004 breeding seasonis over, and the success ratethis year is shocking: it’s nonexistent;complete failure,unprecedented in recordedtimes. The results from Orkneyare coming in, too, and appearto be almost as catastrophic.The reason, most believe, isclimate change”Malcolm Tait on the 2004-05 breedingcollapse of some UK seabirds colonies(Tait, 2004)Climate change threatens Tufted Puffins at Canada’slargest puffin colonyThis section illustrates how climatechange is affecting bird populationdynamics by acting on factors suchas nesting, clutch size, and fledglingsurvival as well as general reproductivesuccess. These factors affect “newrecruitment”, the number of newindividuals added to a given population.In Europe:■A trend of warm, sunny June weatherlinked with increased survival in spottedflycatcher offspring initially suggeststhat a warming climate could increasethe productivity of some bird species;however these tendencies may notdominate in the short and long term toactually increase populations (DEFRA,2005). Some pied flycatcher populationsin Europe suffered from climate change,(see case study 1). Furthermore, climatechange is predicted to bring wettersprings to some temperate zones,and this is expected to decreasechick survival rates in some species(DEFRA, 2005).Photo: Kevin Schafer, © WWF Canon9 For example, changes in rainfall due to climate change could alter food availability. If a population is at a low density, it might be unaffected, but if it is atmaximum density, climate change could affect the population via food scarcity (Saether et al., 2004).10 Birds whose young hatch with their eyes closed, naked or near naked, and are incapable of departing from the nest, and are fed by the parents.11 Hatched with eyes open, covered with down, and can leave the nest immediately.Bird Species and Climate Change: The Global Status Report37Climate Risk

Breeding Success(chicks fledgedper breeding pair)Figure 91.51.00.5AbandonmentRate (% of breedingpairs whichabandoned eggs)Figure 9. SoutheastFarallon Island,California: Breedingsuccess for Cassin’sauklet (blue) andabandonment rate(red). In 2005 thebreeding colony wasabandoned en mass, anunprecedented event.From Sydeman et al. ( inpress).0.01970 1975 1980 1985 1990 1995 2000 2005YearIn the Arctic:■Approximately half of the Arcticbreeding grounds of geese and Calidridwaders (migratory Arctic wading birdssuch as sandpipers) would be lost witha doubling of CO 2by the period 2080 to2099, according to UNEP. A simplisticextrapolation would suggest loss ofbreeding habitat for 4-5 million geese(down from the current 10.4 million) and7.5 million Calidrid waders (currently14.5 million; Zöckler and Lysenko, 2000).In North America:■In spring 2005, an unprecedentedseabird breeding decline occurredon the continent’s west coast, withbodies of Brandt’s cormorants, deadfrom starvation, found in numbersup to 80 times higher than previousyears in some areas, and decreasedbreeding recorded for common murres(guillemots) and Cassin’s auklets(Parrish, 2005). Cassin’s auklets atCalifornia’s Southeast Farallon Islandbreeding colony abandoned the site■en masse in May -- behaviour neverwitnessed in the 36 years of study there-- and completely failed to breed. InCanada, only eight per cent of Cassin’sauklets nesting at the Triangle Islandcolony were successful, the worstyear on record. A two month delay innortherly winds also delayed coastalspring upwelling of nutrient rich waters,radically reducing phytoplankton.Fish species that prey on the planktonalso declined, as did the seabirds thatprey on fish (Sydeman et al., in press).According to Peterson (2005), “Since theupwelling season began so late, it wasthe mismatch between the expectationof birds and fish encountering abundantfood and when the abundant food wasactually present that explained thefailure of birds and fish this summer.”This illustrates the potentially profoundecosystem effects of shifts in oceancurrents expected with climate change.Off Canada’s west coast two decadesof unusually warm temperaturesassociated with climate changebetween 1975 and 2002 led toBird Species and Climate Change: The Global Status Report38Climate Risk

Breeding Success(chicks fledged 0.50per breeding pair)Figure 101.000.75Figure 10: At TriangleIsland, Canada onlyeight per cent ofCassin’s auklets bredsuccessfully in 2005,the worst year on record(Sydeman et al., inpress).0.250.001993 1995 1997 1999 2001 2003 2005Year■drastically decreased growth ratesand fledging success of tufted puffinnestlings, with fledging success nearzero when waters were warmest; thebirds are considered highly vulnerableto climate change, which could makethe site of Canada’s largest puffincolony unsuitable for breeding for thisspecies (Gjerdrum et al., 2003).In coastal southern California, thebreeding success of four bird species(rufous crowned sparrow, wrentit,spotted towhee and California towhee)in semi-arid coastal sage scrub droppedto 3 per cent of its former level, from2.37 fledglings per pair in 2001 (a normalyear) to 0.07 fledglings per pair during2002, the driest year in the region’s 150-year climate record. Only 6.7 per centof pairs attempted to nest that year,versus 88.4 per cent in 2001. While itis difficult to definitively link the 2002drought to climate change, precipitationin this region is expected to decreaseand become more variable with globalwarming. Even a modest increase in thefrequency of arid conditions would makethese species vulnerable to extinction ina dry year (Bolger et al., 2005).In South America:■Endangered Galápagos penguinpopulations have halved since theearly 1970s because the adult penguinsbecome emaciated (sometimes dying)and fail to reproduce during severe ElNiño years (Boersma, 1998). Populationsdropped precipitously after the 1982-3 El Niño, and recovered only slowly.There are no suitable foraging areasfor the penguins outside the Galápagos(Boersma, 1999). Because climatemodels predict El Niños to become morefrequent in future (Timmerman et al.,1999), climate change is expected tofurther reduce these small, restrictedpopulations of Galápagos penguinand threaten them with extinction(Boersma, 1998).Bird Species and Climate Change: The Global Status Report39Climate Risk

In Australia:■Abnormally high 2002 ocean surfacetemperatures at the southern part ofAustralia’s Great Barrier Reef (GBR)altered the availability and accessibilityof fish prey species for the region’swedge-tailed shearwaters. A strongrelationship was shown between theunusually warm w aters, reducedability of adults to provide for chicks,decreased chick growth rates, andreproductive failure. According toSmithers et al. (2003), “As SST [seasurface temperatures] continue to risewith global climate change, our resultspredict substantial detrimental effectson seabird populations of the GBR.”CASE STUDY 5: NORTH SEAUnprecedented breeding failure ofseabirdsIn 2003 and 2004 news reports citedhundreds of dead seabirds, includingguillemots, puffins, razorbills andfulmars washing up off NorthernFrance, Belgium and coastal UK.In 2004 the Royal Society for theProtection of Birds (RSPB) reportedthat among six key North Sea seabirdspecies nesting on Shetland andOrkney colonies, tens of thousandsof these long-lived, slow breedingseabirds failed to raise any young;shortages of a prey species calledsandeels is likely to be the direct cause(Lanchbery, 2005).For example, on the Shetland Islands,7,000 pairs of great skuas producedonly a handful of chicks, while 1,000pairs of Arctic skuas produced nosurviving chicks at all for the 2004breeding season. Starving adultbirds ate those chicks that did hatch.Shetland’s 24,000 pairs of Arcticterns and more than 16,000 pairs ofCommon guillemot, (Uria aalge)kittiwakes are also thought to havesuffered near total breeding failure(Lanchbery, 2005). According to theRSPB, populations of some speciessuch as Arctic skuas are reachingcritically low levels, with a bleakoutlook for the future (RSPB, 2004d).A partial recovery in productivityfor North Sea birds followed in 2005as sandeels returned. However, thescarcity of larger sandeels (thosehatched in 2004) made it more difficultPhoto: Kevin Schafer, © WWF CanonBird Species and Climate Change: The Global Status Report40Climate Risk

for adults to achieve breedingcondition and resulted in one ofthe latest breeding seasons everrecorded. This delay resulted instarvation of some chicks, becausesandeels become unavailable later inthe season.These events are still underinvestigation, however, researchershave linked this wide-spread breedingfailure to a large-scale change inmarine ecosystems in the North Sea,caused in part by climate change(Lanchbery, 2005). The shortage ofsandeels is linked to both warmerwaters and to reduced planktonabundance (Lanchbery, 2005; Arnottand Ruxton, 2002).North Sea temperatures weresignificantly higher in 2003 and 2004than the 30-year average (1961-1990).Climate change has caused North Seatemperatures to rise 1°C in thelast 25 years -- a huge change for amarine ecosystem.According to Lanchbery (2005), “Insummary it would appear that a largescalechange in marine ecosystems isoccurring in the North Sea, caused inpart by climate change. The planktonregime most certainly has changedand it is hard to find an explanationother than sea temperature rise thatadequately accounts for it. Sandeelnumbers have declined and a changein sea temperature coupled with achange in the plankton population(also induced by a temperaturechange) seems a likely explanation.”Figure 11: Unprecedented decline in reproductive success in 2004 for some North Seacolonies of guillemots, followed by partial recovery in 2005. The breeding failures have beenlinked to food chain disruptions caused in large part by climate change (from JNCC, 2005).Figure 11: Breeding success of common guillemot0.90.80.7Chicksfledgedper pair0.60.50.40.30.2Fair isle (Shetland)Marwick Head (Orkney)Skomer (Wales)Isle of May (SE Scotland)Handa (NW Scotland)0.101985 19901995 2000 2005Bird Species and Climate Change: The Global Status Report41Climate Risk

5.1.1 A note about climate extremesThe above example on arid-land birdsfrom California’s southern coast showsthe disastrous effect that extremeweather -- in this case the driest everyear in a 150-year climate record -- on avian reproduction (Bolger et al.,2005). Increased frequency of weatherextremes will negatively impact adultbirds, as well as their young, in summerand winter (DEFRA, 2005). Theseevents can dramatically reduce birdpopulations and recovery can bevery slow.The effects of climate extremes (moreheat waves, storm events and droughts,and more variable temperatures) weredescribed in detail in section 2, and herewe additionally note that, according tovan Vliet and Leemans (2006), “therewill be large changes in the frequencyand magnitude of extreme eventsand consequently, unpredictable, butdevastating impacts on speciesand ecosystems even with a moderateclimate change (an increase of 1to 2°C).”Ecosystems and birds within themare responding especially rapidlyand vigorously to these large events(van Vliet and Leemans, 2006; KleinTank, 2004), and this can explainthe unexpectedly swift response toclimate change seen in ecosystemsworldwide (van Vliet and Leemans,2006). Furthermore, failure to accountfor these effects means that projections,including those of the IPCC, are likely tounderestimate future impact levels (vanVliet and Leemans, 2006).5.2 The effects of climate changeon adult survivalThis section focuses on how climatechange is influencing bird populationsizes by affecting adult survival.Migratory species in Europe andelsewhere will be vulnerable to climateimpacts across all their habitats,including the Arctic, where such impactsare expected to be extreme. Migratorybirds that breed in the UK and Europebut spend winter in Africa will bevulnerable to increased levelsof drought predicted for the Sahelregion of Africa (see section 6 forfurther details).In cooler climates, winter survival is animportant determinant of population.Thus the survival rate of some speciesin Europe has increased in recentdecades with warming winters (seeexample below).However, it is not yet possible todetermine whether climate change willincrease these bird populations overall(EEA, 2004) because the many variablesinvolved make such effects complicatedto predict. A population’s adaptationto increased winter survival is flexibleand depends on competition andpredator/prey interactions. Accordingto the European Environment Agency(2004), “Some species will benefit andtheir population will increase whileothers could be adversely affected”.An example from North America(see below) illustrates how a climatechange, in this case warming, cancause population increases followed byreductions as warming further impactsthe birds’ environment (Meehan, 1998).Bird Species and Climate Change: The Global Status Report42Climate Risk

In Europe:■■■In France, pooled data on 77 terrestrialbird species revealed a “highlysignificant” 14 per cent decline inthe overall abundance of this nation’sbird population from 1989-2001, withclimate change being “the likely causeof an important and rapid reductionof population abundance of severalspecies,” according to Julliardet al. (2003).Survival rates of five European birdspecies (grey heron, common buzzard,cormorant, song thrush and redwing)wintering in Europe have increased 2-6 per cent per 1˚C rise in temperature,most likely because foraging is easier(EEA, 2004). However, as outlinedabove, it is not yet possible to determinewhether climate change will increasethese bird populations overall(EEA, 2004).The numbers of adult whitethroat, amigratory bird that breeds in Britainbut overwinters in Africa, decreasedmore than 90 per cent following a 1968drought in the Sahel, and have still notrecovered to their former levels (DEFRA,2005). This illustrates the vulnerabilityof these European migratory birds toextreme events, and to increased levelsof drought predicted for the Sahel regionwith climate change.In North America:■While warming temperatures linked toclimate change initially allowed a blackguillemot breeding colony to gain afoothold in northern Alaska in the 1960s,the continued effects of warming arenow driving the birds away. The birdsrely on small Arctic cod, which are foundnear pack ice. But in recent decadesthe ice has receded further offshore,making foraging difficult and resultingin reduced immigration of the birds andlower adult survival in some colonies(Meehan, 1998).In the Southern Ocean:■6ClimateA radical, 94 per cent populationcrash of the rockhopper penguinat sub-Antarctic Campbell Island isattributed in part to warming climateconditions that are altering birdhabitats (IPCC, 2001b). The penguin’snumbers declined from 1.6 million in1942 to 103,000 breeding penguins in1985 (Cunningham and Mores, 1994)with the most severe phase of thedecline coinciding with substantialshifts (warming) in December-February sea-surface temperature. Inone colony, the penguin’s numberstemporarily increased after the seascooled temporarily. Cunningham andMores (1994) conclude that “rising seatemperatures are associated with thedecline, which may have been caused bychanges in the penguins’ food supply;there is no evidence that terrestrialfactors have been responsible.”change andbird extinction“… anthropogenic climatewarming at least ranksalongside other recognizedthreats to global biodiversity …[and] is likely to be thegreatest threat in many if notmost regions.”Thomas et al., 2004Bird Species and Climate Change: The Global Status Report43Climate Risk

6.1 The scale of climate change riskto general biodiversityExtinction, the demise of every lastindividual of a given species, is the mostserious consequence of climate changefor birds as a whole. Climate changehas already caused well-documentedcases of extinction of approximately 70species of harlequin frogs in Central andSouth America (Pounds et al., 2006), aswell as the local extinction (extirpation 12 )of two checkerspot butterfly populationsin California (McLaughlin et al., 2002).With further climate change local andglobal extinctions are likely. This threatexists even for bird species currentlyconsidered of safe conservation status(Birdlife, 2004a).As noted above, a key threat withanthropogenic climate change is therapid rate of change, which leavesspecies little time to adapt (Leemansand Eickhout, 2004). In particular, speciesin some northern polar regions will beforced to adjust to rates of warmingseveral times higher than mid-latitudes.Thomas et al. (2004) were the first tobroadly delineate extinction risk due toclimate change. They reveal that withminimum expected levels 13 of globalwarming, 18 per cent of all terrestrialplants and animals could be committedto extinction by 2050; with moderateglobal warming this figure rises to24 per cent; and with a maximumclimate change scenario 35 per centof all terrestrial plants and animalscould be committed to extinction by2050 (Thomas et al., 2004). They findthat in all, one million species may becommitted to extinction by 2050.Thomas et al. (2004) further state that“anthropogenic climate warming at leastranks alongside other recognized threatsto global biodiversity … [and] is likelyto be the greatest threat in many if notmost regions.” Putting this threat intoperspective, mid-range climate changescenarios are expected to producegreater extinction rates than habitatloss, currently deemed the top threat tobiodiversity (Thomas et al., 2004).More recent work by Malcolm et al.(2006) focuses on biodiversity hotspotsand finds that with a doubling of CO 2in 100 years, projected extinctionsranged from 1 to 43 per cent of endemicplants and vertebrate species, withan average extinction of 11.6 per cent.This analysis revealed that “estimatedglobal-warming-induced rates ofspecies extinctions in tropical hotspotsin some cases exceeded those due todeforestation, supporting suggestionsthat global warming is one of themost serious threats to the planet’sbiodiversity” (Malcolm et al., 2006).Although an analysis by Thuiller etal. (2005) on European plants findslower extinction rates than Thomas etal. (2004), they nonetheless note thatextinction risk from global warming maybe large even under moderate climatescenarios. Under a high climate changescenario 14 they find a mean speciesloss 15 of 42 per cent and species turnoverof 63 per cent, with the percentage ofspecies loss exceeding 80 per cent insome areas (north-central Spain and theCevennes and Massif Central in France).12 Extirpations are localised or regional extinctions of populations. Extirpation is of concern because it can reduce the overall genetic diversity of a givenspecies, since isolated populations may have unique genetic attributes not found in other populations elsewhere on the globe (DEFRA 2005). Extirpationis becoming increasingly common as habitat is carved up by human development, creating barriers that prevent mixing between populations.13 In Thomas et al. (2004) projections for a minimum expected climate change scenario refer to a mean increase in global temperature of 0.8 - 1.7°C andin CO 2of 500 p.p.m.; mid-range scenarios refer to global temperature increases of 1.8 - 2.0°C and CO 2increases of 500 - 550 p.p.m.v.; and maximumscenarios to global temperature increases of >2.0°C and CO 2increases >550 p.p.m.14 A1-HadCM3: Concentrations of CO 2increase from 380 ppm in 2000 to 800 ppm in 2080, and global temperature rises by 3.6 K.15 “Species loss does not necessarily imply the immediate loss of a species from a site, rather it may imply a potential lack of reproductive success andrecruitment that will tend to extinction on a longer time scale” (Thuiller et al., 2005).Bird Species and Climate Change: The Global Status Report44Climate Risk

CASE STUDY 6 : EuropeWorld’s largest grouse threatenedwith local extinction by 2050confined to Caledonian pinewoodand conifer plantations mainly in theeastern Highlands of Scotland.The capercaillie is found throughoutnorthern forests stretching fromScandinavia to Siberia and in highlyfragmented populations in temperatemountainous areas of westernand central Europe. The westernand central European capercailliedistributions have undergoneserious decline over the last century,with many populations at risk oflocal extinction.The capercaillie is one of the UK’smost threatened birds. Capercaillienumbers in the UK declined drasticallyfrom 10,000 birds in the 1970s toapproximately 1,000 birds in the late90s. By 2005 the population stabilisedat around 2,000 birds. The bird isClimate change is already associatedwith poor breeding success of thecapercaillie due to increasinglyprotracted spring warming (Moss,et al., 2001). Wet summers, a featureof climate change in the UK, directlyimpact on this species because highrainfall reduces chick survival.However, the bird will becomeincreasingly threatened because itspotential climate space is reducedunder all climate scenarios, droppingby as much as 99 per cent from itscurrent distribution in worst casescenarios of global warming (Berryet al., 2001). This scenario could seethe capercaillie disappear from its UKhabitat by 2050.# of grid cellsindicatingpresenceFigure 12: Capercaillie : reduced climate space10080604020High climatechange scenarioLow climatechange scenarioFigure 12:Projectionsshowing habitatdecline for thecapercaillie in 2020and 2050, underboth low (0.9˚C) andhigh (2.4˚C) climatechange scenarios.The number ofgrid cells refer toareas of climaticallysuitable habitat.0Baselineclimate2020s2050sBird Species and Climate Change: The Global Status Report45Climate Risk

6.1.1 Additional reasons for concern“... many of the most severeimpacts of climate change arelikely to stem from interactionsbetween threats ... rather thanclimate acting in isolation.”Thomas et al., 2004The risk of extreme weather events(see section 2.3 and 5), to which birdsand other groups respond strongly, is afactor not included in many estimatesof climate risk. Research that considersthis risk finds that there are “manymore reasons for concern” that willmake it impossible, under rapid climatechange, to uphold the UN Convention onBiodiversity’s aim to stem the rateof biodiversity decline significantly by2010 (van Vliet and Leemans, 2006;WWF, 2004).In addition, climate change is alsoexpected to interact with other humandisturbances such as habitat loss andfragmentation (see section 4.1), speciesinvasion and CO 2buildup to disruptcommunities and wipe out entirepopulations (Root et al., 2003; Poundsand Puschendorf, 2004; Thomas et al.,2004; Peterson et al., 2002). The term“extinction spasm” has been used todescribe the scenario posed by theadditional threat of climate changewhen combined with currenttrajectories of habitat loss (Lovejoyand Hannah, 2005b).Taken together, these factors explainwhy species are responding morestrongly than expected from the average0.8°C (Hansen et al., 2005) of globalwarming that has occurred over the pastcentury (Leemans and van Vliet, 2004).Therefore we may consider that currentfigures do not represent upper limitsto extinction risk from climate change(Pounds and Puschendorf, 2004).However, the full consideration of risk tobirds and other species due to climatechange is extremely difficult to model,and is further complicated by the rarityof good datasets on wildlife (EEA, 2004).6.2 Estimating the scale ofextinction risk to birds“Climate change will resultin many extinctions … Bothlocal and global extinctions arelikely, even of species currentlyconsidered safe.”Birdlife, 2004aAs discussed above, evidence ismounting that some bird species maybe unable to adapt to climate changebecause of direct climate effects,alteration of their habitats, phenologicalmismatch or miscue, range shiftsand contractions, and the disruptionand “tearing apart” of ecosystems.These threats put bird species at risk ofextinction. But what level of risk canwe expect?As yet there are no global-scalestudies providing a comprehensiveassessment of extinction risk tobirds from climate change. However,the biodiversity extinction analysisdescribed above by Thomas et al. (2004)Bird Species and Climate Change: The Global Status Report46Climate Risk

includes projections of extinction riskfor endemic bird species in European,Mexican, Australian and South Africansample regions, based on data fromregions of high biodiversity over 20 percent of the earth’s surface. This datais given in the following regional casestudies, along with additional regionalresearch and examples of extinctionrisk to individual bird species or groups,where possible.Many extinction estimates are separatedinto projections that allow for speciesdispersal (a shift to new ranges), andthose that assume no dispersal ispossible. Real world outcomes are morelikely to lie between these two scenarios(Thomas et al., 2004).6.2.1 REGIONAL CASE STUDYExtinction risk for European birdsOf Europe’s 524 bird species, 226 haveunfavourable conservation status,with the outlook for many populationsdeclining over the past decade(Birdlife, 2004b).In terms of the threat from climatechange, Europe has warmed morethan the global average, with a 0.95°Cincrease since 1900. The warming hasbeen greatest in north-west Russiaand the Iberian Peninsula (EEA, 2004).In future, the worst impacted Eurasiancountries will be Russia, Sweden,Finland, Estonia, Latvia, Iceland,Kyrgyzstan, Tajikistan, and Georgia,each with more than 50 per cent ofexisting habitat at risk through eithercomplete loss or via change into anotherhabitat type due to climate change(WWF, 2000). Mediterranean Europeis also identified as likely to sufferhotter, drier summers towards the endof the century (IPCC, 2001b). As notedin previous sections, climate changeis already affecting birds in Europe. InCentral Europe it has already been foundto be a more important determinant ofbird population trends than land-usechange and “... climate change might becurrently the most important threat forbirds in Europe” (Lemoine, 2005).Huntley et al. (2006) find that the threatto European birds posed by shrinkingand shifting climate space is substantial,particularly for species that are highlyspecialised and restricted in theirdistribution. With warming by 2100 ofapproximately 2.5°C, species richnessfor 426 bird species native to Europe asbreeding species is reduced by 8.6 percent under the most optimistic scenario,which assumes all species will be able toshift to new climatically suitable ranges.The pessimistic scenario assumesbirds are unable to shift at all and findsspecies richness would decline to 60per cent of its current levels (Huntley etal., 2006). These estimates do not allowthe possibility of bird species shiftinginto Europe from Africa but find thateven if this did occur, it “will not alterthe general pattern of declining speciesrichness in southern Europe,” accordingto Huntley et al. (2006).The birds most at risk of regionalextinction in Europe were 19 specieswith zero potential future climaticallysuitable range under at least one climatescenario; another ten species havepotential future distributions of 10 percent or less than that of present. (NoneBird Species and Climate Change: The Global Status Report47Climate Risk

FrequencyFigure 139060300HadCM3ECHAM4GFDL0 2040 60 80100Figure 13: Frequencyplot showingpercentage overlapbetween presentand future breedingdistributions of 426European-breeding birdspecies under threeclimate scenarios. Notemany more species areprojected to have zerooverlap (left side) thanare expected to have90 per cent or greateroverlap (right side).From Huntley et al.,2006.Overlap(%)of these 29 species are endemic toEurope, however.) Overall, 25 per centof the species breeding in Europe todayhave less than a 10 per cent overlap intheir present and future distributions orfuture distributions that are less than10 per cent that of present (Huntleyet al., 2006).Research noted in section 4 (Birdlife,2004a) found that for eight speciesof endemic European birds, there isless than 20 per cent overlap betweencurrent and future ranges, according toclimate models; and for three of thesespecies the overlap was zero. Examplesbelow elaborate on the serious climaterisk to such endemic birds, includingthe Scottish crossbill and Spanishimperial eagle.Separate global warming extinctionrisk projections from the Thomas et al.(2004) meta-analysis described abovereveal that 4-6 per cent of endemicEuropean birds could be committed toextinction under a maximum climatechange scenario, provided bird speciesare able to disperse freely. If nodispersal is possible 16 , the number ofspecies committed to extinction jumpsto 13-38 per cent (depending on themethod of calculation used 17 ) under aclimate change scenario with a globaltemperature increase of >2°C.It is not possible to accurately estimatethe extent to which these forecastscan be applied to groups outsidethe study areas and non-endemicbirds. However, for a crude first orderestimate, if the extinction rate of 38 percent were applied to Europe as a whole,it would indicate a climate-inducedextinction or extirpation on the levelof 200 bird species. This broad brushfigure is useful in so far as it tells us thatextinction levels from climate changewill not be a handful of birds, but thatwith high estimates of global warmingthe local, regional or total extinctionsof dozens of bird species in Europe 18is plausible.16 Regarding dispersal ability, as mentioned above, the reality for most species is likely to exist somewhere between the two extremes of complete dispersalor non-dispersal.17 Method one uses changes in the summed distribution areas of all species. Method two uses the average proportional loss of the distribution area of eachspecies. Method three considers the extinction risk of each species in turn. For a more detailed description, see Thomas et al. (2004)18 Note that caution must be applied in converting per cent extinction to number of species: Thomas et al. (2004) based their research on endemic species;however, because many of the total number of European species will be found elsewhere, the fixed number could be more acurately said to representregional (European) extinction rather than total extinction.Bird Species and Climate Change: The Global Status Report48Climate Risk

ProjectedpercentageextinctionFigure 14: European birds40302010Thomas et al. (2004) indicate Europeanbirds might have lower than averagerisk of extinction from climate changethan some other regions these authorsexamined. However, others includingJulliard et al. (2003) note that because“climate change occurs in addition toglobal land use change, there is in factlittle reason to be too optimistic.” Thisis particularly true in Western Europe,which is under the double negativeinfluence of climate change and land usechange (Julliard et al., 2003; Huntley etal., 2006). Indeed accurately predictingextinction rates in Europe is highlycomplicated by its heavily populatedand intensively managed landscape.As noted in section 4, in addition tofacing natural barriers (mountains,water bodies and large arid zones)birds may be unable to shift to areasthat are urbanised, used for agricultureor otherwise intensively managed,or are polluted or unprotected. If theyunable to shift, they may face extinction(Huntley et al., 2006; Birdlife, 2004a).0no dispersaldispersal1 2 3Method of calculationData in Figure 15 below furtherillustrates how dispersal ability affectsthe vulnerability of Europe’s top tenclimatically endangered bird species.Authors Thomas et al. (2004b) note that,“Future studies that take account of theavailability of natural areas are likelyto result in even higher estimates ofextinction rate.”Some European birds at risk ofextinction:■■Marmora’s warbler is under high threatfrom climate change. With a currentpopulation of about 30-50 thousandpairs, this small bird breeds on westernMediterranean islands and winters inNorthern Africa. Unless it can disperseelsewhere, it faces complete loss of itshabitat with climate change (Huntleyet al., 2006), a victim of the hotter, drierweather expected in the Mediterraneandue to global warming.The endangered Spanish imperialeagle is restricted largely to naturalFigure 14: Estimatesof extinction in Europefor a maximum climatechange scenario rangefrom 13 to 38 per cent ifbird species are unableto disperse to newclimatically suitablehabitat. Vertical barsindicate percentage ofbird species expectedto become extinctin Europe with >2°Cof global warming,according to threedifferent methods ofcalculation (see abovenote). Inability todisperse (medium blue)is indicative of a muchhigher rate of extinctionrate than if dispersal ispossible (dark blue).Data from Thomas et al.(2004).Bird Species and Climate Change: The Global Status Report49Climate Risk

Figure 1510080Projected % 60reductionin range40200Spotlessstarling Azure-wingedmagpieCitril finch Red kite ParrotcrossbillIcterinewarblerMarmora’swarblerno dispersaldispersalLittle crake Dunnock Crested titFigure 15: Projected percent range reductionsfor Europe’s top 10climatically threatenedbird species undera maximum climatechange scenario. Notepotential future rangeis highly dependent onbirds’ ability to disperse(from Thomas et al.,2004b). Yet Europe’sintensively managed,heavily populatedlandscape could posemajor barriers todispersal (RSPB/WWF,2003).European bird species■parks and reserves, mainly in Spainbut also in Portugal and Morocco.Climate scenarios predict that its entirecurrent habitat will become unsuitable(Huntley et al., 2006). Even though newclimatically suitable areas are expectedto be even larger than its current habitat,there may be insufficient undisturbedand protected areas available to supportit -- an example of the barriers Europeanbird species face as climate changeforces distribution shifts complicated byland use factors.The red kite, a medium-sized raptor, willsuffer up to 86 per cent loss of habitatdue to climate change. It is an almostexclusively European species, with thepossible exception of some populationsof uncertain status in NorthernMediterranean Africa. It is currentlyseverely threatened by habitat loss andother human impacts over much of itsEuropean range. Its survival alreadylargely depends on conservationmanagement and protected areas(Thomas et al., 2004b).■■The Scottish crossbill will lose 100 percent of its range because the climateof its current Scottish highland habitatwill change substantially by the end ofthe century due to climate warming,according to Huntley et al. (2006).By that time, the climate currentlyexperienced by this bird in Scotland willonly be found in Iceland. Unless it canrelocate or adapt to conditions it hasnever experienced in Scotland, theseresearchers find it will be at “extremerisk of global extinction as a result ofclimate change.”Species at most immediate risk ofextinction in the UK are those that breedin Arctic-alpine habitat in Scotland. Thisincludes snow buntings and dotterels.As temperatures rise with climatechange, lower-altitude vegetation willmove up-slope and encroach on thisalready scarce habitat. With no higheraltitude ground to move to, UK Arcticalpinehabitat will start to decreaseand may disappear completely by 2050(RSPB, 2004b).Bird Species and Climate Change: The Global Status Report50Climate Risk

ProjectedpercentageextinctionFigure 16: Mexican birds40302010With No DispersalMid - rangeclimate changeMinimum expectedclimate changeFigure 16: Extinctionrisk to Mexican birdspecies if no dispersalis possible, given aminimum and midrangeclimate scenario,both of which predictthe same level ofextinction risk. Methodsof calculation are thesame as describedabove. Data fromThomas et al. (2004).01 2 3Method of calculation6.2.2 REGIONAL CASE STUDYExtinction risk for Mexican birds“Although only limitednumbers of species will faceentirely unsuitable conditionsfor persistence, others willexperience drastic reductionsand fragmentation ofdistributional areas, or extendtheir distributions, creating newnatural communitieswith unknown properties…severe ecological perturbationsmay result.”Peterson et al. (2002) on a climatechange scenario for MexicoMexico’s high habitat biodiversitysupports 11 per cent of the world’sbird species, numbering 1,060 species.Ten per cent of these bird species areendemic (Bogart, 1998).Thomas et al. (2004) provide datafor bird extinction risk due to climatechange in Mexico, based on workby Peterson et al. (2002). Assumingdispersal is possible, 2-3 per cent of birdspecies are predicted to become extinctunder a minimum climate scenario (0.8- 1.7˚C), and 3-4 per cent under a midrangeclimate scenario (1.8 - 2.0˚C).Under the “no dispersal” scenario,both minimum and mid-range climatescenarios provide an extinction risk of 5-8 per cent (see Figure 16).Local extinctions are predicted to beparticularly high in the Chihuahuandesert. The above analysis confirmsthat flat regions of the world may bevulnerable to species loss if even asmall change in climate requires manyspecies to disperse massive distancesto find new climatically suitable habitat(Peterson et al., 2002).Peterson et al. (2002) further note thatspecies turnover in some areas ofBird Species and Climate Change: The Global Status Report51Climate Risk

Mexico will be greater than 40 per cent,and state that, “Although only limitednumbers of species will face entirelyunsuitable conditions for persistence,others will experience drastic reductionsand fragmentation of distributionalareas, or extend their distributions,creating new natural communities withunknown properties” and that “severeecological perturbations may result.”This additional risk of “reshuffledcommunities” is discussed in detailabove (section 4.2).6.2.3 REGIONAL CASE STUDYExtinction risk for Australian birds“Extinction rates caused bythe complete loss of coreenvironments are likely to besevere, non-linear, with lossesincreasing rapidly beyond anincrease of 2.0˚C of warming...”Williams et al. (2003) on risk to birds ofAustralia’s Wet TropicsMexican and southwestern US birdspecies at risk of extinction:The cape pygmy owl is a Mexican birdthreatened by climate change. This bird isgeographically isolated to the tip of BajaCalifornia in the Sierra de la Laguna pineand pine-oak forest at 1,500 - 2,100m, anddeciduous forest down to 500m in winter.The Goldman’s song sparrow and Baird’sjunco are other climatically threatenedbird species found in Mexico (Thomaset al., 2004b).The southwestern willow flycatcher is anendangered species that breeds alongrivers, streams, or other wetlands insouthwestern US states and Texas. Itsnumbers have plummeted in the last centuryas a result of habitat destruction. Globalwarming is expected to contribute to hotter,drier conditions in this region, and this couldcause the species to become extinct as moreof its fragile habitat is lost. The goldencheekedwarbler and the black-capped vireoare two other endangered bird species thatface a similar threat (NWF/ABC, 2002).Australia has 740 extant native birdspecies, 19 of which 98 are nationallythreatened. Due to their evolvingin relative geographic isolation,approximately 40 per cent of Australia’sbird species are endemic (Departmentof Environment and Heritage, 2004).Ecosystems particularly sensitive toclimate change include Australia’shigh altitude mountain areas, due toprojected reductions in winter snowcover; and highland northern Australianrainforests which are projected todecrease in area by 50 per cent withless than a 1°C increase in temperature(CSIRO, 2006). Thomas et al. (2004) giveestimates for extinction risk within thelatter zone, a region of high biodiversityin Australia’s northeast, known as theAustralian Wet Tropics. The level ofextinction risk is comparatively high: 7-10 per cent extinction under a minimumclimate scenario (0.8 - 1.7˚C globaltemperature increase), and 49-72 percent under a maximum climate scenario(>2.0˚C global temperature increase).19 A further 21 Australian bird species are presumed extinct.Bird Species and Climate Change: The Global Status Report52Climate Risk

ProjectedpercentageextinctionFigure 17: Australian birds (Wet Tropics Bioregion)806040Maximum expectedclimate changeMinimum expectedclimate changeFigure 17: Extinction riskfor birds in Australia’sWet Tropics Bioregionwith dispersal, underboth a minimum andmaximum climatechange scenario.Methods of calculationare the same asdescribed above. Datafrom Thomas et al.(2004).2001 2 3Method of calculationRelated research by Williams et al.(2003) on the Australian Wet Tropicsbioregion finds: “Extinction ratescaused by the complete loss of coreenvironments are likely to be severe,non-linear, with losses increasingrapidly beyond an increase of 2.0˚C of[global] warming and compounded byother climate-related impacts.”New research also finds that up to 74 percent of rainforest birds in north-easternAustralia will become threatened(including 26 species now criticallyendangered) as a result of mid-range(3.6˚C of regional warming) climatechange within the next 100 years (Shooet al., 2005a).Upland birds are expected to be mostaffected, as they are most likely tobe immediately threatened by evensmall temperature increases (Shooet al., 2005a). These conditions arecreating what scientists have called animpending environmental catastrophe(Williams et al., 2003).Some Australian bird species at riskof extinction:■The golden bowerbird occupies coolhabitat in Australia’s Wet Tropics, onconical mountains surrounded bywarmer lowlands. As temperatures riseand its suitable habitat contracts, theclimate envelope of this endemic birdis predicted to shrink from 1564 km 2 tojust 37 km 2 (a 97.5 per cent reduction),restricting it to two mountain topsunder a scenario with 3˚C of futurewarming, assuming a 10 per cent declinein rainfall. Its habitat is to completelydisappear with between 3 and 4˚C ofwarming (Hilbert et al., 2004).Bird Species and Climate Change: The Global Status Report53Climate Risk

250020001500Habitatarea (km 2 )1000Figure 18Rainfall25% increase10% increaseno change10% decreaseFigure 18. Predictedarea of goldenbowerbird habitat ina number of futureclimate changescenarios, includinga range of changes inrainfall, and from 1 to3˚C of warming (Hilbertet al., 2004).50000 1 2 3Climate warming (ºc)■Climate projections of a 3˚Ctemperature increase, along with a 10per cent decrease in rainfall find thatthe bioclimates of three bird specieswill disappear from the southeasternstate of Victoria: the Western whipbird,mallee emu-wren and the helmetedhoneyeater, with seven other species“severely affected” by loss of theirbioclimate (Chambers et al., 2005).6.2.4 REGIONAL CASE STUDYExtinction risk for South African birdsSouth Africa has more than 951 birdspecies (Birdlife, 2006), 35 of whichare threatened (Birdlife, undated). Ingeneral there is poor documentation onSouth African fauna’s responsivenessto climate change (Erasmus et al.,2002), even though Africa has beenidentified as the continent most at riskfrom climate change, in part due to itsaridity (IPCC, 2001b). Africa is expectedto become dryer still, with highertemperatures, more weather anomalies,more frequent El Niños and more fires(IPCC, 2001b).In general, the distributions of birds insouthern Africa are expected to becomemore restricted and contract towardsthe Cape with global warming (Huntleyet al., 2006). According to Lovejoyand Hannah (2005a) “at least one ofthe world’s biodiversity hotspots, theSucculent Karoo in southern Africa, islikely to be massively and negativelyaffected at the double pre-industriallevel [of CO 2].” Under mid-range climatescenarios the Succulent Karoo andNama (another arid biome) are expectedto be greatly reduced and shift to thesoutheast (Simmons et al., 2004).These areas are home to 76 per cent ofsouthern Africa’s endemic birds.A study of a variety of animalgroups, including birds, found thatclimate change would result in rangecontractions for the vast majority (78per cent) of species and that overall 2per cent of the species would becomeBird Species and Climate Change: The Global Status Report54Climate Risk

ProjectedpercentageextinctionFigure 19: South African birds80604020Mid - range climate changeno dispersaldispersalFigure 19: SouthAfrican birds facecomparatively highrates of risk from amid-range climatescenario, even ifdispersal is possible(dark blue). Methods ofcalculation are the sameas described above.Data from Thomas et al.(2004).01 2 3Method of calculationlocally extinct with a 2.5-3.0 ˚C regionaltemperature increase by 2050. Thisanalysis by Erasmus et al. (2002)concludes that “climate change will havea profound impact on terrestrial animalspecies in South Africa”.Thomas et al. (2004) project a relativelyhigh extinction risk due to climatechange for birds in South Africa. The riskis 28-32 per cent for a mid-range climatechange scenario (1.8 - 2.0˚C of globalwarming) allowing for dispersal, and33-40 per cent for a mid-range climatechange scenario with no dispersal.Illustrating the severe blow climatechange can deal to current conservationefforts, major protected areas in theregion, including Kruger NationalPark could lose up to 66 per cent of thespecies they currently protect (Erasmuset al., 2002). Also of concern are findingsthat under a climate change scenario(doubling of pre-industrial levels of CO 2),those areas expected to have the mostbird species are also projected to havethe most dense human populations.This is because both human densityand species richness in South Africa areassociated with water availability, whichis expected to decline in southern Africa.According to van Rensburg et al. (2004),“This means that there is substantialscope for conservation conflicts inthe region...”In Africa:■The tawny eagle is an arid savannaraptor found in Asia and Africa.Projections show that even smallchanges in precipitation predicted withclimate change would likely result inthe birds’ extinction in its African aridsavanna habitat in the southern Kalahari(Wichmann et al., 2003). Even if meanannual precipitation stays the same, butthe inter-annual (year to year) variationincreases just slightly -- by less than 10per cent -- the bird’s populations willdecrease considerably.Bird Species and Climate Change: The Global Status Report55Climate Risk

6.3 Bird groups most at risk ofextinction from climate change“A global average temperaturerise of 2°C in the nextcentury will lead to numerousextinctions, but leave opensome practical managementoptions for the conservationof biodiversity. Temperaturerises beyond this levelare predicted to lead tocatastrophic extinction rates,with few management optionsand a bleak future for bothbiodiversity and people.”Birdlife, 2004aGenerally speaking, species mostvulnerable to extinction are thosewith restricted ranges or boundeddistributions, such as those on theedge of continents, on mountaintopsor small islands. Poor dispersalability, small populations or alreadypoor conservation status additionallyincrease extinction risk. Birds breedingin arid environments are also at high risk(Bolger et al., 2005; Reid et al., 2005).According to Chris Thomas of LeedsUniversity, “mobile generalists maycontinue to prosper, whereas specialistsare likely to continue to decline underthe combined onslaught of habitatloss and climate change” (from RSPB/WWF, 2003). Climate change is alsoexpected to cause invasive species toout-compete native species, becauseinvaders can expand their rangesquickly or tolerate wide-rangingconditions (RSPB/WWF, 2003). Many ofthese factors are behind the heightenedextinction risk for particular groupsof birds described in the followingsections: migratory species, wetland,coastal and seabirds, mountainand island birds, and Antarctic andArctic species.6.3.1 Migratory birds“Migratory species, becausethey rely on spatially separatedsites and habitats, may beespecially vulnerable to theimpacts of climate change,as change in any one of thesites used during the courseof the annual cycle could havepopulation impacts.”DEFRA, 2005Eighty-four per cent of bird specieslisted with the Convention on theConservation of Migratory Species(CMS) face threats from climate change.In fact, the threat of climate changeto migratory birds has been deemedequal to the sum of all other humancausedthreats combined (DEFRA,2005). This high level of threat occursbecause climatic change may affectthese birds in their wintering areas,along their migration routes and in theirbreeding grounds (Aloha et al., 2004).Indeed they are exposed to the summedclimatic risk for each habitat used alongtheir migration path, and the total effectcould prove catastrophic (Huntleyet al., 2006).Bird Species and Climate Change: The Global Status Report56Climate Risk

Climate change is likely to affect thestaging, stopover ecology and fuellingof migratory birds (DEFRA, 2005).Obtaining food for fat reserves, beforeand during the journey is importantbecause migration is energeticallycostly (Bairlein and Hüppop, 2004).Yet changes in prey abundance due toclimate change will affect more than 25per cent of migratory species listed onthe CMS (DEFRA, 2005).As discussed in section 3, climatechange is expected to make longdistancemigrants more vulnerable thanshort-distance migratory birds due tothe great risk to the former of mismatchbetween arrival time in breedinggrounds and peak food availabilitythere. Long-distance migrants couldalso be less adaptable to climaticchange (Bairlein and Hüppop, 2004).Furthermore, long distance migrantsoften rely on a few particular stopoversites, employing predictability as atactic to guide them to high qualityfeeding areas. Yet formerly dependablesites may deteriorate due to drought andvegetation shifts from climate change.In the face of such unpredictability, birdsmaking long flights with few stopoverswould be more vulnerable than thosemigrating in short hops (Bairlein andHüppop, 2004).Of European birds, those on the westernEuropean-African flyway appear toface the most severe consequencesof climate change. This is becausesouthern Spain, Northern Africa andthe Sahel region of Africa, importantstopover sites on this route, willundergo the most severe changes, i.e.desertification or conversion to drierhabitats. For example, the annual rateof desertification in the Sahel is 80,000km 2 per year (or 0.5 per cent; Bairleinand Hüppop, 2004). This meansmigratory birds may need to crossmore hostile habitat, with stagingareas becoming smaller and morespread apart. Such changes in waterregime have been called the mostwidespread threat faced by migratoryspecies (DEFRA, 2005). “Thus questionsarise whether migratory birds fromEurope are able to accommodate suchchanges,” according to Bairlein andHüppop (2004).This is of heightened concern if climatechange causes the distance betweenbirds’ breeding and non-breedingranges to increase, as modellingindicates will be the case for manymigrants between Europe and Africa(Huntley et al., 2006). If longer migratingdistances are “coupled with the lossof a critical stopover site the resultsfor a species might be catastrophic,”according to Huntley et al. (2006).Migratory birds may also be adverselyaffected by changes in wind patternsand increased frequency of extremeevents such as storms. Increasedfrequency of storms in the Caribbeanalready appears to be reducing thenumber of passerine 20 birds reachingtheir breeding grounds (DEFRA, 2005).Such new weather-related threats arepotentially serious for species alreadypushed to their physiological limit bytheir migratory journey, including thered knot and bar-tailed godwit, both ofwhich winter in Europe (DEFRA, 2005).20 The Passeriformes are the very large order of “perching birds” or “song birds”, which include flycatchers, wrens, swallows, waxwings, robins andmockingbirds, to name just a few.Bird Species and Climate Change: The Global Status Report57Climate Risk

Predicting the individual responsesof different species to a wide array ofhabitat changes on migration routesspanning the globe is difficult and ishindered by uncertainty in models anda lack of detailed studies (Barlein andHüppop, 2004). According to Saether(2000), “One frightening consequenceof these findings is that they illustratehow difficult it will be to reliably predictthe effects of large-scale regionalclimate change on ecological systems.”6.3.2 Wetland birds“Given the potentially seriousconsequences of globalwarming for waterfowlpopulations ... society hasyet another reason to act toslow greenhouse warmingand safeguard the future ofthese resources.”Sorenson et al., 1998Under 3-4°C of warming, 85 per centof all remaining wetlands could beeliminated (UNEP, 2005) -- a radicalalteration of wetland birds’ currenthabitat. Some European coastal areas,for example, are forecast to loose up to100 per cent of their wetland stock by2080 (IPCC, 2001b). As a result of thesechanges, 40 per cent of migratory birdspecies face impacts from predictedlowering of water tables, 53 per centfrom changes in water regimes overall.As noted above, these changes inwater regimes are actually the mostwidespread climatic threats to migratorybird species (DEFRA, 2005).Remaining wetlands will face anincreasingly variable hydrological cycle,which would leave inland wetlandsto dry out, resulting in lower speciesdiversity (see case study 3). Coastalmarshes will also be affected, dueto rising sea-level and changes inhydrological balance and severity. Asnoted in Section 2, habitat in estuariesand deltas will be lost if barriers preventa natural retreat as sea levels rise(coastal squeeze; UNEP, 2005; IPCC2001b). One of the most severe threatsto birds, this is a particular problem inEurope where landward extension ofsalt marshes is restricted by hard seadefences, for example by dams anddykes in the Wadden Sea (Böhning-Gaese and Lemoine, 2004; Bairlein andHüppop, 2004).In the Arctic, permafrost melting willcause lakes and wetlands to drainin some areas, while creating newwetlands in others. The balance of theseeffects is unknown, but major speciesshifts are likely as a result (ACIA, 2004).Bird Species and Climate Change: The Global Status Report58Climate Risk

CASE STUDY 7Declining Siberian crane faces threatsin all habitatsThe Siberian crane, a criticallyendangered species numbering3,000 individuals, demonstrates thevulnerabilities of a wetland migratorybird to climate change. It breeds inArctic Russia and Siberia and wintersin China in the middle to lowerreaches of the Yangtze River; a secondpopulation with just 3-8 individualsbreeds in Iran; and a third population,now thought to be extirpated, oncewintered in India. In addition towintering in wetlands, the birds breedin wide open Arctic tundra and taiga 21wetland in landscape that providesgood visibility.Arctic permafrost currently keeps thetundra treeless, but this bird’s habitatis forecast to decline by 70 per centwith global warming, as trees coloniseits habitat; adverse effects on itspopulation are expected as a result(DEFRA, 2005).Furthermore, precipitation hasdecreased in the bird’s winteringgrounds in China since 1965, especiallyduring the last two decades. Yetwhen rainfall events do occur, theyare more intense. Thus both droughtand severe floods are more common,patterns likely to have adverse effecton Siberian cranes. Droughts dryup wetlands for extended periods,affecting food supplies. Intense rainfallThe critically endangered Siberian crane facesnew threats from climate changeevents bring higher water levels.While the cranes can shift to areas ofappropriate depth, the plants they feedon are less able to quickly shift and“high crane mortality due to starvationcould potentially occur,” according toDEFRA (2005).Climate change is also cited as onepossible reason for the demise ofthe population that once wintered inIndia, where droughts have becomemore intense and frequent and humandemand for water is increasing. Thisis thought to be factor behind thispopulation’s dispersal away fromIndia’s Keoladeo National Park, itskey wintering area, and the ensuingextirpation of this population. Thishighlights the negative impacts ofclimate change could have in movingbirds out of protected areas.Photo: Michel Terrettaz, © WWF Canon21 Coniferous boreal forest.Bird Species and Climate Change: The Global Status Report59Climate Risk

In Europe■Climate change has been put forwardas an explanation for the decline ininternationally important water birdspecies in the UK during the period 2001to 2004. This includes the grey ploverand dark-bellied Brent goose, whosepopulations peaked in the early 1990safter long periods of increase. Theyare now showing steady decline (JNCC2005; Collier et al., 2005).In Asia:■The Baikal teal is a water bird that breedsin north-east Siberia and winters inSouth Korea, Japan, and China. Oncecommon, by 1990 only an estimated50,000 remained and the bird is listedas vulnerable. As a bird that nests onlyin marshes it is particularly vulnerableto climate change. Lower water tablesand higher rates of drought equate toreduced available habitat. Habitat lossmay compromise the bird’s abilityto complete its migratory journey(DEFRA, 2005).6.3.3 Coastal and seabirds“As one of the most severethreats, one can consider risingsea levels, which might leadto severe habitat loss incoastal areas.”Böhning-Gaese and Lemoine, 2004Nearly 20 per cent of migratory birdspecies (listed under the CMS) arepotentially affected by loss of coastalhabitat due to climate change-inducedsea level rise (DEFRA, 2005). This addsan additional threat to seabirds, whichhave already undergone a dramaticdeterioration compared to other types ofbirds since 1998 (Birdlife, 2004a).Rising sea levels are expected to ahave a huge impact on lowland coastalhabitats around the world, and coastalbird and seabird species are likely tosuffer as a result (Bairlein and Hüppop,2004). As noted above, some parts ofEurope are forecast to loose up to 100CASE STUDY 8Globally threatened aquatic warblerout of depth with climate changeThe aquatic warbler, Europe’srarest songbird, is a globallythreatened migratory bird with aknown population of 13,500-21,000singing males. Over 90 per cent ofits remaining population is foundin highly fragmented patches inBelarus, Ukraine and Poland; habitatdestruction has eliminated westernEuropean populations, and populationdecline continues at a rate of 40 percent per decade. The birds are thoughtto winter in sub-Saharan Africa.Birds which nest only in marshes, likethe aquatic warbler, will be particularlyvulnerable to climate change. Climatechange is expected to threaten thewarbler by making marsh depths morevariable, pushing water levels above orbelow the 5-12cm range preferred bybreeding birds which nest in marshyzones. Drier summers will also causedeclines in its insect prey. Loss ofhabitat and drought may further affectthe bird in its African wintering groundsand during migration (DEFRA, 2005).Bird Species and Climate Change: The Global Status Report60Climate Risk

per cent of their wetland stock by 2080(IPCC, 2001b; see examples below).Sea level rise, along with stormfrequency and severity will work toinundate low-lying islands, and seabirdnesting colonies on them will be lost(UNEP, 2005). Increased sea level isalso expected to combine with coastalsqueeze to permanently inundatemudflats, and this would impactseverely on wildfowl and wader species(BTO, 2002). These include mudflatsof estuaries, which are importantfeeding sites for birds. Elevated rates oferosion will pose an additional threat,particularly in the tropics, due to moreextreme weather (IPCC, 2001b).Seabirds are showing themselves to bekey early responders to climate change.This group is already being affectedby well-documented prey distributionchanges that are a major threat tomarine ecosystems (Lanchbery, 2005;DEFRA, 2005). Plankton communitieshave been observed to make majorshifts in response to changes in seasurface temperature; this includes shiftsin distribution of up to 10° latitude, anddeclines in abundance to a hundredth ora thousandth of former values. Declinesin krill, which form a key component ofmarine food webs, are considered tobe of special concern. Such ecosystemchanges have already affected thedistribution and abundance of seabirds,such as kittiwakes, and a number ofpenguin species (DEFRA, 2005).In Europe:■Loss of coastal wetlands, importanthabitats for birds, will be extreme insome areas. On Europe’s Atlantic coast,■■0-17 per cent of wetland stock will belost by 2080 due to climate change, onthe Baltic coast 84-98 per cent, and onthe Mediterranean coast 31-100 per cent(IPCC, 2001b).Terns, along with other sea andmarshland birds found in Europe, arevulnerable to sea level rise becausethey nest on low-lying near shoreground. Increasing frequency of stormsurge events due to climate change,particularly in the North Sea, will putfurther pressure on terns due to thethreat of nests being washed out bystorm conditions (Rehfish et al., 2004a).UK coastal habitat supports over onequarter of the East Atlantic “flyway”populations of 10 species of wading bird.International flyway populations of overwinteringsanderling, purple sandpiperand ruddy turnstone are expected toshow continuing decline to 2080 withnumbers decreasing 35-60 per cent dueto climate change (Rehfish et al., 2004b).Furthermore, “curlew populations areexpected to decline over 40 per centin their strongholds of Shetland andOrkney, and ringed plover numbersmay decline by up to 36 per cent in theWestern Isles ...” Even if these birdscan shift their wintering distributionsto match changing climatic conditions,availability of prey and habitat changesin their tundra breeding grounds maywell limit their adaptability.6.3.4. Mountain and island birds“Mountain ecosystemsaround the world, such asthe Australian Wet Tropicsbioregion, are very diverse,Bird Species and Climate Change: The Global Status Report61Climate Risk

often with high levels ofrestricted endemism, and aretherefore important areas ofbiodiversity. … these systemsare severely threatened byclimate change.”Williams et al., 2003Mountain ecosystems are hotspots 22of biodiversity and endemism. Thisis because they compress a rangeof climatic zones and, as a rule,biodiversity, into a relatively shortdistance. These features also makemountain systems vulnerable to climatechange. Even though the dispersaldistances entailed in shifting upslopewith a moving climate are relativelysmall, there are definite limits toupward migration.As a result we face “the completedisappearance of specific environmentaltypes combined with low possibilityof natural dispersal to other suitablehabitats,” according to Williams etal. (2003), and as a result, “we maybe facing an unprecedented loss ofbiodiversity in any mountain biota, anenvironmental catastrophe of globalsignificance.” Mountain bird specieswill experience this elevated threatfrom climate change as their suitablehabitat is reduced and they cannot shiftin response (DEFRA, 2005; Benning etal., 2002). In warmer latitudes, tropicalmountain forests are expected to dryout and be invaded or replaced by lowermountain or non-mountain species(UNEP, 2005).Islands also tend to be biodiversityhotspots -- in fact they containnine of the world’s 12 biodiversityhotspots. This makes their biodiversityparticularly vulnerable to sea-level rise.Their isolation will also limit or preventbirds and other terrestrial animals fromshifting their ranges. This is of particularconcern given that 23 per cent of birdspecies found on small islands arealready threatened (IPCC, 2001b).Thus endemic mountain and islandspecies are vulnerable to extinctionbecause of the limited range of suitableclimate space available to them, andtheir limited ability to shift in responseto changes. Furthermore, they may alsohave small populations. And althoughmany mountain areas have isolatedpopulations of species which may alsobe found elsewhere, their loss couldreduce the overall genetic diversity ofthese species (DEFRA, 2005).In Europe:■Future climate change scenarios predictrange contractions for birds restrictedto high altitudes in the UK, such as thesnow bunting and ptarmigan, and localextinction of the capercaillie by 2050under a high level scenario of globalwarming (See case study 6).In Central America:■Bird species have already been shownto move upslope in response to climaticshifts associated with global warming(see section 4; Pounds et al., 1999).22 Biodiversity hotspots are areas with exceptional concentrations of endemic species facing extraordinary threats of habitat destruction. Twenty-fivehotspots contain the sole remaining habitats for 133,149 (44 per cent) of vascular land plants and 9,732 (36 per cent) of terrestrial vertebrates (IPCC 2001b).Bird Species and Climate Change: The Global Status Report62Climate Risk

In Australia:■Mountain bird species in Australia’snortheastern tropical zone, such as thegolden bowerbird (see section 6.2.3)are threatened by even moderate levelsof warming (Hilbert et al., 2004). Withmid-range regional climate warming of3.6˚C, 74 per cent of Australian rainforestbird species are threatened within thenext 100 years. This includes 26 speciescritically endangered now (Shooet al., 2005a).6.3.5 Antarctic birds“...what we are going to seein the next 10, 20, 30 years isa system that is completelydifferent from the one thatexists now. Adélies [penguins]will become regionally extinct.”William Fraser, Palmer Long TermEcological Research Program (fromGross, 2005)The current rate of Antarctic climatechange implies unprecedented changesto ocean processes -- processes thataffect predators at the top of the foodchain, including seabirds (Croxall,2004). The Antarctic Peninsula, themost northern and biodiverse part ofthat continent, is warming fastest of alllocations in the southern hemisphere.The Western Antarctic Peninsula hasregistered temperature increases on theorder of 6˚C, the largest on the planet,over the past 50 years in line with IPCCpredictions (IPCC 2001b). This cold,dry polar marine ecosystem is beingreplaced by a warm, moist maritimeclimate. Rising temperature andsalinity trends both act to reduce seaice production, and positive feedbackis now accelerating sea ice shrinkage(Meredith and King, 2005). This isof high concern because sea icedynamics drive Antarctic ecosystems(Gross, 2005).Marine prey species in this regionare extremely sensitive to verysmall increases in temperature, andpopulation removal can result fromeven small ocean changes (Meredithand King, 2005). Seasonal ice cover inthe Western Antarctic Peninsula is animportant nursery and breeding groundfor krill, which underpin the SouthernOcean food web and serve as crucialprey for many bird species (IPCC 2001b).Antarctic krill production has alreadydropped markedly with winter seaice declines playing a role (Molineet al., 2004). Thus the ecologicalimplications of climate change for thisarea are significant.Penguin species in the Antarctic aresensitive to climate change (Fraser andHoffman, 2003) and recent changes intheir populations, including a 33 per centdecline in Adélie penguin populations,are a reflection of regional climatechange (Leemans and van Vliet, 2004).According to Croxall (2004), “Althoughmost of the Antarctic marine avifaunais likely to be able to persist or adapt,the effects on certain high-latitudeice-associated species and on othersof already unfavourable conservationstatus (e.g. most albatrosses, somepetrels and penguins) could be seriouson fairly short time scales.”Bird Species and Climate Change: The Global Status Report63Climate Risk

Case Study 9Emperor penguin declines in the faceof Antarctic warmingIn Terre Adélie the emperor penguinpopulation declined 50 per cent dueto reduced adult survival duringa late 1970s period of prolonged,abnormally warm temperatures withreduced sea ice extent (Barbraud andWeimerskirch, 2001; see figure 20). Itis possible this climate anomaly is theresult of global warming.While warmer sea temperaturesbenefited hatching success, they alsodecreased food supply and reducedadult survival. The warming is linked toreduced production of krill, a stapleof the penguin’s diet, and thisHighly susceptible to changes in climate:the emperor penguinadversely affected the penguins.Combined, these opposing effectsresulted in a net decrease in breedingsuccess, showing the emperorpenguin is highly susceptible toenvironmental change (Barbraud andWeimerskirch, 2001; Croxall, 2004).Following this crash, population levelshave stabilized at a new low level.Photo: Kevin Schafer, © WWF CanonFigure 20-4SummerAveragetemperaturesin colony (˚C)Breedingpairs-6-14-16-18-206,0005,0004,0003,0002,000Winter1955 1960 1965 1970 1975 1980 1985 1990 1995 20001955 1960 1965 1970 1975 1980 1985 1990 1995 2000Figure 20: Warmand highly variableclimate through the1970s linked to adecline in breedingemperor penguinpairs. a = summerand winter averagetemperaturesrecorded atDumont D’Urvillemeteorologicalstation. B = numberof breeding pairs ofemperor penguinsat Pointe GéologieAchipelago, TerreAdélie . FromBarbraud andWeimerskirch, 2001.Bird Species and Climate Change: The Global Status Report64Climate Risk

Antarctic seabirds may also be affectedby a southward shift or reduction inthe extent of the Marginal Ice Zone, anarea of variable, often broken ice thatlinks open ocean to the solid ice pack.Birds breeding on the continent may bepositively affected, while sub-Antarcticbreeders are expected to be negativelyaffected. Furthermore, this zone plays akey role in reproduction and recruitmentof krill, and changes to this zone maycause a shift at this level of the foodchain, from krill to other species such ascopepods and fish, with possibly oceanwideconsequences for seabirds andother predators (Croxall, 2004).Shelves, shelf margins and frontalregions such as the Antarctic Polar Frontare particularly important foragingareas to some species, including mostpenguins, and some albatross and petrelspecies. Shifts in nutrient availabilityor upwelling in these areas could havemajor consequences for bird specieson sub-Antarctic islands, because thesebirds cannot easily move their breedingsites (Croxall, 2004).In Antarctica:■Antarctic Peninsula Adélie penguinpopulations have declined by 70 per centon Anvers Island (Palmer Station) overthe last 30 years due to retreating iceand increasing snowfall in response toclimate warming (Fraser and Hoffman,2003; Gross, 2005). “Adélies don’t seemcapable of adjusting anything abouttheir life history… They’re hard-wired totheir breeding area, returning to an areayear after year after year, even thoughconditions are deteriorating,” according■■to William Fraser of the Palmer LongTerm Ecological Research program.These climatic changes could causethe birds to become regionally extinct,according to Fraser (from Gross, 2005).Rising temperatures are causing salps,transparent jelly-like ocean organisms,to replace krill. Most krill-dependentpredators, which include penguins, donot eat salps. Negative impacts on thesepredators are expected as a result (Seesection 4).Food web changes linked to warmingare now considered to have caused theradical decline in rockhopper penguinnumbers on sub-Antarctic CampbellIsland (see section 5.2; Cunninghamet al., 1994).6.3.6 Arctic birds“These vegetation changes,along with rising sea levels,are projected to shrink tundraarea to its lowest extent in thepast 21,000 years... Notonly are some threatenedspecies expected to becomeextinct, some currentlywidespread species areprojected to decline sharply.”ACIA, 2004Climate change is expected to haveits most pronounced influence onArctic habitats (DEFRA, 2005) and byimplication Arctic birds are expected tobe among the most vulnerable.Bird Species and Climate Change: The Global Status Report65Climate Risk

The Arctic has warmed faster than anyother region of the globe in the lastcentury, almost two times faster thanthe global average. This is alreadycontributing to profound environmentalchanges and the trend is set to continue,with 4-7°C of warming expected inthe next 100 years according to someclimate models (ACIA, 2004). Averagesummer sea ice extent has declined 15-20 per cent per decade over the past 30years and overall sea ice volume wasdown by approximately 40 per cent onaverage. If this trend continues perennialsea ice will completely disappear by theend of this century (ACIA, 2004).The Arctic has high importance forbirds because approximately 15 percent of bird species worldwide breedthere. Almost all Arctic bird speciesare migratory, and several hundredmillion of them visit the Arctic eachyear (ACIA, 2004), including 20 milliongeese and waders that winter in Europe,Asia and North America (WWF, 2005a).The majority of Arctic birds breed onthe tundra, the vast treeless plain lyingbetween the Arctic icecap and thetree line to the south, characterisedby permanently frozen subsoil calledpermafrost (DEFRA, 2005).Climate change will cause rapid anddramatic losses in Arctic water birdbreeding habitat (Birdlife, 2004a)through vegetation shifts, predictedto be most extreme for tundra areas(Zöckler and Lysencko, 2000). Overalllosses of current tundra area areprojected to be 40-57 per cent, withexpected new tundra areas to amountto just 5 per cent (Böhning-Gaese andLemoine, 2004). 23 This includes habitatfor several globally endangered seabirdspecies (ACIA, 2004).Vast areas of tundra will undergo a shiftto taller, denser vegetation that favoursforest expansion (UNEP, 2005; ACIA2004; IPCC, 2002). This climaticallyinduced shift could proceed at a rate of0.2 km/year (Birdlife, 2004a), among theworld’s highest rates of migration, andmany species may be unable to shiftsufficiently quickly to keep up (WWF,2000). Tundra-breeding birds knownas waders will not be able to adapt tobushy or tree-like terrain and so, exceptfor a few areas gained by retreatingglaciers, will be unable to gain newhabitats (Zöckler, 2000). Thus importantbreeding and nesting areas in tundrahabitats are expected to decline sharply.As boreal forests spread north theywill also overwhelm up to 60 per centof dwarf shrub tundra, crucial breedinghabitat for ravens, snow buntings,falcons, loons, sandpipers and terns(WWF, 2005a).Climate change is predicted to haveits most immediate effects on arcticseabirds (Meehan, 1998). In fact, rangedisplacements have already begun forsome seabird species (ACIA, 2004).Seabirds which forage at the marginsof sea ice face a drastic reduction inconjunction with the rapid decrease insea ice volume and extent describedabove. This trend is expected tocontinue with further climate change,pushing some seabird species towardextinction (ACIA, 2004).23 A separate analysis shows that if all vegetation shifts with its optimal climate, tundra could decline 41-67 per cent and tundra/taiga 33-89 per centdepending on the climate model (RSPB/WWF 2003).Bird Species and Climate Change: The Global Status Report66Climate Risk

A further threat will come as speciesfrom the south shift their distributionsnorthward in tandem with warming. Asa result, bird species may suffer fromincreased competition and be displacedby invading species (ACIA, 2004).In the Arctic:A study of 25 Arctic water birds showedwide-ranging loss of breeding range dueto changes from global warming with adoubling of CO 2by 2070-2099 (Zöckler &Lysenko 2000). This includes:■➢The globally vulnerable red-breastedgoose, a bird which breeds in ArcticEurope and winters in south easternEurope, would lose 67 per cent of itshabitat with moderate warming of 1.7 ˚Cand 99 per cent of its habitat with moreextreme warming of 5˚C.well as scavenging the ice surface. Canadianpopulations of these gulls have alreadydeclined 90 per cent over the past twodecades (ACIA, 2004).Predatory Arctic birds such as snowyowls and skuas are also expected to beaffected due to reductions in numbers ofprey. The lemming is an important preyspecies which has already declined interms of its populations cycle peaks (itundergoes cyclical population booms), andis expected to decline further with resultantstronger declines for predators; snowy owlpopulations are already in decline(ACIA, 2004).■The tundra bean goose, which wouldlose 76 per cent of its habitat withmoderate warming (1.7˚C) and 93 percent of its habitat with more extremewarming (5 ˚C).The Arctic spoon-billed sandpiper, the onlyglobally threatened sandpiper breedingin the Arctic, is one of the region’s rarestbreeding birds. It will lose 56 per cent of itsArctic tundra breeding area with warming of1.7˚C (moderate projection), displacing morethan 1,300 of the current 2,400 breedingbirds; with 5 ˚C of warming it will facehigher risk of extinction (Zöckler andLysenko, 2000).Sea ice retreats will have serious negativeconsequences for ivory gulls, which nest oncliffs and fish through cracks in sea ice asBird Species and Climate Change: The Global Status Report67Climate Risk

7 ReferencesAhola M., Laaksonen T., Sippola K., Eeva T., Rainio K. &Lehikoinen E. (2004) Variation in climate warming along themigration route uncouples arrival and breeding dates. GlobalChange Biology 10 (9): 1610.Arctic Climate Impact Assessment (ACIA; 2004). Impacts ofWarming; Arctic Climate Impact Assessment. CambridgeUniversity Press, Cambridge, UK.Arnott, S.A. & Ruxton, G.D. (2002) Sandeel recruitment in theNorth Sea: demographic, climatic and trophic effects. MarineEcological Progress Series 238: 199.Barbraud C. & Weimerskirch H. (2001). Emperor penguins andclimate change. Nature 411: 183.Barbraud C. & Weimerskirch H . (2006). Antarctic birds breedlater in response to climate change. Proceedings of the NationalAcademy of Sciences 103 (16): 6248.Bairlein F. & Hüppop O. (2004) Migratory fuelling and globalclimate change. In: Møller, A., Berthold, P. & Fiedler, W (Eds) Birdsand Climate Change, pp. 33. Advances in Ecological Research 35.Elsevier Academic Press.Beaumont L.J., McAllan I.A.W. & Hughes L. A matter of timing:changes in the first date of arrival and last date of departure ofAustralian migratory birds. Global Change Biology 12(7): 1339.Benning T.L., LaPointe D., Atkinson C.T. & Vitousek P.M. (2002)Interactions of climate change with biological invasions and landuse in the Hawaiian Modeling the fate of endemic birds usinggeographic information system. Proceedings of the NationalAcademy of Sciences 99(22):14246.Berry, P.M., Vanhinsberg, D., Viles, H.A., Harrison, P.A., Pearson,R.G., Fuller, R.J., Butt, N. & Miller, F. (2001) Impacts on terrestrialenvironments. In: Harrison, P.A., Berry, P.M. & Dawson, T.P. (Eds)Climate Change and Nature Conservation in Britain and Ireland:Modeling Natural Resource Responses to Climate Change (theMONARCH Project): 43150. Oxford: UKCIP Technical report.Berthold P., Møller A.P. & Fiedler W. (2004) Preface. In: Møller, A.,Berthold, P. & Fiedler, W (Eds) Birds and Climate Change, pp. vii.Advances in Ecological Research 35. Elsevier Academic Press.Birdlife (undated a) Birdlife Europe Program. Available at: http://www.birdlife.org/regional/europe/index.htmlBirdlife (undated b) Birdlife website: Available at: http://www.birdlife.org/worldwide/national/south_africa/index.htmlBirdlife (2004a). State of the world’s birds 2004. A report.Birdlife (2004b). Birds in the European Union: A statusassessment.Birdlife (2006) Email communication, January 25.Boersma P.D. (1998) Population trends of the Galapágos penguin:Impacts of El Niño and La Niña. The Condor: Vol. 100( 2): 245.Boersma P.D. (1999) Impacts of El Niño on Galapagos penguins’body condition and movement. Proceedings of the AmericanAssociation for the Advancement of Science, Pacific Division 18(1): 43.Bogart R.E. (1998) Conserving the Migratory Birds of Mexico’sWetland Ecosystems. Endangered Species Bulletin, July.Böhning-Gaese, K. & Lemoine N. (2004) Importance of ClimateChange for the Ranges, Communities and Conservation of Birds.In: Møller, A., Berthold, P. & Fiedler, W. (Eds) Birds and ClimateChange, pp. 211. Advances in Ecological Research 35. ElsevierAcademic Press.Bolger D.T., Patten M.A. & Bostock D.C. (2005) Avian reproductivefailure in response to an extreme climatic event. Oecologia 142:398-406.Both C., Bouwhuis S., Lessells C.M. & Visser M.W. (2006) Climatechange and population declines in a long-distance migratorybird. Nature 441: 81Both C., Artemyev A.V., Blaauw B., Cowie R.J., Dekhuijzen A.J.,Eeva T., Enemar A., Gustafsson L., Ivankina E.V., Jaervinen A.,Metcalfe N.B., Nyholm N.E.I., Potti J., Ravussin P.-A., Sanz J.J.,Silverin B., Slater F.M., Sokolov L.V., Toeroek J., Winkel W.,Wright J., Zang H. & Visser M.E. (2004) Large-scale geographicalvariation confirms that climate change causes birds to lay earlier.Proceedings of the Royal Society of London B 271: 1657.Both C. & Visser M. E. (2001) Adjustment to climate change isconstrained by arrival date in a long-distance migrant bird.Nature 411: 296.Bradley N.L., Leopold A.C., Ross J. & Huffaker W. (1999)Phenological changes reflect climate changes in Wisconsin.Proceedings of the National Academy of Sciences USA 96: 9701.British Trust for Ornithology (BTO; 2002). The Effect of ClimateChange on Birds. Information pages by David Leech. Available at:http://www.bto.org/research/advice/ecc/index.htm.BTO (2005) Looking for lazy birds. Available at: http://www.bto.org/news/news2005/nov-dec/looking_for_lazy_birds.htm.Brown J.L., Shou-Hsien L., & Bhagabati N. (1999) Long-term trendtoward earlier breeding in an American bird: A response to globalwarming? Proceedings of the National Academy of Sciences 96:5565.Burns C.E., Johnston K.M. & Schmitz O.J. (2006) Global climatechange and mammalian species diversity in U.S. national parks.Proceedings of the National Academy of Sciences 100(20): 11474.Burton, J.F. (1995) Birds and Climate Change. A & C Black.Butler C.J. (2003) the disproportionate effect of global warmingon the arrival dates of short-distance migratory birds in NorthAmerica. Ibis 145(3): 484.Chambers L.E. (2005) Migration dates at Eyre Bird Observatory:links with climate change?Climate Research 29(2): 157.Chambers L..E., Hughes L. & Weston M.A. (2005) Climate changeand its impact on Australia’s avifauna. Emus 105: 1.Collier M., Banks A., Austin G., Girling T., Hearn R. & MusgroveA. (2005) The Wetland Bird Survey 2003/04 Wildfowl and WaderCounts. British Trust for Ornithology Wildfowl & WetlandsTrust, Royal Society for the Protection of Birds & Joint NatureConservation Committee.Bird Species and Climate Change: The Global Status Report68Climate Risk

Cook,A., Fox A.J., Vaughan, D.J. & Ferrigno J.G. (2005) Retreatingglacier-fronts on the Antarctic Peninsula over the last 50 years.Science 22: 541.Coppack, T. & Both, C. (2002) Predicting life-cycle adaptation ofmigratory birds to global climate change. Ardea 90: 369.Cotton P.A. (2003) Avian migration phenology and climatechange. Proceedings of the National Academy of Sciences 100(21): 12219.Crick, H.Q.P. (2004) The impact of climate change on birds. Ibis146 (suppl 1), 48.Crick, H.Q.P., Dudley C., Glue D.E. & Thomson D.L. (1997). UKbirds are laying eggs earlier. Nature 388: 526.Crick, H.Q.P. & Sparks T.H. (1999) Climate change related to egglayingtrends. Nature 399: 423.Croxall J.P. (2004) The potential effects of marine habitat changeon Antarctic seabirds. Ibis 146 (Suppl.1): 90.CSIRO (2006) Climate change impacts on Australia and thebenefits of early action to reduce global greenhouse gasemissions. Preston B.L. & Jones R.N. A consultancy report for theAustralian Business Roundtable on Climate Change.Cunningham D. M. & Moors P. J. (1994) The decline of RockhopperPenguins Eudyptes chrysocome at Campbell Island, SouthernOcean and the influence of rising sea temperatures. Emu 94: 27.Davis A.J., Jenkinson L.S., Lawton J.H., Shorrocks B. & Wood S.(1998) Making mistakes when predicting shifts in species range inresponse to global warming. Nature 391: 783.Department of Environment, Food and Rural Affairs (DEFRA;2005). Climate change and migratory species. A report by theBritish Trust for Ornithology. Available at: http://www.defra.gov.uk/wildlife-countryside/resprog/findings/climatechangemigratory/index.htm.Department of Environment & Heritage (Australia; 2004).Australia’s biodiversity: An overview of selected significantcomponents. Biodiversity series, paper no. 2. Biodiversity Unit.Available at: http://www.deh.gov.au/biodiversity/publications/series/paper2/biod_3.htmlDunn P.O. & Winkler D.W. (1999) Climate change has affectedthe breeding date of tree swallows throughout North America.Proceedings of the Royal Society of London B 266: 2487.Dunn P. (2004) Breeding Dates and Reproductive Performance.In: Møller, A., Berthold, P. & Fiedler, W (Eds) Birds and ClimateChange, pp. 69. Advances in Ecological Research 35. ElsevierAcademic Press.Edwards M. & Johns D. (2005) Monitoring the ecosystemresponse to climate change in the North-East Atlantic. Sir AlistairHardy Foundation for Ocean Science (SAHFOS). Available at:www.sahfos.orgEpstein P.R. (2001) West Nile virus and the climate. Journal ofUrban Health 78(2): 367.Erasmus B.F.N, van Jaarsveld A.S., Chown S.L., Kshatriya M. &Wessels K.J. (2002) Vulnerability of South African animal taxa toclimate change. Global Change Biology 8: 679.European Environment Agency (EEA; 2004) Impacts of Europe’schanging climate. European Environment Agency Report No2/2004.Folkestad T., New M., Kaplan J.O., Comiso J.C., Watt-CloutierS., Fenge T., Crowley P., & Rosentrater L.D.l (2005) Evidence andimplications of dangerous climate change in the Arctic. Presentedat: Avoiding Dangerous Climate Change Conference, Exeter, UK,1 February.Fraser W.R., Trivelpiece W.Z., Ainley D.G. & Trivelpiece S.G. (1992)Increases in Antarctic penguin populations: reduced competitionwith whales or a loss of sea ice due to environmental warming?Polar Biology. 11: 525.Fraser W.R. & Hofmann E.E. (2003) A predator’s perspectiveon causal links between climate change, physical forcing andecosystem response. Marine Ecology Progress Series 265: 1.Gaston A.J., Hipfner J. M. & Campbell, D. (2002) Heat andmosquitoes cause breeding failures and adult mortality in anArctic-nesting seabird. Ibis 144 (2):185.Gaston A.J., Gilchrist H.G. & Hipfner, J.M. (2005) Climate change,ice conditions and reproduction in an Arctic nesting marine bird:Brunnich’s guillemot (Uria lomvia L.). Journal of Animal Ecology74(5): 832.Gjerdrum C., Vallée A.M.J., St. Clair C., Bertram D.F., Ryder J.L. &Blackburn G.S. (2003) Tufted puffin reproduction reveals oceanclimate variability. Proceedings of the National Academy ofSciences 100 (16): 9377.Giles J. (2006) US posts sensitive climate report for publiccomment. Nature 441: 6.Githaiga-Mwicig J.M.W., Fairbanks D.H.K. & Midgley G.(2002) Hierarchical processes define spatial pattern of avianassemblages restricted and endemic to the arid Karoo, SouthAfrica. Journal of Biogeography, 29: 1067.Gordo O., Brotons L.., Ferrer X. & Comas P. (2005) Do changes inclimate patterns in wintering areas affect the timing of the springarrival of trans-Saharan migrant birds? Global Change Biology11(1): 12.Gordon C., Cooper C., Senior C.A., Banks H., Gregory J.M., JohnsT.C., Mitchell J.F.B. & Wood R.A. (2000) The simulation of SST,sea ice extents and ocean heat transports in aversion of theHadley Centre Coupled Model without Flux Adjustments. ClimateDynamics 16: 147.Gross L. (2005). As the Antarctic ice pack recedes, a fragileecosystem hangs in the balance. Public Library of Science3(4). Available at: http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.0030127.Gwinner E. (1996.) Circannual clocks in avian reproduction andmigration. Ibis 138: 47.Hannah L., Lovejoy T.E. & Schneider S.H. (2005) Biodiversity andClimate Change in Context. In: Lovejoy T.E. & Hannah. L. (Ed.)Climate Change and Biodiversity, pp. 3. Yale University Press,New Haven & London.Hansen J, Sato M., Ruedy R., Lo K., Lea D.W., Medina-Elizade M.(2006) Global temperature change. Proceedings of the NationalAcademy of Sciences 103: 14288.Bird Species and Climate Change: The Global Status Report69Climate Risk

Hansen J., Ruedy R., Sato M. & Lo K. (2005) GISS surfacetemperature analysis: Global temperature trends, 2005summation. NASA Goddard Institute for Space Studies andColumbia University Earth Institute. Available at: http://data.giss.nasa.gov/gistemp/2005/.Hilbert D.W., Bradford M., Parker T. & Westcott D.A. (2004).Golden bowerbird (Priondura newtonia) habitat in past, presentand future climates: predicted extinction of a vertebratein tropical highlands due to global warming. BiologicalConservation 116 (3): 367.Huntley B., Collingham Y.C., Green R.E., Hilton G.M., RahbekC. & Willis S. (2006). Potential impacts of climate change upongeographical distributions of birds. Ibis 148: 8.Huntley B., Green R.E., Collingham Y.C. & Willis S.G. (in press).A Climatic Atlas of European Breeding Birds. Barcelona: LynxEdicions.Inouye D.W., Barr, B., Armitage, K.B. & Inouye, B.D. (2000) Climatechange is affecting altitudinal migrants and hibernating species.Proceedings of the National Academy of Sciences 97: 1630.Intergovernmental Panel on Climate Change (IPCC; 1996), ClimateChange 1995: The Science of Climate Change, Contribution ofWorking Group 1 to the Second Assessment Report. HoughtonJ.T., Filho L.G.M., Callander B.A., Harris N., Kattenberg A. &Maskell, K. (Eds). Cambridge Univ. Press, New York, 1995.IPCC (2001a) Climate Change 2001: The Scientific Basis.Cambridge University Press.IPCC (2001b). Climate Change 2001: Impacts, Adaptation andVulnerability. Cambridge University Press.IPCC (2001c) Climate change 2001: Synthesis report. Summaryfor policymakers. Cambridge University Press, Cambridge.IPCC (2002) Climate change and biodiversity. Gitay, H., A. Suárez,R. T. & Watson, O. (Eds) Technical Paper V, IPCC Working Group IITechnical Support Unit.International Union for Conservation of Nature (IUCN; 2004)2004 IUCN Red List of Threatened Species: A Global SpeciesAssessment. The Red List Consortium.Jensen M.N. (2004) Climate warming shakes up species.BioScience 54(8): 722Jenni L. & Kery M. (2003) Timing of autumn bird migration underclimate change: advances in long-distance migrants, delays inshort-distance migrants. Proceedings of the Royal Society ofLondon B 270: 1467.Jones J., Doran, P.J., Holmes, R.T. (2003) Climate and foodsynchronize regional forest bird abundances. Ecology 84 (11):3024.Johnson C.W., Millett B.V., Gilmanov T., Voldseth R.A.,Guntenspergen G.R.& Naugle D.E.(2005) Vulnerability ofnorthern prairie wetlands to climate change. Bioscience 55(10):863.Joint Nature Conservation Committee (JNCC; 2005) UK seabirdsin 2005: Results from the UK Seabird Monitoring Programme.Available at: http://www.jncc.gov.uk/page-3627Karl T.R. & Trenberth K.E. (2005) What is climate change?In: Lovejoy T.E. and Hannah. L. (Eds.) Climate Change andBiodiversity, pp. 15. Yale University Press, New Haven & London.Kendall M.A., Burrows M.T. Southward A.J. & Hawkins S.J.(2004) Predicting the effects of marine climate change on theinvertebrate prey of the birds of rocky shores. Ibis 146: 40.Kitaysky A.S., Kitaiskaia E.V., Piatt J.F. & Wingfield J.C. (2005).A mechanistic link between chick diet and decline in seabirds?Proceedings of the Royal Society of London, B 273: 445.Klein Tank, A. (2004) Changing temperatures and precipitationextremes in Europe’s climate of the 20th century. UtrechtUniversity, Utrecht.Lanchbery, J. (2005) Ecosystem loss and its implications forgreenhouse gas concentration stabilization. Presented at:Avoiding Dangerous Climate Change Conference, Exeter, UK, 1February.Lean G. (2005) Fish numbers plummet in warming Pacific:Disappearance of plankton causes unprecedented collapse in seaand bird life off western US coast. Independent, November 13.Leemans R. & van Vleit R. (2004) Extreme weather: Does naturekeep up? Wageningen University. A report for WWF.Leemans R. & Eickhout B. (2004) Another reason for concern:Regional and global impacts on ecosystems for different levels ofclimate change. Global Environmental Change 14: 219.Lehikoinen E., Sparks T. & Žalakevicius M. (2004) Arrival anddeparture dates. In: Møller, A., Berthold, P. & Fiedler, W (Eds)Birds and Climate Change, pp. 1. Advances in Ecological Research35. Elsevier Academic Press.Lemoine N. (2005) Influence of habitat and climate changeon European bird communities. PhD dissertation. JohannesGutenberg University, Mainz, Germany.Lemoine N. & Bohning-Gaese K. (2003) Potential impact of globalclimate change on species richness of long-distance migrants.Conservation Biology 17(2): 577.Lovejoy T.E. & Hannah L. (2005a) Global greenhouse gas levelsand the future of biodiversity. In: Lovejoy T.E. & Hannah. L. (Eds)Climate Change and Biodiversity, pp. 387. Yale University Press,New Haven & London.Lovejoy T.E. & Hannah L. (2005b) Preface. In: Lovejoy T.E. &Hannah. L. (Eds) Climate Change and Biodiversity. Yale UniversityPress, New Haven & London.Malcolm J.R., Liu C., Neilson R.P. Hansen L. & Hannah L. (2006)Global warming and extinctions of endemic species frombiodiversity hotspots. Conservation Biology 20 (2): 538.Mazerolle D.F., Dufour K.W., Hobson K.A. & den Haan H.E.(2005) Effects of large-scale climatic fluctuations on survivaland production of young in a Neotropical migrant songbird, theyellow warbler Dendroica petechia. Journal of Avian Biology36(2): 155.McLaughlin J.F., Hellmann J.J., Boggs C.L. & Ehrlich P.R. (2002)Climate change hastens population extinctions. Proceedings ofthe National Academy of Sciences 99: 6070.Julliard R., Jiguet F. & Couvet D. (2003) Common birds facingglobal changes: what makes a species at risk? Global ChangeBiology 10 (1), 148.Bird Species and Climate Change: The Global Status Report70Climate Risk

Meehan R., Byrd V., Divoky, G. & Piatt, J. (1998) Implicationsof climate change for Alaska’s seabirds. University of AlaskaFairbanks. Available at: http://www.besis.uaf.edu/besis-oct98-report/Seabirds.pdf.Mills A.M. (2005) Changes in the timing of spring and autumnmigration in North American migrant passerines during a periodof global warming. Ibis 147 (2): 259.Meredith, M. P. & King J. C. (2005) Rapid climate change in theocean west of the Antarctic Peninsula during the second halfof the 20th century. Geophysical Research Letters, 32, L19604,doi:10.1029/2005GL024042.Møller A.P., Berthold P. & Fiedler W. (2004) The challenge of futureresearch on climate change and avian biology. . In: Møller, A.,Berthold, P. & Fiedler, W. (Eds) Birds and Climate Change, pp. 237.Advances in Ecological Research 35. Elsevier Academic Press.Moss R., Oswald J. & Baines D. (2001) Climate change andbreeding success: Decline of the capercaillie in Scotland. Journalof Animal Ecology 70: 47.Moline M.A., Claustre H., Frazer T.K., Schofield O. & Vernet M.(2004) Alteration of the food web along the Antarctic Peninsulain response to a regional warming trend. Global Change Biology10: 1973.Murphy-Klassen H.M. & Heather M. (2005) Long-term trends inspring arrival dates of migrant birds at Delta Marsh, Manitoba inrelation to climate change. Auk 122(4): 1130.National Wildlife Federation/American Bird Conservancy (NWF/ABC 2002). A birdwatcher’s guide to global warming.NWF (undated) Silent spring: A sequel? Available at: http://www.nwf.org/nationalwildlife/article.cfm?issueid=58&articleid=706Noble I., Parikh J., Watson R., Howarth R., Klein R.J.T. AbdelkaderA. & Forsyth T. (2005) Climate Change. In: K. Chopra, R. Leemans,P. Kumar and H. Simons (Eds) Ecosystems and Human Well-Being: Policy Responses, Volume 3. Findings of the ResponsesWorking Group of the Millennium Ecosystem Assessment. IslandPress, Washington, DCPalmer Station Long Term Ecological Research (undated).Available at http://www.lternet.edu/vignettes/pal.html.Parmesan C. (2005) Biotic response: Range and abundancechanges. In: Lovejoy T.E. and Hannah. L. (Eds) Climate Changeand Biodiversity, pp. 41. Yale University Press, New Haven &London.Parmesan C. & Yohe G. (2003) A globally coherent fingerprint ofclimate change impacts across natural systems. Nature 421: 37.Parrish J. (2005) School of Aquatic & Fishery Sciences, Universityof Washington, USA. Direct communication via email. December1. Report in progress.Pearce F. (2002) Nasty neighbors. New Scientist, April 13.Pearce F. (2005) Antarctic Peninsula glaciers in major retreat. NewScientist, April 21.Pendlebury C. J., MacLeod M. G. & Bryant, D. M (2004) Variationin temperature increases the cost of living in birds. The Journal ofExperimental Biology 207 (12): 2065.Peñuelas J., Filella I. & Comas P.E. (2002) Changed plant andanimal life cycles from 1952 to 2000 in the Mediterranean region.Global Change Biology 8 (6): 531.Peterson A.T., Ortega-Huerta M.A., Bartley J., Sanchez-CorderoV., Soberon J., Buddemeier R.H. & Stockwell D.R.B. (2002) Futureprojections for Mexican faunas under global climate changescenarios. Nature 416: 626.Peterson W. (2005) NOAA Northwest Fisheries Science Center,Hatfield Marine Science Center, NOAA. Direct communication viaemail. November 24.Pew Center on Global Climate Change (2004) Observed impactsof global climate change in the U.S. A report by C. Parmesan & H.Galbraith.Pounds A.J., . Bustamante M.R., Coloma L.A., Consuegra J.A.,Fogden M.P.L, Foster P.N., La Marca E., Masters K.L., Merino-Viteri A., Puschendorf R., Ron S.R., Sánchez-Azofeifa G.A., StillC.J. & Young B.E. (2006) Widespread amphibian extinctions fromepidemic disease driven by global warming. Nature 439: 161.Pounds A.J., Fogden M.P.L. & Campbell J.H. (1999) Biologicalresponse to climate change on a tropical mountain. Nature 398,611.Pounds A.J. & Puschendorf R. (2004) Ecology: Clouded futures.Nature 427: 107.Pulido F. & Widmer M. (2005) Are long-distance migrantsconstrained in their evolutionary response to environmentalchange? Causes of variation in the timing of Autumn migration ina blackcap (S. atricapilla) and two garden warbler (Sylvia borin)populations. Annals of the New York Academy of Sciences 1046:228.Reid W. V., Mooney H.A., Cropper A., Capistrano D., CarpenterS.R., Chopra K., Dasgupta P., Dietz T., Duraiappah A.K., Hassan R.,Kasperson R., Leemans R., May R.M., McMichael A.J., Pingali P.,Samper C., Scholes R., Watson R.T., Zakri A.H., Shidong Z., AshN.J., Bennett E., Kumar P., Lee M.J., Raudsepp-Hearne C., SimonsH., Thonell J, & Zurek M. B. (2005) Ecosystems and Human WellBeing. Millennium Ecosystem Assessment Synthesis report.Island Press, Washington DC.Rehfisch M.M., Feare C.J., Jones N.V. & Spray C. (2004a) Climatechange and coastal birds. Ibis 146 (Suppl.1): 1.Rehfisch M.M., Austin G.E., Freeman S.N., Armitage M.J.S. &Burton, N.H.K. (2004b) The possible impact of climate change onthe future distributions and numbers of waders on Britain’s nonestuarinecoast. Ibis 146 (Suppl.1): 70.Richardson A.J. & Shoeman D.S. (2004) Climate Impact onPlankton Ecosystems in the Northeast Atlantic. Science 305(5690): 1609.Root T. & Hughes L. (2005) Present and future phenologicalchanges in wild plants and animals. In: Lovejoy T.E. and Hannah.L. (Eds.) Climate Change and Biodiversity, pp. 61. Yale UniversityPress, New Haven & London.Root T.L., Price J.T., Hall K.R., Schneider S.H., Rosenzweig C.& Pounds J.A. (2003) Fingerprints of global warming on wildanimals and plants. Nature 421 (6918): 57.Pennisi, E. (2001) Early birds may miss the worms. Science291(5513): 2532Bird Species and Climate Change: The Global Status Report71Climate Risk

Root, T.L. 1988. Environmental factors associated with aviandistributional boundaries. Journal of Biogeography 15: 489.Root T.L. & Schneider S. H. (1993) Can Large-Scale ClimaticModels Be Linked with Multiscale Ecological Studies?Conservation Biology 7(2): 256.Royal Society for the Protection of Birds (RSPB) & WorldwideFund for Nature (2003). Global climate change and biodiversity.Green R.E., Harley M., Miles L., Scharlemann J., Watkinson A. &Watts. O. (Eds).RSPB (2004a). Climate change and birds. Information sheet.Available at: http://www.rspb.org.uk/Images/Climate%20change%20and%20birds_tcm5-56407.pdfRSPB (2004b). The state of UK’s birds.RSPB (2004c) Climate change fears over breeding failure.Available at http://www.rspb.org.uk/england/southeast/reserves/failure.asp.RSPB (2004d) Disastrous year for Scotland’s seabirds. Availableat: http://www.rspb.org.uk/scotland/action/disastrousyear.asp.RSPB (2005) North Sea fishing ban as sandeel numbers plummet,June 10. www.rspb.org.uk/policy/marine/fisheries/sandeelban.asp.RSPB (2005b) Climate change affecting birds in Northern Ireland.http://www.rspb.org.uk/nireland/climateandbirds.asp.RSPB (undated). Why climate matters for British wildlife.Available at: http://www.rspb.org.uk/climate/facts/britishwildlife.asp.Sanderson F.J., Donald P.F., Pain D.J., Burfield I.J. & van BommelF.P.J. (2006) Long-term population declines in Afro-Palearcticmigrant birds. Biological Conservation 131: 93.Sanz J.J. (2003) Large-scale effect of climate change on breedingparameters of pied flycatchers in Western Europe. Ecography26(1): 45.Sanz J.J., Potti J., Moreno J., Merino S. & Frias O. (2003) Climatechange and fitness components of a migratory bird breeding inthe Mediterranean region. Global Change Biology 9 (3): 461.Schiegg K., G. Pasinelli,J. R. Walters & S. J. Daniels. 2002.Inbreeding and experience affect response to climate change byendangered woodpeckers. Proceedings of the Royal Society ofLondon B 269:1153.Sekercioglu (2004) Ecosystem consequences of bird declines.Proceedings of the National Academy of Sciences. 101(52):18042.Saether B.-E. (2000) Weather Ruins Winter Vacations. Science:288 (5473): 1975.Saether B.-E., Sutherland W.J. & Engen S. (2004) Climateinfluences on avian population dynamics. In: Møller, A., Berthold,P. & Fiedler, W (Eds) Birds and Climate Change, pp. 185. Advancesin Ecological Research 35. Elsevier Academic Press.Shoo L.P., Williams S.E. & Hero J.-M. (2005a) Climate warmingand the rainforest birds of the Australian Wet Tropics: Usingabundance data as a sensitive predictor of change in totalpopulation size. Biological Conservation 125(3): 335.of trends in distribution area and population size of species withclimate change. Global Change Biology 11(9): 1469.Simmons R.E., Barnard P., Dean W.R.J., Midgley G.F., Thuiller W.& Hughes G. (2004) Climate change and birds: perspectives andprospects from southern Africa. Ostrich 2004, 75(4): 295.Smithers B.V., Peck D.R., Krockenberger A.K. & Congdon B.C.(2003) Elevated sea-surface temperature, reduced provisioningand reproductive failure of wedge-tailed shearwaters (Puffinuspacificus) in the southern Great Barrier Reef, Australia. Marineand Freshwater Research 54(8): 973.Sokolov, L.V., Markovets, M.Yu, Shapoval, A.P. & Morozov, YuG. (1998) Long-term trends in the timing of spring migration ofpasserines on the Courish Spit of the Baltic Sea. Avian Ecologyand Behavior 1: 1.Sorenson L.G., Goldberg R., Root T.L. & Anderson M.G. (1998)Potential effect of global warming on waterfowl breeding in theNorthern Great Plains. Climatic Change 40: 343.South Pacific Regional Environment Programme (SPREP).Environmental Monitoring and Assessment 49: 263.Stervander M., Lindström Å., Jonzén N. & Andersson A. (2005)Timing of spring migration in birds: long-term trends, NorthAtlantic Oscillation and the significance of different migrationroutes. Journal of Avian Biology 36 (3): 210.Støkke B.G., Moller A.P., Saether B.-E., Goetz R. & Gutscher H.(2005) Weather in the breeding area and during migration affectsthe demography of a small long-distance passerine migrant. TheAuk 122: 637.Strode P.K. (2003) Implications of climate change for NorthAmerican wood warblers (Parulidae). Global Change Biology 9:1137.Sydeman W. (2005) Sooty shearwater distribution and abundanceoff southern California. Presentation to CalCOFI conference, SanDiego, USA December 5.Sydeman W.J., Bradley R.W., Warzybok P., Abraham C.L., JahnckeJ., Hyrenbach K.D., Kousky V., Hipfner J.M.,& Ohman M.D. (inpress) Planktivorous auklet ptychoramphus aleuticus responsesto the anomaly of 2005 in the California current.Tait M. (2004) If only seabirds could vote. The Ecologist 34 (7):14.Tait M. (2005) Against the Clock. The Ecologist 35 (2): 25.Thomas C.D., Cameron A., Green R.E., Bakkenes M., BeaumontL.J., Collingham Y.C., Erasmus B.F.N., De Siquiera M.F., GraingerA., Hannah L., Hughes L., Huntley B., Van Jaarsveld A.S., MidgleyG.F., Miles L., Ortega- Huerta M.A., Peterson A.T., Phillips O. &Williams S.E. (2004) Extinction risk from climate change. Nature427: 145.Thomas C.D., Cameron A., Green R.E., Bakkenes M., BeaumontL.J., Collingham Y.C., Erasmus B.F.N., De Siquiera M.F., GraingerA., Hannah L., Hughes L., Huntley B., Van Jaarsveld A.S., MidgleyG.F., Miles L., Ortega- Huerta M.A., Peterson A.T., Phillips O. andWilliams S.E. (2004b) Additional data from above study listed onthe University of Leeds website. Available at http://www.leeds.ac.uk/media/current/extinction.htmThomas C.D. & Lennon J.L. (1999). Birds extend their rangesnorthwards. Nature 399: 213.Shoo, L.P. Williams S.E. & Hero J.-M. (2005b) Potential decouplingBird Species and Climate Change: The Global Status Report72Climate Risk

Thomas D.W., Blondel J., Perret P., Lambrechts, M.M. &Speakman J.R. (2001) Energetic fitness costs of mismatchingresource supply and demand in seasonally breeding birds.Science 291(5513): 2598.Thuiller W., Lavorel S., Araujo M.B., Sykes M.T., Prentice I.C.(2005) Climate change threats to plant diversity in Europe.Proceedings of the National Academy of Sciences 102(23): 8245.Timmermann A., Oberhuber J., Bacher A., Esch M., Latif M. &Roeckner E. (1999) Increased El Niño frequency in a climate modelforced by future greenhouse warming. Nature 398: 694-697Torti V.M., Dunn P. & Scott R. (2005). Variable effects of climatechange on six species of North American birds. Oecologia 145(3):486.Townsend M. & Sadler R. (2004) North Sea birds dying as watersheat up. The Observer, June 20.Tryjanowski P., Kuniak S. & Sparks T. 2002. Earlier arrival of somefarmland migrants in western Poland. Ibis 144: 62.Turner J., Lachlan-Cope T.A., Colwell S., Marshall G.H. &Connolley W.M. (2006) Significant Warming of the AntarcticWinter Troposphere. Science 311(5769): 1914.United Nations Environment Program (UNEP; 2005). Biodiversityand climate change. Online fact sheet available at: http://www.unep-wcmc.org/climate/impacts.htm.UNEP (2006) Summary of the second global biodiversity outlook.Note by the Executive Secretary. Conference of the Parties to theConvention on Biological Diversity, 8th Meeting, p. 6.Van Rensburg B.J., Erasmus B.F.N., van Jaarsveld A.S., GastonK.J. & Chown S.L. (2004) Conservation during times of change:correlations between birds, climate and people in South Africa.South African Journal of Science 100: 266.Van Vliet A. & Leemans R. (2006) Rapid species’ responses tochanges in climate require stringent climate protection targets.In: Schellnhuber H. J., Cramer W., Nakícénovic N., Wigley T.,& Yohe G. (Eds) Avoiding Dangerous Climate Change, pp 135.Cambridge University Press, Cambridge.Veit R.R., Pyle P. & McGowan J.A. (1996) Ocean warming andlong-term change in pelagic bird abundance within the Californiacurrent system. Marine Environmental Progress Series 139:11.Webster P.J., Holland G.J., Curry J.A. & Change H.-R. (2005)Changes in tropical cyclone number, duration, and intensity in awarming environment. Science 309:1844.Wichmann M.C., Jeltsch W., Dean W.R.J., Moloney K.A.and Wissel C. (2003) Implications of climate change for thepersistence of raptors in arid savanna. Oikos 102: 186.Williams S.E., Bolitho E.E. & Fox S. (2003) Climate change inAustralian tropical rainforests: an impending environmentalcatastrophe. Proceeding of the Royal Society of London B 270:1887.Withgott J. (2003) Refugee species are feeling the heat of globalwarming. New Scientist, January 4, pp. 4.World Wildlife Fund (WWF; 2000) Global warming and terrestrialbiodiversity decline. Malcolm J.R. & Markham A.WWF (2002) Habitats at risk: Global warming and species loss inglobally significant terrestrial ecosystems. Malcolm J.R., Liu C.,Miller L.B., Allnutt T. & Hansen L..WWF (2004) Extreme weather: Does nature keep up? Leemans R.& van Vleit R., Wageningen University.WWF (2005a) 2° is too much! Evidence and implications ofdangerous climate change in the Arctic. WWF International ArcticProgramme.WWF (2005b) Vulnerability assessment of the North East AtlanticShelf Marine Ecoregion to climate change. Baker T.WWF (2005c) Climate change impacts in the Mediterraneanresulting from a 2˚C global temperature rise. Giannakopoulos C.,Bindi M., Moriondo M., LeSager P. & Tin T.Zöckler C. & Lysenko I. (2000) Water birds on the edge: Firstcircumpolar assessment of climate change on Arctic-breedingwater birds. United Nations Environment Programme & WorldConservation Monitoring Centre. Available at: http://www.unepwcmc.org/climate/waterbirds/report.pdf.Žalakevicius M. & Švažas S. (2005) Global climate change and itsimpact on wetlands and waterbird populations. Acta ZoologicaLituanica 14(3): 211.Veit R., McGowan J., Ainley D., Wahl T. & Pyle P. (1997) Apexmarine predator declines ninety percent in association withchanging oceanic climate. Global Change Biology 3(1): 23.Vince, G. (2005) Are sea birds becoming too dumb to survive?New scientist, November 9.Visser M.E., van Noordwijk A.J., Tinbergen J.M. & Lessells C.M.(1998) Warmer springs lead to mistimed reproduction in GreatTits (Parus major). Proceedings of the Royal Society of London.B 265: 1867.Visser M.E., Both C. & Lambrechts M.M. (2004) Global climatechange leads to mistimed avian reproduction. In: Møller, A.,Berthold, P. & Fiedler, W. (Eds): Birds and Climate Change, pp. 89.Advances in Ecological Research 35. Elsevier Academic Press.Walther G.-R., Post E., Convey P., Menzel A., Parmesan C., BeebeeT.J.C., Fremont J.-M., Hoegh-Guldberg O. & Bairlein F. (2002)Ecological responses to recent climate change. Nature 416: 389.Bird Species and Climate Change: The Global Status Report73Climate Risk

Appendix ACommon and Scientific Names of BirdSpecies Mentioned in This Report(Scientific names shown in parentheses)aquatic warbler (Acrocephalus paludicola)Adélie Penguin (Pygoscelis adeliae)Baikal teal (Anas formosa)Baird’s junco (Junco bairdi)Berwick’s swan (Cygnus columbianusberwickii)blackcaps (Sylvia atricapilla)Brunnich’s guillemots (Uria lomvia)Cape longclaw (Macronyx capensis)Cape pygmy-owl (Glaucidium hoskinsii)capercaillie (Tetrao urogallus)Cassin’s auklet (Ptychoramphus aleuticus)checkerspot butterfly (Euphydryas edithabayensis)chiffchaffs (Phylloscopus collybita)collared flycatcher (F. albicollis)common buzzard (Buteo buteo)common guillemot (Uria aalge)emperor penguin (Aptenodytes forsteri)godwit (Limosa lapponica)golden bowerbird (Prionodura newtonia)Goldman’s song sparrow (Melospizagoldmani)great tit (Parus major)grey heron (Ardea cinerea)helmeted honeyeater (Lichenostomusmelanops cassidix)hoopoe (Upapa epops)ivory gull (Pagophila eburnea)keel-billed toucan (Ramphastos sulfuratus)mallee emu-wren (Stipiturus mallee)Marmora’s warbler (Sylvia sarda)Mexican jay (Aphelocoma ultramarina)nuthatch (Sitta europaea)pied flycatcher (Ficedula hypoleuca)purple sandpiper (Calidris maritima)red-breasted goose (Branta ruficollisrossicus/serrirotris)red kite (Milvus milvus)red knot (Calidris canutus)resplendent quetzal (Pharomachrusmoccino)ringed plover (Charadrius hiaticula)rockhopper penguin (Eudyptes chrysocome)ruddy turnstone (Arenaria interpres)sanderling (Calidris alba)Scottish crossbill (Loxia scotica)Siberian crane (Grus leucogeranus)snow buntings (Plectrophenax nivalis)snowy owl (Bubo scandiacus)sooty shearwater (Puffinus griseus)Spanish imperial eagle (Aquila adalberti)spoon-billed sandpiper (Eurynorhynchuspygmaeus)spotted flycatcher (Muscicapa striata)tawny eagle (Aquila rapax)tree swallows (Tachycineta bicolor)tufted puffin (Fratercula cirrhata)tundra bean goose (Anser fabalis)western whipbird (Psophodes nigrogularis)white-fronted goose (Anser albifrons)whooper swan (Cygnus cygnus)willow tit (Parus montanus)wood warbler (Parulidae)Bird Species and Climate Change: The Global Status Report74Climate Risk

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