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Afewmillionyearsago,someSouthAmericantortoiseswoundupintheocean,possiblywashedouttoseaby
floodwaters.Oncethere,theytuckedintheirheadsandfeetandpatientlyfloated,eitheràlacarteoronraftsofvegeta-tion.Eventually,afewfortunateindividualsstrucklandintheGalápagos,wheretheycrawledashore,foundasnack,settled
in,andmultiplied—withthoseoneachislandadaptingtolocalconditions. Thisisthebestscientifichypothesisregardingtheoriginofthe14distinctivepopulations(frequentlyrecognizedasseparatesubspecies)ofGalápagosGiantTortoises(Chelonoidis nigra)thatevolvedinthearchipelago.Thesevolcanicislands,
T R A V E L O G U E
IRCF REPTILES & AMPHIBIANS • VOL15, NO 4 • DEC 2008 189TABLE OF CONTENTS
T A B L E O F C O N T E N T S
F E A T U R E A R T I C L E S
Chasing Bullsnakes (Pituophis catenifer sayi) in Wisconsin: On the Road to Understanding the Ecology and Conservation of the Midwest’s Giant Serpent ...................... Joshua M. Kapfer 190
The Shared History of Treeboas (Corallus grenadensis) and Humans on Grenada: A Hypothetical Excursion ............................................................................................................................Robert W. Henderson 198
R E S E A R C H A R T I C L E S
The Texas Horned Lizard in Central and Western Texas ....................... Emily Henry, Jason Brewer, Krista Mougey, and Gad Perry 204 The Knight Anole (Anolis equestris) in Florida
.............................................Brian J. Camposano, Kenneth L. Krysko, Kevin M. Enge, Ellen M. Donlan, and Michael Granatosky 212
C O N S E R V A T I O N A L E R T
World’s Mammals in Crisis ............................................................................................................................................................. 220 More Than Mammals ...................................................................................................................................................................... 223 The “Dow Jones Index” of Biodiversity ........................................................................................................................................... 225
H U S B A N D R Y
Captive Care of the Central Netted Dragon ....................................................................................................... Shannon Plummer 226
P R O F I L E
Kraig Adler: A Lifetime Promoting Herpetology ................................................................................................ Michael L. Treglia 234
C O M M E N T A R Y
The Turtles Have Been Watching Me ........................................................................................................................ Eric Gangloff 238
B O O K R E V I E W
Threatened Amphibians of the World edited by S.N. Stuart, M. Hoffmann, J.S. Chanson, N.A. Cox, R. Berridge, P. Ramani, and B.E. Young .............................................................................................................. Robert Powell 243
CONSERVATION RESEARCH REPORTS: Summaries of Published Conservation Research Reports ................................. 245 NATURAL HISTORY RESEARCH REPORTS: Summaries of Published Reports on Natural History ................................. 247 NEWBRIEFS ...................................................................................................................................................................................... 248 EDITORIAL INFORMATION ..................................................................................................................................................... 251 FOCUS ON CONSERVATION: A Project You Can Support ............................................................................................... 252
Front Cover. Shannon Plummer.Totat et velleseque audant mo estibus inveliquo velique rerchil erspienimus, quos accullabo. Ilibus aut dolor apicto invere pe dolum fugiatis maionsequat eumque moditia erere nonsedis ma sectiatur ma derrovitae voluptam, as quos accullabo.
Back Cover. Michael KernTotat et velleseque audant mo
estibus inveliquo velique rerchil erspienimus, quos accullabo. Ilibus
aut dolor apicto invere pe dolum fugiatis maionsequat eumque
moditia erere nonsedis ma sectia-tur ma derrovitae voluptam, as
IRC
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REPTILES & AMPHIBIANSC O N S E R V AT I O N A N D N AT U R A L H I S T O R Y
WWW.IRCF.ORG/REPTILESANDAMPHIBIANSJOURNAL
Decline and Rise of Galápagos TortoisesTeresaBergen
Free-lancewriter,Portland,Oregon(http://teresabergen.com)([email protected])
Photographsbytheauthor.
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Gianttortoiseseathard-to-digestgrass,whichquicklycomesouttheotherend,onlypartiallydigestedandstillrecognizablygrassy.
Copyright©2013.TeresaBergen.Allrightsreserved.
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IRCFREPTILES&HIBIANS•20(1):23–29•MAR2013
1,000kmwestoftheEcuadorianmainland,werenamedby16th-centurySpanishexplorers(galápago=tortoise)andwereneverconnectedtoanotherlandmass. AlthoughtheancestorsofsomeislandpopulationsmighthavearrivedseparatelyfromSouthAmerica,theoriginsofsomearethesubjectofconsiderablespeculation.Oneexpla-nationfortheirpresenceontheislandsofPintaandIsabelainvolvesadistressed19th-centuryship.“Wecannotprove,butwhatmighthavehappened,isthatboatwascollectinggianttortoisesondifferentislands,”saidOrlandoRomero,anaturalistwiththeGalápagosNationalParkService.“Maybetheoceanwasverychoppyandtheboatwasfulloftortoisesandwaterwascomingin,andmaybetheydecidedtodumpgianttortoisesfromdifferentislands.” Ifyou’denjoy speculatingwithnaturalists about tor-toisesandotherfauna,aGalápagoscruisemightberightforyou.IwasfortunatetospendaweekinlateJanuaryontheLetty,a20-passengershipownedbytheEcuadoriancompanyEcoventura.TheLettyisnotforpeoplewhowantcruiseshipamenitieslikepools,casinos,andgiftshops.Instead,shepro-videsadiningareaandsundeckforsocializingwithshipmates,asmalllibraryfocusedontheGalápagos,andabriefingareawhereeverynightthenaturalistsexplaintheislands’history. Ourgrouphadtwoguides.OrlandoRomero,whocametothe islandsfrommainlandEcuador in1974,andIvanLopez,areveryexperiencedandknowledgeablenaturalists.Sincesomepassengerswerecontenttoadmirethesceneryand,infact,snoozedduringthebriefings,bothOrlandoandIvanwereeagertoansweranyquestionsbythoseinterestedinthenittygrittyofanimalbehavior.
Travails of Humans and Animals in Centuries PastBeforetheGalápagosNationalParkwasestablishedin1959,theremainingGalápagosanimalshadsurvivedafewcenturiesofanythinggoes.Humancontacthaddoomedsomespeciestoextinction. Pirates,whalers,andbuccaneerspliedthesewatersuntilEcuadorclaimedtheGalápagosin1832.Amongotherthings,theislandsinitiallyservedasapenalcolonyandasugarplan-tation,and—ifyoubelieveallthestoriesthenaturaliststell—asapotentialsitefora19th-centurynudisthotel. Theislands,starkandisolated,haveneverbeenaneasyplacetolive.Storiesofscandal,danger,adventure,murder,vio-lence,andmysteryabound.RomerooncegotlostforthreedaysontheislandofSantaCruz.Whenhefinallyfoundapond,thewaterwasn’tentirelyfresh;hehadtostrainitthroughhisT-shirttoavoiddrinkingthefecesofagianttortoise. Gianttortoiseswereespeciallyhardhitbyearlyvisitors.Sincetortoisescanliveforuptoayearwithoutfoodorwater,sailorsstackedlivingturtlesintheholdsofships,killingthemforfreshmeatduringtheirvoyage.Merchantsharvestedtor-toisesforfat,whichlitstreetlightsonmainlandEcuadorand
otherpartsofSouthAmerica.Inthelater1800s,scientificexpeditionsroutinelykilledtortoises,dryingtheirskinstotakehomeasresearchtrophies. Beforetheseslow-movingreptilesencounteredhumans,theymayhavenumbered250,000.Nowthetotalpopula-tionintheGalápagos iscloserto25,000.GianttortoisesoftheSeychelleIslandsintheIndianOceanweresimilarlyexploited.ThoseonAldabra(Aldabrachelys gigantea)haverecoveredthankstoanunusuallylonghistoryofconserva-tionefforts,butsubspecificallyrelatedformsonotherislandsintheSeychelleswerethoughttohavebecomeextinctuntil1999,when12individualssurvivingincaptivitywereshowntoexhibitcharacteristicsofthe“extinct”forms.Thelatterarenowthesubjectofacaptivebreedingandreintroductionpro-grambytheNatureProtectionTrustofSeychelles.
WhalersheadingforAntarctichuntinggroundsstackedlivingturtlesintheholdsofships,killingthemforfreshmeatduringtheirvoyage.
LonesomeGeorge, theworld’s lastPinta Island tortoise, livedat theCharlesDarwinResearchStationuntilhisdemisein2012.
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Breeding Giant TortoisesSince 1965, thenational parkhas collaboratedwith theCharlesDarwinResearchStation(CDRS)onagianttortoisecaptivebreedingprogram.ThestationonSantaCruzIslandiswhereLonesomeGeorge,theworld’smostfamoustor-toise,liveduntilhisdemisein2012.Asfarasanyoneknows,George,aPintaIslandtortoise,wasthelastofhiskind. My group visited the research station on a pleasantThursdaymorning.Afewcloudshungintheskyaswestrodepathwaysbetweengiantpricklypearcacti,atortoisefavorite.SantaCruzwasthelushestislandwevisited;someareasstarkasmoonscapes.Wealsosawthefirstbuildingswe’dseensinceboardingtheboatonSunday,andthefirstsouvenirshops. Tenofthe14distinctpopulationsofgianttortoisesareextant.HalfofthesehailfromtheislandofIsabela,whereadifferentformevolvedoneachoftheisland’sfivevolcanoes.Tortoisesaredomeshaped, saddlebacked,or inbetween,dependingontheirhomeisland’svegetation.Inplaceswithplentyoffoodontheground,grazingdome-shapedtortoises
thrive.OntheextremelydryislandofEspañola,asaddle-backedvarietydevelopedinordertoreachplantsasmuchasameterabovetheground.Regardlessofform,thetortoiseskeepgrowinguntiltheydie,albeititatincreasinglyslowerratesastheyage. Evenwithhumansmostlymindingtheirmannersontheislandsthesedays,othercreaturesstillposethreatstotortoisesurvival.BlackRats(Rattus rattus)—hitchhikersinadver-tentlyintroducedlongago—eattortoiseeggs,asdopigs.Introducedcats,dogs,goats,andendemicGalápagosHawks(Buteo galapagoensis)feastonhatchlings. Tortoiseslaysevenoreighteggsinaclutch,burythem,andmoveon.Afterleavingtheminthenestforacoupleofmonths,scientistsdigthemupandtransportthemtotheresearchstation.They learnedby trialanderror tomarkthetopsofeggs,becausefailingtomaintaintheegg’sorigi-nalpositionmeansdeathfortheembryo.Intheolddays,Romerosaid,“Theywerenotverycareful.Theyweretakenbyboats,sloshingtheembryos.”NowtheislandsofIsabelaandSanCristóbalhavetheirownbreedingprograms,sothoseeggsaremovedshorterdistances. Onceattheresearchstation,eggsaresortedbyislandandincubated.Sincetemperaturedictateswhetherhatch-lingswillbemaleorfemale,scientistsdecidewhichwouldbemoreadvantageousforthepopulation.Oncetheeggshatch,thetinyhatchlings—soft-shelledandthesizeoftennisballs—areputindarkboxesforamonthtosimulatethetimethey’dspendundergroundinthewild.Thencometwoyearsinasmallenclosure,followedbythreetosixyearsinalarger,morenaturalarea.Visitorscanseetheselittleguys,whodon’tlooklikethey’regoingtogrowintothegiantstheybecome. Allhatchlings’shellsarecolor-codedbyisland,andeachindividualismicro-chippedandassignedanumber.Whentheirshellsare20–25cmlong,scientistsreleasetheyoungtortoisesintothewild.Thishappensduringtherainysea-son,whenthefruitsandflowersonwhichtheyoungtortoisesdependaremostabundant. ThebreedingprogramhasbeenespeciallysuccessfulontheislandofEspañola.Inthe1970s,theoutlookwasbleakforEspañolatortoises.Onlytwomalesandtwelvefemaleswanderedtheisland,notbumpingintoeachotherfrequentlyenoughtobreed.ScientistsbroughttheEspañolatortoisestotheresearchstation,wheretheyseemedcontenttolivecom-fortablelivesassingles.Infact,theydidn’tevenseemtoknowhowtobreed.Thescientistsdecidedtheyneededanothermaletostirupsomehealthycompetition. TheSanDiegoZoohadthetortoiseforthejob.ZooofficialsagreedtorepatriatetheirEspañolatortoise,whichthezoohadcollectednearly50yearsearlier.So,in1977,heflewhometotheGalápagosonaUnitedAirlinesflight. Lopezlikestotellthestoryinhistypicallyracyfashion.“HewasnamedDiego—orProfessorDiego,becausehehad
Hatchlingsatthebreedingcenterresideforamonthindarkboxes(top)tosimulatethetimethey’dspendundergroundinthewild—thencometwoyearsinasmallenclosure(bottom).
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abookunderhisarmandhesaid,‘Comeon,babies,I’mgoingtoteachyou.’” ApparentlyDiego’stortoiseKamaSutrahadalltherightmoves,becausesooneveryonewasmating.Theresearchcen-terhassincesent1,700tortoisesbacktoEspañola.Diegohimself,nowaboutacenturyold,stillresidesattheresearchcenter.Visitorscanwatchhimrelaxinhisprivatepond. Unfortunately,thestoryofPintatortoisesisnotsohappy.In1971,abotanystudentfoundGeorgeonPinta,wheretor-toiseswerethoughttobeextinct.Georgewasrelocatedtotheresearchcenter.ScientiststriedinvaintointerestGeorgeinsimilartortoisesoftheoppositesex.Oneintrepidscientistevenworkedone-on-onewithGeorgeonaprogramofmanualstimulation,butultimatelyhereffortsborenofruit. DespiteGeorge’sdeath,scientistsstillhaven’tgivenup.HopesnowhingeonidentifyinglivingPintatortoisesinzoosandotherprivatecollectionsaroundtheworldthroughDNAtesting.IfscientistsfindtherightDNA,theymighttrytobringthosetortoisesbacktotheGalápagosandrecoverthePintapopulation. VisitorstoSantaCruzcanseeGeorge’sformerresidenceandaplaquecommemoratinghim.Inthefuture,hisbodymightbemountedanddisplayed.
Visitors to the station also will see Galápagos LandIguanas(Conolophus subcristatus).TheCDRSrescued60sur-vivorsin1976andlaunchedabreedingprogram.Theselargelizardshadbeendecimatedbyintroducedspecies,especiallycatsanddogs.Populationshavebeenreestablishedonseveralislandswheretheiguanashadbeenextirpated.
Wild Tortoise WatchingVisitorscanalso seewild tortoisesonSantaCruz,where3,500individualshavefreerunoftheisland.Yellowtortuga-crossingsignsremindmotoriststoslowdown. Males generally make their homes in the highlands,wherefoodismostabundant,butmuchoftheyearisspentonamatingtrek.Femalespreferlivinginthemangrovesneartheocean.Thelowlands,wherefemaleslive,areonlythreeorfourmilesaway,butmovingatgianttortoisespeed,thejourneytakesthreemonths. OurgroupvisitedPrimiciasRanch.Visitorsmaywalkaroundadmiringandphotographingtortoises, thenrelaxwithabeeratthefarm’sbarandbuyEcuadorianchocolateorabagofGalápagoscoffeebeansinthegiftshop. Gianttortoiseslivemostlyquiet,solitarylivesinthehigh-lands.Despitetheirimpressivesizes—someweighmorethan
Inthe1970s,onlytwomalesandtwelvefemaleswanderedtheislandofEspañola.Diego,repatriatedfromtheSanDiegoZoo,triggeredamatingfrenzy.Theresearchcenterhassincesent1,700tortoisesbacktoEspañola.
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TheCharlesDarwinResearchStationrescued60survivingGalápagosLandIguanas(Conolophus subcristatus)in1976andlaunchedabreedingprogram.
GalápagosLandIguanasweredecimatedbyintroducedspecies,especiallycatsanddogs.ThishandsomemaleispartofthelargecolonyonSouthPlazasIsland.
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PopulationsofGalápagosLandIguanashavebeenreestablishedonseveralislandswheretheiguanashadbeenextirpated.TheseindividualsonNorthSeymourIslandaredescendantsofancestorsrelocatedfromBaltraIslandinthe1930s.
ThetortoisesonSantaCruzhavefreerunoftheislandandareremarkablyunfazedbytouristsgettingcloseforasouvenirportrait.
ThePrimiciasRanchprovidesvisitorswithopportunitiestoadmireandphotographtortoises,thenrelaxwithabeeratthefarm’sbar.
Attheranch’sgiftshop,JamieAbbotttriesonanemptytortoiseshellwhileIvanLopezcheersheron.
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250kg—they’resimpleanimalslackingexternalearsandteeth.Theyeathard-to-digestgrass,whichquicklycomesouttheotherend,onlypartiallydigestedandstillrecognizablygrassy,andmuchinevidenceonthefarm.Whennoteating,theycoolthemselvesinfreshwaterponds.They’reremarkablyunfazedbytouristsgettingcloseforasouvenirportrait. Wewerefortunatetowitnesstortoisesmating.Aren-egadefemalehadcomeuptothehighlands,andaresidentmalewastakingfulladvantage.Sincethemaleisontopandmuch larger,wecouldn’t see the femaleatall.This slowproductionofthrustsandgruntslastsaboutanhour.Theonlyothernoisegianttortoisesmakeisahissingsoundwhen
surprised,usuallyaccompaniedbyretractingextremities.Asinmanyturtles,themale’splastronisroundedtofacilitatemountingthefemale.Otherwise,hemighttipover. Visitorscouldexamineanemptyshellnearthegiftshop.Severalpetitemembersofourgroupcrawledinsideandtriediton.Theyreportedthatitwasatightsqueezeandrathersmelly. ThegianttortoisesaremuchliketheGalápagosthem-selves.Boththetortoisesandtheislandssitquietlyinplainsightofscientists,revealingtheirmysteriesslowlyandonlytothemostpatientandcommittedpeople.“Weknowlotsaboutgianttortoises,”saidRomero,whohasplumbedislandmyster-iesfornearly40years.“Butwedonotknoweverything.”
If You GoVisitorstotheGalápagoscanbookaland-basedorboat-basedtrip.UnlessyougetasseasickasDarwindid,aboatismoreconvenient.Sincetheshipnavigateswhileyousleep,you’llbeabletogofartherthanonaday-longboattrip.Mealsalsoareprovided.IcanvouchforEcoventura(www.ecoventura.com/home.aspx). IalsoheardgoodthingsaboutNationalGeographicExpeditions. Most people fly into Guayaquil on mainlandEcuador,stayanight,andthenflytotheGalápagos.Thecountry’slargestcity,Guayaquiloftengetsabadrapforbeingdirtyanddangerous.Ispentfivedaysthereandhadagoodtime.IthelpedthatonfourofthosefivedaysIvisitedParqueSeminario,otherwiseknownastheiguanapark.ThisiswhereGreenIguanas(Iguana iguana)liveintrees,comingdownduringthedaytocommunewith
thetownspeople,whoneverseemtotireofphotograph-ingthem,ignoringsignstonotfeedthem,andsneakinguponthemtogentlypulltheirtails(don’ttrythisintheGalápagosoryou’llbedeported).IfyouvisittheiguanaparkandtheGalápagos,you’llget tosee threekindsofiguanas:Marine(Amblyrhynchus cristatus)andLandIguanas,whichareendemictotheislands,andGreenIguanasonthemainland.Ah,aniguananirvanaforliz-ardlovers. InGuayaquil,IstayedafewnightsinaboutiquehotelcalledElManso(http://manso.ec/en/)andtwonights at theOroVerde (www.oroverdehotels.com).Bothwereclean,safe,andstaffedwithfriendlypeople.ElMansohashostelbedsaswellasprivaterooms,andwillappealtobudgettravelersandthosewholiketointeractmorewithlocalsandotherguests.BusinesstravelerswillfeelmoreathomeattheOroVerde.Bothhaveon-siterestaurants.
The Green Iguanas (Iguana iguana) of Parque Seminario inGuayaquil(commonlycalledthe“iguanapark”)liveintrees,comingdownduringthedaytocommunewiththetownspeople,whoneverseemtotireofphotographingthem,ignoringsignstonotfeedthem,andsneakinguponthemtogentlypulltheirtails.
Sharingapopsicleatthe“iguanapark”inGuayaquil.