TABLE OF CONTENTS IRCF REPTILES & AMPHIBIANS • 19(4):271 ...
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IRCF REPTILES & AMPHIBIANS • 19(1):64–66 • MARCH 2012 INTRODUCED SPECIES IRCF REPTILES & AMPHIBIANS CONSERVATION AND NATURAL HISTORY WWW.IRCF.ORG/REPTILESANDAMPHIBIANSJOURNAL 64 B urmese Pythons (Python molurus bivittatus or P. bivitta- tus) have been reported to consume 25 species of adult birds in Everglades National Park, Florida (Dove et al. 2011), but until now no records documented this species eating bird eggs. Here we report three recent cases of bird-egg consump- tion by Burmese Pythons and discuss egg-eating in basal snakes. On 8 January 2011, an adult (2.78 m snout-vent length [SVL], 3.14 m total length [TL], 13.9 kg) female Burmese Python was captured on a canal bank (L-29) adjacent to U.S. Highway 41, near Everglades National Park, Miami-Dade County, Florida (25.76200°N, 80.78211°W; WGS84). The lower GI tract included a small amount of decomposed feath- ers, small heavily digested bones, and the crushed, but intact, remains of two bird eggs. These egg remains were deposited (EVER 44949) in the South Florida Collections Management Center, Everglades National Park, Homestead, Florida. Many small pieces of eggshell fragments were attached to the white egg membranes (Fig. 1) making species identification pos- sible. We used techniques described in Dove et al. (2008) to obtain DNA sequences for cytochrome c oxidase subunit 1 (CO1) from the intact egg membranes. DNA sequences were compared to the Barcode of Life Database (www.boldsystems. org/views/login.php) to obtain 100% matches to Limpkin (Aramus guarauna). The color of the eggshell fragments con- sisted of grayish white ground color with faint pinkish-brown, buff splotches on the outside, and the inner shell was white (not blue as in other bird species), which is congruent with an account for this species (Bryan 2002). Following DNA iden- tification, the eggshell fragments were compared to reference specimens of Limpkin eggs at the Smithsonian Institution for verification. Pigmentation of the eggshells is evidence that the eggs were laid and not part of a consumed adult bird. Pigmentation is secreted in the uterus of most birds just prior to laying and is the final step in egg production (Proctor and Lynch 1993). We did not find associated with this sample any evidence of embryos or black downy feathers typical of Limpkin chicks. On the morning of 21 May 2011, the Miami-Dade Fire Rescue Venom Response Unit responded to a rural resi- dence in southwestern Miami-Dade County (25.54646°N, 80.54573°W; WGS84) following a report that a python was seen near the nest of a free-ranging Guineafowl (Numida Consumption of Bird Eggs by Invasive Burmese Pythons in Florida Carla J. Dove 1 , Robert N. Reed 2 , and Ray W. Snow 3 1 Smithsonian Institution, Division of Birds, NHB E-600, MRC 116, Washington, District of Columbia 20560, USA ([email protected]) 2 U.S. Geological Survey, Fort Collins Science Center, 2150 Centre Ave, Bldg C, Fort Collins, Colorado 80526, USA ([email protected]) 3 National Park Service, Everglades National Park, 40001 State Road 9336, Homestead, Florida 33034, USA ([email protected]) Fig. 1. Two Limpkin (Aramus guarauna) crushed but intact eggs (top; EVER 44949) recovered from a Burmese Python digestive tract and com- pared to a reference Limpkin specimen (below; USNM 25786) for size and color patterns. The arrow shows fragments of eggshells from the python sample placed on the museum specimen for color comparison. Photograph by Don Hurlbert, Smithsonian Institution.
Transcript of 64 - International Reptile Conservation Foundation (IRCF)€¦ · INTRODUCED SPECIES IRCF REPTILES...
IRCFREPTILES&HIBIANS•19(1):64–66•MARCH2012
I N T R O D U C E D S P E C I E S
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
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BurmesePythons(Python molurus bivittatus orP. bivitta-tus)havebeenreportedtoconsume25speciesofadult
birdsinEvergladesNationalPark,Florida(Doveetal.2011),butuntilnownorecordsdocumentedthisspecieseatingbirdeggs.Herewereportthreerecentcasesofbird-eggconsump-tionbyBurmesePythonsanddiscussegg-eating inbasalsnakes. On8January2011,anadult(2.78msnout-ventlength[SVL],3.14mtotallength[TL],13.9kg)femaleBurmesePythonwascapturedonacanalbank(L-29)adjacenttoU.S.Highway41,nearEvergladesNationalPark,Miami-DadeCounty,Florida(25.76200°N,80.78211°W;WGS84).ThelowerGItractincludedasmallamountofdecomposedfeath-ers,smallheavilydigestedbones,andthecrushed,butintact,remainsoftwobirdeggs.Theseeggremainsweredeposited(EVER44949)intheSouthFloridaCollectionsManagementCenter,EvergladesNationalPark,Homestead,Florida.Manysmallpiecesofeggshellfragmentswereattachedtothewhiteeggmembranes(Fig.1)makingspeciesidentificationpos-sible.WeusedtechniquesdescribedinDoveetal.(2008)toobtainDNAsequencesforcytochromecoxidasesubunit1(CO1)fromtheintacteggmembranes.DNAsequenceswerecomparedtotheBarcodeofLifeDatabase(www.boldsystems.org/views/login.php)toobtain100%matchestoLimpkin(Aramus guarauna).Thecoloroftheeggshellfragmentscon-sistedofgrayishwhitegroundcolorwithfaintpinkish-brown,buffsplotchesontheoutside,andtheinnershellwaswhite(notblueasinotherbirdspecies),whichiscongruentwithanaccountforthisspecies(Bryan2002).FollowingDNAiden-tification,theeggshellfragmentswerecomparedtoreferencespecimensofLimpkineggsattheSmithsonianInstitutionforverification.Pigmentationoftheeggshellsisevidencethattheeggswerelaidandnotpartofaconsumedadultbird.Pigmentationissecretedintheuterusofmostbirdsjustpriortolayingandisthefinalstepineggproduction(Proctorand
Lynch1993).WedidnotfindassociatedwiththissampleanyevidenceofembryosorblackdownyfeatherstypicalofLimpkinchicks. On themorningof21May2011, theMiami-DadeFireRescueVenomResponseUnitrespondedtoaruralresi-denceinsouthwesternMiami-DadeCounty(25.54646°N,80.54573°W;WGS84)followingareportthatapythonwasseennearthenestofafree-rangingGuineafowl(Numida
Consumption of Bird Eggs by Invasive Burmese Pythons in Florida
CarlaJ.Dove1,RobertN.Reed2,andRayW.Snow3
1SmithsonianInstitution,DivisionofBirds,NHBE-600,MRC116,Washington,DistrictofColumbia20560,USA([email protected])2U.S.GeologicalSurvey,FortCollinsScienceCenter,2150CentreAve,BldgC,FortCollins,Colorado80526,USA([email protected])
3NationalParkService,EvergladesNationalPark,40001StateRoad9336,Homestead,Florida33034,USA([email protected])
Fig. 1.TwoLimpkin(Aramus guarauna)crushedbutintacteggs(top;EVER44949)recoveredfromaBurmesePythondigestivetractandcom-paredtoareferenceLimpkinspecimen(below;USNM25786)forsizeandcolorpatterns.Thearrowshowsfragmentsofeggshellsfromthepythonsampleplacedonthemuseumspecimenforcolorcomparison.PhotographbyDonHurlbert,SmithsonianInstitution.
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meleagris domesticus)with10eggsthathadrecentlydisap-peared.TheVenomUnitcapturedanadult(2.27mSVL,2.61mTL,6.73kg)maleBurmesePythonattheresidenceat11:00AMthesameday.Duringtransport,thesnakeregur-gitatedaGuineafowlhen(928g)and10intacteggs(fiveofthesearedepictedinFig.2).ThelandownerclaimedthatthiswasthesecondtimeshehadnotedthedisappearanceofaGuineafowlanditseggs,butshehadnotpreviouslyobservedasnake.Thepythonisnowcatalogued(USNM558849)intheherpetologicalcollectionsattheSmithsonianInstitution.TheregurgitatedGuineafowleggsmeasured45.6–49.0x35.3–37.8mmandweighed30–36g,suchthateacheggrepresentedapproximately0.5%ofthepython’sbodymass.Limpkineggsaverage55–64x41–47mm(Walters1994).Theserepresentexceptionallysmallindividualpreyitemsforsnakesofthissize. Inadditiontothetwoexamplesdescribedabove,birdeggfragmentswerefoundintheintestineofathirdBurmesePythonfromU.S.Highway41nearEvergladesNationalPark,butevidencewasinsufficienttoidentifythespeciesofbird. Durophagy(consumptionofhard-shelledobjects)isrela-tivelyuncommonamongsnakes(Savitsky1983).Specializedegg-eaters(e.g.,Dasypeltis)exhibitasuiteofmorphologicalandbehavioraltraitsallowingthemtoingesteggsthatareverylargeinrelationtothesizeofthesnake’shead(Gans1952,GartnerandGreene2008),butfewsnakesaresohighlyspe-cialized.CundallandGreene(2000:326)statedthatonlytheColubroideahavemorphologicalspecializationsforhandling
preyitemsthataredifficulttohandle(suchasverylargeeggs),andthatsuchprey“arecorrespondinglyrareorabsentfromthedietsofmorebasalsnakes.”Manycolubroidsnakesthatocca-sionallyconsumerelatively(tothesnake’shead)largebirdeggsexhibitpointedorbladelikehypapophyses(ventralprocesses)onanteriorvertebraethatservetobreaktheeggshellintheesophagus(Mullin1996),andthepresenceofhypapophyseshasbeendescribedasa“criticallimitingfactor”inconsumptionoflargebirdeggsbysnakes(CundallandGreene2000:320). BurmesePythonsexhibithypopophysesoncervicalverte-brae(Fig.3),buttheselackthesharpprojectionsorbladelikeventralsurfaces(cf.ratsnakes;Mullin1996)usuallyassociatedwithspecialistegg-eaters.Thehypapophysesareprominentinanteriorvertebrae(toapproximatelyvertebrum#48,atabouttheleveloftheheart),afterwhichtheyundergorapidreductioninsize.Theyendassmallventralridgesonvertebralcentrabyapproximatelyvertebrum#58,wellbeforethestomach(per-sonalobservation,basedonvertebraefromamaleTL265cmandSVL232.5cm[EVER66690]capturedintheEverglades).TheGuineafowleggsconsumedbythepythonwereentireatthetimeofregurgitation,suggestingthateitherthehypa-pophysesarenotusedtocrusheggsorthattheseeggsweretoosmalltobeengagedbythehypapophyses.Giventheabilityofpythonstodigestevenlargebones,wedoubtthataninabilitytophysicallybreakaneggshellduringingestionwouldimpedeapython’sabilitytoaccesstheegg’scontentsduringdigestion. Our observations of egg eating in Burmese Pythonsarenotuniqueamonglarge-bodiedbasalsnakes,asYellow
Fig. 2.FiveoftenentireGuineafowl(Numida meleagris domesticus)eggsregurgitatedbyaBurmesePython.PhotographbyR.W.Snow,EvergladesNationalPark.
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Anacondas(Eunectes notaeus)inSouthAmericaconsumebirdeggs(StrüssmannandSazima1991;T.Waller,pers.comm.,June2011).Interestingly,weareunawareofanyreportsofconsumptionofavianeggsamongGreenAnacondas(E. muri-nus),BoaConstrictors(Boa constrictor),ReticulatedPythons(Broghammerus reticulatus),orthelargeAfricanpythons(P. natalensisandP. sebae;ReedandRodda2009;T.Waller,J.Rivas,R.W.Henderson,pers.comms.,June2011). SeveralspeciesofcolubroidsnakesnativetoFloridaareknowntoconsumebirdeggs(ErnstandErnst2003).OurobservationsconfirmthatinvasiveBurmesePythonsconsumenotonlyadultbirdsbutalsoeggs,suggestingapreviouslyunrecognizedriskfromthisintroducedpredatortonestingbirds.Howfrequentlysuchpredationmightoccurorwhetheritrepresentsaconsiderableincreaseinthebaselinerateofpredationonbirdeggsbynativesnakesisdifficulttoassess,althoughpythonswouldbecapableofeatingeggstoolargeforconsumptionbymostnativesnakes.Overall,theimpactsofinvasivepythonpredationonnativebirdpreypopulationsremainpoorlyunderstood.
AcknowledgmentsThisworkwas fundedbyEvergladesNationalPark.WethankA.Flanagan,J.Ketterlin,J.Fobb,E.Santiago,andM.Rochfordforassistanceinthefieldandlab.F.Dahlan(SmithsonianInstitution,FeatherIdentificationLab)pro-cessedDNAsamples.C.Ernst,H.W.Greene,C.Milensky,andG.H.Roddaprovidedcommentsonpreviousversionsofthemanuscript.AllresearchmetanimalcareguidelinesofEvergladesNationalPark.Anyuseoftrade,product,orfirmnamesisfordescriptivepurposesonlyanddoesnotimplyendorsementbytheU.S.Government.PhotographswereprovidedbyDonHurlbert(SmithsonianInstitution)andR.W.Snow(EvergladesNationalPark).
Literature CitedBryan,D.C.2002.Limpkin(Aramus guarauna),No.627.In:A.PooleandF.Gill
(eds.),The Birds of North America Online.TheBirdsofNorthAmerica,Inc.,Philadelphia,Pennsylvania.
Cundall, D. and H.W. Greene 2000. Feeding in snakes, pp. 293–33 In: K.Schwenk(ed.),Feeding.AcademicPress,SanDiego,California.
Dove,C.J.,N.C.Rotzel,M.Heacker,andL.Weigt.2008.UsingDNAbarcodesto identifybirds involved inbirdstrikes.Journal of Wildlife Management72:1231–1236.
Dove,C.J.,R.W.Snow,M.R.Rochford,andF.J.Mazzotti.2011.Birdsconsumedby the invasiveBurmesePythonPython molurus bivittatus inEvergladesNationalPark,Florida,USA.Wilson Journal of Ornithology123:126–131.
Ernst C.H. and E.M. Ernst. 2003. Snakes of the United States and Canada.SmithsonianBooks,Washington,D.C.
Gans,C.1952.Thefunctionalmorphologyoftheegg-eatingadaptationsofthesnakegenusDasypeltis.Zoologica37:209–244.
Gartner,G.E.A.andH.W.Greene 2008.AdaptationintheAfricanEgg-eatingSnake:Acomparativeapproachtoaclassicstudyinevolutionaryfunctionalmorphology.Journal of Zoology (London)275:368–374.
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Proctor,N.S.andP.J.Lynch.1993.Manual of Ornithology.YaleUniversityPress,Princeton,NewJersey.
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Savitzky,A.H.1983.Coadapted character complexes in snakes: Fossoriality,piscivory,anddurophagy.American Zoologist23:397–409.
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Fig. 3.AnteriorvertebraefromaBurmesePython(Python molurus bivit-tatus orP. bivittatus)(267cmSVL;EVER66690),showinghypapophy-sesbelowthecentrumofeachvertebrum.PhotographbyR.W.Snow,EvergladesNationalPark.
