TABLE OF CONTENTS IRCF REPTILES & AMPHIBIANS • … · 2015-03-17 · IRCF REPTILES & AMPHIBIANS...
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IRCF REPTILES & AMPHIBIANS • 20(1):20–22 • MAR 2013 Here I document copulation of Cottonmouths (Agkistrodon piscivorus) observed at approximately 1630 h on 27 August 2012 in a small inlet of Blue Creek, Covington County, Alabama (31.14449N, 86.67554W). The pair was discovered while conducting surveys of the surrounding seep- age habitat. The snakes were discovered in copula (hemipene intro- mission was confirmed), facing opposite directions (Fig. 1). They remained motionless in this position for 15 min until, in an attempt to obtain a closer vantage point, I disturbed them. On my approach, the female became agitated and pro- ceeded to drag the male away from my position. At first, she attempted to drag her partner to higher ground, but being sig- nificantly smaller, the attempt was unsuccessful. After several minutes, while the male remained passive, the female dragged the male roughly 2 m through the water and onto the oppo- site bank (Fig. 2). The female then climbed on top of the male, while both snakes were still partly submerged (Fig. 3). C urrent information regarding the timing of mating in wild snakes is almost wholly reliant on the anecdotal evidence of chance encounters (Aldridge and Duvall 2002). Also, implicit correlates of mating, such as male-male com- bat, often are used to determine mating seasons of viperids, largely because encounters with copulating pairs occur so infrequently (Wharton 1966, Graham et al. 2008, Siegel et al. 2009). Recently, analyses using hormonal and histologi- cal correlates of reproductive cycles have been employed in attempts to estimate mating periods (Graham et al. 2008). However, as Graham et al. (2008) noted, these factors can be inconsistent across snake species and, hence, direct evidence from witnessed copulation events remains a valuable foun- dation from which to draw reliable conclusions about mat- ing seasons. Therefore, additional reports of mating events in snakes, including those species for which information is already available, will enhance our understanding of mating in those species. A Chance Encounter with Copulating Cottonmouths ( Agkistrodon piscivorus) George C. Brooks Department of Animal and Plant Sciences, University of Sheffield, South Yorkshire, S10 2TN, UK ([email protected]) Photographs by the author. 20 IRCF REPTILES & AMPHIBIANS CONSERVATION AND NATURAL HISTORY Copyright © 2013. George C. Brooks. All rights reserved. WWW.IRCF.ORG/REPTILESANDAMPHIBIANSJOURNAL Fig. 1. The original position of two copulating Cottonmouths (Agkistrodon piscivorus) in Covington County, Alabama on 27 August 2012 at approxi- mately 1630 h. Fig. 2. The female attempts to drag the male out of the water on the opposite bank.
Transcript of TABLE OF CONTENTS IRCF REPTILES & AMPHIBIANS • … · 2015-03-17 · IRCF REPTILES & AMPHIBIANS...
IRCFREPTILES&HIBIANS•20(1):20–22•MAR2013
Here I document copulation of Cottonmouths(Agkistrodon piscivorus)observedatapproximately1630hon27August2012inasmallinletofBlueCreek,CovingtonCounty,Alabama(31.14449N,86.67554W).Thepairwasdiscoveredwhileconductingsurveysofthesurroundingseep-agehabitat. Thesnakeswerediscoveredincopula(hemipeneintro-missionwasconfirmed),facingoppositedirections(Fig.1).Theyremainedmotionlessinthispositionfor15minuntil,inanattempttoobtainacloservantagepoint,Idisturbedthem.Onmyapproach,thefemalebecameagitatedandpro-ceededtodragthemaleawayfrommyposition.Atfirst,sheattemptedtodragherpartnertohigherground,butbeingsig-nificantlysmaller,theattemptwasunsuccessful.Afterseveralminutes,whilethemaleremainedpassive,thefemaledraggedthemaleroughly2mthroughthewaterandontotheoppo-sitebank(Fig.2).Thefemalethenclimbedontopofthemale,whilebothsnakeswerestillpartlysubmerged(Fig.3).
Currentinformationregardingthetimingofmatinginwildsnakesisalmostwhollyreliantontheanecdotal
evidenceofchanceencounters(AldridgeandDuvall2002).Also,implicitcorrelatesofmating,suchasmale-malecom-bat,oftenareusedtodeterminematingseasonsofviperids,largelybecauseencounterswithcopulatingpairsoccursoinfrequently(Wharton1966,Grahametal.2008,Siegeletal.2009).Recently,analysesusinghormonalandhistologi-calcorrelatesofreproductivecycleshavebeenemployedinattemptstoestimatematingperiods(Grahametal.2008).However,asGrahametal.(2008)noted,thesefactorscanbeinconsistentacrosssnakespeciesand,hence,directevidencefromwitnessedcopulationeventsremainsavaluablefoun-dationfromwhichtodrawreliableconclusionsaboutmat-ingseasons.Therefore,additionalreportsofmatingeventsinsnakes,includingthosespeciesforwhichinformationisalreadyavailable,willenhanceourunderstandingofmatinginthosespecies.
A Chance Encounter with Copulating Cottonmouths (Agkistrodon piscivorus)
GeorgeC.Brooks
DepartmentofAnimalandPlantSciences,UniversityofSheffield,SouthYorkshire,S102TN,UK([email protected])
Photographsbytheauthor.
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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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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
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Fig. 1.TheoriginalpositionoftwocopulatingCottonmouths(Agkistrodon piscivorus)inCovingtonCounty,Alabamaon27August2012atapproxi-mately1630h.
Fig. 2.Thefemaleattemptstodragthemaleoutofthewaterontheoppositebank.
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IRCFREPTILES&HIBIANS•20(1):20–22•MAR2013
Duringthisentireperiod,thepairremainedlockedviathemale’shemipene(Fig4). Thefemalewasidentifiedbyitssmallsizeincomparisontoitspartnerandclosescrutinyofthepositionofthemale’shemipene.Male-biasedsexualsize-dimorphismhaspreviouslybeendocumentedinA. piscivorus(HillandBeaupre2008).Inaddition,thefemalewasintheprocessofecdysis(Fig5).Thepresenceofsloughononeindividualisconsistentwithpreviousobservationsofpitvipers;femalessheddingpriortomatingmightindicateafunctionallinkbetweenthesetwoprocesses(Kubieetal.1978,Ashton2003). Interestingly,Fitch(1975)notedasimilarcopulationencounterinDiadophis punctatus,inwhichonlythefemalebecameagitatedwhendisturbed,resortingtodragginghermalepartnerinanattempttoescape.Fitch(1975)offerednoexplanation for thisbehavioralpeculiarity,andtomyknowledge,nootherstudyhasmentionedsimilarpassive-nessincopulatingmalesnakes.Unfortunately,thepaucityofinformationregardingreproductiveandbehavioralecologyinsnakespreventsanassessmentofwhethertheseobservationsrepresentanythingmorethancoincidence. Clearlymoreworkisneededtoobtainabetterunder-standingofmatingbehavior in snakes,beginningwithamorepreciseestimateofwhenmatingoccurs.Histologicalandobservational evidenceprovidedbySiegel andSever(2007)suggestedthatA. piscivorusdisplaysbiennialbreeding,withmatingseasonsinthespringaswellasinlatesummer/earlyautumn.ThisobservationjoinsseveralothersthathavereportedmatingA. piscivorusinlatesummer/earlyautumn(summarizedinGrahametal.2008),whichcorrespondswiththepeakoftestosteroneproduction,aswellasspermatogen-esisandtheenlargementoftherenalsexsegment (Johnsonetal.1982,Zaidanetal.2003,Grahametal.2008).
AcknowledgementsFundingforthisresearchwasprovidedbyIOS-1051367toT.Langkilde.SpecialthanksgotoSeanGrahamforhisconstructivecommentsonanearlierdraftthatgreatlyimprovedthemanuscript.
Literature CitedAldridge,R.D.andD.Duvall.2002.Theevolutionofthematingseasoninthe
pitvipersofNorthAmerica.Herpetological Monographs16:1–25.
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Fig. 3.Thefemaleclimbsontopofthemalewhilebothsnakesarestillpartlysubmerged.
Fig. 4.Themalehemipene;thetwosnakesremainedlockedforthedura-tionoftheobservation(~40min).
Fig. 5.Remnantsofecdysisarestillvisiblenearthetailofthefemaleobscuringthehemipene.
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Kubie,J.L.,J.Cohen,andM.Halpern.1978.Sheddingenhancesthesexualattrac-tivenessofoestradioltreatedgartersnakesandtheiruntreatedpenmates.Animal Behaviour26:562–570.
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