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210 IRCF REPTILES & AMPHIBIANS • VOL 16, NO 4 • DEC 2009 Increasing development in northeastern Kansas poses a distinct threat to Timber Rattlesnakes (Crotalus horridus) along much of the western limits of the species’ distribution. SUZANNE L. COLLINS, CNAH WALKER, DORR, BENJAMIN, AND PISANI

210 IRCF ReptIles & AmphIbIAns - University of …people.ku.edu/~gpisani/Walker-etal-TRs12-09.pdf210 IRCF ReptIles & AmphIbIAns • Vol 16, no 4 • DeC 2009 Increasing development

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Page 1: 210 IRCF ReptIles & AmphIbIAns - University of …people.ku.edu/~gpisani/Walker-etal-TRs12-09.pdf210 IRCF ReptIles & AmphIbIAns • Vol 16, no 4 • DeC 2009 Increasing development

210 IRCFReptIles&AmphIbIAns•Vol16,no4•DeC2009

IncreasingdevelopmentinnortheasternKansasposesadistinctthreattotimberRattlesnakes(Crotalus horridus)alongmuchofthewesternlimitsofthespecies’distribution.

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IRCFReptIles&AmphIbIAns•Vol16,no4•DeC2009 211

successful Relocation of a Threatened suburban Population of Timber Rattlesnakes

(Crotalus horridus): combining snake ecology, Politics, and education

mindyl.Walker1*,JenniferA.Dorr2,RebeccaJ.benjamin1,andGeorgeR.pisani3

1Departmentofbiology,RockhurstUniversity,KansasCity,mo64110([email protected])2lenexaAnimalControloffice,lenexa,Ks66215

3KansasbiologicalsurveyandecologicalReserves(Kbs/KsR),lawrence,Ks66044

ReloCAtIonoFtImbeRRAttlesnAKes

C rotalus horridushasageographicrangecoveringsomewhatmorethantheeasternthirdofthecontinentalUnitedstates

(brown1992,1993;martin1992;pisanietal.1972),withinwhichitsdistributionispatchy(Clarketal.2007).thisexten-siveareaincludesdiverseclimaticextremestowhichthespecieshasadaptedsuccessfully(brown1993;martin1992,2002;Fitchandpisani2004,2006a,2006b).oftheseveralU.s.speciesinthegenusCrotalus,C. horridushasamongthemost,ifnotthemost,interactionswithhumans,primarilybecauseitoccursnearpopula-tioncentersinsomeofthemostdensely-populatedareasofthecountry.thus,inadditiontodepredationbyhumanshuntingthesnakesforbountyorcommercialcollection(brown1993,leClere2005), increasingdevelopmentofruralareashasanimpactonaggregation(denandbirthing)sitesaswellassummerfeeding-breedingranges.thissituationisnot,ofcourse,limitedtoC. hor-ridus(ReinertandRupert1999,ernst2004;seealsotheintroduc-tioninnowaketal.2002)or,infact,eventocrotalids(butleretal.2005a,2005b). Inthelasttwodecades,increasingpubliceducationeffortsbyscientistsconductingresearchonC. horridusandothermem-

bersofthegenus(ernst2004),alongwithanincreasingecologicalawarenessbythegeneralpublic,hasresultedinanattitudeshift(howeverslight)towardincreasingtoleranceofthespecies’frequentoccurrencealongsidehumanactivities(brown1993).nonetheless,increasingdevelopment(especiallyinnortheasternKansas,whichgenerallylacksthephysiographicbarrierstodevelopmentfound

AlargeadultmaletimberRattlesnake(Crotalus horridus).theredpaintonthebasalrattleallowsforindividualrecognitionwithouthandlingtheanimal.

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likeotherspeciesofsnakesinhabitingareasexperiencinghumanencroach-ment,timberRattlesnakescrossingroadsorthermoregulatingonwarmpavementarevulnerabletovehiculartraffic.

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212 IRCFReptIles&AmphIbIAns•Vol16,no4•DeC2009 WAlKeR,DoRR,benJAmIn,AnDpIsAnI

inmanyeasternstates)posesadistinctthreattothisspeciesalongmuchofthewesternlimitsofitsdistribution(Fitch1999,pisaniandFitch2005,edwardsandspiering2005),whichremainslit-tle-knowninthispartofitsrangedespite56yearsofearliersnakeresearchinthearea(Fitch1999).thespeciesisclassedassInC(speciesinneedofConservation)bytheKansasDepartmentofWildlifeandparks;however,thatlisting,usedinotherstatesaswell(e.g.,Adams2005),carriesnolegalprotectionsforthespeciesoritshabitat. timberRattlesnakesarehighlysecretive,which,alongwiththeirwell-knowngenerallyinoffensivedisposition(Ditmars1936,sealy2002)andtherelativeinfrequencyofenvenomationsfromsnakesencounteredinthewild(e.g.,Keyler2005),perhapshascontributedtotheirsuburbansurvival.Wherethesnakesoccurinproximitytohumandevelopment,sightingsoftencausealarmforresidentswhoareconcernedforthesafetyofhumansandpets.often,snakesdiscoveredclosetohumanhabitationeitherarekilledorareremovedbylocalanimalcontrolpersonnel.Inmostinstances,sightingsclosetohumanhabitationinvolvematuremaletimberRattlesnakes,whichhavelargerhomerangesthanfemalesorjuve-niles(sealy2002).Inpart,thiswiderrangingreflectsmatesearch-ing(Clarketal.2007). Unfortunatelybutinevitably,thepoliticsofeducated,peace-fulcoexistencebetweenencroachinghumansandnativepitvipersinvolveaveryfragilebalance.municipalitiesfacingtheveryreal

prospectofexpensivelitigationduetoanenvenomation(irrespec-tiveofwhetherthehumanoritspetwasfundamentallytoblame)occurringinapublicpark,golfcourse,orresidentialneighborhoodmostlikelywillstronglyconsidereradicationofthesnakes.Unlike,forexample,northernnewYork,withlargetractsofstate-ownedlandandsnakedensinsiteswithageologythatwouldprohibitdevelopmentforhumanuse,thisscenarioisespecially likelyinareassuchasJohnsonCounty,Kansas,whereheavypopulation

AtimberRattlesnakeinaresidentialareaneartheoriginaldensite.

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AlthoughtimberRattlensnakesusuallyareconsideredtobeterrestrialspecies,arborealbehaviorisnotuncommon.

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IRCFReptIles&AmphIbIAns•Vol16,no4•DeC2009 213ReloCAtIonoFtImbeRRAttlesnAKes

growthhasextendedcitylimitsintotheeasilydevelopedtimberRattlesnakehabitats.

Background: the lenexa, Kansas Population.—proposedandactualdevelopmentoflandwithintheCityoflenexausedashabi-tatbytimberRattlesnakesprovidedanopportunitytotest theeffectofrelocatinganentirepopulation(oratleastmostofone)toothersuitablehabitatremotefromdevelopment.lenexaAnimalControl(lpD-AC)occasionallyreceivedcomplaintsabouttimberRattlesnakespreviousto2005.however,duringJune2005,onelenexaresidentcontactedlpD-ACseventimestoreportarattle-snakeinhisyard,whichwaspartofanewdevelopmentborderingagolfcourse.Ineachinstance,eitherlpD-ACoralenexapoliceofficerrespondedandremovedthesnake;snakeswererelocatedtoalessresidentialareawithin2kmofwheretheyoriginated.thisresi-dentwasverytolerantofthesnakes,butdidnotwanttheminteract-ingwithhissmalldogs.hisyardwaswellgroomed—freeofdebrisormaturelandscaping.someresidentsoftheadjacentsuburbanareaseemednotoverlyafraidofthesnakes,whichwerenotatallshyabouttraversingmowedgrassyardsinresidentialareas. Construction workers on sites bordering this residenceadmittedtolpD-ACthat theywerekillingadditionaltimberRattlesnakesfoundunderscrapmaterialsontheirjobsites.severalrattlesnakesalsowerefoundinadditionalyardsanddeadonnewlypavedroadsinthearea.lpD-ACcontactedseverallocalresourcesto

learnmoreabouttheoccurrenceoftheserattlesnakesinsuchahighconcentration;theconclusionwasthatthesnakesmostlikelyweremovingtowhatwasoncetheirsummerforaginghabitat(meadow).lpD-ACinitiatedapubliceducationcampaignaboutcoexistingwithrattlesnakes,andhostedaworkshopwithareaauthorities(JosephCollins,Danasavorelli,andRodWittenberg)speakingaboutrattlesnakebehavior,habitat,andtheneedfortoleranceandconservation.WittenbergandsavorellibothassistedlpD-ACinsearchingforlocaldens,butdidnotlocateanylikelysites. In late fall 2006, Dorr was informed by a lenexa Cityemployeeofadenwith“hundredsofrattlesnakes.”Whenaskedforfurtherinformation,Dorrwasreferredtoanotheremployee,mikeshipman,whohadlocatedtheden.shipman,acityinspec-tor,advisedthathefrequentlyobservedseveralrattlesnakes(amorerealisticnumber)inaspecificareainearlyfall2006.InFebruary2007,DorrandRodWittenberg(UniversityofArkansas)evalu-atedtheareashipmanidentifiedasasnakeden.Althoughtheareawasfrozen,theydeterminedthatitseemedtobealikelylocationforapotentiallylargepopulationoftimberRattlesnakes.Dorrwasadvisedofpendingdevelopmentoftheareaforalargeretailcenterandwasaskedwhether“itwouldbebettertobulldozethesnakeswhiletheyweresleepingortrytodestroythemaftertheycameoutoftheirden.”neitherwasaparticularlytastefulorethicaloptionforAlargemalefoundbeneathadownedroadsignattheoriginaldensite.

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maleandfemaletimberRattlesnakescourtinginasuburbanbackyardinlenexa,KansasinJuly2009.notethelandscapingfabric,whichinsomeinstancescanhaveadverseeffectsonentangledsnakes.thesephotographsweretakenbythehomeowner.

table 1. publiclandownershipbystate(fromnRCm1999).

State % of State’s total Area State Rank

newYork 36.97 10

pennsylvania 14.74 20

Arkansas 11.85 22

WestVirginia 9.92 24

missouri 6.02 33

massachusetts 5.54 35

Iowa 1.04 49

Kansas 0.92 50

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DorrorWittenberg,whoweretoldthatworkwastobeginonthesiteinmarch2007. Dorr contacted the Kansas Department of Wildlife andparks(KDWp)toinformthemoftheplanneddevelopmentinanattempttostopordelaytheconstruction.KDWprespondedinlateFebruary2007andbroughtpisaniintoassessthesituation.pisaniindependentlyhadinvestigatedrattlesnakereportsfromaresidentnorthofthenewlyimpoundedlakelenexaandanadja-centrecreationareathatseemedtopisaninottohaveageologythatwouldprovidesuitablehibernationsites.WiththenewinformationfromDorrandWittenberg,adecisionwasmadetocaptureasmanysnakesaspossibleatemergenceandtomovethemtoanewloca-tiontotestanewmodelforconservationrelocation.emergenceofthispopulationwasexpectedinAprilandmay(Wittenberg,pisani,unpublisheddata).pisanidraftedafundingproposal;DorrandWittenbergmetwiththeprivatelandownertoaskforpermissiontoremovethesnakes.thelandownerwastolerantofthesnakesandexpressedinterestinthestudy.hegrantedpermissionforsnakestoberemovedfromhislandandagreedtodelayconstructiononthisportionofthesiteforaslongaspossible. thethreateneddensitewaslocatedin~2haofroadrubbledumpedintoanortheast-facingcreekvalleyduringreconstruc-tionofanadjacentKansasstatehighwaybetween1980and1984.therubblewascappedwith~1mofdirtfill.theperipheryof

therubbledumpconsistedoflargelyexposedconcreteslabsandculverts;thesoil-coveredsurfacealsocontainedconcreteculvertendsandassortededgesofconcreteslabs.Depthoftherubblewas~1.5–3.0m,andtheflatsurfaceofthedumpwasvegetatedbygrassesandforbstypicalofhighlydisturbedroadsideareas.lackinganyoverstory,thesurfacereceivedfullinsolation.WhilewedonotknowwhenthepopulationofC. horridusinitiallycolonizedthesite,thepopulationage-sizestructuresuggestedatimeperiodofatleast10–15years,probablylonger,basedonacomparisonofthispopulationstructuretothatofadenbeingmonitoredbyhenryFitchandpisanisince2003(pisani,unpublisheddata).Fitch(pers.comm.)notedthatthedenhadbeenlargelyextirpatedbyconstruc-tionactivityintheearly1990s,butcontinuingstudiesindicatedarecoveredpopulationof~60timberRattlesnakes. InadditiontoemergingC. horridus,collectorsalsoencoun-teredover90individualsofotherreptiles(Elaphe obsoleta, Terrapene ornata, Lampropeltis triangulum, Agkistrodon contortrix, Diadophis punctatus, Coluber constrictor)usingtheden.thiswasfurthersug-gestiveofawell-establishedcommunity.

Background: the Arguments For and Against Moving “Nuisance” [venomous] Snakes.—thedebateovertheefficacyofmoving“nuisance”snakes(almostuniformlyvenomousspecies),inadditiontootherherpetofauna,asaconservationmeasurehasgone

AlargemaletimberRattlesnakecoiledattheoriginaldensite.

geo

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originalhibernaculumaftersomedevelopmentinsummer2007.

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Aportionoftheoriginalhibernaculum,anextensivesystemofroadrubble,priortodevelopment.

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table 2. size, mass, and survival of transmittered timberRattlesnakesinspring2007.*=gravid.p=predation,e=exposureaftersuccessfulhibernationandemergence.

sex mass(g) sVl(cm) tl(cm) survival

F 519 92.0 6.4 Y

M 450 91.4 7.6 n(p)

F* 490 74.3 4.5 n(e)

M 1,248 116.0 9.0 Y

F* 409 75.3 4.4 Y

M 459 92.5 7.8 Y

F 327 74.0 5.8 Y

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IRCFReptIles&AmphIbIAns•Vol16,no4•DeC2009 215ReloCAtIonoFtImbeRRAttlesnAKes

onovermanyyears,andnodoubtwillcontinue.opinionshaverangedfromdecidedlynegative(Doddandseigel1991,Reinert1991,ReinertandRupert1999)toguardedoptimism(burke1991,sealy2002,ernst2004,butleretal.2005a).Insomeinstances,relocationeffortssomewhatmagnifiedtheinitialproblem(butleretal.2005b).Doddandseigel(1991)madethewell-takenpointthat“...theburdenofproofisontheinvestigatortoshowthataself-sus-tainingpopulation[hasbeenestablished]beforedeclaringsuccess.”thiscanbedifficulttoevaluateifsnakesaresimplyrelocatedintoanotherpopulation.Additionally,asmorethanafewthreatenedherpetofaunalpopulationsareofspecieswithlengthylifespansandprolongedreproductivecycles,well-plannedrelocationeffortsoftenmightbebaseduponlessthanunequivocalindicationsofsuccess. overthetimelineofthedebate,muchhasbeenlearnedaboutthebehavioralcharacteristicsofsnakesingeneral,includingacon-siderablebodyofliteratureoncrotalidsocialbehavior(e.g.,Cobbetal.2005,Clarketal.2007,Clark2004,AldridgeandDuvall2002,Weldonetal.2002).Additionally,thevariousargumentsagainstthepracticeofrelocation(byanyofitssynonymsinthecitationsabove)sometimeshavebeenbroadwithrespecttotaxa,andhaveincludedtaxawithwidelydisparatedispersalpotentials(e.g.,burke1991). theconcernsadvancedinthereferencescitedabove,aswellasothers,haveelucidatedsomebasicconcernsthatconservationistsinterestedinsucheffortsmustconsider.theseare:(1)Relocationsideallyshouldnotbemadeintoanextantpopulationwithanestab-lishedsocialorder;(2)Asacorollary,relocationsofindividualsofasocialspeciesshouldbeimplementedinawaythatdoesnotforcetherelocatedanimalstosurvivethestressesthatmaybeattendanttofittingintoanestablishedsocialstructure;(3)Investigatorsshouldnotrelocateindividualsorpopulationsofvagilespecies(i.e.,fishtoadifferentdrainage,birds,insects,etc.)inawaylikelytocontaminatethegeneticmakeupofotherpopulations;(4)Investigatorsshouldascertainthesuitabilityofhabitatstotheirspecies-of-questionpriortotherelocation. Inallinstanceswehavefoundandcitedvariouslyinthisintro-duction,severalunderlyingsimilarities,whichinlightoftheabove-mentionedgainsinknowledgeofsnakebiology,seemtohavecon-tributedtotheresultsreportedbyothers.theseare:(1) nuisancesnakeswerecollectedatvaryingtimesoftheyear

(andpublishedreportssometimeshaveencompassedsnakesrelocatedatdifferenttimesthroughseveralyearsofastudy)basedupontheiroccurrenceinhumanhabitatswheretheycausedalarm;

(2) snakesgenerallywerecollected/movedsinglywithoutregardtonaturallyoccurringfamilygroups;

(3) snakesweresometimestransportedmanykmfromtheirsitesofcapture(8–172kminReinertandRupert1999);

(4) snakeswererelocatedintoestablishedconspecificpopulations(andthussocialstructures);

(5) Releasemicro-sitesatthenewlocationwerenotchosenwithregardtoforagingorhibernationhabitatsthesnakeswouldneedforsurvival;

(6) snakeswerenotnecessarilyhandledinwaysthatminimizedstresspriortorelocation.

severalpublishedreportsamongthosewecitedaboveindicatedthatdistantrelocationofindividualsnakesusuallyresultsinthedeathoftheanimal,eitherbyfailuretolocateshelterfrompreda-

torsinthenewareaorafailureinfalltolocatesuitablehibernationsites.Wedonotfindthissurprisinggiventhecurrentknowledgeofcrotalidsociality.snakestakenfromvariedfamilygroupsattimeswellafteregressanddepositedintoaresidentpopulationthathasitsownestablishedsocialorderprobablywouldbesubjecttocon-siderableexpendituresofenergydevotedtoresource-orientation,and also substantive exposure topredation through increasedmovement.particularlyinstructiveisthenotationbyReinertandRupert(1999),whoindicatedthatbyseptember1991(thesec-ondseasonoftheirstudy),sometranslocatedsnakeswereobservedtohaveformedassociativerelationshipswitheachotherandwithresidents. predationlossesalonemaynotalwaysbeagoodindicatorofrelocationfailure.so,whileincreasedmovementsurelydoesfac-torintosnakevulnerability,Fitchandpisani(2004,2005)expe-riencedcloseto50%predationlossoftransmitter-bearingtimberRattlesnakes in a resident population, most probably (pisani,unpublisheddata) fromavianpredators (Red-tailedhawksorunknownspeciesofowls).suchhighlossesinareaswithhighpopu-lationsofrelativelylargeraptors(orparticularlyadeptones—Fitchandpisani2005;ernst2008,pers.comm.)maynotbeunusual.becauserelocationeffortsoflessthan20kmmaywellmeanthattherelocationsitestillisveryvulnerabletohumanincursion,weques-tiontheweightingofallanthropogenicmortalitycausesequally,orequaltolossesfromnaturalpredation.so,forexample,exten-sivedailymovementsofadisorientedrelocatedtimberRattlesnakemayresultinitsabandoningspecies-typicalroad-avoidancebehav-ior(AndrewsandGibbons2005),anditsdeathasaroadkillcanbeattributedtothatbehavior.however,ifhumansawareofthechanceoffindingsnakesatarelocationsitedosoandkilloneormoreofthesnakes,weviewthatasunfortunatebutnotasmortalitythatnecessarilydetractsfromthesuccessoftherelocation. telemetry isatime-intensivemethodology.Consequently,most relocation studies, in addition to the variables discussedabove,haveusedreasonablyfewspecimens,andhavenotalwayshadcomparativesamplesavailable.Anexceptionisnowaketal.(2002).theyconductedalimitedbutrigorousexperimentaltestoftheeffectsoftranslocationonCrotalus atrox.evenso,snakeswererelocatedtothenewsiteatvaryingtimesofyearandnotnecessarilyfromthesamefamilygroup.

theseniorauthortrackingrattlesnakeswithimplantedradiotransmitters.

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Whilesingle-specimenrelocationsareacknowledgedtogener-allyfarepoorly,wehypothesizedthatcaptureofallavailableadultsandyounguponemergencefromasingledeninspringandrelocat-ingthemtosuitableotherhabitatwouldresultinminimalpopu-lationdisorientation,stress,andconcomitantlosses.Wefurtherhypothesizedthat,asC. horriduslargelyorientsbyscent-trailing(especiallyyoungfollowingadults—Weldonetal.1992,Cobbetal.2005),mass-reintroductionduringthespringtoarockforma-tionsuitedtofuturehibernationwouldallowdispersionofadults(tofeedingandbirthinggrounds),effectivelyestablishingscenttrailsthatwouldleadbacktothenewdensiteinthefall.Wefeltthatarelocationthustimedwouldgivesnakesthebestopportunitytoorienttonewhabitatduringwarmerweather. ourmodelwasdevelopedusingtheknowledgethatC. horri-dusisalong-lived(brown1993andpers.comm.,pisaniandFitch2002)andhighlysocial(Cobbetal.2005,Clark2004,AldridgeandDuvall2002,Weldonetal.1992)species.ourunderlyingbeliefwasthat,ifaconsiderablenumberofsnakesfromadencouldbecaptureduponfirstemergenceinspring,kepttogether,andthenreleasedtogetherintoasuitabledenning/foraging/birthinghabitatseveralkm(but<20km)distantfromtheiroriginalden,theywouldreorientandestablishthemselvesasagroupinthenewsite.

MethodsseveralpotentialreleasesiteswereassessedbypisaniandDorrduringFebruaryandearlymarch2007usingthefollowingcriteria:• presenceofalimestonestratumthatweatheredtoproduce

deep fissures,with rock fracturedbyapparentmechanicalweatheringpluspenetrationoftreeroots,andhavingseveralcreviceswithsurfaceopenings>6cminwidth;

• southerly(se–sW)exposure;• Adjacentgrasslandandforbfields(naturaland/orcultivated)

that,combinedwithedgehabitat,wouldsupportanabundantpopulationofsmallmammals(potentialpreyspecies);

• Abundantedgehabitat;• nearbysourcesofpermanentwater;• minimalnearbyhumandevelopment;• landownedbyacountyormunicipalgovernment(andthus

protectedfromdevelopment)thatwouldagreetohosttheproject;

• noknownextantpopulationofC. horridus;• Readilyaccessibletotheresearchteamfortracking.

Ingeneral,thesitesoughtwastoreflectthecharacteristicsofthehabitatsusedbyC. horridusstudiedbyFitchandpisani(2004,2005,2006a,2006b).Allbutonewererejectedforfailuretomeetallofthecriteria.thesiteselectedforthereleasewasnotknowntohavearesidentpopulationofC. horridus(thompson,pers.comm.topisani;pisani,personalobservation),andwasafewkilometersfromtheoriginaldenlocation. the forested portion of the site is dominated by matureChinquapin(Quercus muehlenbergii andQ. prinoides)andburr(Q. macrocarpa)oaksandshagbarkhickory(Carya ovata),whichistypicaloftimberRattlesnakehabitatinKansas(Fitch1958).theprairiesarecharacterizedbybigbluestem(Andropogon gerardii)aswellasprairiepepper(Lepidium densiflorum),Cord(Spartina pec-tinata),switch(Panicum virgatum),Indian(Sorghastrum nutans),andKentuckyblue(Poa pratensis)grasses,anddottedwithprairieforbssuchasvarioussedges(Carex spp.),asters(Asterspp.),andmilkweeds(Asclepias spp.).thisoak-hickoryforest interspersedwithopenareasprovidesextensiveecotonalzones,ideallyflankedbyshelterandbaskinghabitats.Inordertofurthercharacterizethesemicrohabitats,weassessedthedensityanddiversityofprey(smallmammal)speciesbyplacingthreeparallelgridscomprising100totalshermantraps.theareasampledwasanapproximately230x110-m(25,500-m2)tractoflandencompassingthreedistincttypesofhabitat.one-thirdofthetrapsweresituatedintheforest,one-thirdintheedgezone,andtheremainderintheprairie.trapsweresetintheafternoonsandcheckedforthreeconsecutivemorn-ings,andmammalsweremarkedwithtemporarydesignations.thetrapswerethenallowedtoliefallowforonenight,followedbytwoadditionaldaysoftrapping.thebailey-modifiedlincoln-peterson(bailey1952) indexwasemployedtoapproximate thepopula-tiondensityofeachspecies,andmargalef’sd(margalef1958)andshannon’sdiversity(shannonandWeaver1949)indiceswereusedtoassesssmallmammalcommunitystructure. FollowingaprotocoltrainingsessionbylDp-AC,snakeswerecapturedbyinvestigatorsandtrainedvolunteersatthelenexadensiteinApril2007,andwereprocessedasfollows:(1)markedbyuniquescale-clips(scalessavedforpendingDnAanalysis)andsub-

WAlKeR,DoRR,benJAmIn,AnDpIsAnI

RodWittenberg,UniversityofArkansas,conductsatrainingsessionforpersonsinvolvedwiththisstudy.

habitatattherelocationsite.Alargemalewasfoundbeneaththeselogssoonafterrelease.

min

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IRCFReptIles&AmphIbIAns•Vol16,no4•DeC2009 217

cutaneousimplantationofapassiveIntegratedtransponder(pIt)RFIDtag(AVIDsystems);(2)Collectedpopulationdataonsex,bodysizes,mass,etc;(3)Implantedtransmittersintoselectedsnakessotheirmovementsandsurvivalcouldbemonitored;(4)ReleasedinoneortwogroupspReFeRAblYbyheadingthemintothenewdenholesotheycouldre-emerge,scent-trailthefirstindividualstodisperse,anddisperseinapatternthat,forthem,wouldbereason-ablynormal. Inordertominimizestresstoanimalswhosenaturalmove-mentsweplannedtomonitor,capturedsnakeswereplacedasgen-tlyaspossibleusingaluminumtongsintocleanplasticbucketsfortransporttotheholdingand/orsurgeryfacilities(cf.nowaketal.2002).thisprocedureminimizedhandling,wassaferbothforthesnakes(keepingstresstoaminimum)andinvestigators,andmini-mizedthetransferofhumanscenttotheskinofsnakes.Insubse-quenthandlingduringprocessing,andthereafterasrequiredduringthestudytoassesspost-releasefeedingorreproductivestatus,snakeswere “tubed”byusing36-inchaluminumtongs and inducingsnakestoenterrigid-wallacrylictubeschosentolimittheirabilitytoturn.oncethehead/neckwereinthetube,animalsweregraspedatthetube/bodyjunctureforsafehandling,whichalsominimizedanimalstressandstruggling. twenty-ninetimberRattlesnakeswerecollectedandprocessedin2007,and22wererelocatedtothenewdensitewithin2–3daysofcapture.thesevenotherswereheldfortransmitterimplanta-tionandlaterrelease;delayedreceiptofelectronicsand,inafewcases,waitingforecdysispriortosurgeryresultedinsnakesbeingreleasedatthenewsiteanywherebetween2daysand5weeksafterinitialcapture.snakesemergingtogetherwerehousedtogetherdur-ingholdingperiods.Inmid-summer2007,lpD-ACwascalledtoremovealargemaletimberRattlesnakecourtingamaturefemaleintheyardofaresidence.thismaleboreadistinctiveseriesofdorsalscarsandwasrecognized(shipman,pers.comm.)asbeingfromthedenthreatenedwithdevelopment.thefemale’sdenoforiginisunknown.siteofcapturewas~6kmeastofthethreat-enedden(straightlinemeasure),andevenacircuitousrouteforthatmalewouldhavetakenhimthroughseveraldenselypopulatedneighborhoods.thesetwosnakeswere fittedwithtransmittersandreleasedatthenewsitetocomparetheirsubsequentbehaviorwiththatofthegroup-relocatedsnakesmovedearlierin2007.

surgerieswereperformedpertheestablishedprotocolforthespecies(ReinertandCundall1982,Reinert1992,hardyandGreene2000)usingisofluraneanesthetic.telemetrytransmittersandassociateditemswerepurchasedfromWildlifematerialsInternational,Inc.(murphysboro,Illinois;transmitterweight11–12g).transmittermassasapercentofsnakebodymassrangedfrom<1%to3.5%,withanaverageof2.2%.transmitterswerepositionedsothattheir

ReloCAtIonoFtImbeRRAttlesnAKes

hibernaculumatthereleasesiteintherelocationarea.notethefractured,southwest-facinglimestoneoutcropinmatureoak-hickoryforest.

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flattenedsurfacewasincontactwiththesnake’sventralmuscula-ture,withtheflexiblewireantennaextendedthroughtheprimaryincision, thence subcutaneously cephalad.Apreviously appliedmonofilamentanchorsuturearoundthebaseoftheantennawirewassecuredthroughthebodymusculaturetopreventshiftingofthetransmitterandpossibleintestinaltransferwithsubsequentexpulsioninfeces(pearsonandshine2002).snakesthatwereslowtorecoverfromanesthesiawereresuscitatedbyinsertinganendotrachealtube,followedbyevacuationofinhaledanestheticbyinvestigatorexhala-tionintothetubeaccordingtotheprotocol.snakesthereafterwerekeptincaptivityfor24–48hoursat21–24°Ctoassurebothcom-pleterecoveryfromanesthesiaandwoundclosure.theythenwerereleasedingroupsatthenewdensite. A timber Rattlesnake report form modeled on one inuseby thenaturalhistoryDivision,missouriDepartmentofConservation(briggler2001)wasdevelopedfordistributiontothegeneralpublicneartheselectedreleasesite.

ResultsBehavior and Relative Movements.—thetranslocatedsnakes,ingeneral,behavedasmightbepredictedfromstudiesofnearbypopulations(Fitch1999;Fitchandpisani2004,2006a,2006b).the aerialphotographs illustrate each individual’smovementsthroughoutthefirst(2007)andsecond(2008)seasons,respec-tively.snake#435crossedintoaprohibitedareaandcouldnotbepreciselylocatedin2008,butradiocontactwasnotlost.Forthisreason,shewasremovedfromstatisticalanalyses.Circumferentialforagingloopdistancesoftheremainingfivemonitoredsnakesfrombothactiveseasons,inadditiontothatofagravidsnakeintroducedin2008(#045),areindicatedinthegraph.Apairedt-testoffor-agingloopdistancesindicatedthatthe2008foragingloopsweresignificantlysmaller(P =0.0007)thanthosein2007.Duringbothseasons,snakestendedtoutilizeedgezonehabitatsmorefrequentlythanforestedorprairieareas. table2indicatesthemeasurementsandsurvivalormortalityofeachoftheoriginalsnakescapturedduringthe2007season.onelarge,vagilemaleisthoughttohavejoinedaresidentpopulationoftimberRattlesnakeswithahibernaculum~2km(1.26mi)northoftherelocationsite.Despitesomeattrition(onesnaketopredationinyear1,onetoexposureaftersuccessfulhibernationandemergence

inyear2),thetwogravidfemalesgavebirthtoanunknownnumberofyoung,perhapsasmanyastenbasedonfolliclecountsatcapture.moreover,thegravidfemalethatwasaddedtothepopulationin2008gavebirthtosix(observed)young.

Small Mammal Community Structure.—Atotalof30 smallmammals was captured and marked in the study area, withPeromyscus leucopus (White-footedmouse) andP. maniculatus(Deermouse)togethercomprising76.7%(40and36.7%,respec-tively)ofthetotalcaptures.Microtus ochrogaster(prairieVole)andBlarinabrevicauda(northernshort-tailedshrew)represented16.7and6.7%ofthetotalindividualsmarked,respectively.halfoftheanimalswerecapturedintheprairie,whereas33.3%weretrapped

WAlKeR,DoRR,benJAmIn,AnDpIsAnI218 IRCFReptIles&AmphIbIAns•Vol16,no4•DeC2009

Aerialviewofthereleasesite(¶)andnewhabitat(1903ft=580m).eachsnake’sforagingloopforthefirst(2007)activeseasonisindicatedbyadifferentcolor.

Aerialviewofthereleasesite(¶)andnewhabitat(1903ft=580m).eachsnake’sforagingloopforthesecondactiveseason(2008)isindicatedbyadifferentcolor.notethat#435crossedintoaprohibitedarea;dotsrepre-sentsitesofgreatestsignalstrengths.

Comparisonsofthetotalcircumferentialforagingloopdistances(meters)traveledbyeachtelemeteredindividualduringthe2007and2008activeseasons.

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inthewoodsandonly16.7%intheedgezone.thismayexplainwhytherattlesnakesweremostcommonlyfoundintheecotonalareas, thereby strategically affording themselves access tobothhabitatswiththehighestconcentrationsofprey.smallmammaldensityinthesampledareawasrelativelylow,atavalueof0.001animal/m2.populationsizeestimatesinthisareaforeachspeciesweredeterminedtobe15individualsofPeromyscus leucopus,11P. maniculatus,6Microtus ochrogaster,and2Blarina brevicauda.margalef’sdiversityindex,whichevaluatessmallmammalspeciesrichnessinthearea,was0.882,indicatingaverytaxonomicallyrichsmallmammalfauna.shannon’sdiversityindex,whichconsidersevennessoftheinclusivepopulations,wasdeterminedtobe1.75.thisdiversityvalueistypicalofempiricaldata(commonlyrangingfrom1.5to3.5;magurran2004)unlessvastnumbersofspeciesaresampled.preydensityanddiversityvaluesmaybeunderestimatedduetosmallsamplesizeandsamplearea,yetthesedataseemtoindicateahealthypopulationoftimberRattlesnakepreyspeciesattherelocationsite,comparabletothatfoundinotherlocations(Fitchetal.1984).

Discussion and Conclusionsmostrelocationstudies(includingours)haveinvolvedtrackingasmallnumberofsnakes(<25)andhavenotincludedtheexperi-mentalcomponentinthedesignofnowak,etal.(2002),making

detailedstatisticalevaluationofparameterssuchasobservedhomerangesizetemptingbutbasicallyinvalid.Fitchandpisani(2004,2006a)foundthathomerangesoftrackedtimberRattlesnakesinanaturallyresidentpopulationcloselyreflectedtheoverallphysi-ographyoftheavailablehabitat(smalltractsofopenhabitattran-sectedbywoodedledges),makingdetaileddescriptionviavariousstatisticalconstructsanunprofitableexerciseforasmallsamplesize.Additionally,thecomparisonofstatisticallydescribedhomerangesizesofvariousauthors’studypopulations,whilehavinganattractivemathematicalappeal,failstointegrate(andinfactdeflectsattentionfrom)thequestionofresourceavailability.thus,asanyindividualsnakemovesfromahibernaculumtoanactivityrangeeachseason,theannuallychangingresourceavailabilityitencoun-ters(foodabundance,necessarythermoregulationsites,changesinplantcommunitygrowthorcover—inKansasnotinfrequentlyalteredbycontrolledburns,etc.)alongwithnaturaland/oranthro-pogenicbarriers,will,webelieve,determineitshomerangeshapeandsizeforthatseason.Foranextensivereviewofthepitfallsinher-enttotheapplicationofdetailedstatisticalhome-rangemodelstosmalldatasetsseeAebischeretal.(1993). Wedonotquestiontheconclusion(sealy2000,2002;nowaketal.2002)thatshortdistance(<50m)relocationof“nuisance”rattlesnakesispreferabletolongerdistancerelocations.theauthorsandcolleaguesoftenhaverespondedtoruralandsuburbancallsregarding“nuisance”timberRattlesnakes,andhavemovedthesnake50–300mfromitspointofhumaninteraction.Usually,wetellthealarmedhumanwewill“takethesnakeaway.”Althoughsuchsnakeswerenottracked,weactedinthebeliefthatthissDtwaspreferabletothehumankillingthesnake,andmostincidentsseemtohavebeenresolvedfavorablyastheencounterwaspurelybychanceandusuallydoesnotrecur. neitherdowequestiontherecommendationsregardingthedesirabilityofeducatinganencroachinghumanpopulationabouttheprobabilityofencounteringvenomoussnakes inwhathavebecomesharedhabitats.Indeed,someoutstandingsuccessesrelatetothe latter(ernst2004,sealy2000)andwearedevelopingasimilarlenexaplanwiththesupportofthecitygovernment.Webelievethat,insuchsituations,goodmodelsforrelativelyshort-distancerelocationofpopulationstomoresecureareas(possiblysupplementedbycarefulsitingandconstructionofartificialdens—seeernst2004reC. viridis)areadditionalvaluablemanage-

two-day-oldtimberRattlesnake;oneofsixnewbornsobservedoutsidetherookeryofarelocatedfemaleinseptember2008.

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220 IRCFReptIles&AmphIbIAns•Vol16,no4•DeC2009 WAlKeR,DoRR,benJAmIn,AnDpIsAnI

menttoolsthatalsocanbeintegratedwithpubliceducation.thatthenatureoftheoriginallenexadenwasentirelyanthropogenicisitselfofconsiderableinterest,withobviousimplicationsforsnakeconservation.Augmentationorde novoestablishment(ernst2004)ofsuitabledensitesisalargelyuntestedconservationmethod,butobservationsontheoriginaldenofourpopulation,combinedwithpreliminaryresultsofernst(2004)andaveryfewothers(edwards,pers.comm.)suggestthatsnakesofseveralcrotalidgeneramayread-ilyacceptsuitableanthropogenicdens.Forexample,Agkistrodon piscivorusutilizeshibernaculainanthropogenicdamrubbleandisactiveinanthropogenicditches(savitzky2002andpers.comm.).Wehereadvancethesuggestionthatanyplannednewdensitesbepreparedinwinterorspring,andthentreatedwithwholecornandsunflowerseedtomorerapidlyattractasmallrodent(snakeprey)population. thedocumentedhighnatalphilopatry(Clarketal.2007)ofC. horridus(e.g.,individualsrecruittosamehibernaculumastheirmother)alsoisvaluabletoconservationeffortsbecauseitsuggeststhatsuccessfulrelocationofgravidfemalesthatgivebirthatthenewsiteandthendentherewillestablishthenewpopulation.themodelweemployed,headstartingthemajorityofrelocatedsnakesattheinvestigator-selectednewdensiteearlyafteremergence,makesuseofthesocialcharacteristicsofthespeciestoreducethestressofrelocationandhopefullytherebytoincreasesurvival.

therelocatedsnakesranged,survived,andbehavedseasonallyinafashionthatmirrorsundisturbedpopulationswithin50km.baseduponbehaviorandsurvivalofthetrackedsnakesthroughthesecondfullactivityseasonafterrelocation,duringwhichtimetheirforagingloopsbecamelesserraticandsignificantlysmaller,webelievethisefforthasbeensuccessful,andthatourresultsprovideamorerealisticdefinitionofsuccessthanothershavedemanded.oureffortmayhavebeenuniqueinthattheoriginaldenplainlywasslatedfordestructionandsuitablerelocationhabitatwasfoundareasonable(toofarforthesnakestoreturn;notsofarastocausepopulationgeneticsalteration)distanceaway.Wealsohopethatthisrelocationwillprovideamodelforthefuturesalvageofpopulationsofthisandrelatedspeciesthatarethreatenedbyhabitatdestructionviadevelopment.evidenceexiststhatmuchfartherrelocationsofsmallcolubridscansuccessfullyestablishapopulation(Clark1970).Carefulapplicationofthemodeltocrotalidsdeservesconsideration. thetimberRattlesnakeReportFormwillbeemployedbypersonneloftheCityoflenexaandKansasDepartmentofWildlifeandparksasdesiredtogaininformationonthisspeciesfromthegeneralpublic,aswellasraiseawarenessofthepublictothesnakesasavaluablecomponentoflocalecosystems.Wehopethatsuchfeedbackwillbeusefulinassessingtheproximityofotherpopula-tionsofthisspeciestohumanhabitation.Italsowillbehelpfulinmonitoringdispersalofreleasedsnakes.

AcknowledgmentsRandallDavisallowedusfreeaccesstohispropertysowecouldremovethesnakes,andthetwaddlefamilyprovidedaccesstotheirlandtotrackrelocatedsnakes.thelenexapoliceDepartment,lenexapublicWorks,thehumanesocietyoftheUnitedstates,KansasDepartmentofWildlife andparks, and theChickadeeCheckoffoftheKansasDepartmentofWildlifeandparkscontrib-utedfundstosupporttheproject.Additionally,thelenexapoliceDepartmentgraciouslyallowedallofthesurgeriesanddatacollec-tiontobedoneintheirtrainingroom.employeesfromlenexaAnimalControl,thelenexapoliceDepartment,lenexapublicWorks and the lenexa Information technology Departmentassistedinsnakecollection.specialthanksgotomikeshipman,beckyColin,hopemason,andsergeantDaveogilvie.Crystal,thanksfortoleratinguskeepingbucketsfullof“yourgreatestfear”in theoffice.logistic supportof JohnsonCountyparkpoliceofficerbilliethompsonandChiefDanFieldsaremostgratefullyacknowledged.Additional funding fromRockhurstUniversitythroughanRUpresidentialGrantwasimportanttothesuccessofthework.Galenpittman,Fieldstationmanager(KansasbiologicalsurveyandecologicalReserves)alloweduseofshermanlivetrapstoassessmammalpopulationsatthenewsite.membersoftheKansasCityherpetologicalsocietyandotheruniversitystudentsassistedinthecollectionandtrackingofthesnakes,asdidWilliamDonovan,seanKimbrell,lindaandDylanlehrbaum,DavidJewell,andJoeybrown.JoshuaRiepeassistedwithdataentry.midwesttongsgenerouslycontributedthepIttags,expertise,equipment,andtheopportunityforDorrtoattendVenomWeek.Wildlifematerialsagreedtobuildthetransmittersonshortnoticetosupportresearchonconservationofthespecies.thankstonateDavis,DanKeyler,Roymalleappah,RonDrain,andRulonClark;yoursupport,kindwords,andguidanceareappreciated.specialthanksgotoRodWittenbergandpatKoontz,whobroughtgreatpersonalpassionfor

Femalenearherrookery(withnewbornsinside).theseniorauthorisinthebackground.

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timberRattlesnakestotheproject.Rod,thankyouforyourhoursofresearchandthetrainingyouprovidedtovolunteers.

ReferencesAdams,J.p.2005.homeRangeandbehaviorofthetimberRattlesnake(Crotalus

horridus).Unpublishedm.s.thesis,marshallUniversity,WestVirginia.

Aebischer,n.J.,p.A.Robertson,andR.e.Kenward.1993.Compositionalanalysisofhabitatusefromanimalradio-trackingdata.Ecology74:1313–1325.

Aldridge,R.D.andD.Duvall.2002.evolutionofthematingseasoninthepitvi-persofnorthAmerica.Herpetological Monographs16:1–25.

Andrews,K.m.andJ.W.Gibbons.2005.howdohighwaysinfluencesnakemove-ment?behavioralresponsestoroadsandvehicles.Copeia2005:772–782.

bailey,n.t.J.1952.Improvementsintheinterpretationofrecapturedata.Journal of Animal Ecology21:120–127.

briggler,J.2001.timberRattlesnakesightingReportForm.Missouri Herpetological Association Newsletter(14):23.

brown,W.s.1993.Biology, Status, and Management of the Timber Rattlesnake (Crotalushorridus): A Guide for Conservation.herpetologicalCircularno.22.societyforthestudyofAmphibiansandReptiles,oxford,ohio.

brown,W.s.1992.emergence,ingress,andseasoncapturesatdensofnortherntimberRattlesnakes,Crotalus horridus,pp.251–258.In:J.A.Campbellande.D.brodie,Jr.,(eds.),Biology of the Pit Vipers.selvapress,tyler,texas.

brown,W.s.1991.FemalereproductiveecologyinanorthernpopulationofthetimberRattlesnake,Crotalus horridus.Herpetologica47:101–113.

burke,R.l.1991.Relocations,repatriationsandtranslocationsofamphibiansandreptiles:takingabroaderview.Herpetologica47:350–355.

butler,h.,b.malone,andn.Clemann.2005a.Activitypatternsandhabitatpref-erencesoftranslocatedandresidenttigersnakes(Notechis scutatus)inasub-urbanlandscape.Wildlife Research32:157–163.

butler,h.,b.malone,andn.Clemann.2005b.theeffectsoftranslocationonthespatialecologyoftigersnakes(Notechis scutatus)inasuburbanlandscape.Wildlife Research32:165–171.

Clark,D.R., Jr.1970.ecologicalstudyof theWormsnake (Carphophis vermis)Kennicott.University of Kansas Publications, Museum of Natural History19:85–194.

Clark,R.W.2004.Kinrecognitioninrattlesnakes.Proceedings of the Royal Society of London B(supplement)271:s243–s245.

Clark,R.W.,W.s.brown,R.stechert,andK.R.Zamudio.2007.Integratingindi-vidualbehaviorandlandscapegenetics:thepopulationstructureoftimberRattlesnakehibernacula.Molecular Ecology16:1–12.

Cobb,V.A., J.J.Green,t.Worrall, J.pruett, andb.Glorioso.2005. Initialden location behavior in a litter of neonate Crotalus horridus (timberRattlesnakes).Southeastern Naturalist4:723–730.

Ditmars,R.l.1936.The Reptiles of North America.Doubleday&Co.,newYork.

Dodd,C.K.,Jr.,andR.A.seigel.1991.Relocation,repatriationandtransloca-tionofamphibiansandreptiles:Aretheyconservationstrategiesthatwork?Herpetologica47:336–350.

edwards,J.andD.spiering.2005.timberRattlesnakeworkwithprivatelandown-ersinminnesota,pp.9–10.In:Timber Rattlesnake (Crotalushorridus) Biology and Conservation in the Upper Mississippi River Valley.ConferenceReport,st.mary’sUniversityofminnesota,Winona.

ernst,R.D.2004.Lethbridge Rattlesnake Conservation Project: 2003 Progress Report.AlbertasustainableResourceDevelopment,FishandWildlifeDivision,AlbertaspeciesatRiskReportno.81,edmonton.

Fitch,h.s.1958.homeranges,territories,andseasonalmovementsofvertebratesofthenaturalhistorymuseum.University of Kansas Publications, Museum of Natural History11:63–326.

Fitch,h.s.1999.A Kansas Snake Community: Composition and Changes Over 50 Years.Kriegerpublishing,malabar,Florida.

Fitch,h.s.,V.R.Fitch,andW.D.Kettle.1984.Reproduction,populationchangesandinteractionsofsmallmammalsonanaturalareainnortheasternKansas.University of Kansas Museum of Natural History Occasional Paper(109):1–37.

Fitch,h.s.andG.R.pisani.2004.AfieldstudyofthetimberRattlesnakeinleavenworthCounty,Kansas.Journal of Kansas Herpetology(11):18–24.

Fitch,h.s.andG.R.pisani.2005.Disappearanceofradio-monitoredtimberRattlesnakes.Journal of Kansas Herpetology(14):14–15.

Fitch,h.s.andG.R.pisani.2006a.thetimberRattlesnake innortheasternKansas.Journal of Kansas Herpetology(19):11–15.

Fitch,h.s.andG.R.pisani.2006b.RapidearlygrowthinnortheasternKansastimberRattlesnakes.Journal of Kansas Herpetology(20):19–20.

hardy,D.l.andh.W.Greene.2000.Inhalationanaesthesiaofrattlesnakesinthefieldforimplantationoftransmitters.Sonoran Herpetology13:109–113.

Keyler, D. 2005 timber Rattlesnake (Crotalus horridus) bites in the UppermississippiRiverValley,pp.11–12.In:Timber Rattlesnake (Crotalushorri-dus) Biology and Conservation in the Upper Mississippi River Valley.ConferenceReport,st.mary’sUniversityofminnesota,Winona.

leClere, J. 2005. timber rattlesnakes in northeastern Iowa. pp. 12–13. In:Timber Rattlesnake (Crotalus horridus) Biology and Conservation in the Upper Mississippi River Valley.ConferenceReport,st.mary’sUniversityofminnesota,Winona.

magurran,A.e.2004.Measuring Biological Diversity.blackwellscience,malden,massachusetts.

margalef,D.R.1958.Informationtheoryinecology.General Systems Bulletin3:36–71.

martin,W.h.2002.lifehistoryconstraintsonthetimberRattlesnake,(Crotalus horridus)atitsclimacticlimits,pp.285–306.In:G.W.schuett,m.höggren,m.e.Douglasandh.W.Greene(eds.),Biology of the Vipers.eaglemountainpublishing,eaglemountain,Utah.

martin,W.h.1992.phenologyofthetimberRattlesnake(Crotalus horridus)inanunglaciatedsectionoftheAppalachianmountains.pp.259–277.In:J.A.Campbellande.D.brodie,Jr.,(eds.),Biology of the Pit Vipers.selvapress,tyler,texas.

nowak,e.m.,t.hare,andJ.mcnally.2002.managementof“nuisance”vipers:effectsoftranslocationonWesternDiamond-backedRattlesnakes(Crotalus atrox),pp.533–560.In:G.W.schuett,m.höggren,m.e.Douglasandh.W.Greene(eds.),Biology of the Vipers.eaglemountainpublishing,eaglemountain,Utah.

nRCm(nationalResourcesCouncilofmaine).1999.publiclandownershipbystate.<http://www.nrcm.org/documents/publiclandownership.pdf>.

pearson,D.J.andR.shine.2002.expulsionofintraperitoneallyimplantedradio-transmittersbyAustralianpythons.Herpetological Review33:261–263.

pisani,G.R.,J.t.Collins,ands.R.edwards.1972.Are-evaluationofthesubspeciesofCrotalus horridus.Transactions of the Kansas Academy of Science75:255–263.

pisani,G.R.andh.s.Fitch.2005.The Timber Rattlesnake in Kansas.ConservationActionplan–Kansas.ReportsubmittedtotheU.s.Fish&Wildlifeservice,Washington,D.C.

pisani,G.R.andh.s.Fitch2002.longtimerecaptureofatimberRattlesnake(Crotalushorridus).Journal of the Kansas Herpetological Society1(3):15–16.

Reinert,h.K.1992.Radiotelemetricfieldstudiesofpitvipers:Dataacquisitionandanalysis,pp.185–197.In:J.A.Campbellande.D.brodie,Jr.,(eds.),Biology of the Pit Vipers.selvapress,tyler,texas.

Reinert,h.K.1991.translocationasaconservationstrategyforamphibiansandrep-tiles:somecomments,concerns,andobservations.Herpetologica47:357–363.

Reinert,h.K.andD.Cundall.1982.Animprovedsurgicalimplantationmethodforradio-trackingsnakes.Copeia1982:702–705.

Reinert,h.K.andR.R.Rupert.1999.Impactsoftranslocationonbehaviorandsur-vivaloftimberRattlesnakes,Crotalus horridus.Journal of Herpetology33:45–61.

savitzky,b.C.A.1992.laboratorystudiesonpiscivoryinanopportunisticpitviper,theCottonmouth,Agkistrodon piscivorus,pp.347–368.In:J.A.Campbellande.D.brodie,Jr.(eds.),Biology of the Pitvipers.selvapress,tyler,texas.

sealy,J.b.2000.short-distancetranslocationsoftimberRattlesnakesinanorthCarolina state park. Report to the north Carolina Wildlife ResourcesCommission,nongameandendangeredWildlifeprogram,northside.

sealy,J.b.2002.ecologyandbehaviorofthetimberRattlesnake(Crotalus hor-ridus)intheUpperpiedmontofnorthCarolina:Identifiedthreatsandcon-servationrecommendations,pp.561–578.In:G.W.schuett,m.höggren,m.e.Douglasandh.W.Greene(eds.),Biology of the Vipers.eaglemountainpublishing,eaglemountain,Utah.

shannon,C.e.andW.Weaver.1949.The Mathematical Theory of Communication.UniversityofIllinoispress,Urbana.

Weldon,p.J.,R.ortiz,andt.s.sharp1992.thechemicalecologyofcrotalinesnakes,pp.309–319.In:J.A.Campbellande.D.brodie,Jr.(eds.),Biology of the Pitvipers.selvapress,tyler,texas.