Reptiles and amphibians in deep canyons : the Big Jacks and Little Jacks Creek drainages of Owyhee County, Idaho PDF
Preview Reptiles and amphibians in deep canyons : the Big Jacks and Little Jacks Creek drainages of Owyhee County, Idaho
BLMLIBRARY 88055389 97-1 IDAHOBUREAUOFLANDMANAGEMENT January1997 Reptiles and Amphibians in Deep Canyons: The BigJacks and LittleJacks Creek Drainages ofOwyhee County, Idaho QL 84.2 .L352 no. by 97-1 MarkF.Gerber Dr.JamesC.Hunger AaronAmes JeffStewart Ld52 no. ReptilesandAmphibiansinDeepCanyons: oj<]-l TheBigJacksandLittleJacksCreekDrainagesofOwyheeCounty,Idaho Achallengecost-shareagreementbetween U.S.BureauofLandManagementand BoiseStateUniversity December13,1996 MarkF.Gerber Dr.JamesC.Munger AaronAmes JeffStewart DepartmentofBiology,BoiseStateUniversity,Boise,ED83725 INTRODUCTION ManyofthereptilesandamphibiansthatliveinsouthernIdahocanbefoundinthe canyonsofOwyheecounty. However,ofthefewstudiesonreptilesandamphibiansthathave beenconductedinOwyheecounty(Diller1981,Mungeretal.1993,1994,Beck1994)nonehave beenconductedinthedeepcanyonareas,suchasBigJacksandLittleJacksCreeks. These canyons,whichcanreachadepthof400meters,containhabitatsuitableformanynativereptiles andamphibians. However,itispresentlyunknownwhethercanyonsrepresentahotspotof herpetologicaldiversity,andthereforeareworthyofprotection,orwhethertheyarerelatively depauperate,oraresomewhereinbetween. Thisstudywillexaminethediversityandabundance ofreptilesandamphibiansindeepcanyonsofOwyheeCounty,andshouldthereforeprovidea modelforothersimilarareasinSouthernIdaho. Forthepurposesofthisreport,allareaswithin theBigJacksandLittleJacksCreeksdrainageswillbereferredtoasthe"studyarea". Theterm "herp"isusedinthisreporttocollectivelyrefertoreptilesandamphibians. OfthespeciespotentiallyfoundinthestudyareatheSpottedFrogislistedbytheU.S. FishandWildlifeService(USFWS)asacandidatespecies,theIdahoDepartmentofFishand Game(IDF&G)asaspeciesofspecialconcernA(priorityspecies),andbytheBureauofLand Management(BLM)asasensitivespecies.TheNorthernLeopardFrogandtheMojave Black-collaredLizardarelistedbytheBLMassensitive,andbyIDF&Gasaspeciesofspecial concernA. TheWesternToadislistedasanIDF&GspeciesofspecialconcernC(undetermined status)andbytheBLMassensitive. TheWesternGroundSnake,andtheLongnoseSnakeare listedbyIDF&GasspeciesofspecialconcernB(peripheralspecies). Thisstudywasdesignedprimarilyasasurveytodeterminepresenceorabsenceof reptilesandamphibiansofthedeepcanyonsoftheBigJacksandLittleJackscreekdrainages,and toprovidebaselinedataforfuturestudies. Inaddition,wecollecteddatatodetermine movement patternsofsnakesinthevicinityofParkerTrailonBigJacksCreek. METHODSANDMATERIALS Twomethodsofdeterminingpresenceofherpswereutilized;driftfencesinconjunction withfunneltraps,andvisualencountersearches. Thesetwomethodswereemployedinfour regimes:upland,rirn,midslope/draws,andcanyonbottom. Theuplandregimewasnotactively surveyed. Reptilesfoundinthisregimewere,therefore,incidentaltothestudy,andincluded roadsightings(bothdeadandalive)andreptilesthatwereseenwhiletravelingwithinthestudy site. Rimsightingsincludedanimalsencounteredwithin100moftherim,includingthose capturedindriftfencearrays. Mid-slopesightingswerecharacterizedbydraws,talusbenches, andothersuitablehabitatthatwasbelowthecliffthatdefinedtherimregime,butdidnotinclude talusthatactuallyemergedontothecanyonbottom. Someareasofextremelysteepcanyonwalls didnothaveamid-sloperegime. Thecanyonbottomwasdefinedtoincludeallsandbars,and talusordirtthatactuallyemergedontothefloorofthecanyon. DriftFenceinstallationandconstruction: Twentysevendriftfencearrayswereplacedin andnearBigJack'sCreekCanyon,asshowninFig.1. Driftfenceswereconstructedoftwo sectionsofmaterial,eitherconstructiongradesiltfenceorstripsofsheetmetalflashing. Forty-threesectionswereconstructedofsteelflashing,eachsectionusedapiece21"wideby25* long. Theedgeofeachsectionwasburiedaminimumofsixinchesunderground. Onplateaus andwindyslopesthebottomfourincheswasbentoverbeforeburyingtokeepthefencefrom blowingoutoftheground. Steelfencingwasinstalledinatrenchthatwasnodeeperthansix inchesandonlywideenoughtofitthesteelinwiththebottomfourinchesbentatarightangleto thefence(Fig.2). Eightsectionswereconstructedofsiltfence,eachsectionwastwenty-fivefeet longbythreefeetwidewithatwobytwowoodenpostateachendandtwospacedevenly betweentheendposts. Thepostsweredrivenintothegroundatanglessotheyonlycontacted thefenceatthetop. Threefootlongstriplathewasusedtobracecloththatsaggeddueto unevenground. Twenty-sevenarrayswereerected,25ofwhichwerecomprisedof2sections andtheremainderofonetwenty-fivefootsectionofsteelfenceeach. Ofthetwenty-sevenarrays, eightwerecomprisedofonesectionofsteelfenceandonesectionofsiltfence,withtheobjective ofdeterminingwhetherornottherewasadifferenceineffectivenessofeachtypeoffence. FunnelTraps: Funneltrapswereconstructedofaluminumwindowscreen. Apieceof screenwascut24"ononesideand20"ontheother. Thispiecewasrolledintoacylinder24" longandstapledtogetherwithhouseholdstaples. Oneendofthecylinderwasflattened,folded over,andclippedwithclothespins. Tomakethefunnel,ahalfcirclewascutfromthesame materialasthebodyandrolledintoafunnelwithadiameterof22cmatthewidestpoint. The pointendofthefunnelwascutofftomakeaholethatwasabout3cmacross. Thisfunnelwas insertedintotheopenendofthecylinderandstapledinplacewiththesmallholeinsidethetrap (Fig.3). Oneachsectionofdriftfencewereplacedfourfunneltraps,twooneithersideofeach endofthefence. Eachfunneltrapwasplacedtightlyagainstandparalleltothefencewiththe openingfacingthecenterofthesectionofdriftfenceasinfig.3. Adirtrampwasconstructed intotheopeningofthefunneltraptokeepreptilesfrompassingunderneaththetrapandtohelp guidethemintothetrap. Togivereptilesaplaceofrefugefromthesun,apieceofcardboard FCirgeuerke,O1w.yLioiceaetCioo.n,oIfddarhiof.tfEeanccehaarrrraayyscwointshiisnteBdigofJtawcoKs V 19 _/ leNftwfllGEGieohiiaetn-nlebtnehoegolehcWen,wtnonlerdehweCtlstsetdhiwiohhtennenoofGeeegdrfnts,tWNreicdoahttdaorefnrehplidsa;dsseafNteipitbht:-dwwsHdeefreeeeSlwaeIsefrawpanefdsetesnicnrtnedtEedosehlcghieaneBimBdalbsOn,eefa.nte.betnahldDDtenhreet,oT.leFcedrSew,FetFod(daseh,,wreefpre(iipnnarsaefeteWodonnnrrhotmd.tldopwneaaEemtHedtHbnhtIiretdtehoiolfeohoineneNeanncsdtltWurWhahtlsAteerbehahhneeaerNeaaeodln,y,en)pSwnEdsddtpndaAsh)we.osCn,iBeinefdAdddeCtraT,etw.ir,t.enrhiaxCheadipEte,Ipsb,nhEDfsEyEaa-Aai,taNtnneWthta-odanehnSnded .—.'".;- "If-,VIf 2222201234 J1j1r x50. SiltFenceInstalled (brokenlinedepictsundergroundconfiguration) Figure2a. Configurationofsiltfenceinstallation. steeldriftfenceinstalled -:;;:-7:E4" [Straitenlinedepictsundergroundconfiguration) xd Figure2b. Steeldriftfenceinstallationconfiguration. Figure3.Positionoftrapsonthedriftfenceend. wasplacedinsideeachtrapandashadeofwood,cardboard,orbrancheswasplacedoverthetop. SiteSelection: Arrayswereplaced,whenpossible,atthejunctionofhabitattypeswithin eachregimebecauseofthegreaterlikelihoodoffindingreptilestherethatweremovingbetween habitattypestoforage. Arrayswereplacedintheregimedefinedforrim,mid-slope,andbottom ofthecanyon. Placementofthedriftfencearrayswasdecidedonsiteandonaper-arraybasis. Positioningofthearrayswasbasedonpracticalplacementwithregardseaseofinstallation,and presenceofappropriatehabitat. .orlng: Thearrayswerecheckedonathreedayrotatingbasistoavoidcasualties. Eachtrapwasremovedandthoroughlyexaminedforthepresenceofanimals. Ifasnakewas caughtinthetrap,itwasremovedandsex,length,andspecieswererecorded. Eachsnakewithin a5kmradiusofParkerTrailwasmarkedwithauniquenumbersoitcouldbeidentifiedif recaptured. Themarksweremadeontheventralscalesintherearthirdofthesnakesbody. Scaleswereclippedtoflankthenumberofundippedscalesforeachdigitofthemarkednumber. Forexample,threeclippedscaleswiththreeundippedscalesbetweenthefirsttwoclippedscales andfourbetweenthesecondandthirdclippedscaleswouldconstitutenumberthirty-four. Lizardsthatwerecaughtintrapswerenotmarked,butallotherdatawasrecordedasforsnakes. Animalsotherthanreptilesoramphibians(e.g.,birdsandmammals)werereleasedandnodata wastakenotherthannotingtheirpresenceinthetrap. VisualSearches: VisualsearchesconsistedofselectingasectionofcanyonwithintheBig JacksandLittleJacksCreeksdrainagesthatwasreasonablyaccessible,andhikingthatsection lookingforreptiles. Whileperformingvisualsearches,rocksandothersurfacedebriswere turned. Allreptilesthatwerecapturedweresexedandsized,butnotmarkedunlesstheywere within5kmofthedriftfencearrays. Surveyareasoutsidethetrappingareawereonlysurveyed once. Allhabitatthatwasdisturbedwhenperformingavisualsearchwasreplacedasclosetoits originalconditionaspossible. Whenweencounteredaskinfromareptile,itwasidentifiedto species,andrecordedasacapturebutnotewasmadethatitwasaskin. Wealsonotedthecloud cover,temperatureinCelsius,time,location,andanydistinguishingfeaturesofthereptiles encountered. VisualsearchesofBigJackscreekconsistedofareassouthoftheCottonwood/BigJacks creekconfluencethreemilesandnorthoftheCottonwood/BigJackscreekconfluencetothe WickahoneyCreekconfluence. Wealsoconductedvisualencountersearchesfor1/4minorth andsouthofwhereBigJackscreekcrossesBattlecreekroad. WesurveyedCottonwoodcreek fromCottonwoodspringstotheBigJackscreekconfluence. Wesurveyedaonemilesectionof BigJackscreek,fivemilessouthoftheBigJacks/LittleJackscreekconfluence. TheconfluenceofBigJacks/LittleJackscreekwassurveyedextensivelyaswellas tributariesinthevicinityandsurroundinghills. Thisareawasvisitedonthreeoccasionsbecause ofthefrequencythatwepassedthroughonourwaytoothersectionsofthecreeks. Thebench abovetheconfluencewassearchedaswellasRattlesnakecreekwhichdrainsthebenchintoLittle Jackscreek. LittleJackscreekwassurveyedinfewerplacesbecauseoflimitedaccesspoints. We surveyedaonemilesectionofthecreeknearOXreservoirandapproximatelytwomilessouthof theconfluencewithBigJackscreek. WealsosurveyedapproximatelyonemileofLittleJacks creekoneithersideoftheRattlesnakecreekconfluence,andaonemilesectionbeginning approximatelytwomilessouthoftheRattlesnakecreekconfluence. Inadditiontothemaincreeksweconductedvisualencountersurveysinotherareasthat containedapparentlygoodhabitatforherps. Mostoftheseareasfellalongroadsthattravelled paralleltothemaincreeks. Theareasthatwevisitedontheseoccasionswere: HoleinRock,Big HorseBasinGap,RattlesnakeGulch,Wickahoney,WhitesReservoir,MudFlatRoadandShoofly CutoffRoad. RESULTS Atotalof623reptileswereencounteredduringthecourseofthestudy. Twohundred eighty-fivereptileswerecaughtintherimregime,53werecaughtmid-slope,and116were caughtonthecanyonbottom. Theremaining169reptileswereincidentaltothestudy. Snakes: Sixspeciesofsnakeswerefoundinthecanyonsofthestudyarea: GopherSnakes, WesternWhipsnakes,WesternRattlesnakes,NightSnakes,WesternTerrestrialGartersnakes,and WesternRacers. Anadditionaltwospeciesthatwerefoundincidentaltothestudy:Western GroundSnakes,andLongnoseSnakes. Snakeswerefoundinapproximatelythesamenumbers ontherimasinthecanyonbottoms. Onlyasmallpercentofthesnakesfoundwerefound mid-slope(Fig.4). Snakesamountedtoaboutonethirdofallreptilescaughtontherim,asdid snakescaughtmid-slope. Snakesaccountedforabout80%ofallreptilescaughtonthecanyon bottom. Eighty-ninesnakesweremarkedwithin5kmofParkerTrail. Atotalrecapturecountof eachspeciesappearsinFig.5. Lizards: Sevenspeciesoflizardswerefoundinthecanyonssurveyed;Side-blotchedlizards, WesternFencelizards,DesertHornedlizards,ShortHornedlizards,LongnoseLeopardlizards, WesternWhiptails,andWesternSkinks. Oneadditionalspecieswasfoundincidentaltothe study,theMojaveBlack-collaredlizard. Lizardscomprisedabout70%ofthereptilesfoundon therim,andtwo-thirdsofthosereptilesfoundmid-slope. Lizardsaccountedforonlyabout20% ofthereptilesfoundonthecanyonbottom;lizardswerefoundalmoststrictlyontherim(Fig.6). Amphibians: Therewasonlyonespeciesofamphibianfoundinthestudyarea,PacificTreeFrog,which wasidentifiedbyJimMunger,bycall. Allotherswereincidentaltothestudy. Thisfrog accountedforonepercentofallherpsfoundonthecanyonbottom. : HerpSurveyData1995 Snakes Caught in Each Regime 100 80 "£ 60 O W Q) ecn </> 40 «: 20 w--: ml,:ill1"^" T.elegans C.viridis H.torquata total P.catenifer M.taeniatus C.constrictor species Figure 4. HerpSurveyData1995 Capture Rate for6 Species 110 100 90 xD:) 80 - OCO 70 MCaptured1x 0O3 60 ^Captured2x CQD. Captured3x .CocO 50 EQCaptured4x LTLOJ 40 - eaCaptured5x o 30 20 10 P.catenifer M.taeniatus C.vindis H.torquata T.elegans C.constrictor Species Figure 5.
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