Distribution of the Wolverine in ldaho as Determined by Mail ...

Craig R. Groves, ldahoNaluralHertageProgram, ldahoDepartmenl of F sh and Game,600 SouthWalnutStreet,P.O Box 25, Bo se, ldaho83707

Distributionof the Wolverinein ldaho as Determined by MailQuestionnaire Abstract The {olverire was once thought to be €xtincr in Idaho, but reports of its occurrencepersisr.In order to bette. determine the status and distribution of this rare species,questionnaiiesvere sent to biologists and trappers state{ide in 1985. Responses to the queslioDnairesresulted in l0 confirmed and 89 probable reports ofwolve.ines in Idaho bet{een 1960and 1987.At least thr€€ areas in rhe state (Selkirk Mountains, Lochsa and Kelly Cre€l drainages,Sawroothand Srnoky Mounrains) appear to contain {olverine populalions.Thes€a.eascan be characterizedas.emote, mounlainoushabitat {ith little hunan disturbance. The presenrday distribution of the rolverine in Idaho is probably in the mountainous portions of !h€ state from $e Sourh Fork of the Boise River norlh to the Canadian border. Although this survey has provided insights into tbe current disrribution of the volverine in Idaho, detailed analysis on population status and ecology are need€d.

Introduction Wolverine(CuloguLo\numbersdeclinedsteadily in the contiguousUnited States(Wilson 1982) afterthe late 1800s.Today,they are uncommon in the lower 48 states and likely only occur in Oregon,Washington,California,Idaho, Montana, and Wyoming. Davis(1939)believedthe wolverineto be extinct in Idaho by the 1930s. Pengelly(1951)summarizedsevenrecordsof wolverinein Idaho from 1930 to 1949.These recordswere primarily from the northern Idaho countiesof Bonner, Boundary,Kootenai,and Shoshone. The next verifiedrecordsof wolverinesin the stateweretwo kills, one in northern Idaho in 1953 and one in southernIdaho in 1954. Larrisonand Johnson(1981)consideredthe wolverineto be rare and restrictedin distribution to areasnorth of the SalmonRiver Mountainsand to the mountainsof southeastern Idaho. Becauseof its restricteddistribution and apparentrarity in Idaho,the IdahoDepartmentof Fish and Gamehas classifiedthe wolverineas a protected speciessince 1965. In addition, Region I of the U.S. ForestService,which includesnorthernIdaho,and the U.S. Bureauof Land Managernentin Idaho havedesignatedthe wolverineas a SensitiveSpecies. The U.S. Fish and Wildlife Service,underthe authorityof the EndangeredSpeciesAct, haslisted the wolverine asa candidatefor federallistingasa threatened or endangeredspecies(U.S. Fish and Wildlife Se*ice l9B5). To better determinethe status

and distributionof the wolverinein Idaho, I mailedquestionnaires to wildlife biologistsand registeredtrappersthroughoutldaho in 1985. The purposeof this paper is to report the results of the l9B5 survey. Methods During May 1985,questionnaires on wolverine sightingsweremailedto all Idaho Department of Fish and Game biologists,conservationofficers,and land managers; wildlife biologistsin Idahoemployedby the U.S.ForestService,U.S. Bureau of Land Management,U.S. Bureauof Reclamation,and the U.S. Fish and Wildlife Service; academiciansand graduatestudentsin biology, zoology,and wildlife departmentsat Idaho universitiesand colleges;NongameCiti zensAdvisoryCommittees;the NationalAudubon Societychaptersin Idaho;and statepark managers.Concurrently,similar questionnarres were rnailedto trapperslicensedby the IdahoDepart, ment of Fish and Came. The questionnairesent to biologistsasked respondents to provideinformationon the date, location(placename,county,latitude/longitude or township-range-section), habitat type, and type of observation (animal, tracks, scat) they had made,if any, during the last 25 years.Biologists werealsoaskedto providethe name,address,and phonenumber of other peoplethey knew who had informationon wolverinesightingsin the sIate. NorthwestScience,Vol. 62, No. 4, l9B8

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Eachlicensedtrapperwassenta coverletterexplaining the purposeof the wolyerinesuney along with an addressedand postage-paid p o s l c a r fdo r t h e mt o r e t u r nw i t hi n f o r m a t i o on n wolverinesightings.The postcardprovidedthem with space to list their name, address,and t e l e p h o nneu m b e r t: h e i rg e n e r atlr a p p i n ga r e a ; a "yes" or "no" on whetherthey had trapped ot seenwolverinesor wolverinesign during the Iast 25 years; and the date and area r,rhere wolverinesor sign had been observed. Follow-uptelephonecallsweremadeto all individuals(biologistsand trappers)that responded positivelyto the wolverinesurvey,Confirmedwolvedne reportsconsistedof either a photograph or a carcass.For thosereportsthat were not confirmed (i.e., sightings of wolverines or tracks), respondents wereaskedfor a descriptionof the animal, thei leyel of confidencethat they had seena wolve oe or tracksof a wolverine,whether theyhad previouslyseena $olverine,the distance and amount of time of their observation,and their amountof experienceas a biologistor trapper. If the observerlackedconfidencein his/her observation,poorly describedthe animal,or saw it for a short time spanand/orat a gteat distance, I did not includethe wolverineobservationin this report. Sightings of wolverinesor wolverine tracksincludedin this paper are referredto as probablereports.

Resultsand Discussion 0ne hundredeighty-fiveof the 296 biologistswho weremailedthe questionnaire respondedto the survey for a return rate of 62.5 percent (Table l). Thirty-seven of these185 reponsesreported o b s e r v a l i o nosf r n o l v e r i n eosr * o l r e r i n e s i g n . Thirty-fiveof 427 respondingtrappersreported o b s e r v a t i o nosf w o l r e r i n e so r w o l v e r i n es i g n . Somepositiveresponses from biologistsand trappers included information on more than one w o l v e r i n er e p o r t .T h i r t y . f i v ep o s i t i v er e p o r t s r e l u r n e db 1 b i o l o g i s tos r t r a p p e r sw e r Fn o t i n cluded in this report due to insufficient information or lack of credibilityin the report. The surveyresultedin only l0 confirmed reportsof wolverinein Idahobetveen1960and 1986 (Table l, Figure 1).' Eight of these l0 'lnformation

on rhe obsener'sname,affiliation,date ofobser, vation, and exact location of obseryationfor confirmed and probabie .eports is available fron the author on request.

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reportscamefrom northernIdaho north of the LochsaRiver, and all but two reports rderefrom nationalforestlands.Five of the reportsoccurred between1960and 19?5while the other half occurred between1976and 1986. I documented89 probablereportsof wolverinesor wolverinetracks between1960and February1987(Tablel, Figure l). Nine of these reports(10%)occurredfrom 1960-1969, 28 (32%) from 1970-1979, and 52 (58%)from 1980-1987. Twenty-onepercentof the probablereportswere f r o mB o n n p a r n dB o u n d a r cy o u n t i e isn e x l r e m e northernIdaho.Eighteenpercentof the reports occunedin the north-centralcountiesof Clearlvater and Idaho, and another22 percent came from a clusterof south-central counties(Custer, E I m o r pB . l a i n e .C a m a sa. n d B o i s e ) . At leastthree areasin ldaho, from which confirmed and probablereportswerereceived,appear to containwolverines. Theseareasare the Selkirk Mountainsadjacentto and north of Priest Lake,the Lochsaand Kelly Creekdrainages,and the headwatersof the South Fork and Middle Forhsof the BoiseRiver (i.e.,Sawtooth-Smoky Mountains)(Figure l). Severalconfirmedreports alsooccurredin the PurcellMountainsnorth of the KootenaiRiver,but all ofthesereportswere prior to 1965.Becausethe longevityofwolverines in the wild is 8-10 years(Wilson 1982),these reportswere not indicativeof present-day occupancyby wolverines. Concentrationsof probablereportsindicated that wolverinesalso likely occur in Fremont Countyadjacentto YellowstoneNationalPark and in the upper St. Joe and Coeurd'AleneRiver drainages.The Selwayand SalmonRiver drainagesin centralIdahowereconspicuously absent of any confirmedreportsand containedonly a few probablereports. The lack of wolverine reportsin theseareasmay reflecttheir roadless nature and low densityof people,particularly biologistsand trappers.If we assumethat wolverinesdo occur in theseareas,then the presenlday distributionof wolverines in Idahois in the mountainouspoftionsof the statefrom the South Fork of the BoiseRiver north to the Canadian border. In a study of wolverinesin westernMontana, Hornockerand Hash(198t)concludedthat wily h e r eh u m a na c t i v i l y d c r n e sor r r e m o t er " o u n t rw wasminimal appearedessentialto maintaining

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Figure t. Disrribution of wolverine reporls in Idaho, 1960-1987.See lexr for definilion of confirned and probable reports.

Wolverinein Idaho

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TABLE I . Sumnary of q uestionnairesmailed,responserates,and resultingnumbersof confirm€dand probablewolverinerepo.rs. S e el e r r f o . d e L a i l

Category

Numberof

Nunber of

Quesiionnanes Mailed

Quesrionnai.es R e t u r n e d( % )

Biologists

296+

Trappers

I,500

Total

I,?96

t3s (62.5%) 42?(28.s%) 612(34.t%)

N u m b e ro f Posilrye Respoms (%)

Contirmed Volverine Reporls

s7 (2070) 3s (8.2%)

6

72 (rt.gya)

4 t0

N u l n b e ro f P r o h a b l e Wolverine Reports Total

5 ? ++

Sightings

l6

32

l6

89

32

t6

+ Twentv'oneresponseswere receivedfron indiriduals nor included in the original (n=296) mailins. Eteren ofthe 2t .esponses w e r e p o s i t i v eT . h o s ep o s i t i v er e s p o n s etsh a t r e s u l t e di n p r o b a b l ew o l v e r i n er e p o r r s{ e . e i n c l u d e di n t h i s t a b t e( + + i .

a viable wolverinepopulation. Although results of this surveycan offer no insights to the viabili. ty of wolverinepopulationsin Idaho,it doesappearthat wolverines are occupyinglarge,mountainous,essentiallyroadlessareasin Idaho. In the Montana study, wolverines used both wildernessand non-wilderness areas,although the latter areaswere used primarily in winter whenhumanactivitv wasminimal. Suchmay also be the casein Idaho becausemany of our reports occurredduring winter. G. Koehler (pers. comm.) suggestedthat volverinesmay be increasingin northernIdaho due to numerousreports.Hoak et a/. (1982)made a similarconclusion for the wolverinein western Wvoming. Becausemore than half of the wolverine rcport"compiledduringthissurveyor"cuted betweenl9B0 and 1987,thereis a tendenc y t o s i m i l a r l ys u g g e stl h a l u o l v e r i n c a s re increasingin Idaho. However,such a conclusion couldbe misleading.In analyzingthe historical abundanceof wolverinesin Washingon, Johnson (1977)correctlypointedout that in earliertimes lessaccess wasavailableto remoteareasand the total numberof peoplein the field wasless.In a d d i t i o nn, o e f f o r t t o a s . e m b l ei n f o r m a t i o n on wolverinedistribution,such as in the present survev,rvasconductedin the past.Thus,the increasingnumberof wolverinereportsin Idaho from 1960 to l9B7 could just as easilybe attributedto greateraccess to remoteareas,more

LiteratureCited D a v i s ,V . B . 1 9 3 9 .T h e R e c e n rm a n m a l s o f I d a h o .C a x r o n P r i n t e r s ,C a l d r e l l , I d a h o . G a r d n e rC , . L . , W . B . B a l l s r d ,a n d R . H . J e s s u p1. 9 8 6 L . ons distance movement by an adulr wolverine.J. Mam, mal.67:603.

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people in the field, and no prior surveyefforts, as to increasingnumbersof wolverinesin the state.

Surveyssuchasthis onecanprovideinsights to the distributionof a speciesbut are of little aid ir estimatingpopulationsize.Hornocker's and Hash's (1981)study in wesrernMontana showedthat wolverinesoccupy annual home rangesof approximately 400km,. A recentstudy of r,yolverines in Alaska documenteda long distancemovementof 378 km by an adult wolverine (Gardner et al, 1986). In addition, longevityof wolverinesin the wild is 8-10years with a possiblemaximumof l8 years(Wilson 1982).Thus, over severalyears a small number of individualscould be responsible for a large number of sightingsover widespreadareasin Idaho. Resultsof this survey indicate where wolverineslikely occur in the state. What is needednow is informationon the size,status,and ecologyof wolverinepopulationsin Idaho. Acknowledgments K. Reesekindly assistedin the distributionof the questionnaire.Many thanks are due to G. Kalteneckerand P. Petersonfor assistance in mappirg and computerizingdata from the survey.Thanksalsoto J. Beecham,B. W. 0'Gara, W. Melquist,and two anonymousreviewersfor helpful commentson the manuscript. Hoal, J. H., J. L. Weaver,and T. W. Clark. t982. Wotyerines i n { e s t e r n W y o n i n g . N o r t h { . S c i . 5 6 : 1 5 9t 6 t . H o r n o c l e r ,M . C . , a n d H . S . H a s h . 1 9 8 t . E c o l o g ] o { t } e w o l y e r i n ei n n o f r h w e s r e r n M o n r a n a .C a n . J . Z o o l . s9:1286-I30r.

. h i s t o r i c aal n a l y s i so f { o l v e . i n e a b u n ,ohnsonR , . E . 1 9 7 ?A dance and distrib!rtion in Washington. Murrelet 58:13-16. L a r r i s o nE , . J . , a n d D . R . J o h n s o n1. 9 8 1 M . annals of ldaho. U n i v e r s i t yP r e s so f I d a h o , M o s c o w ,I d a h o . Penge)ly,W. L. 1951.Recentrecordsoi "olverines in Idaho. I. Manmal 32:224-225.

U.S. Fish and Wildli{e Service. 1985. Endangered and t h r e a t e n e dw i l d l i f ea n d p l a n t s ;r e v i e wo f v e n e b r a t e wildlife. Federal Register 50,3795?-3?967. Vilson, D. E. 1982V . o l v e r i n e ./ n J . A . C h a p n a na n d C . A . Feldhamer(eds.)Wild Mannals o{ North America, J o h n s A o p k i n s U n i v e r s i t y P r e s s , B a l t i m o r e .P p . 644.652.

Receioed, 10 December1987 Acceptedfor publication 22 February 1988

Wolverinein Idaho

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