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Factors affecting settling survival and viability of black bears reintroduced to FelsenthalNational Wildlife Refuge ArkansasAuthor(s) Brandon J Wear Rick Eastridge Joseph D ClarkSource Wildlife Society Bulletin 33(4)1363-1374Published By The Wildlife SocietyDOI httpdxdoiorg1021930091-7648(2005)33[1363FASSAV]20CO2URL httpwwwbiooneorgdoifull1021930091-764828200529335B13633AFASSAV5D20CO3B2

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The Interior Highlands Gulf Coastal Plain andDelta regions of Arkansas once supported largenumbers of black bears (Ursus americanusHolder1951) Unregulated market hunting coupled withextensive habitat loss led to the extirpation of bearsthroughout most of the state by the early 1900s

(Smith et al 1991) One small population of bearspersisted and has since recovered in what is nowWhite River National Wildlife Refuge (NWR) locat-ed in the Delta region (Holder 1951 Smith 1985Smith et al 1991White 1996)

The Gulf Coastal Plain of Arkansas was not inhab-

ARKANSAS BEAR REINTRODUCTION 1363

Wildlife Society Bulletin 2005 33(4)1363ndash1374 Peer refereed

Address for Brandon J Wear Department of Forestry Wildlife and Fisheries 274 Ellington Plant Sciences Building University ofTennessee Knoxville TN 37996 USA present address for Wear Louisiana Department of Wildlife and Fisheries 2000 QuailDrive RM 436 Bator Rouge Louisiana 70898 Address for Rick Eastridge Arkansas Game and Fish Commission 2 NaturalResources Drive Little Rock AR 72205 USA Address for Joseph D Clark United States Geological Survey Southern Appalachi-an Research Branch 274 Ellington Plant Sciences Building University of Tennessee Knoxville TN 37996 USA e-mailjclark1utkedu

Factors affecting settling survival andviability of black bears reintroduced to

Felsenthal National Wildlife RefugeArkansas

Brandon J Wear Rick Eastridge and Joseph D Clark

Abstract We used radiotelemetry and population modeling techniques to examine factors related topopulation establishment of black bears (Ursus americanus) reintroduced to FelsenthalNational Wildlife Refuge (NWR) Arkansas Our objectives were to determine whether set-tling (ie establishment of a home range at or near the release site) survival recruitmentand population viability were related to age class of reintroduced bears presence of cubstime since release or number of translocated animals We removed 23 adult female blackbears with 56 cubs from their winter dens at White River NWR and transported them 160km to man-made den structures at Felsenthal NWR during spring 2000ndash2002 Total move-ment and average circuity of adult females decreased from 1 month 6 months and 1 yearpost-emergence (F214 =197 Plt0001 and F214 =576 P=0015 respectively) Meanfirst-year post-release survival of adult female bears was 0624 (SE=0110 SEinterannual=0144) and the survival rate of their cubs was 0750 (SE=0088 SEinterannual=0109) Thehoming rate (ie the proportion of bears that returned to White River NWR) was 13Annual survival for female bears that remained at the release site and survived gt1-yearpost-release increased to 0909 (SE=0097 SEinterannual=0067 Z=35 Plt0001) Basedon stochastic population growth simulations the average annual growth rate (λ) was 1093(SD=0053) and the probability of extinction with no additional stockings ranged from056ndash130 The bear population at Felsenthal NWR is at or above the number afterwhich extinction risk declines dramatically although additional releases of bears couldsignificantly decrease time to population reestablishment Poaching accounted for at least3 of the 8 adult mortalities that we documented illegal kills could be a significant imped-iment to population re-establishment at Felsenthal NWR should poaching rates escalate

Key words black bear Felsenthal poaching population model reintroduction Ursus americanusWhite River

Wear et al (Gene)qxp 372006 357 AM 363

ited by a reproducing population of bears althoughoccasional sightings of solitary animals werereported Bear populations in Arkansas and else-where in the Southeast often exist in small isolatedfragments of wooded habitat (Pelton 1991) andmay be more vulnerable to extinction because ofdemographic or stochastic events (Levins 1970Griffith et al 1989 Hanski 1996) Bears may not bewell adapted to colonize fragmented habitats bynatural dispersal (van Manen 1991 Clark et al2002) Although the considerable dispersal capa-bilities of male black bears have been well docu-mented (Kemp 1976 Young and Ruff 1982Schwartz and Franzmann 1992) female black bearstypically do not disperse residing instead within aportion of their motherrsquos home range (Kemp 1976Alt 1978 Rogers 1987a Schwartz and Franzmann1992) In addition bears have relatively low repro-ductive rates (Bunnell and Tait 1981) a characteris-tic that limits population growth and natural colo-nization ability (Hanski 1991 Hastings 1991) Thusreintroduction may be necessary to facilitate therecolonization process (Clark et al 2002)

Homing or philopatry (ie return to place of ori-gin) in black bears following translocation is com-mon (Rogers 1973 Beeman and Pelton 1976Rogers 1987b) and bears suffer increased associat-ed mortality (Rogers 1986 Fies et al 1987 Stiver1991 Comly 1993 Riley et al 1994 Eastridge andClark 2001) Thus homing is a major obstacle toblack bear reintroduction success (Eastridge andClark 2001 Clark et al 2002) Older bears femalesthe presence of cubs abundant food large translo-cation distances and physiographic barriers (egrivers mountain ranges) are thought to reducehoming propensity (Beeman and Pelton 1976Singer and Bratton 1980 McArthur 1981 Rogers1986 Fies et al 1987 Clark et al 2002) A winter-den technique was evaluated in Tennessee where-by denning females with neonates were removedfrom their dens and transported to dens at the rein-troduction site (Eastridge and Clark 2001) Thattechnique was shown to reduce total distancemoved from the release sites net distance movedmean daily distance moved circuity and mortalityrates (Eastridge and Clark 2001)

Although occasional sightings of solitary animalshad been reported in the Gulf Coastal Plain ofArkansas sightings of females and cubs had notbeen documented Consequently the ArkansasGame and Fish commission (AGFC) and the UnitedStates Fish and Wildlife Service (USFW) proposed a

plan to translocate bears to Felsenthal NWR in theGulf Coastal Plain from White River NWR wheresimilar habitat and flooding conditions occurred(Smith 1985 White 1996 Oli et al 1997) Ourobjectives were to 1) estimate survival recruit-ment and homing rates of translocated femaleblack bears and evaluate relationships betweenthose parameters and age class presence of cubsand time elapsed following translocation and 2)evaluate relationships between population viabilityand number of bears translocated time followingtranslocation and the manner in which varianceestimates were applied in stochastic simulations ofextinction risk

Study areaWhite River NWR was in the Lower Mississippi

Riverine Forest Province (Bailey 1995) and encom-passed portions of Arkansas Desha Monroe andPhillips counties in eastern Arkansas (Figure 1)This 65000-ha refuge varied from 5ndash16 km inwidth and contained a 145-km portion of the WhiteRiver Flooding inundated approximately 75 ofWhite River NWR annually most often during win-ter and spring

Felsenthal NWR was in the Southern MixedForest Province (Bailey 1995) and encompassedportions of Ashley Bradley and Union counties insoutheastern Arkansas (Figure 1) Felsenthal NWRwas about 26000 ha in size with about 4000 hacomprised of upland forest communities andgt16000 ha comprised of bottomland hardwoodsFelsenthal Lock and Dam approximately 5 kmnorth of Louisiana formed the 6000-ha FelsenthalPool which increased to gt14500 ha during winterflooding

Vegetation on both refuges occurred along a con-tinuum of decreasing flood tolerance from lowestto highest elevations (Fredrickson and Heitmeyer1988) Bottomlands contained willow oak (Quer-cus phellos) water oak (Q nigra) Nuttall oak (Qnuttallii) sweetgum (Liquidambar styraciflua)and sugarberry (Celtis laevigata) Overcup oak (Qlyrata) and bald cypress (Taxodium distichum)occurred on poorly drained sites especially back-water areas oxbows and depressions The uplandsites in and adjacent to Felsenthal NWR were dom-inated by loblolly pine (Pinus taeda) White RiverNWR was surrounded by agriculture

Climate was similar on the 2 refuges with abun-dant rainfall throughout the year Mean annual pre-

1364 Wildlife Society Bulletin 2005 33(4)1363ndash1374

Wear et al (Gene)qxp 372006 357 AM Page 1364

cipitation at White River and Felsenthal was 131and 143 cm respectively (National Oceanic andAtmospheric Administration [NOAA] 2000) Winterand spring were the wettest seasons with Marchprecipitation on both areas averaging about 14 cm

MethodsCapture and handling

We captured bears at White River NWR and atnearby Montgomery Island and Big Island duringsummer 1998ndash2001 with Aldrich spring-activatedfoot snares (Aldrich Animal Trap Company ClallamBayWash) We equipped snares with swivels andautomobile hood springs to minimize injuries tocaptured animals (Johnson and Pelton 1980) Weimmobilized captured bears with a 21 mixture ofketamine hydrochloride (Ketasetreg Fort DodgeAnimal Health Fort Dodge Ia) and xylazinehydrochloride (Rompunreg Bayer CorporationShawnee Mission Kan) We administered theimmobilization drug intramuscularly with a pushpole at a dosage of 44 mg of ketamine hydrochlo-ride and 22 mg of xylazine hydrochloride per kg ofestimated body mass We monitored body temper-aturepulseand respiration throughout each immo-

bilizationWe classified adult fe-

male bears that showedvaginal swelling or a pink-ish vaginal discharge asbeing in estrus (Wathen1983) We consideredbears in estrus or not lac-tating during summertrapping to be prospec-tive candidates for wintertranslocation and fittedthese bears with MOD-500 radiocollars (TelonicsIncorporatedMesa Ariz)We extracted the firstupper premolar fromeach bear for aging by ce-mentum annuli analysis(Willey 1974) At the con-clusion of handling eachbear we administeredyohimbine hydrochloride(Lloyd Laboratories Shen-andoah Ia) an antagonistto xylazine hydrochloride

through the sublingual vein at a dosage of 02mgkg of body mass We conducted all proceduresaccording to University of Tennessee Animal CareProtocol 906

TranslocationWe tracked females trapped and radiocollared

the previous summer to their winter dens duringFebruary and March2000ndash2002 to document pres-ence of cubs Because gt90 of black bears at WhiteRiver NWR used elevated tree cavities for winterdens (Oli et al 1997) accessibility of dennedfemales was determined in large part by the overallstability of the den treedimensions of den entranceand cavity height of opening and distance to denfloor

Once translocation candidates had been identi-fied we returned to the den site in March to earlyApril ascended the den tree and immobilized thefemale using either push pole blowgun or dartrifle We removed the cubs and secured andremoved the adult female in a cargo net or safetyharness We applied mentholated salve to the bod-ies of cubs and to the nose of the adult female tohelp prevent cub abandonment (Eastridge 2000)and intramuscularly injected the adult female with

Arkansas bear reintroduction bull Wear et al 1365

Figure 1 Location of White River National Wildlife Refuge and Felsenthal National WildlifeRefuge Arkansas


oxytocin to promote lactation Finally we placedthe cubs with the female in an aluminum cage andtransported the family group by vehicle toFelsenthal NWR

We normally held bears overnight at FelsenthalNWR and reimmobilized them the following dayWe placed the female and cubs in wooden denboxes (12 m L times 09 m W times 09 m H with a 56-cm-diameter circular opening at the front) that we con-structed and placed in various locations at therelease site We established those den sites in areasabove the 100-year flood stage in elevation and iso-lated from areas of high public use

RadiotelemetryWe radiomonitored recently translocated bears

each day to determine the date of den emergenceas evidenced by increased movements For the firstmonth following den emergence we radiolocatedtranslocated bears daily by ground or aerial teleme-try We gradually reduced the frequency to weeklyradiolocations for each bear

We performed ground telemetry with a modelTR-4 receiver (Telonics Incorporated Mesa Ariz)and a 5-element Yagi antenna (Wildlife MaterialsInc Carbondale Ill) using triangulation and theloudest signal method (Springer 1979) For eachlocation we obtained 3 azimuths that formed anglesbetween 30o and 150o collecting those azimuthswithin a time interval of lt50 minutes If trianglesformed by the 3 azimuths were gt2 ha in size wecollected additional azimuths Those procedureshelped identify spurious azimuths and significantanimal movement while azimuths were being col-lected (Schmutz and White 1990) We obtainedmost radiolocations between 0800 and 2000 hours

We obtained aerial locations from fixed-wing air-craft with an H-antenna (Telonics IncorporatedMesa Ariz) attached to each wing strut and con-nected with coaxial cable to a switch box andtelemetry receiver inside the cabin We obtainedlocations by flying the aircraft toward the loudestsignal When the aircraft was directly over the bearwe recorded the position with a Global PositioningSystem

We estimated the accuracy of our bear radioloca-tions in 2000 and 2001 by placing radiocollarsthroughout the study area in locations similar toactual bear locations We estimated the location ofeach test collar with the same proceduresdescribed above for ground and aerial telemetryWe then calculated distance from the actual loca-

tion to the estimated location to obtain an error dis-tribution (Schmutz and White 1990 Zimmermanand Powell 1995)

MovementsTranslocations could result in mortality homing

or settling we used several parameters to quantifyand categorize these types of movements Meandaily movement a measure of rate of travelwas cal-culated by dividing total movement by number ofdays the bear required to move that distance Wedetermined net movement a measure of release-site fidelity or settling by calculating the straight-line distance between the starting point and theending point We determined circuity a measure ofdirected movement by dividing net movement bytotal movement For example a circuity value of 0indicated the animal returned to its starting pointor never left it (ie net movement=0) whereas avalue of 1 indicated the animal moved directly awayfrom its starting point along a linear pathway (ienet movement = total movement Eastridge andClark 2001) We calculated total movement andmean daily movement with the Animal Movementextension (Hooge and Eichenlaub 1997) inArcViewregreg (Environmental Systems ResearchInstitute Incorporated Redlands Calif) To charac-terize movement behavior subsequent to releasewe compared circuity total movement net move-ment and daily movement by time after den emer-gence (ie 1 month 6 months and 1 year) withanalysis of variance only using bears for which anentire year of telemetry data had been collectedWe used log transformations of total movementnetmovement and daily movement to approximatenormality We estimated mean bearings of bearmovements subsequent to release and calculatedRaleighrsquos z-values to determine whether those bear-ings differed from random (White and Garrott1990 Hooge and Eichenlaub 1997) to evaluatewhether bears tended to return in the direction oforigin (ie White River NWR) We used linearregression to assess relationships between move-ment characteristics and bear age to determinewhether older bears were less likely to exhibithoming behavior

SurvivalWe used the Kaplan-Meier staggered-entry pro-

cedure (Pollock et al 1989) to estimate annual sur-vival of adult females during the period lt1 yearafter release and survival of those adult females



that survived gt1-year post-release Bears that lostradiocollars bears whose signals were lost beforethe completion of the study and bears that perma-nently left the area were censored at that time(Pollock et al 1989) We compared survival overthe 3 years of study with a log-rank test using a cor-rected Bonferonni critical value (P = 0053) andcompared survival lt1 year post-release with sur-vival gt1-year post release with a Z-test (Pollock etal 1989) We estimated homing rates by re-estimat-ing first-year post-release survival but treating sur-viving bears that permanently left the study area asmortalities We then subtracted that rate from thesurvival rate previously estimated to determine thehoming rate

We visually observed bear family groups at regu-lar intervals to assess survival of translocated cubsand litters We performed cub counts at 2 and 4months post-release when cubs were approxi-mately 4 and 6 months of age respectively We con-sidered sightings reported by the public to be validcounts if an individual female bear and her litterwere sighted on multiple occasions the same num-ber of cubs was reported each time and locationswere consistent with telemetry data

Population growth and viabilityWe used a population model (RISKMAN version

19000 Ontario Ministry of Natural ResourcesToronto On) to estimate population growth (λ)and probability of extinction RISKMAN employeda Monte Carlo approach to estimate the uncertain-ty of population trajectories given estimates of pop-ulation size and demographic parameters (Taylor etal 2001) The model was based on estimates of cubsurvival litter survival subadult male and femalesurvival adult male and female survival litter pro-duction rate and the probability of producing 1-2- 3- or 4-cub litters Litter survival was the proba-bility that gt1 cub in a litter survived Litter pro-duction rate was the probability that unencum-bered females (ie without the previous yearrsquoscubs) would produce a litter Taylor et al (19872001) suggested using interannual variation of rateparameters in RISKMAN rather than pooled varia-tion therefore we used interannual standard errors(SEinterannual) for vital rate parameters for our sto-chastic simulations We estimated male survivalrates litter production rates and litter size proba-bilities from data collected at White River NWR (REastridge AGFC unpublished data) Male survivalat White River was estimated with Cormack-Jolly-

Seber techniques (Burnham et al 1987 Lebreton etal 1992) and recruitment statistics were based onvisual cub counts (R Eastridge AGFC unpublisheddata)

Estimates of variance of population parameterstypically are a product of both parameter uncer-tainty and environmental variability (White 2000)RISKMAN allowed the partitioning of that varianceinto parameter and environmental componentsParameter uncertainty is mimicked in RISKMAN byselecting parameter values from a user-defined dis-tribution and applying those values at the begin-ning of each simulation trial Environmental varia-tion is mimicked by reselecting parameter valuesfor each year of the simulation trial We partitionedvariance at 75 for parameter uncertainty and 25for environmental variability (7525) and thereverse (2575) to evaluate sensitivity of modeloutcomes to different variance proportionments(Taylor et al 2001 2002) We used the covarianceoption in RISKMAN to simulate non-independenceof parameter variances because environmentalvariation likely would affect both survival andreproductive rates of all age classes and the covari-ance option would allow for this and other corre-lated effects in the stochastic trials We did notinclude density-dependent effects in the simula-tions

We performed 5000 stochastic simulations foran initial population size of 28 (the estimated 2003population of adults and cubs with no additionalstockings) We used the estimated standing age dis-tribution as the starting condition to estimate λover a 10-year period We estimated the proportionof trials in which the population declined to extinc-tion during a 50-year period We then performed1000 stochastic simulations to estimate extinctionrates given different initial population sizes withstable age distribution starting conditions

ResultsTranslocation

We translocated 23 adult female black bears witha cumulative total of 56 cubs from White RiverNWR to Felsenthal NWR (approximately 160 km)We translocated 6 adult females and 15 cubs 4adult females and 10 cubs and 13 adult females and31 cubs to Felsenthal NWR from 25ndash29 March2000 27 Februaryndash13 March 2001 and 12 Marchndash4April 2002 respectively Other than cubs no malebears were translocated



MovementsWe obtained 75 locations of

test radiocollars from June2000 through August 2001Proportions of test locationsobtained by aerial and groundtelemetry approximated theproportion of bear locationscollected by each of thosemethods during the study Themean distance from the esti-mated location to the actuallocation was 109 m for aerialand ground telemetry com-bined 95 of the estimatedlocations were within 324 mof the actual location

Total movement of translo-cated adult female bears duringthe first month after den emer-gence averaged 427 km (SE=141) and ranged from 2ndash251km Daily movements netmovementsand circuity for thefirst month averaged 923 m (SE=324) 266 km (SE=94) and047 (SE=006) respectively

Total movement of survivingadult females 6 months afteremergence averaged 2226 km(SE = 495) and ranged from52ndash747 km Mean daily move-ment net movement and cir-cuity the first 6 months aver-aged 1132 m (SE=253) 342km (SE = 77) and 014 (SE =003) respectively

Total movement of adult fe-males that survived to 1 yearafter emergence averaged 3112km (SE = 1163) and rangedfrom 110ndash750 km Mean daily movement net move-ment and circuity after 1 year averaged 782 m (SE=291)331 km (SE=131) and 009 (SE=004) respec-tively Total movements and circuity differed by timesince emergence (F214 =197 Plt0001 and F214 =576 P = 0015 respectively) but net movements(F214 =160 P=0236) and daily movements (F214 =324 P=0070) did not Only 4 of 20 radiocollaredbears had mean bearings that differed from random(Raleighrsquos zgt204 Plt005) Of those 4 howevermean bearings were in the direction of White River

NWR (about 40o) ranging from 202ndash682o (Figure2) Circuity and net movement after 6 months wereless for older bears (r2 = 0423 P = 0012 and r2 =0423 P=0012 respectively) We detected no otheragendashmovement relationships (Pgt0104)

SurvivalWe estimated survival of 23 adult female bears

monitored between March 2000 and January 2003Three of 8 mortalities were the result of poachingand poaching was the suspected cause of an addi-


Figure 2 Post-release movements of black bears reintroduced to Felsenthal NWRArkansas 2000ndash2002


tional death One bear was killed due to a vehiclecollision and cervisitis contributed to the death ofanother We were unable to determine causes ofthe remaining 2 mortalities

First-year post-release survival of adult female bearstranslocated in 2000 2001 and 2002 was 0833 (SE=0170) 0333 (SE=0193) and 0595 (SE=0155) re-spectively (Table 1)but differences by year were notdetected (χ2

0015lt1857 1 df Pgt0173) Overall firstyear survival was 0624 (SE = 0110 SEinterannual =0144) Annual second-year survival for all femalebears that survived gt1-year post-release was 0909(SE = 0097 SEinterannual = 0067) which was higherthan survival during the first year after release (Z=350 Plt0001) Likewise gt1-year post-release sur-vival did not differ by year (χ2

0015 lt060 1 df Pgt0438) Cub survival was 0750 (SE=0088 SEinteran-

nual=0109) and litter sur-vival was 0900 (SE=0090SEinterannual = 0167) nei-ther differed by year(χ2

0015lt1611 dfPgt0205and χ2

0015 lt 20 1 df P gt0157 respectively) Whenwe excluded bears thatsuccessfully returned toWhite River NWR (n=4) insurvival rate estimates theoverall survival rate de-clined to 0492 (SE=0101ie492 of the bears rein-troduced to FelsenthalNWR survived and re-mained there or elsewherein the Gulf Coastal Plainafter 1 year) Conversely133 (x- = 0133 SE =0140) of the reintroducedbears returned to WhiteRiver NWR

Population growth and viabilityBased on the 2003 standing age distribution and

population parameter estimates (Table 2) our sim-ulations resulted in a mean population size after 10years of 743 (SD=395 7525 variance proportion-ment) bears at Felsenthal NWR with a geometricmean λ of 1093 (SD=0053) Variance was highlower and upper 95th percentiles were 18 and 171respectively The median population size after 10years (69) was lower than the mean because upperestimates of population size inflated the mean buthad less effect on the median Given the standingage distribution the probability of declining toextinction during a 50-year period ranged from056ndash130 depending on variance proportion-ment (2575 and 7525 respectively Figure 3)Extinction was possible throughout the 50-year


Table 1 Survival rates (S) of bears reintroduced to Felsenthal National Wildlife Refuge Arkansas 2000ndash2003

Adult female Adult femaleCub survival Litter survival (lt1 year after release) (gt1 year after release)

Year Deaths S SE Deaths S SE Deaths S SE Deaths S SE

2000 3 0625 0171 0 1000 0000 1 0833 0170 0 1000 00002001 0 1000 0000 1 0500 0354 2 0333 0193 1 0800 02072002 3 0786 0110 0 1000 0000 4 0595 0155 0 1000 0000Overall 6 0750 0088 1 0900 0090 7 0624 0110 1 0909 0097SE interannual 0109 0167 0144 0067

Figure 3 Probabilities of extinction for bears reintroduced to Felsenthal NWR Arkansas givena starting population size of 28 and standing age distribution The dark solid line represents avariance proportionment of 75 attributable to the parameter estimate and 25 to environ-mental variation (7525) and the dotted line represents a 2575 proportionment


period for the 7525 variance proportionment butdeclined after about 30 years for the 2575 propor-tionment

The extinction probability was successively lesswith greater starting population sizesbut the sever-ity of that effect declined after an initial populationsize of about 20 was reached (Figure 4) Estimatesof extinction risk with 25 of the variance attribut-able to parameter uncertainty and 75 to environ-

mental variation were lower than the reverse pro-portionment (Figure 4) but the relationship withinitial population sizes was similar

DiscussionTime since reintroduction was an important

aspect of bear movement dynamics Generallybears that returned home or exhibited homingbehavior did so within the first month followingden emergence Philopatric females traveled quick-ly and in a directed path not appearing to be con-strained by landscape attributes or land covertypes In contrastbears that extensively moved butdid not return home tended to follow riverscreeksor bayous Non-homing bears generally reducedmean daily movements during the first monthReintroduced bears in Tennessee exhibited similarrestricted movements after 9 months with mostrestricting their movements within 6 months aftertranslocation (Eastridge 2000)

The presence of cubs also was an important fac-tor in reintroduction success In all but 2 instancesfemales that attempted to return home during ourstudy had no cubs when observed Furthermorewhen the 2 females with surviving cubs that leftFelsenthal NWR were recaptured and translocatedback to Felsenthal they eventually establishedhome ranges there In previous studies of bears

translocated in the South-east females with cubsalso exhibited reducedpost-release movementsand demonstrated greateraffinity to the reintroduc-tion site than unencum-bered females (Comly1993 Eastridge and Clark2001)

Mean first-year survivalof adult females translo-cated to Felsenthal NWR(0624) was lower thanthat of winter-releasedbears in Tennessee (088Eastridge and Clark 2001)but was greater than thesurvival rates of hard-released (ie nondenningbears with no acclimationperiod at the release site)black bears in Wisconsin


Table 2 Black bear population parameter estimates used forpopulation modeling Felsenthal National Wildlife RefugeArkansas 2003

Parameter x- SEinterannual

Cub-of-the-year (COY) survivala 0750 0109Litter COY survivala 0900 0167Subadult (1ndash3) survival (M) b 0690 0150Subadult (1ndash3) survival (F) a 0909 0067Adult (4+) survival (M)b 0690 0150Adult (4+) survival (F)a 0909 0067Litter production rateb 0733 0019Probability of COY litter = 1b 0416Probability of COY litter = 2b 0324Probability of COY litter = 3b 0232Probability of COY litter = 4b 0028Mean litter sizeb 1872 0096

a Based on data from this studyb Based on data from bears at White River NWR (R

Eastridge AGFC unpublished data)

Figure 4 Probabilities of extinction for bears reintroduced to Felsenthal NWR Arkansas givendifferent starting population sizes (stable age distributions) and a variance proportionment of75 attributable to the parameter estimate and 25 to environmental variation (light line) and25 attributable to the parameter estimate and 75 to environmental variation (dark line)


(056 Massopust and Anderson 1984) or Virginia(037 Comly 1993) First-year post-release survivalof female bears translocated in 2001 (0333) wasnoticeably lower than first-year survival estimatesfrom 2000 (0833) and 2002 (0595) even thoughstatistical differences were not detected In 2001we translocated bears earlier in the year becauseextensive winter flooding at White River NWRforced many females from their winter dens Thetranslocated bears had younger possibly less-resilient cubs Those cubs suffered high mortalityrates after translocation which may have resultedin greater post-release movements and increasedmortality among adult females

In all instances (n=5) number of yearlings withadult females in winter dens corresponded withnumber of cubs observed during cub counts theprevious autumn Our visual assessments were aneffective alternative to affixing radiotransmitters toyoung cubs (LeCount 1987 Echols et al 1999) Wewere able to identify a period of time when cubssuffered higher mortality although the cause ofdeath could not be determined All cubs weobserved gt4 months after release (6 months of age)survived to yearling age That finding was similar topreviously reported black bear cub survivorship(Erickson 1959 Rogers 1977 LeCount 1987)

Although we did not have sufficient data to esti-mate the proportion of variance in model inputs

attributable to parameteruncertainty versus envi-ronmental variation ourabsolute estimates ofextinction were relativelyinsensitive to the vari-ance proportionment inRISKMAN However thepattern of extinction var-ied with variance propor-tionment extinctionswere possible throughoutthe 50-year period withthe 7525 proportionmentcompared with mostextinctions occurringwithin 30 years with the2575 proportionmentThat was because the7525 simulations werelargely determined by theinitial randomized start-ing values and conse-

quently extinction probabilities did not decrease asthe population size increased over timeas were the2575 simulations Regardless of variance propor-tionment extinction probabilities decreased mostrapidly when we increased the starting populationsize in our simulations from 5 to 20 adults withcubs and was less affected by starting populationsgt20

We documented 1 instance when females bredand produced cubs at Felsenthal NWRout of 3 pos-sible occasions in 2002 and 1 of 1 in 2003 (x- =0500 SEinterannual = 0333) Those females werepresent at Felsenthal NWR and were not encum-bered with cubs during the previous breeding sea-sons thus breeding necessarily occurred atFelsenthal We documented 2 unmarked males onFelsenthal NWR during our study and we speculatethat nontranslocated males sired those cubs Onemale incidentally captured by a landownerwas tooold (gt3) to have been reintroduced as a cub Wecaptured another male while attempting to snareand recollar a translocated female MicrosatelliteDNA analysis indicated that this young malethough not one of the cubs translocated toFelsenthal was closely related (T King UnitedStates Geological Survey personal communication)and was probably a natural immigrant from theWhite River NWR population We did not docu-ment any non-reintroduced adult females at


Most female bears at White River National Wildlife Refuge denned in large trees Photo byClint Turnage


Felsenthal NWR The low litter production rate wasnot unexpected given the low numbers of breed-ing-age males present at Felsenthal When we mod-eled extinction risk with the 050 estimate of litterproduction during the first 10 years of populationreestablishment the risk of extinction during thatperiod only slightly increased (016 to 038)

We based our population projections on theassumption that habitat conditions would result inconstant survival and production rates over timeWe did not model the potential for declining habi-tat quantity and quality in the region in the futureLikewise we did not model density effects whichcould alter vital statistics as the populationapproaches carrying capacity Our estimates ofrisk therefore are useful for comparing variousmanagement scenarios and less useful as absolutemeasures of risk of population decline below spe-cific thresholds

Management implicationsThe den boxes proved to be an effective alterna-

tive to locating natural den sites at the reintroduc-tion area Females with cubs generally remained inthe den boxes for the few weeks prior to the nor-mal time of den emergence We were limited by theavailability of dry sites for den-box placement atFelsenthal NWR but we plan to test den boxesplaced on trees in inundated areas

Numerous studies have emphasized the impor-tance of releasing an adequate number of foundingindividuals to ensure population establishment(Griffith et al 1989 Smith and Clark 1994 Saltz1995Wolf et al 1996 Pelton and van Manen 1997)but there is a point of diminishing returns at whichadditional stockings become less effective(Eastridge and Clark 2001) It appears that thegreatest effect of increased stockings of bears atFelsenthal NWR has already been achievedHowever time to achieve population reestablish-ment goals could be accelerated with additionalstockings largely due to the relatively low popula-tion growth rate

At least 3 of 8 adult female mortalities were theresult of poaching We consider this level of poach-ing to be a potential obstacle for bear populationreestablishment at Felsenthal NWR Althoughgt70 of local residents surveyed prior to this studysupported bear reintroduction (R Eastridge AGFCunpublished data)even a minimal number of oppo-nents could have a dramatic impact on the success

of the project if poaching escalates Education pro-grams should strive to inform a generally support-ive public that the actions of a few threaten thebear reintroduction program

Finally extensive post-release movements oftranslocated bears should be expected andexplained to the public The release site should beviewed only as a starting point with settling any-where in the region accepted as a criterion for suc-cessful reintroduction In our study the local newsmedia tended to emphasize the nonsuccessfulreleases (ie mortality homing) thus detractingfrom the overall success of the project

Acknowledgments We wish to express ourappreciation to Arkansas Game and FishCommission the University of TennesseeDepartment of Forestry Wildlife and Fisheries theUnited States Geological Survey and the UnitedStates Fish and Wildlife Service for providing fund-ing housing personnel vehicles and otherresources We would like to acknowledgeAnderson-Tully Deltic Timber Corporation GeorgiaPacific and Plum Creek timber companies forallowing access to their lands during this projectH Allen and members of the Montgomery IslandHunting Club provided housing transportationandvolunteers to aid in trapping bears on their landsThanks go out to all of the dedicated personnelfrom the Arkansas Game and Fish CommissionWhite River NWR and Felsenthal NWR for theirassistance and to J Goad for conducting theradiotelemetry flights CTurnage was an especial-ly valuable member of our field crew J Langstonprovided logistical support We conducted all pro-cedures according to University of TennesseeAnimal Care Protocol 906 Finally we deeplyappreciate the editorial comments of F van ManenS King and D Etnier along with the AssociateEditor and anonymous reviewers on earlier draftsof this manuscript

LLiitteerraattuurree cciitteeddALT G L 1978 Dispersal patterns of black bears in northeast-

ern Pennsylvania ndash a preliminary report Eastern Workshopon Black Bear Management and Research 4186ndash199

BAILEY R G 1995 Description of ecoregions of the UnitedStates United States Department of Agriculture PublicationNumber 1391

BEEMAN L E AND M R PELTON 1976 Homing of black bears inthe Great Smoky Mountains National Park InternationalConference on Bear Research and Management 387ndash95



BUNNELL F L AND D E N TAIT 1981 Population dynamics ofbears ndash implications Pages 75ndash98 in CW Fowler and T DSmitheditors Dynamics of large mammal populations JohnWiley and Sons New York New York USA

BURNHAM K P D RANDERSON G CWHITE C BROWNIE AND K HPOLLOCK 1987 Design and analysis methods for fish survivalexperiments based on releasendashrecapture AmericanFisheries Society Monograph 5

CLARK J D D HUBER AND C SERVHEEN 2002 Bear reintroduc-tions lessons and challenges Ursus 13335ndash345

COMLY L M 1993 Survival reproduction and movement oftranslocated nuisance black bears in Virginia ThesisVirginiaPolytechnic Institute and State University Blacksburg USA

EASTRIDGE R 2000 Experimental repatriation of black bears tothe Big South Fork area of Kentucky and Tennessee ThesisUniversity of Tennessee Knoxville USA

EASTRIDGE R AND J D CLARK 2001 Evaluation of 2 soft-releasetechniques to reintroduce black bears Wildlife SocietyBulletin 291163ndash1174

ECHOLS K N J HIGGINGS VASHON D D MARTINA DVASHONAND MRVAUGHAN 1999 An expandable radiocollar for black bearcubs Wildlife Society Bulletin 31380ndash386

ERICKSONAW 1959 The age of self-sufficiency in the black bearJournal of Wildlife Management 23401ndash405

FIES M L D D MARTINAND GT BLANK JR 1987 Movements andrates of return of translocated black bears in VirginiaInternational Conference on Bear Research and Management7369ndash372

FREDRICKSON L H AND M E HEITMEYER 1988 Waterfowl use offorested wetlands of the southern United Statesan overviewPages 307ndash323 in M W Weller editor Waterfowl in winterUniversity of Minnesota Press Minneapolis USA

GRIFFITH B J M SCOTT J W CARPENTER AND C REED 1989Translocation as a species conservation tool status and strat-egy Science 245477ndash480

HANSKI I 1991 Single-species metapopulation dynamics con-cepts models and observations Biological Journal of theLinnean Society 4217ndash38

HANSKI I 1996 Metapopulation ecology Pages 13ndash43 in O ERhodes R K Chesser and M H Smith editors Populationdynamics in ecological space and time University ofChicago Press Chicago Illinois USA

HASTINGSA 1991 Structured models of metapopulation dynam-ics Pages 57ndash71 in M Gilpin and I Hanski editorsMetapopulation dynamics Academic Press London UnitedKingdom

HOLDERT H 1951 A survey of Arkansas game Arkansas Gameand Fish Commission Little Rock USA

HOOGE P NAND B EICHENLAUB 1997 Animal movement exten-sion to Arcview Version 11 Alaska Biological ScienceCenter United States Geological Survey Anchorage USA

JOHNSON K G AND M R PELTON 1980 Prebaiting and snaringtechniques for black bears Wildlife Society Bulletin 846ndash54

KEMP G A 1976 The dynamics and regulation of black bearUrsus americanus populations in northern AlbertaInternational Conference on Bear Research and Management3191ndash197

LEBRETON J D K P BURNHAM J CLOBERTAND D RANDERSON 1992Modelling survival and testing biological hypotheses usingmarked animals a unified approach with case studiesEcological Monographs 6267ndash118

LECOUNT A L 1987 Causes of black bear cub mortalityInternational Conference on Bear Research and Management

775ndash82LEVINS R 1970 Extinction Pages 77ndash107 in M Gerstenhaber

editor Some mathematical questions AmericanMathematical Society Providence Rhode Island USA

MASSOPUST J LAND R KANDERSON 1984 Homing tendencies oftranslocated nuisance black bears in northern WisconsinEastern Workshop on Black Bear Research and Management766ndash73

MCARTHUR K L 1981 Factors contributing to effectiveness ofblack bear transplants Journal of Wildlife Management 45102ndash110

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION 2000Climatological data annual summary Volume 105 Number13 Asheville North Carolina USA

OLI M K HA JACOBSONAND B D LEOPOLD 1997 Denning ecol-ogy of black bears in the White River National WildlifeRefuge Arkansas Journal of Wildlife Management 61700ndash706

PELTON M R 1991 Black bears in the Southeast to list or not tolist Eastern Workshop on Black Bear Research andManagement 10155ndash161

PELTON M RAND FTVAN MANEN 1997 Status of black bears inthe southeastern United States Pages 31ndash44 in A L Gaskiand D F Williamson editors Proceedings of the SecondInternational Symposium in the Trade of Bear Parts TrafficUSAWorld Wildlife FundWashington DC USA

POLLOCK K H S R WINTERSTIEN C M BUNCK AND P D CURTIS1989 Survival analysis in telemetry studies the staggeredentry design Journal of Wildlife Management 537ndash13

RILEYS JKAUNERDMACEAND MJMADEL 1994 Translocationof nuisance grizzly bears in northwestern Montana Ursus 9567ndash573

ROGERS L L 1977 Social relationships movements and popu-lation dynamics of black bears in northeastern MinnesotaDissertation University of Minnesota Minneapolis USA

ROGERS L L 1986 Effects of translocation distance on frequen-cy of return by adult black bears Wildlife Society Bulletin 1476ndash80

ROGERS L L 1987a Effects of food supply and kinship on socialbehaviourmovementsand population growth of black bearsin northeastern Minnesota Wildlife Monographs 97

ROGERS L L 1987b Factors influencing dispersal in black bearPages 75ndash84 in B D Chepko-Sade and Z T Haplin editorsMammalian dispersal patterns the effects of social structureon population genetics University of Chicago PressChicago Illinois USA

ROGERS M J 1973 Movements and reproductive success ofblack bears introduced into Arkansas Proceedings of theSoutheastern Association of Game and Fish Commissions 27307ndash308

SALTZ D 1995 Minimizing extinction probability due to demo-graphic stochasticity in a reintroduced herd of Persian fallowdeer Dama dama mesopotamica Biological Conservation7527ndash33

SCHMUTZ JAAND G CWHITE 1990 Error in telemetry studieseffects of animal movement on triangulation Journal ofWildlife Management 54506ndash510

SCHWARTZ C C AND A W FRANZMANN 1992 Dispersal and sur-vival of subadult black bears from the Kenai PeninsulaAlaska Journal of Wildlife Management 56426ndash431

SINGER F JAND S P BRATTON 1980 Black bearhuman conflictsin the Great Smoky Mountains National Park InternationalConference on Bear Research and Management 4137ndash149



SMITH K GAND J D CLARK 1994 Black bears in Arkansas char-acteristics of a successful translocation Journal ofMammalogy 75309ndash320

SMITH K G J D CLARK AND P S GIPSON 1991 History of blackbears in Arkansas over-exploitation near elimination andsuccessful reintroduction Eastern Workshop on Black BearResearch and Management 105ndash14

SMITHT R 1985 Ecology of black bears in a bottomland hard-wood forest in Arkansas Dissertation University ofTennessee Knoxville USA

SPRINGER JT 1979 Some sources of bias and sampling error inradio triangulation Journal of Wildlife Management 43926ndash935

STIVER W H 1991 Population dynamics and movements ofproblem black bears in Great Smoky Mountains NationalPark Thesis University of Tennessee Knoxville USA

TAYLOR M K F BUNNELL D DEMASTER R SCHWEINSBURG AND JSMITH 1987 Anursus a population analysis system for polarbears (Ursus maritimus) Ursus 7117ndash125

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TAYLOR M K M OBBARD B POND M KUCAND DABRAHAM 2001RISKMAN stochastic and deterministic population modelingRISK MANagement decision tool for harvested and unhar-vested populations Government of Nunavut IqaluitNunavitTerritory Canada

VAN MANEN FT 1991 A feasibility study for the potential rein-troduction of black bears into the Big South Fork Area ofKentucky and Tennessee Tennessee Wildlife ResourcesAgencyTechnical Report Number 91ndash3 Nashville USA

WATHENW G 1983 Reproduction and denning of black bearsin the Great Smoky Mountains Thesis University ofTennessee Knoxville USA

WHITE G C 2000 Population viability analysis data require-ments and essential analyses Pages 289ndash331 in L Boitaniand TKFullereditors Research technologies in animal ecol-ogy controversies and consequences Columbia UniversityPress New York New York USA

WHITE G C AND RA GARROTT 1990 Analysis of wildlife radio-tracking data Academic Press San Diego California USA

WHITETH JR 1996 Black bear ecology in forested wetlands ofthe Mississippi Alluvial Valley Dissertation Mississippi StateUniversity Starkville USA

WILLEY C H 1974 Aging black bears from first premolar toothsections Journal of Wildlife Management 3897ndash100

WOLF C M B GRIFFITH C REEDAND SATEMPLE 1996 Avian andmammalian translocationsupdate and reanalysis of 1987 sur-vey data Conservation Biology 101142ndash1154

YOUNGBFAND RLRUFF 1982 Population dynamics and move-ments of black bears in east central Alberta Journal ofWildlife Management 46845ndash860

ZIMMERMAN JW AND RA POWELL 1995 Radio telemetry errorlocation error method compared to error polygons and errorellipses Canadian Journal of Zoology 731123ndash1133

Brandon J Wear (photo) is a non-game biologist with theLouisiana Department of Wildlife and Fisheries working onLouisiana black bears He has worked as a nongame biologistwith the Tennessee Wildlife Resources Agency and for theNational Park Service evaluating the experimental release of elkin Great Smoky Mountains National Park Brandon received hisMS and BS in wildlife and fisheries science from theUniversity of Tennessee Knoxville His graduate work focusedon evaluating the restoration of black bears to southernArkansas Brandonrsquos professional interests include wildlife andhabitat restoration large-carnivore ecology and populationdynamics Rick Eastridge is a wildlife biologist with theArkansas Game and Fish Commission serving as bear programcoordinator He received his BS and MS in wildlife and fish-eries science from the University of Tennessee Knoxville Hisprimary interests include bear ecology and managementJoseph D (Joe) Clark is a research ecologist and Branch Chiefof the USGS Southern Appalachian Field Branch at theUniversity of Tennessee He received an MS in wildlife biolo-gy from the University of Georgia and a PhD in zoology fromthe University of Arkansas Joe is interested in populationdynamics habitat modeling and management of threatenedand endangered species and has worked with a variety of mam-mal species including black bear elk Florida pantherriver otter and muskrat

Associate editor Jacob Bowman



The Interior Highlands Gulf Coastal Plain andDelta regions of Arkansas once supported largenumbers of black bears (Ursus americanusHolder1951) Unregulated market hunting coupled withextensive habitat loss led to the extirpation of bearsthroughout most of the state by the early 1900s

(Smith et al 1991) One small population of bearspersisted and has since recovered in what is nowWhite River National Wildlife Refuge (NWR) locat-ed in the Delta region (Holder 1951 Smith 1985Smith et al 1991White 1996)

The Gulf Coastal Plain of Arkansas was not inhab-

ARKANSAS BEAR REINTRODUCTION 1363

Wildlife Society Bulletin 2005 33(4)1363ndash1374 Peer refereed

Address for Brandon J Wear Department of Forestry Wildlife and Fisheries 274 Ellington Plant Sciences Building University ofTennessee Knoxville TN 37996 USA present address for Wear Louisiana Department of Wildlife and Fisheries 2000 QuailDrive RM 436 Bator Rouge Louisiana 70898 Address for Rick Eastridge Arkansas Game and Fish Commission 2 NaturalResources Drive Little Rock AR 72205 USA Address for Joseph D Clark United States Geological Survey Southern Appalachi-an Research Branch 274 Ellington Plant Sciences Building University of Tennessee Knoxville TN 37996 USA e-mailjclark1utkedu

Factors affecting settling survival andviability of black bears reintroduced to

Felsenthal National Wildlife RefugeArkansas

Brandon J Wear Rick Eastridge and Joseph D Clark

Abstract We used radiotelemetry and population modeling techniques to examine factors related topopulation establishment of black bears (Ursus americanus) reintroduced to FelsenthalNational Wildlife Refuge (NWR) Arkansas Our objectives were to determine whether set-tling (ie establishment of a home range at or near the release site) survival recruitmentand population viability were related to age class of reintroduced bears presence of cubstime since release or number of translocated animals We removed 23 adult female blackbears with 56 cubs from their winter dens at White River NWR and transported them 160km to man-made den structures at Felsenthal NWR during spring 2000ndash2002 Total move-ment and average circuity of adult females decreased from 1 month 6 months and 1 yearpost-emergence (F214 =197 Plt0001 and F214 =576 P=0015 respectively) Meanfirst-year post-release survival of adult female bears was 0624 (SE=0110 SEinterannual=0144) and the survival rate of their cubs was 0750 (SE=0088 SEinterannual=0109) Thehoming rate (ie the proportion of bears that returned to White River NWR) was 13Annual survival for female bears that remained at the release site and survived gt1-yearpost-release increased to 0909 (SE=0097 SEinterannual=0067 Z=35 Plt0001) Basedon stochastic population growth simulations the average annual growth rate (λ) was 1093(SD=0053) and the probability of extinction with no additional stockings ranged from056ndash130 The bear population at Felsenthal NWR is at or above the number afterwhich extinction risk declines dramatically although additional releases of bears couldsignificantly decrease time to population reestablishment Poaching accounted for at least3 of the 8 adult mortalities that we documented illegal kills could be a significant imped-iment to population re-establishment at Felsenthal NWR should poaching rates escalate

Key words black bear Felsenthal poaching population model reintroduction Ursus americanusWhite River







































































































































































































Wear et al (Gene)qxp 372006 357 AM 74

national wildlife refuge, arkansas bioone ( ... affecting...and population viability were related to...

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