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Denning ecology of and Asiatic black bears in the

Ivan V. Seryodkin1, Alexei V. Kostyria2, John M. Goodrich3'5, Dale G. Miquelle3, Evgeny N. Smirnov4, Linda L. Kerley3, Howard B. Quigley3, and Maurice G. Hornocker3

'Pacific GeographicalInstitute, Russian Academy of Sciences, Radio Street 7, Vladivostok,Primorski Krai, Russia, 690041 2Biologyand Soil Sciences, Russian Academy of Sciences, 159 StoletiyaStreet, Vladivostok,Russia, 690022 3HornockerWildlife Institute and WildlifeConservation Society, 2023 Stadium Drive, Suite la, Bozeman, MT59719, USA 4Sikhote-AlinState Biosphere ,Terney, Primorski Krai, Russia, 692150

Abstract: We observed differences in den types, den site characteristics,and chronology of denning between radiocollaredbrown bears ( arctos) and Asiatic black bears (U. thibetanus)on and near the Sikhote-Alin Biosphere Zapovednik in the Russian Far East during 1993-2002. Of 27 Asiatic black dens, 17 (63%) were in hollow , 6 (22%) in groundnests, 3 (11%) in caves under rocks, and 1 (4%) was in an old excavated den. Of 12 brown bear dens, 9 were burrows excavated into hillsides, 2 underrock outcroppings,and 1 was a groundnest. We comparedelevation, percent slope, aspect, and location on slope of 20 brown and 31 Asiatic black bear dens between , sexes, and with 100 randomcoordinates, used to representavailability. Brown bearsdenned at higher elevations and on steeper slopes than Asiatic black bears and selected higher elevations and steeper slopes than were generallyavailable. Black bears selected flat areasmore often than available. Female black bearsemerged from dens laterthan did males, and female black bearswith cubs emerged later than barrenfemales. One brown and 1 Asiatic black bear abandoneddens in response to inves- tigatordisturbance. While in dens, 1 Asiatic blackbear was killed by a ( ) and 2 other Asiatic black bears survivedpredation attempts, one by a tiger and one by a brownbear. dens may be importantfor Asiatic black bears for protectionagainst predators.To increase survival and repro- duction, we recommendprotecting potential den trees from logging and adjustinghunting seasons and practicesto reducemortality of adultfemales.

Key words: Asiatic black bear, brown bear, denning, Russian Far East, Sikhote-Alin Zapovednik, Ursus arctos, Ursus thibetanus

Ursus 14(2):153-161 (2003)

Denning ecology is importantto bear survival and disturbanceat dens may reduce reproductive success reproduction,hence its documentation is essential to through cub abandonment and increased overwinter conservationplanning for bears. American black bears weight loss (Tietje and Ruff 1980, LeCount 1983, (U. americanus) often select specific den types, pre- Goodrich and Berger 1994). Denning chronology often to reduce sumably energy expenditureand increase cub differs among sex and age classes, and adjustinghunting survival (Johnson and Pelton 1979, 1981; Lentz et al. seasons to these differences provides a mechanism for Alt 1983; 1984). Specific den types also may be im- regulatingharvest (Bromlei 1965, Lindzey and Meslow portant for predatoravoidance, especially for females 1976, Johnson and Pelton 1979). with cubs and Meslow (Lindzey 1976, Rogers and Mech Very little informationexists on the denning ecology Ross et 1981, al. 1988, Pikunov et al. 1991). of Asiatic black bears, particularlyin Russia. Further, although brown bear denning ecology has been well studied in and , it has received 5email: [email protected] little attentionin the Russian Far East (Bromlei 1965,

153 154 DENNINGOF BROWN AND ASIATIC BLACK BEARS * Seryodkin et al.

Hazumiand Maruyama1986, Pikunov et al. 1991, Reid Sikhote-Alin Zapovednik is in the coastal region et al. 1991, Yudin 1993, Xu et al. 1994). Asiatic black of the Far Eastern Temperateclimate zone and has a bears are considered ecologically equivalent to North monsoon climate characterizedby seasonal changes in Americanblack bears (Schaller et al. 1989, Reid et al. prevailing winds. Strong western and northwestern 1991) and probablyexhibit similarregional variationin winds prevail in winter on the eastern macroslope, but denning ecology (review in Hayes and Pelton 1994). winter winds are calm on the wester macroslope. Brown bear denning habits also vary throughouttheir Shielded by the mountains,the western macroslopehas range (Stroganov 1962, Vroom et al. 1980). Therefore, a continentalclimate with greaterextremes of temper- it is difficult to draw inferences from data from other ature;the eastern macroslope is moderatedby the sea, populations,and regional data is needed to characterize and has high humidity and milder temperatures.Mean population-specificdenning ecology (Vroomet al. 1980, temperaturein Januarywas -12.4? C near the coast in Weaver and Pelton 1994). Temey and -22.6? C on western slopes. We examineddenning ecology of both bearspecies on Snow depth and distributionis uneven in the Sikhote- andnear the Sikhote-AlinBiosphere Zapovednik (strictly Alin region. Mean Januarysnow depth in Temey for ) in the Russian Far East to establish 1992-2002 was 24.2 cm, but in the mountains and on a baseline database which can assist much needed sites protected from winds snow cover usually was conservation planning. Here, Asiatic black bears are >70 cm. Ground freezes 1.5-2 m deep occur on both near the northernextent of their range. They are listed macroslopes. All weather data were from Sikhote-Alin underCITES Appendix I (Wilson and Reeder 1993) and, Zapovednikand Temey WeatherStation records. until recently (1997), were listed as an endangered covered >90% of the Zapovednik and domi- species in the Russian Red Data Book (Borodin et al. nantforest types on easternslopes includedoak (Quercus 1984). Both species can be legally harvestedin dens and, mongolica) near the coast and mixed conifer- with the opening of Russia's bordersin 1992, increased forest inland and at higher elevations, access to internationalmarkets has lead to intensive legal dominated by Korean pine (), larch and illegal harvest to satisfy the demand for bear (Larixcajanderi), and birch (Betula spp.). Westernslopes derivatives (Seryodkin and Pikunov 2002). Logging were dominatedby spruce-fir(Picea-Abies spp.) . may influence den ecology due to loss and alterations,cutting of cavity trees, and increaseddensity of roads, increasing access for poachers and hunters Methods Sikhote-Alin (Bromlei 1965, Abramov 1972, Kostoglod 1981, Kerley We capturedbears on the east side of the on trailsand near et al. 2002, Seryodkinand Pikunov 2002). Additionally, Mountainswith Aldrichfoot snaresset Kucherenko(1974) argued that destructionof denning tiger and bear mark trees, tiger kills, or bait (Goodrich bears were trees by huntersis a potentiallimiting factor for Asiatic et al. 2001). During 1993-97, incidentally black bears in the Russian Far East. captured in snares set for , but we trapped specifically for bears during 1998-2002. We anesthe- Study area tized all bears with a mixtureof ketaminehydrochloride We studied bears on and near the Sikhote-Alin (Aveco, Fort Dodge, Iowa, USA and Pharma- and State Biosphere Zapovednik (4,000 km2) near the vil- ceuticals, Fort Collins, Colorado, USA) xylazine Kansas, USA; dosage: lage of Terey, Primorye Krai, in the Russian Far hydrochloride(Mobay, Shawnee, and 2.2 for Asiatic East (44?46'N, 135?48'E), during 1993-2002 (Fig. 1). 4.4 mg/kg ketamine mg/kg xylazine ketamineand 3.6 Sikhote-Alin Zapovednik is closed to the public; this black bears;7.2 mg/kg mg/kg xylazine or Telazol? dose the same restrictedaccess provides ideal conditions for collecting for brown bears), (intended Fort baseline data in undisturbed . Sikhote-Alin as for ketamine;Fort Dodge Health, Dodge, Zapovednikis borderedby the Sea of Japanto the east Iowa, USA) (Kreeger 1996). were and and tattooed and bisected by the Sikhote-Alin Mountains, which All bears weighed ear-tagged with an identification number. Standard morphologi- parallel the coastline and are characterizedby low cal measurementswere taken, blood was collected, and rolling hills near the coast and steep slopes and braided was extractedfor cementumannuli creekand river valleys fartherinland. The westernmacro- a firstpremolar tooth and Jonkel 1966). All females and slope is wide and gentle, but the eastern macroslope is aging (Stoneberg males were fitted with radiocollars(MOD- shortand steep. Mean elevationof mountainpeaks is 800 most adult or Mesa, Arizona, USA). For m. The highest peak within the Zapovednikis 1,598 m. 400 MOD-500, Telonics, Ursus 14(2):153-161 (2003) DENNINGOF BROWNAND ASIATIC BLACK BEARS * Seryodkinet al. 155 our analysis, we also included 2 of den data from an orphanedbear cub Russia that was captive for 6 months before being radiocollared and released in April 1997. We collected den data from winter 1993-94 throughwinter 2001-02, but - most data were collected during 3 winters (1999-2002). We monitored radiocollaredbears from the ground, on foot and from vehicles, and from the air using an Antonov-2 biplane, MI-2 helicopter, or a MI-8 helicopter. Ground locations were collected by triangulationwith 2- or 3-elementYagi antennas,by approachingto 100-400 m and partially circling the bear, by visual observation, and by locating tracks in an area where we detected a bear's radio signal. We calculated den entry dates based on the median date between the first location at the den site and the previous location for weekly locations. Emergence dates were calculated as the median date between the last location at the den site Fi St ' area (dotted for of den of and the subsequentlocation. lines) investigation ecology Asiatic black tbears and brown bears, Russian Far East, 1993-2002. Because den abandonmentdue to investigator disturbance is common Manville (e.g., 1983, Goodrich and Berger 1994), we maps with 5-m contourintervals. We measuredpercent avoided approachingoccupied dens closely. Rather, to slope by counting the number of contour lines 50 m locate dens, we waited until a bear's movements were above and 50 m below the den site. If 1:25,000-scale localized for at least two weeks and then approached maps were not available, we estimated all parameters, on foot from downwind to quietly approximately100 m except percent slope, from 1:100,000-scale maps. We and circled the den. We searched partially that area for could not measure percent slope from 1:100,000 maps a den afterthe bear emergedin spring.In some cases we because contour intervals were too great for accurate were unable to locate the den or the den was too remote measurements. Aspect of slope was divided into 4 to but aerial and access, repeated groundlocations were categories:north (316-45?), east (46-135?), south (136- sufficiently accurate (within 200 m) to define an 225?), and west (226-315?). approximateden site. We included these locations with We comparedelevation, aspect, percent slope, whether observed dens in our of analysis environmental dens occurredon level areas,and position on slope of den parameters. For comparing differences in den entry sites between species, sexes, and with 100 random and emergence dates between pregnant and barren locations in our study areato determineif bears selected females, we defined a female as if we pregnant detected environmentalparameters. We defined our study area as < -year-old cubs with the female den following a minimum convex polygon (Hayne 1949) containing We emergence. may have failed to detect litters that 90% of the telemetrylocations from all bears combined died after shortly emergence. (2,957 km2). We used 100 randomlocations because we We estimated elevation, of percent slope, aspect believed this would sufficiently estimate availability of slope, and position on or slope (lower, middle, upper the variables measured within the study area. We for den sites from third) 1:25,000-scale topographic classified a component as "selected" or "preferred"

Ursus 14(2):153-161 (2003) 156 DENNINGOF BROWN AND ASIATIC BLACK BEARS * Seryodkinet al. when use was greater(P < 0.05) thanavailability (Mann- comparedwith randomlocations (U = 205, P = 0.001; Whitney U-test or log-likelihood ratio [G]; Zar 1984). Table 1). Female Asiatic black bears denned at lower We treated data collected on the same individual in elevations than did males (U = 53, P = 0.030) and differentyears as independentrandom events and pooled tended to select sites at elevations lower than those them. This may increase the true I errorabove the associated with randomlocations (U = 298, P = 0.067; stated alpha (Machlis et al. 1985), so conclusions must Table 1). be treated with caution. However, large samples from Brown bears always denned on slopes, whereas different individuals were logistically impossible to Asiatic black bears selected for flat areas in creek or collect because bears on our study area were secretive river bottoms (G = 10.2, 2 df, P = 0.006; Table 2). and occurredat low densities, and our study area was Brown bears used steeper slopes than did Asiatic black remotewith limited access. bears (U = 94, P < 0.001), and males of both species selected for steeper slopes compared with random locations (U = 701, P = 0.035 for black bears and U = Results 166, P = 0.006 for brown bears;Table 1). Male brown Den types bearsdenned on steeperslopes thandid females (U= 12, We observed 27 Asiatic black bear dens (9 inhabited P = 0.036). Brown bears selected den sites on the upper by females and 18 by males) belonging to 15 different third of slopes (G = 12.3, 2 df, P = 0.002), whereas bears (4 females and 11 males): 17 (63%) were in black bears that denned on slopes were not selective for hollow trees, 6 (22%) in on the ground,3 (11%) in position on slope (G = 0.3, 2 df, P = 0.846). Neither caves or under rocks, and 1 (4%) in an old excavated brown nor black bears selected aspect (Table 2). brown bear den. Most tree dens (14) were cottonwood but 2 were in (Populus maximowicziiand P. koreana), Denning chronology oak (Quercusmongolica) and 1 in a Koreanpine (Pinus We failed to detect interspecific differences in den level in 63% koraiensis). Entranceswere above ground entry or emergence dates or intraspecificdifferences in the rest. Ground of the tree dens and at ground level in den entry dates (Table 3). Female black bears emerged nests were shallow (=70 cm deep), circulardepressions from dens laterthan did males (U = 25, P = 0.026), and approximately90 cm in diameterand usually lined with, female black bears with cubs emerged later than barren and sometimes covered with, conifer boughs. females (U = 0, P = 0.034; Table 3). Most bears entered inhabited We observed 12 brown bear dens (6 by dens priorto the firstwinter snow, but some bears stayed females and 6 by males) belonging to 10 differentbears active well into winter:3 adultmale brownbears did not (5 females and 5 males). Brown bears denned pre- den until late Decemberand one adultfemale black bear dominantlyin burrows, which they excavated horizon- did not enter her den until 6 January. tally into hillsides beneathtree (9 dens), but 2 adult female bears denned under rock outcroppings and 1 Human disturbance, , and mortality adult male denned in a ground similar to those We accidentally disturbed 2 bears in their dens by describedfor Asiatic black bears. The ground nest was approachingtoo closely on 3 occasions. In the firstcase, adult female used by a bear after it abandonedits excavated den on we approachedwithin 3 m of a solitary of an oak tree. She our approach.None of the dens were used more than black bear denned in the base and established once by a radiocollaredbear of either species duringthe abandonedher den shortly after we left 3 km study. a new den in the base of an oak tree approximately m away. We approachedthat den to approximately60 m before Den site characteristics and she charged to within 20 running away, did not locate her third We measured den site characteristicsfor 31 Asiatic abandoningher second den. We an adultmale brown bear in black bear dens (21 dens inhabitedby 12 differentmales den. In the second instance, den ran when we He and 10 dens inhabitedby 4 females) and 20 brown bear an excavated away approached. a second den in a nest. dens (11 dens inhabitedby 7 males and 9 dens inhabited established ground 2 and 1 instance of 7 females; Table 1). Brown bears denned at higher We detected predationattempts by bears. In 1998, elevations than did Asiatic black bears (U = 151, P = successful predationon denned February male brown bear to prey on an 0.002; Table 1). Male brown bears denned at higher an adult attempted bear denned in the base of elevations than did female brown bears (U = 17.5, P = adult male Asiatic black tree with a entrance.Tracks 0.012) and selected areas with higher elevations a cottonwood ground-level Ursus 14(2):153-161 (2003) DENNINGOF BROWNAND ASIATIC BLACK BEARS * Seryodkinet al. 157

Table 1. Characteristics of den sites used by Asiatic black bears and brown bears on and near the Sikhote-Alin Biosphere Zapovednik, Russian Far East, 1993-2002. Elevation Species Species (m) Slope (%) cohort meana SD n mean SD n Asiatic all 585a 181 31 31a 9 31 male 629b 197 21 37b 4 21 female 491b 97 10 25 10 10 Brown all 775a 229 20 37a 5 16 male 872c,d 170 11 39c,d 3 8 female 655d 244 9 34d 5 8 Random 610c 253 100 28b,c 14 100 alike letters in italicswithin columns indicatea significantdifference (Mann-Whitney U, P < 0.05).

in the snow and marks on the tree indicated that the cavity, and we believe the bear either denned on the brown bear tore open the den entrance, but the black groundor was not in its den when the tiger attackedit. In bearapparently escaped predationby climbing the inside the unsuccessfulattempt, several tiger beds were located of the hollow tree. This Asiatic black bear subsequently near an Asiatic black bear den we located in late May, abandonedthat den and relocatedin a tree with a ground- 19 days after the bear, a female with new cubs, had left level entrance about 500 m away. Tracks in the snow the den. The entranceto the den, located beneatha rock and marks on the tree indicated that a brown bear also outcropping,was too small for the tiger to gain access, attemptedto prey on this black bearin its second den, but but tiger hair aroundthe outside andjust on the inside of despitethe threatthe black beardid not abandonthis den. the den indicated that it had attemptedto do so. The In 2 cases tigers attemptedto prey on denned bears, number of tiger bed sites indicated that the tiger had once successfully and once unsuccessfully. A radio- been in the area for at least a day. collared adult male tiger killed and ate a radiocollared One adultfemale black bear, denned in a groundnest adult male Asiatic black bear on 5 December 1998. The with >1 yearling, died of unknown causes in her den. bear's movements had been localized for 14 days, We discovered the carcass in the den in early May and it had but we were suggesting denned, unable to locate little fleshy materialremained. Tracks of her offspring, a den site because light snow had covered most of the tooth marks on her remains, and lack of tracks or other and bear tracks. Blood and claw tiger marks indicated evidence of predatorssuggest that she was eaten by her that the tiger climbed and extracted the bear from 2 yearling offspring. different trees, one of which was a cottonwood large enough to contain a bear den. However, it is very unlikely that a tiger could extract a bear from a tree Discussion Pooling data from individuals may have biased our results if individualstend to select for den types or site Table 2. of Slope aspect bear dens used by Asiatic characteristics.Our sample sizes were too smallto test for black bears and brown bears on and near the differencesamong individuals,but use of Sikhote-Alin Biosphere Zapovednik, Russian Far non-parametric East, 1993-2002. statistics should have made our tests conservative.If a bias exists, it may be most pronouncedin our analysis of Numberof dens den site characteristicsbecause individualsoften denned Aspect brownbear blackbear in the same area within theirhome range. N (316-45?) 6 7 E (46-135?) 8 3 Den types S 4 (136-225?) 3 Asiatic black bears used a of W (226-135?) 2 5 greatervariety den types than did brown bears. Flat This result is consistent with existing information from the Riverbottom 0 region (Bromlei 1965, 10 Abramov et al. Ridge top 0 3 1977), and use of trees, rock outcrop- pings, and ground nests has been observed elsewhere

Ursus 14(2):153-161 (2003) 158 DENNINGOF BROWN AND ASIATIC BLACK BEARS * Seryodkin et al.

Table 3. Den entry and emergence dates for Asiatic black bears and brown bears on and near the Sikhote-Alin Biosphere Zapovednik, Russian Far East, 1993-2002. Enterdate date Species (mm/dd) Emerge (mm/dd) Den period cohort mediana SD range n median SD range n (days) Asiatic all 11/23 21 10/31-01/09 19 04/11 18 03/15-05/29 22 140 male 11/23 21 10/31-12/26 11 04/07a 14 03/15-05/03 15 136 female 11/22 19 11/12-01/09 8 04/a 19 04/07-05/29 7 153 pregnantfemale 12/02 11 11/16-12/07 3 05/11b 11 05/10-05/29 3 169 barrenfemale 11/19 24 11/12-01/09 5 04/12b 10 04/07-04/30 4 138 Brown all 11/21 20 11/01-12/23 11 04/09 16 03/26-05/19 14 146 male 12/20 21 11/01-12/23 6 04/04 12 03/26-04/23 7 126 female 11/03 10 10/30-11/24 5 04/12 16 04/10-05/19 7 169 pregnantfemale 11/13 19 11/03-11/24 2 05/12 12 04/25-05/19 3 176 barrenfemale 11/03 0 11/03-11/03 2 04/10 0 04/10-04/10 2 158 aLikeletters in italicswithin columns indicate a significantdifference (t-test, P < 0.05). Comparisonsbetween species were made only for both sexes combined.

(Hazumi and Maruyama1986, Reid et al. 1991). How- of Asiatic black bears (Yudin 1993). Although use of ever, we detected a greaterdiversity of den types used ground dens may increase predationrisk from brown by Asiatic black bears than other researchers(Sysoev bears and tigers, it probably decreases predation risk 1960, Kucherenko1974, Pikunov et al. 1991). Radiote- from people because hunters in Russia often monitor lemetry provides a less biased sample than either potentialden trees for bears (Abramov 1972). snowtracking(a traditionalstudy technique in Russia), Brown bear dens were similar to those described for which is biased toward cohorts that are more active many other regions in Eurasia and North America Klaver duringsnow months, or monitoringspecific dens, which (Stroganov 1962, Bromlei 1965, Servheen and is biased towardden types such as hollow trees that are 1983, Judd et al. 1986, Pazhetnov 1990). The lower be more easily located. Asiatic black bears most often variability in den types used by brown bears may denned in cavity trees. Tree dens likely provide greater related to the ability of brown bears to dig and hence thermalprotection, particularly in areas where snow is create their own dens. less likely to provide insulating cover, and they may provide greaterprotection from predation(Johnson and Den site characteristics site Pelton 1981). Predationon Asiatic black bearsby brown Brown bears were more selective for den black bears and denned bearsand tigers is common (Bromlei 1965, Yudakovand characteristicsthan were Asiatic Nikolaev 1987, Khramtsov1993), but neithertigers nor at high elevations, on steep slopes, and on the upper characteristicshave been brownbears are proficienttree climbers.Our observation thirdof slopes. Similarden site thatone Asiatic black bear survived2 predationattempts reportedfor brown bears elsewhere (Vroom et al. 1980, Klaver Judd et al. Most by brown bears in 2 differenttree dens suggests that tree Servheen and 1983, 1986). concludedthat these conditionstend to dens provide protectionagainst predation. authorshave trap whereas Use of ground dens by Asiatic black bears has been snow in the den entrance,providing insulation, have a shallow roof that documentedin many areas (Abramov 1972, Reid et al. dens on lesser slopes would and would be 1991, this study), and some authors have argued that would provide less thermal protection to et al. 1980, Servheen groundnests are used by Asiatic black bears only when more likely collapse (Vroom Judd et al. cavity trees are not available (Abramov 1972, Pikunov and Klaver 1983, 1986). Asiatic black bears et al. 1991). Although we did not measure availability In contrast to brown bears, bottoms at lower of trees suitable for denning, it is unlikely that avoided slopes and preferred river cavity tree suitable tree den sites were limiting on our study area, elevations, where the probabilityof findingpotential trees of much of which has never been logged, or was selectively dens likely was greater. Large cavity (63% bear cottonwoods, occur logged >45 years ago. We arguethat use of groundnests Asiatic black dens), especially in creek and river bottoms, and are for denning, although infrequent, is characteristic almost exclusively Ursus 14(2):153-161 (2003) DENNINGOF BROWNAND ASIATICBLACK BEARS * Seryodkinet al. 159 therefore more closely associated with flat areas and human disturbance is low (Craighead and Craighead lower elevations. 1972, Elgmork 1978). Denned Asiatic black bears were subject to preda- Denning chronology tion by both tigers and brown bears. Although tigers Contraryto previous studies of denningchronology of prey on adultbrown bears (Kaplanov1948; J. Goodrich, Asiatic black bears in Russia, we failed to detect unpublisheddata), we did not detect predationby tigers a difference in den entry dates between sexes (Bromlei on dennedbrown bears. Brown bear selection of den site 1965, Khramtsov 1990). Female American black bears and den type may reduce risk of predation by tigers in many populations enter dens earlier than males because tigers infrequentlyused such high elevations (J. (O'Pezio et al. 1983, Hellgrenand Vaughan 1989, Smith Goodrich, Wildlife ConservationSociety, unpublished et al. 1994), although in Idaho, Beecham et al. (1983) data) and brown bears could likely defend the narrow found that pregnantfemales entered dens before males tunnel at the entrance of an excavated den. Denned and barren females entered dens later. We failed to North American black bears have reportedly been detect a difference in den entry dates between pregnant preyed upon by grizzly bears, ( lupus), and barrenfemales and between pregnantfemales and and other black bears, but such reports are rare (Ross males. However, our sample size of pregnant females et al. 1988). was small (n = 3) and all 3 gave birth during the same , so our results must be interpretedwith caution. Brown bear females entered dens earlier than males in Managementimplications our study, a general patternreported previously in the Our data suggest that tree dens may be importantto Russian Far East and elsewhere (Bromlei 1965, Judd et overwinter survival of Asiatic black bears and to al. 1986, Yudin 1993). increase survival, potential den trees, especially cotton- Female Asiatic black bears emerged from dens later woods, should be protected from logging and de- than males, and females with cubs emerged last. structionby hunters,who often destroy den trees while Brown bears followed a similar pattern,but differences extracting bears from dens (Bromlei 1965, Abramov were not significant, likely because of small sample 1972, Kostoglod 1981, Seryodkin and Pikunov 2002). sizes. This pattern has been reported previously for Cottonwoods are not highly valuable for timber ex- both species in the Russian Far East and for brown traction in the Russian Far East, particularlybecause bears elsewhere, as well as for American black bears largertrees usually are decayed. However, to protectden (Bromlei 1965, O'Pezio et al. 1983, Judd et al. 1986). trees, logging companies could be made aware of the Female Asiatic black bears with cubs emerged later importance of cottonwoods to Asiatic black bears in when compared with emergence dates reported for planning road constructionand access (skidder trails). female brown and American black bears with cubs Repair of den trees destroyed by hunters has been dates >1 are (emergence May rarely reported)even at suggested as well (Kostoglod 1981), but we strongly latitudes much further north and areas with more recommend against this in the Russian Far East until severe winters (Tietje and Ruff 1980, Miller 1990, legislation is in place and enforced to protect denned Smith et al. Whether this is a 1994). characteristicof bears from illegal harvest. Repairing these trees may the species or a response to regional variables, such as encouragebears to den in trees known to and monitored abundant is unclear. predators, by hunters and poachers, resulting in even greater harvest of denned bears. Human disturbance, predation, and mortality Reproductive females and their cubs can be better Bears on our area were sensitive to of study approach protectedby prohibitinghunting bears in dens. Currently, and abandoned dens in 3 instances when we such is legal in Russia and results in large too approached closely. Abandonment due to human numbersof orphanedcubs (J. Goodrich, Wildlife Con- disturbanceis common in North American black bears servation Society, unpublished data). Hunting seasons (e.g., Manville 1983, and Stratheam Kolenosky 1987, may be adjustedto furtherprotect reproductive females, Hellgrenand and resultin Vaughan 1989) may increased as for Americanblack bears (Lindzey and Meslow 1976, winter activity, overwinter and greater weight loss, cub Johnson and Pelton 1979, O'Pezio et al. 1983). For abandonment and Ruff Goodrich (Tietje 1980, and example, for brown bears in this study area, a season Berger 1994). Brown bears also are sensitive to human beginning on 1 December and ending about 15 April disturbance and may select den sites in areas where would protectmost adultfemales while allowing hunters Ursus 14(2):153-161 (2003) 160 DENNINGOF BROWN AND ASIATIC BLACK BEARS * Seryodkinet al. to take adult males, if hunting denned bears were pro- GOODRICH,J.M., ANDJ. BERGER.1994. Winter recreationand hibited. For Asiatic black bears, the season could start hibernatingblack bears Ursus americanus.Biological Con- later. servation67:105-110. , L.L. KERLEY,B.O. SCHLEYER,D.G. MIQUELLE,K.S. QUIGLEY,E.N. SMIRNOV,I.G. NIKOLAEV,H.B. QUIGLEY,AND Acknowledgments M.G. HORNOCKER.2001. Captureand chemical anesthesia was the Intemational Bear of tigers. Wildlife Society Bulletin 29:533-542. Funding provided by ANDM.R. PELTON.1994. Habitatcharacteristics Foundation and International Association for Bear HAYES,S.G., of female black bear dens in northwestern Arkansas. Research and Parts of this researchwere Management. InternationalConference on Bear Research and Manage- conducted under The Siberian which Tiger ProjectTM, ment 9(1):411-418. The National The was funded by Geographic Society, HAYNE,D.W. 1949. Calculationof size of .Journal National and Wildlife Save The Tiger Fund, of Mammalogy30:1-18. Foundation, The National Wildlife Federation, Exxon HAZUMI,T., AND N. MARUYAMA. 1986. Movements and home Corporation, Wildlife Conservation Society, The ranges of Japanese black bears in Nikko. International Charles EngelhardFoundation, Disney Wildlife Fund, Conferenceon Bear Researchand Management6:99-101. TurnerFoundation, and RichardKing Mellon. We thank HELLGREN,E.C., ANDM.R. VAUGHAN.1989. Denning ecology I. Nikolaev, B. Schleyer, N. Reebin, A. Reebin, A. of black bears in a southeasternwetland. Journalof Wild- Moskalenko,V. Melnicov, A. Saphonov,V. Schukin,N. life Management53:347-353. behavior of Pukhovoy, M. Klyagin, A. Zborovsky, T. Ulizio, Y. JOHNSON,K.G., ANDM.R. PELTON.1979. Denning MountainsNational Park. Chicherin,J. Beecham, C. Pelton, and V. Solomatinfor black bears in the Great Smoky their assistance with data collection and A.A. Astafiev Proceedings Annual Conference SoutheasternAssociation of Fish and Wildlife 33:239-249. and M.N. Gromyko of Sikhote-Alin State Biosphere Agencies AND . 1981. Selection and of dens andD.G. Pikunovof the Pacific , availability Zapovednik Geographical for black bears in Tennessee. Journal of Wildlife Institute for the logistical and administrativesupport Management45:111-119. to conductthis work. necessary JUDD,S.K., R.R. KNIGHT,AND B.M. BLANCHARD.1986. Den- ning of grizzly bearsin the Yellowstone NationalPark area. InternationalConference on BearResearch and Management Literaturecited 6:111-117. ABRAMOV,V.K. 1972. -chestedbear and its conservation KAPLANOV,L.G. 1948. Tiger in the Sikhote-Alin.Pages 18-49 in the Far Eastern USSR. Pages 3-5 in V.E. Sokolov, in S.I. Ognev and V.G. Geptner, editors. Tiger. . of editor. Ecology, , conservation, and use . Moscow Organization for the Investigation of bears. Nauka, Moscow, Russia. (In Russian.) Nature,Moscow, Russia. (In Russian.) ANDD.G. PIKUNOV.1977. Dens of , A.G. VELIZHANIN, KERLEY,L.L., J.M. GOODRICH,D.G. MIQUELLE,E.N. SMIRNOV, 95-96 in white-chested bears in . Pages I.G. NIKOLAEV,H.B. QUIGLEY,AND M.G. HORNOCKER. and their V.E. Sokolov, editor. Rare species 2002. Effects of roads and human disturbanceon Amur conservation.Nauka, Moscow, Russia. (In Russian.) tigers. ConservationBiology 16:1-12. Black bear cub due to of ALT,G.L. 1984. mortality flooding KHRAMTSOV,V.S. 1990. On entry of dens by white-chested nataldens. Journalof Wildlife 48:1432-1434. Management bears in southernPrimorye. Bulletin Moscow Organization J.J., D.G. REYNOLDS,AND M.G. HORNOCKER.1983. BEECHAM, for Investigationof Nature,Biology Branch95(3):32-33. Black bear activities and den characteristicsin denning 1993. On bear-tiger relations in the spurs of west-central Idaho. International Conference on Bear Zapovedniy ridge. Pages 70-72 in I.E. Chestin and S.M. Research and Management5:79-86. Uspenskiy, editors. Bears of Russia and adjacentcountries BORODIN,A.M., A.G. BANNIKOV,AND V.E. SOKOLOV.1984. _ state of populations.Volume 2. Argus, Moscow, Russia. USSR red book. Volume 1. Lesnaya Promyshlennost, (In Russian.) Moscow, Russia. (In Russian.) KOLENOSKY,G.B., AND S.M. STRATHEARN.1987. Winter den- BROMLEI,G.F. 1965. Bears of the south Far Eastern USSR. of black bears in east-centralOntario. International Nauka, Moscow-Leningrad,Russia. (In Russian.) ning Conferenceon Bear Researchand Management7:305-316. CRAIGHEAD,F.C., JR., AND J.J. CRAIGHEAD.1972. Data on KOSTOGLOD,V.E. 1981. Repair of destroyed bear dens of denning activities and behavior obtained by white-chested bears. Pages 155-156 in G.F. Bromlei, using wildlife .International Conference on Bear editor. Rare and terrestrialspecies in the Far Researchand Management2:84-106. endangered U.S.S.R. Far Eastern Scientific Center, U.S.S.R. ELGMORK,K. 1978. Humanimpact on brown bearpopulations. Eastern of Sciences, Vladivostok, Russia. (In Russian.) Biological Conservation13:81-103. Academy

Ursus 14(2):153-161 (2003) DENNINGOF BROWNAND ASIATIC BLACK BEARS * Seryodkin et al. 161

KREEGER,T.J. 1996. Handbook of wildlife chemical immobi- SERVHEEN,C., ANDR. KLAVER.1983. Grizzly bear dens and lization. InternationalWildlife VeterinarySciences, Incor- denning activity in the Mission and RattlesnakeMountains, porated,Laramie, , USA. . InternationalConference on Bear Research and KUCHERENKO,S.P. 1974. Black (white-chested)bear. Lesnaya Management5:201-207. Promyshlennost,Moscow, Russia. (In Russian.) SERYODKINI.V., ANDD.G. PIKUNOV.2002. Brown and Hima- LECOUNT,A.L. 1983. Denning ecology of black bears in layan bear resources in PrimorskiKrai: conservation and central Arizona. International Conference on Bear sustainableuse issues. Pages 366-368 in V.G. Saphonov, Research and Management5:71-78. editor. Recent problems of natureuse, biology, and LENTZ,W.M., R.L. MARCHINTON,AND R.E. SMITH.1983. farming.Kirov Press, Kirov, Russia. (In Russian.) Thermodynamicanalysis of northeasternGeorgia black SMITH,M.E., J.L. HECHTEL,AND E.H. FOLLMAN.1994. Black bear dens. Journalof Wildlife Management47:545-550. bear denning ecology in interiorAlaska. InternationalCon- LINDZEY,F.G., ANDE.C. MESLOW.1976. Winter dormancyin ference on Bear Research and Management9(1):513-522. black bears in southwestern Washington. Journal of STONEBERG,R.P., ANDC.J. JONKEL.1966. Age determinationof Wildlife Management40:408415. black bears by cementumlayers. Journalof Wildlife Man- MACHLIS,L., P.W.D. DODD,AND J.C. FENTRESS.1985. The agement 30:411-414. pooling fallacy: problemsarising when individualscontrib- STROGANOV,S.U. 1962. Carnivorous of . USSR ute more than one observationper data set. Zeitochriftfur Academyof Sciences, Moscow, Russia. (In Russian.) V.P. 1960. Tierpsychologie68:201-214. (In German.) SYSOEV, Hunting in the Far Eastern taiga. Book MANVILLE,A.M. 1983. Human impact on the black bear in Publishers, Khabarovsk, Russia. (In 's lower peninsula. InternationalConference on Russian.) ANDR.L. RUFF.1980. Bear Research and Management5:20-33. TIETJE,W.D., Denning behavior of black bears in forest of . of MILLER,S.D. 1990. Denning ecology of brown bears in Journal Wildlife 44:858-870. southcentralAlaska andcomparisons with a sympatricblack Management S. AND R.T. bear population. InternationalConference on Bear Re- VROOM,G.W., HERRERO, OGILVIE.1980. The of winter den sites of bears in Banff search and Management8:279-287. ecology grizzly National Alberta. O'PEzIO,J., S.H. CLARKE,AND C. HACKFORD.1983. Chronol- Park, InternationalConference on Bear Research and Management4:321-330. ogy of black bear denning in the Catskill region in New ANDM.R. PELTON.1994. York. InternationalConference on Bear Research and WEAVER,K.M., Denning ecology of black bears in the Tensas River Basin of Louisiana. Inter- Management5:87-94. national Conference on Bear Research and PAZHETNOV,V.S. 1990. Brown bear. Agropromizdat,Moscow, Management 9(1):427-433. Russia. (In Russian.) WILSON,D.E., ANDD.M. REEDER.1993. Mammal of PIKUNOV D.G., P.V. PHOMENKO,AND S.I. KOVALYONOK.1991. species the World: a taxonomic and geographicreference. Smith- Dens of white-chested bears. Pages 242-251 in B.P. sonian InstitutionPress, D.C., USA. Zavatsky and Y.G. Shvetsov, editors. Bears of the USSR. Washington, Xu, L., Y.Q. MA, Z.X. GAO,AND F.Y. LIu. 1994. Character- Nauka, Novosibirsk, Russia. (In Russian.) istics of dens and selection of denning habitatfor bears in REID,D., M.D. JIANG, Q.T. TENG, Z.S. QIN, AND J.C. Hu. 1991. the south Xiaoxinganling Mountains,. International of the Asiatic black bear in Ecology (Ursus thibetanus) Conferenceon Bear Research and China. Mammalia Management9(1):357- Sichuan, 55:221-237. 362. ROGERS,L.L., ANDL.D. MECH.1981. Interactionsof wolves YUDAKOV,A.G., AND I.G. NIKOLEAV.1987. of the and black bears in NortheasternMinnesota. Journal of Ecology Amur tiger. Nauka, Moscow, Russia. (In Russian.) Mammalogy62:434-436. YUDIN, V.G. 1993. The . Pages 479-491 in Ross, P.I., G.E. HORNBECK,AND B.L. HOREJSI.1988. Late M.A. Vaisfeld and I.E. Chestin,editors. Bears: brown bear, denning black bears killed a bear. Journal of by grizzly , Asian black bear. Nauka, Moscow, Russia. 69:818-820. (In Russian.) SCHALLER,G.B., Q.T. TENG,K.G. JOHNSON,X.M. H.M. WANG, ZAR, J.H. 1984. Biostatistical analysis. Prentice-Hall, Inc., SHEN, AND J.C. Hu. 1989. The of feeding ecology giant Englewood, New Jersey, USA. pandas and Asiatic black bears in the TangjiaheReserve, China. 212-241 in J.L. Pages Gittleman,editor. Received: 19 July 2002 behavior,ecology, and evolution. Cornell UniversityPress, Accepted: 7 March 2003 Ithaca,New York, USA. Associate Editor: F. van Manen

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