Assessing the conservation status of species of concern is greatly aided by unbiased estimates of population size. Population size is one of the primary parameters determining urgency of conservation action, and it provides baseline data against which to measure progress toward recovery. Asiatic black bears (Ursus thibetanus) and sun bears (Helarctos malayanus) are vulnerable to extinction, but no statistically rigorous population density estimates exist for wild bears of either species. We used a camera-based approach to estimate density of these sympatric bear species. First, we tested a technique to photograph bear chest marks using 3 camera traps mounted on trees facing each other in a triangular arrangement with bait in the center. Second, we developed criteria to identify individual sun bears and black bears based on chest-mark patterns and tested the level of congruence among 5 independent observers using a set of 234 photographs. Finally, we camera-trapped wild bears at 2 study areas (Khlong E-Tow, 33 km², and Khlong Samor-Pun, 40 km²) in Khao Yai National Park, Thailand, and used chest marks to identify individual bears and thereby derive capture histories for bears of each species. Average congruence among observers' identifications of individual bears was 78.4% for black bear and 92.9% for sun bear across sites. At Khlong E-Tow, we recorded 13 black bears (8 M, 4 F, 1 unknown sex) and 8 sun bears (1 M, 5 F, 2 unknown sex). At Khlong Samor-Pun, we recorded 10 black bears (6 M, 4 F) and 6 sun bears (4 M, 2 F). We used a spatially explicit capture–recapture method, resulting in density estimates of 8.0 (SE  =  3.04) and 5.8 (SE  =  2.31) black bears per 100 km² and 5.9 (SE  =  3.07) and 4.3 (SE  =  2.32) sun bears per 100 km² for each study area, respectively. Our camera trap design and chest-mark identification criteria can be used to estimate density of sun bears and black bears, enhancing knowledge of the conservation status of these threatened and little-known bear species.

Polar bears (Ursus maritimus) are managed by the 5 nations where they occur (Canada, Greenland/Denmark, Norway, Russia, United States) using discrete subpopulations. In Canada, polar bears are harvested throughout their range, and several subpopulations are managed by more than one jurisdiction; therefore, recent management focused on ensuring sustainable polar bear harvests. Consequently, the subpopulation from which harvested bears are removed and the geographic boundaries of that subpopulation must be correctly identified. However, boundaries of the Southern Hudson Bay (SH) subpopulation have not been verified using satellite radio-telemetry data. Sea ice duration has already declined in Hudson Bay and James Bay, and both the duration and distribution of sea ice are predicted to decline greatly in the next century; therefore, it is important to document current habitat use patterns to assess the potential impacts of climate change. We used a probabilistic approach to describe the utilization distribution for the SH subpopulation based on data from 1997–2003 from 26 adult female bears fitted with satellite collars and assessed whether the currently accepted boundaries represent the population utilization distribution. We conclude that the SH boundaries do reflect the current spatial distribution of adult female bears in this subpopulation. Our analysis provides a benchmark to compare to the future distribution and habitat use of this subpopulation in response to effects of climate change and identifies future research needs to investigate polar bear distribution in James Bay and in the area near the boundary between the SH and Western Hudson Bay management zones.

Non-invasive genetic sampling (NGS) methods have been instrumental in providing robust population abundance and density estimates of bears. We conducted a small pilot study to (1) evaluate 2 NGS methods of hair traps and bear rubs in the Russian Far East (RFE) on sympatric populations of Asiatic black bears (Ursus thibetanus) and brown bears (Ursus arctos), and (2) to identify potential DNA marker sets for future study. Genetic analysis required 6 microsatellite markers to definitively identify individuals plus a gender marker, and closed population models estimated 142 Asiatic black bears and 18 brown bears. Spatially-explicit mark–recapture (SECR) density estimates for brown bears were 3 bears/100 km². Inflated Asiatic black bear estimates resulted from a lack of recaptures, although using combined detection data from the 2 NGS methods was found to improve precision for abundance estimates. Capture probabilities were higher for brown bears than for Asiatic black bears, but overall recapture probabilities were low for both species. The frequency of rubbing declined from June to August, possibly due to bears leaving the study area, and Asiatic black bears were detected less frequently on rubs than brown bears, suggesting that species-specific ecology must be incorporated into future study designs. We recommend that future applications of NGS in the RFE improve capture probabilities by sampling earlier in the season to mitigate geographic closure violation for abundance estimates and to increase the number of detections for robust spatially explicit capture–recapture analyses. Our results demonstrate that NGS methods have strong potential for monitoring of bear populations in the RFE.

Historically abundant throughout Mississippi, American black bears (Ursus americanus) have declined due to habitat loss and overharvest. By the early 1900s, the bear population was estimated at <12 individuals, and Mississippi closed black bear hunting in 1932. However, habitat loss continued and by 1980 suitable habitat was estimated at 20% (20,234 km²) of historic levels (101,171 km²) with the decline continuing. Although black bear abundance is currently unknown, a recent increase in occurrence reports and documented reproduction suggests the population may be increasing. There have been 21 reported nuisance complaints since 2006, of which 7 were apiary damage. Additionally, 31 bear mortalities were reported since 1972; 80% were human caused. Government and private organizations have emphasized education on bear ecology and human–bear coexistence, while habitat restoration through land retirement programs (e.g., Conservation Reserve and Wetland Reserve Programs) will improve habitat abundance and suitability for black bears. Black bears are naturally recolonizing Mississippi with current state agency management directed at supporting population reestablishment through habitat conservation and species protection.

We assessed human attitudes toward brown bears (Ursus arctos) and their acceptance from 3,789 questionnaires collected in northwest Lithuania in 2009. We present results on the (1) value placed upon brown bears by respondents, (2) acceptable distances for these animals from the residence of respondents, (3) assessments of possible damage and economic losses, (4) management options preferred in different situations, and (5) respondent opinions regarding brown bear numbers in the country. There are no permanent brown bear populations in the country. We found that Lithuanians attributed high value to the species, but that 82.4% of respondents reported they would fear for the safety of their families knowing bears inhabit forests. On average, 60 to 70% of respondents will not accept bears closer than 10 km. In this respect, the re-establishment of bear populations in Lithuania would be not appreciated by most inhabitants. We found that 22.5% of respondents would like to have action taken against bears even if they lived far from settlements. Scaring away and shooting of the bears were the significantly most preferred options in situations where the bears might be encountered near human settlements or in cases where they actually threaten human life. An increasing concern about the environment and involvement in outdoor activities were correlative to a positive attitude toward an increase in bear populations. Exceptions to this were with berry and mushroom pickers; these groups generally were against any growth in the bear population. A total eradication of bears or a reduction in their numbers were the preferred options by farmstead and village dwellers, whereas urban respondents generally favored a population increase. The main conclusion of our study is that acceptance of this species, which at this moment do not inhabit country, is similar to acceptance of other large carnivore species.

We measured American black bear (Ursus americanus) responses to hikers, small power skiffs, kayakers, and overnight campsites within coastal salt marsh foraging areas. To accomplish this, we experimentally approached bears in the intertidal and supratidal zones of Aialik Bay (AB) and Nuka Bay (NB), Kenai Fjords National Park, Alaska. We chose these areas due to their different levels of human activity (AB  =  high, NB  =  low). In the first experiments, we determined the overt response distances (ORD: when bears first responded to our approaches) and flight initiation distances (FID: the distance at which bears were pushed from their original location) for 118 black bear groups involving 136 bears. We found no difference between ORD response to power skiffs and versus kayaks, nor between those responding to kayaks versus foot approaches. However, bears first responded to power skiffs 50 m farther than first responses to foot approaches. There was no difference in FID between all modes of approach. There were no differences in response intensities (a qualitative scale depicting strength of bear response to human presence at both the ORD and FID) between any of the modes of approach. There were no differences in bear minutes/hour (minutes of bear presence in the study area/hour of observation) or numbers of bears at NB and AB before or after campsites were present. There was, however, a difference in levels of bear activity in NB and AB when campsites were in place: AB bear minutes/hour decreased by 50% and NB bear minutes/hour increased by 75%. We recommend minimum approach distances of 170 m for skiffs and kayaks and 116 m for hikers to minimize bear displacement by visitors to the park. Additionally, we suggest people avoid camping in saltmarsh areas so as to leave bears undisturbed.

The Louisiana black bear (Ursus americanus luteolus) is comprised of 3 subpopulations, each being small, geographically isolated, and vulnerable to extinction. Hurricanes Katrina and Rita struck the Louisiana and Mississippi coasts in 2005, potentially altering habitat occupied by this federally threatened subspecies. We used data collected on radio-telemetered bears from 1993 to 1995 and pre-hurricane landscape data to develop a habitat model based on the Mahalanobis distance (D²) statistic. We then applied that model to post-hurricane landscape data where the telemetry data were collected (i.e., occupied study area) and where bear range expansion might occur (i.e., unoccupied study area) to quantify habitat loss or gain. The D² model indicated that quality bear habitat was associated with areas of high mast-producing forest density, low water body density, and moderate forest patchiness. Cross-validation and testing on an independent data set in central Louisiana indicated that prediction and transferability of the model were good. Suitable bear habitat decreased from 348 to 345 km² (0.9%) within the occupied study area and decreased from 34,383 to 33,891 km² (1.4%) in the unoccupied study area following the hurricanes. Our analysis indicated that bear habitat was not significantly degraded by the hurricanes, although changes that could have occurred on a microhabitat level would be more difficult to detect at the resolution we used. We suggest that managers continue to monitor the possible long-term effects of these hurricanes (e.g., vegetation changes from flooding, introduction of toxic chemicals, or water quality changes).

Bears are large, charismatic mammals whose presence often garners conservation attention. Because healthy bear populations typically require large, contiguous areas of habitat, land conservation actions often are assumed to benefit co-occurring species, including other mammalian carnivores. However, we are not aware of an empirical test of this assumption. We used remote camera data from 2 national parks in Sri Lanka to test the hypothesis that the frequency of detection of sloth bears (Melursus ursinus) is associated with greater richness of carnivore species. We focused on mammalian carnivores because they play a pivotal role in the stability of ecological communities and are among Sri Lanka's most endangered species. Seven of Sri Lanka's carnivores are listed as endangered, vulnerable, or near threatened, and little empirical information exists on their status and distribution. During 2002–03, we placed camera traps at 152 sites to document carnivore species presence. We used Poisson regression to develop predictive models for 3 categories of dependent variables: species richness of (1) all carnivores, (2) carnivores considered at risk, and (3) carnivores of least conservation concern. For each category, we analyzed 8 a priori models based on combinations of sloth bear detections, sample year, and study area and used Akaike's information criterion (AIC_c) to test our research hypothesis. We detected sloth bears at 55 camera sites and detected 13 of Sri Lanka's 14 Carnivora species. Species richness of all carnivores showed positive associations with the number of sloth bear detections, regardless of study area. Sloth bear detections were also positively associated with species richness of carnivores at risk across both study years and study areas, but not with species richness of common carnivores. Sloth bears may serve as a valuable surrogate species whose habitat protection would contribute to conservation of other carnivores in Sri Lanka.

We characterized annual and seasonal home ranges (HR) of 27 female Asiatic black bears (Ursus thibetanus) during 2003–11 in Karuizawa, Nagano Prefecture, Japan. Mean annual HR size for bears calculated by the 95% fixed kernel method was 10.0 km² (SD  =  8.5) and differed depending on the year. However, annual HR sizes were not affected by reproductive status (with or without cubs) or age (subadult or adult). Home ranges tended to be larger in summer than in autumn. We speculate that a contributing factor to differences in HR size was annual or seasonal fluctuation of food resources. Annual shifts in HR centers and HR overlaps were estimated to be 1.2 km (SD  =  0.9) and 0.55 km (SD  =  0.13), respectively. Seasonal shifts in HR centers and seasonal overlaps were 1.1 km (SD  =  1.1) and 0.54 km (SD  =  0.12), respectively. Together, these results suggest that female Asiatic black bears in our study area do not migrate long distances seasonally or annually.

Over-winter denning is a critical component of grizzly bear (Ursus arctos) fitness. Consequently, identifying and protecting denning habitat is important for grizzly bear management. We evaluated small-scale den-site selection by comparing grizzly bear den sites (n  =  21) in the Southern Lakes region, Yukon, Canada to random locations within 100 m of dens. We measured indices of structural stability (slope at den opening, tree and shrub cover, percent soil <2 mm), and security (horizontal cover) at each den site and random location, and used mixed model analysis of variance to determine selection. Our results indicated selection for both steeper slopes and horizontal cover, suggesting that stability and security are important components of den-site selection at small spatial scales.

We investigated the distribution and diet of brown bears (Ursus arctos) in the Upper Mustang Region (UMR) of the Annapurna Conservation Area (ACA) in Nepal by interviewing local residents (n  =  166) and collecting bear sign (n  =  109). Residents reported that brown bears predominantly used the Dhalung and Chungjung pastures and the Damodar Kunda Valley of the UMR from May to November, as well as the unprotected area between this region and Shey–Phoksundo National Park. We conducted dietary analyses on 56 bear scats; bears were predominately carnivorous in the UMR. Plant matter comprised 8% of fecal volume in scats. Small mammal hair was the most commonly identified item (75%), with marmots (Marmota himalayana; 46%) being the largest contributor. In addition, hair from ungulates (14%) and livestock (10%) were identified in scats. Few bear depredations occurred between 2003–10 in the UMR.

The brown bear (Ursus arctos) is distributed throughout parts of northern and central Europe and Asia. Within Asia, its distribution extends to the northern, northeastern, and central Asian countries. In Afghanistan, brown bears are distributed in the northeastern parts including the Darwaz region, Badakhshan. However, the actual status and distribution of the species are not known in Afghanistan. We documented brown bears in Darwaz, where there have been no previous records confirming the presence of the species. Brown bear occurrence was confirmed through public reports during personal interviews, field evidence, and documentation of alleged bear depredation cases. Seventy-two percent of the informants stated that brown bears occur in Darwaz, and depredation complaints were recorded from 17 villages across the area. The highest numbers of complaints were from Nusai District. Cattle, especially bulls, were the major victims of alleged brown bear depredation in the region.