Interactions between brown bears (Ursus arctos) and anadromous salmon (Oncorhynchus spp.) constitute a unique energy pathway that facilitates nutrient cycling between marine and terrestrial ecosystems. Previous studies have documented variation in salmon consumption by brown bears; however, few have addressed potential anthropogenic factors influencing consumption. We assessed diet of brown bears on Hokkaido Island, Japan, using carbon and nitrogen stable isotopes to determine the effect of demographic (age and sex) and environmental (developed and undeveloped area) factors on salmon consumption. We collected thigh bones from 190 harvested bears from 1996 to 2011 and samples of their major dietary foods from 2009 to 2011, and we then estimated the potential contributions of these foods to the diets of brown bears using a Bayesian mixing model. Brown bears consumed more herbs, fruits, and corn than terrestrial animals or salmon at the population level. However, the dietary contribution of salmon varied widely among bears; in some cases, it comprised >30% of the total diet. Salmon consumption also varied by bear age class, sex, and location. Low salmon consumption by adult females with cubs suggested avoidance of salmon-spawning areas to minimize risk to their cubs. Bears inhabiting undeveloped areas were more likely to consume salmon than those inhabiting developed areas, suggesting that human activities restrict brown bears' salmon consumption. The lower salmon intake of Hokkaido brown bears compared with Alaskan brown bears may be attributed in part to extensive human development on Hokkaido Island, including in-stream structures that preclude salmon migrations and agricultural crops that provide an alternative food subsidy.

Managers of American black bears (Ursus americanus) must maintain populations to ensure viability and opportunities for sport harvest, and minimize human–bear conflict (HBC). Harvest is a cost-effective management tool in most jurisdictions, and intuitively it seems that with fewer bears, there should be fewer conflicts. Therefore, managers may attempt to achieve both objectives by manipulating the harvest. Further, because data describing harvest and HBC are frequently collected, managers sometimes infer changes in population status from trends in harvest and HBC. However, evidence that larger harvests reduce HBC is lacking, and changes in harvest metrics and the frequency of HBC may be independent of bear density. Understanding relationships among food availability, hunter effort, harvest, and HBC could help managers avoid making invalid inferences about population status from data describing harvest and HBC, and evaluate whether management actions are having intended results. We investigated relationships among food availability, HBC, and harvest at landscape scales in Ontario, Canada, 2004–2011. We hypothesized that HBC and harvest would be negatively correlated with food availability; that HBC would be negatively correlated with prior harvest; and that harvest would be positively correlated with number of hunters. We used Spearman rank correlation to test hypotheses. Human–bear conflict was negatively correlated with food availability across Ontario, and in the 2 administrative regions where food availability varied synchronously. Total harvest and the proportion of females in the harvest were negatively correlated with food availability across Ontario and in one region. Human–bear conflict was not correlated with prior harvests, providing no evidence that larger harvests reduced subsequent HBC. Given the variation in natural foods, harvest is unlikely to prevent elevated levels of HBC in years of food shortage unless it maintains bears at low densities—an objective that might conflict with maintaining viable populations and providing opportunities for sport harvest.

In the absence of information on species in decline with contracting ranges, management should emphasize remaining populations and protection of their habitats. Threatened by anthropogenic pressure including habitat degradation and loss, sloth bears (Melursus ursinus) in India have become limited in range, habitat, and population size. We identified ecological and anthropogenic determinants of occurrence within an occupancy framework to evaluate habitat suitability of non-protected regions (with sloth bears) in northeastern Karnataka, India. We employed a systematic sampling methodology to yield presence–absence data to examine a priori hypotheses of determinants that affected occupancy. These covariates were broadly classified as habitat or anthropogenic factors. Mean number of termite mounds and trees positively influenced sloth bear occupancy, and grazing pressure expounded by mean number of livestock dung affected it negatively. Also, mean percentage of shrub coverage had no impact on bear inhabitance. The best fitting model further predicted habitats in Bukkasagara, Agoli, and Benakal reserved forests to have 38%, 75%, and 88%, respectively, of their sampled grid cells with high occupancies (>0.70) albeit little or no legal protection. We recommend a conservation strategy that includes protection of vegetation stand-structure, maintenance of soil moisture, and enrichment of habitat for the long-term welfare of this species.

Foraging decisions and movement strategies by animals often involve a trade-off between meeting nutritional demands and minimizing risk of predation. We evaluated the influence of space use and movement patterns of maternal female grizzly bears (Ursus arctos) on cub (defined as first year of life) survival in eastern Interior Alaska, USA, during 2008–2012. We monitored 9 GPS radiocollared females that produced 28 cubs in 12 litters (x¯ litter size  =  2.3, range  =  2–3). The estimated annual cub survival rate was 0.39 (95% CI  =  0.20–0.57). In all cases the entire litter survived or died prior to den entrance. All cubs in a litter died either concurrently or within 14 days in 5 of 7 litters lost. Sixty-nine percent of cub mortality occurred between 31 May and 16 June. We did not document cub mortality before 31 May. Females with surviving cubs remained within 1 km of the den for a longer period following emergence than those that lost cubs. Between den emergence and the onset of vegetation green-up, females with surviving cubs used fewer habitat patches and remained in individual habitat patches longer than females that lost their cubs later in the summer. Females with surviving cubs exhibited different activity patterns compared with females that lost their cubs, particularly by moving less between midnight and mid-morning during 15 May–16 June. Once vegetation green-up occurred, movement rates of all maternal females were similar except that females with surviving cubs continued to move less during the morning hours (0000–1200 hr). We did not find evidence that the body size of the mother was a factor explaining cub survival nor was there evidence that cub survival was directly influenced by human causes. The most successful behavioral strategies used by maternal females to maximize cub survival appeared to be a combination of limiting movements to a few habitat patches between den emergence and vegetation green-up and limiting activity between midnight and mid-morning. We suggest that the ability to find and exploit suitable habitat patches during this period of limited resources may have allowed females to alter movements temporally and spatially and provision themselves and their cubs more effectively. This strategy was likely effective for both minimizing exposure to infanticidal adult bears and allowing cubs to maximize energy efficiency.

The Andean bear (Tremarctos ornatus), the only extant ursid in South America, lives in páramo and montane forest ecosystems and is classified as vulnerable on the International Union for Conservation of Nature Red List (Goldstein et al. 2008). In Podocarpus National Park in southern Ecuador, Andean bears exhibit patchy foraging behavior on Puya eryngioides, a small terrestrial bromeliad. The objective of this study (conducted during summer 2011 in Podocarpus National Park) was to determine which factors influence foraging by characterizing and contrasting the biological and physical surroundings of foraged and unforaged P. eryngioides patches within a larger feeding site. The majority of our variables did not differ between foraged and unforaged patches at the measured scale, but we found evidence that foraging choices might be influenced by aspect, microtopography, P. eryngioides density, and distance from cover. These results provide a foundation for future research into food resources and foraging behavior by Andean bears, which is critical information for conservation in the changing and increasingly fragmented páramo ecosystem.

The giant panda (Ailuropoda melanoleuca) is a global conservation icon, but its habitat selection patterns are poorly understood. We synthesized previous studies on giant panda habitat selection. We confirmed that pandas generally selected forests with moderate to high bamboo densities, mid-elevations, both primary and secondary forests, and areas more distant from human activities. Pandas did not select steep slopes. We also highlighted the interactive effects among different habitat components, such as weaker selection for gentle slope and large patch size in disturbed secondary forests compared with primary forests. Pandas selected for land cover and disturbance at the level of the geographic range and selected for variables such as slope and bamboo density at the level of the home range. Furthermore, selection for higher bamboo cover did not change with bamboo availability, but selection against secondary forest declined as availability of this forest type increased. Our results have implications for the conservation of pandas, particularly the need for inclusion of areas previously seen as less suitable (e.g., moderate slopes and secondary forest) in protected area and habitat restoration planning.

The Andean bear (Tremarctos ornatus) is found throughout the Andes Mountains from Venezuela to Bolivia. However, little is known about its distribution and range in southern areas, including Argentina. Our objective was to develop a genetic marker to identify this species by analysis of non-invasive samples (i.e., hair or feces). We designed a primer pair to amplify a 115–base-pair fragment within cytochrome b of mitochondrial DNA. We successfully amplified the expected fragment in samples from Argentina (collected during 2 periods [1993 and between 2006 and 2008]) having sequences highly similar to Andean bear reference sequences in GenBank; and we identified 2 haplotypes in samples from northwest Argentina. We confirmed the presence of Andean bears in Argentina, which extends the known southern distributional limit about 150 km. Further studies employing our approach will allow for a comprehensive assessment of the potential distribution and southernmost range of this species.

The survival of large and mobile species in the face of habitat loss and fragmentation depends on several factors, including the landscape configuration of subpopulations and the dispersal capabilities of the species. We performed a landscape analysis of the Bolivian Tropical Andes to determine whether remaining habitat patches were suitable in terms of ecological characteristics and potential connectivity for the long-term survival of the Andean bear (Tremarctos ornatus). First we built a ruled-based model to identify key patches or areas large enough to sustain a viable population by using knowledge of Andean bear habitat requirements and movement patterns. Second, we estimated potential functional connectivity among these areas applying a cost-distance analysis based on estimates of the resistance to movement through the landscape. Finally, we quantified the proportion of these key patches and corridor habitats within the Bolivian protected area system. The rule-based model identified 13 key patches covering 21,113 km² corresponding to a maximum estimated population of 3,165 adult bears. Using cost-distance analysis, all 13 key patches were potentially connected to ≥1 other key patch. Twelve of the patches were at least partially protected by national parks, and 40% of areas considered suitable as corridors were included within a protected area. Although the current protected area system includes suitable bear habitat, large portions of key patches and corridors are unprotected, which could eventually lead to fragmentation and habitat loss if these areas are not protected.