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Wildlife managers conduct population inventories to monitor species, particularly those at‐risk. Although costly and time consuming, grid‐based DNA hair‐snag sampling has been the standard protocol for grizzly bear inventories in North America, while opportunistic fecal DNA sampling is more commonly used in Europe. Our aim is to determine if low‐cost, low‐effort scat sampling along roads can replace the current standard. We compare two genetic non‐invasive techniques using concurrent sampling within the same grid system and spatially explicit capture–recapture. We found that given our methodology and the present status of fecal genotyping for grizzly bears, scat sampling along roads cannot replace hair sampling to estimate population size in low‐density areas. Hair sampling identified the majority of individual grizzly bears, with a higher success rate of individuals identified from grizzly bear samples (100%) compared to scat sampling (14%). Using scat DNA to supplement hair data did not change population estimates, but it did improve estimate precision. Scat samples had higher success identifying species (98%) compared with hair (80%). Scat sampling detected grizzly bears in grid cells where hair sampling showed non‐detection, with almost twice the number of cells indicating grizzly bear presence. Based on our methods and projected expenses for future implementation, we estimated an approximate 30% cost reduction for sampling scat relative to hair. Our research explores the application of genetic non‐invasive approaches to monitor bear populations. We recommend wildlife managers continue to use hair‐snag sampling as the primary method for DNA inventories, while employing scat sampling as supplemental to increase estimate precision. Scat sampling may better indicate presence of bear species through greater numbers and spatial distribution of detections, if sampling is systematic across the entire area of interest. Our findings speak to the management of other species and regions, and contribute to ongoing advances of monitoring wildlife populations. [ABSTRACT FROM AUTHOR]

To assess the trophic position of the exceptionally large-sized brown bears from the Pleistocene of Yakutia, we used stable nitrogen and carbon isotope analyses of the collagen contained in fossil bones and teeth. Modern brown bears of Yakutia were compared to the large Pleistocene predators. As a result of the measurements taken for the Pleistocene bears, we obtained δ13С values typical of terrestrial ecosystems and relatively high δ15N values typical of such Pleistocene predators as the cave lion. We explain the high δ15N values of the bone collagen of the study fossil bears, as well as other Pleistocene brown bears of Yakutia and Chukotka, by (1) the absence of large competitors such as Arctodus simus, which allowed the bears to use large amounts of animal food; (2) the physiological effect of hibernation, expressed in an increased content of 15N in the bone collagen; and (3) an increased content of 15N in vegetation due to more severe climatic conditions, which affects the isotopic composition of the entire mammoth fauna of western Beringia. The δ13C and δ15N values of modern brown bears in Yakutia indicate a plant diet, suggesting that the modern brown bears (compared to fossils) occupy a fundamentally different trophic niche adapted to the modern low-productivity ecosystems of Yakutia. [ABSTRACT FROM AUTHOR]

Hibernation is an adaptive strategy to survive harsh winter conditions and food shortage. The use of well‐insulated winter dens helps animals minimize energy loss during hibernation. Brown bears (Ursus arctos) commonly use excavated dens for hibernation. Physical attributes of excavated dens are expected to impact the bear's heat retention and energy conservation. The objective of this study was to examine the determinants of cavity size of excavated dens and the impact of physical attributes of excavated dens on energy conservation in hibernating bears, hypothesizing that bears excavate dens in a way to minimize heat loss and optimize energy conservation during hibernation. We predicted that den cavity size would be determined by the bear's body size and that older bears would excavate better‐fitting cavities to minimize heat loss, due to their previous experience. We further predicted that physical attributes of excavated dens would affect the bears' posthibernation body condition. Our results revealed that bears excavated a den cavity in relation to their body size, regardless of sex, and that older bears tended to excavate better‐fitting den cavities compared to young bears, as we expected. Older bears excavated better‐fitting den cavities, suggesting a potentially experience‐based shift with age in den‐excavation behavior and an optimum cavity size relative to a bear's body size. Our key finding is that insulation of excavated dens provided by wall/rood thickness and bedding materials had a significant positive effect on bears' posthibernation body condition. We believe that our study provides new insight into how not only the quality of denning habitat, but also the quality of dens may affect hibernating animals, by presenting a potential adaptive aspect of den preparation (age effect on efficiency in den excavation) and effect of den attributes on the posthibernation body condition of brown bears. [ABSTRACT FROM AUTHOR]

Body size reflects realized physiological niche width at the population level and provides insights into the potential resiliency of a species to natural and anthropogenic perturbations to ecosystems. We analyzed patterns of American black and brown bear body size through a meta‐analysis of data from 18 studies conducted across North America, to evaluate the effects of species, sex, latitude, sympatry, and harvest. We used a bootstrap model selection procedure, which accounted for differences in sample size and population variation between studies, to investigate patterns in body mass. As expected, we found that brown bears were generally larger than black bears and both species were sexually dimorphic (i.e., males were generally larger than females). Black bear body size was not related to latitude, whereas brown bear body size was greatest at intermediate latitudes, possibly due to the presence of salmon. Neither sympatry nor harvest was associated with body size for either species at the geographic scale of our meta‐analyses, but both may warrant consideration at the local scale. Body size, as an index of population health, reflects phenotypic plasticity within species and populations and may serve as a useful indicator of niche utilization. Indeed, understanding large‐scale physiological patterns such as these can assist in understanding past, present, and future changes to realized niches and subsequent resiliency of species and populations. [ABSTRACT FROM AUTHOR]

Hibernation represents an adaptation for coping with unfavorable environmental conditions. For brown bears Ursus arctos, hibernation is a critical period as pronounced temporal reductions in several physiological functions occur.Here, we review the three main aspects of brown bear denning: (1) den chronology, (2) den characteristics, and (3) hibernation physiology in order to identify (a) proximate and ultimate factors of hibernation as well as (b) research gaps and conservation priorities.Den chronology, which varies by sex and reproductive status, depends on environmental factors, such as snow, temperature, food availability, and den altitude. Significant variation in hibernation across latitudes occurs for both den entry and exit.The choice of a den and its surroundings may affect individual fitness, for example, loss of offspring and excessive energy consumption. Den selection is the result of broad‐ and fine‐scale habitat selection, mainly linked to den insulation, remoteness, and availability of food in the surroundings of the den location.Hibernation is a metabolic challenge for the brown bears, in which a series of physiological adaptations in tissues and organs enable survival under nutritional deprivation, maintain high levels of lipids, preserve muscle, and bone and prevent cardiovascular pathologies such as atherosclerosis. It is important to understand: (a) proximate and ultimate factors in denning behavior and the difference between actual drivers of hibernation (i.e., factors to which bears directly respond) and their correlates; (b) how changes in climatic factors might affect the ability of bears to face global climate change and the human‐mediated changes in food availability; (c) hyperphagia (period in which brown bears accumulate fat reserves), predenning and denning periods, including for those populations in which bears do not hibernate every year; and (d) how to approach the study of bear denning merging insights from different perspectives, that is, physiology, ecology, and behavior. [ABSTRACT FROM AUTHOR]

There is a long and contentious history of brown bear (Ursus arctos) harvest management in Alaska, USA, the state that hosts the largest brown bear population in North America. In the mid‐1990s, the Alaska Board of Game set the population objective for brown bears in Game Management Unit 13 A, located in interior southcentral Alaska, to be reduced by 50% to improve survival of moose (Alces alces) calves. The Board began further liberalizing brown bear harvest regulations for the unit beginning in regulatory year 1995, though adult females and their dependent offspring (i.e., cubs <2 yrs old) were protected. To evaluate progress toward this abundance objective, we captured and collared bears between 2006 and 2011 and conducted a capture‐mark‐resight density survey during summer 2011 for comparison to a similar baseline survey conducted in 1998. We report the results of the density survey and vital rates estimated from resight histories of collared bears and harvest information spanning from 1985 (10 years before establishment of the population objective) to 2012. There was a 25–40% reduction in abundance between 1998 and 2011. Population growth rates derived from density estimates and a matrix population projection model indicated that the population declined by 2.3–4.2% annually. We estimated harvest rates to be 8–15% annually, but harvest composition data indicated no changes in skull size, age distribution, or overall sex ratio. There was evidence of an increase in the proportion of older females in the harvest. Demographic analysis indicated high reproductive output and recruitment, potentially indicating a density‐dependent compensatory response to reduced population size. Despite 13 years of harvest rates in excess of what had previously been considered to be sustainable for this population, the objective of reducing bear abundance by 50% had not been achieved as of 2011. The protection of females and dependent offspring in our study population appears to be a sufficient safeguard against a precipitous population decline while still permitting progress toward the population objective through high harvest on other segments of the population. © 2020 The Wildlife Society. We report harvest records, density estimates, and survival and reproductive estimates for a brown bear population in Alaska being managed for a 50% abundance reduction. After 16 years of liberal harvest regulations, the population reduction objective had not been met, likely because of regulatory protection of reproductive females and their dependent young. [ABSTRACT FROM AUTHOR]

Throughout the animal kingdom, antipredator mechanisms are an evolutionary driving force to enable the survival of species classified as prey. Information regarding a predator's location can be determined through chemosensory cues from urine, faeces, visual and/or acoustic signals and anal gland secretions; and in several lab and field-based studies it has been seen that these cues mediate behavioural changes within prey species. These behaviours are often linked to fear and avoidance, which will in turn increase the prey's survival rate. In many studies dogs (Canis lupus familiaris) have been used as a predator species, however, no research has addressed a dog's innate ability to detect predator scents, hence the rationale behind this study. We assessed the innate ability of the untrained domestic dog to detect faecal scents of wild Eurasian brown bear (Ursus arctos arctos) and European lynx (Lynx lynx). The study monitored 82 domestic dogs across the UK and Norway. The dogs were exposed to the two predator faecal scents from Eurasian brown bear and European lynx, a herbivore faecal scent of Eurasian beaver (Castor fiber) and water control. Measurements were taken upon the time spent within a 40 cm radius of each scent and changes in the dog's heart rate when within this 40 cm radius. We found dogs spent a decreased length of time around the predator scents and had an increased heart rate in relation to their basal heart rate. We conclude that dogs can innately sense predator scents of brown bear and lynx and elicit fear towards these odours, as shown through behavioural and physiological changes. [ABSTRACT FROM AUTHOR]

Human–bear conflicts resulting from livestock depredation and crop use are a common threat to the brown bear Ursus arctos throughout its range. Understanding these conflicts requires the recording and categorization of incidents, assessment of their geographical distribution and frequency, and documentation of the financial costs and the presence of any preventative measures. Damage compensation schemes can help mitigate conflicts and, in some cases, improve acceptance of bears. This study aims to elucidate the major factors determining the patterns of damage caused by bears, examine the effectiveness of preventative measures in reducing such damage, and identify bear damage hotspots in Croatia. Our analysis is based on damage reports provided by hunting organizations to the Croatian Ministry of Agriculture during 2004–2014. The highest number of claims were made for damage to field crops and orchards. Damage to livestock, agricultural crops and beehives resulted in the highest total cost to farmers. Damage to beehives and to automatic corn feeders for game species incurred the highest cost per damage event. We identified a hotspot for bear damage claims in Croatia, located near Risnjak National Park and the border with Slovenia. Damage appears higher in areas that have more villages closer to protected areas and a greater per cent of forest cover, indicating a synergistic effect of protected environments that facilitate bear movements and the presence of human activities that provide easily accessible food for bears. [ABSTRACT FROM AUTHOR]

Mammals usually adjust behavioral patterns when exposed to disturbances. Elusiveness and low-risk time selection may reduce their stress in periods of highest risk. In Europe, brown bears (Ursus arctos) coexist with humans in densely populated and modified landscapes and, consequently, are exposed to human-caused disturbances during the daytime hours. Furthermore, intraspecific interactions might also influence their behavioral responses, especially during the mating season. Activity patterns of several large carnivores have been thoroughly studied; however, research is scarce for relocated populations. Here, we report the activity patterns in the reintroduced brown bear population in the Pyrenees. We expected the bears to reduce their activity depending on the type and level of disturbances. We analyzed individual behavior of both sexes (males, solitary females, and females with offspring) and age groups (adults and subadults) using camera-trap surveys under different types of intraspecific and anthropogenic disturbances. In general, bears were more active during the night (2200–0600 h) and avoided peaks of human activity (1000–1800 h). Furthermore, with the increasing nocturnal disturbance of adult males during the mating season, females with offspring and subadults were more active during daylight. This suggests that vulnerable individuals showed high tolerance for human presence. These results contribute to improve our knowledge of how a threatened and relocated bear population behaves in a human-modified landscape of southern Europe. Further research on this population will be crucial to establish optimal management interventions during translocations, and the prevention of human-bear encounters and conflicts. [ABSTRACT FROM AUTHOR]

Ecological flexibility within animal populations can allow for variation in resource use and foraging decisions. We estimated brown bear (Ursus arctos) diet composition in Gates of the Arctic National Park and Preserve, Alaska from 2013 to 2015 to evaluate how variation in foraging behavior influences body condition and size. We used stable carbon (δ13C) and nitrogen (δ15N) isotope analyses of sectioned brown bear hair samples to evaluate assimilated diet. We then developed a set of a priori linear models to evaluate differences in the diet composition of brown bears (n = 80) in relation to body fat (%) and mass. The proportion of meat (salmon [Oncorhynchus keta] and terrestrial meat combined) in the diet from July through late September varied between male and female bears, with males ( x - = 62%, SD = 30) assimilating significantly more meat than females ( x - = 40%, SD = 29). Most of the meat consumed came from marine-derived resources for males (53% of the total diet or 86% of the meat) and females (31% of the total diet or 77% of the meat). As we found the range of observed diets was unrelated to physiological outcomes (i.e., percentage body fat), we suggest that ecological flexibility within populations may provide an adaptive advantage by allowing individuals to reduce competition with conspecifics by foraging on alternate food resources. Identifying variable foraging behaviors within a population can allow for a better understanding of complex behaviors and, ultimately, lead to more informed management decisions related to habitat use, development, and harvest. [ABSTRACT FROM AUTHOR]

Relatively little is known about the feeding ecology of grizzly bears (Ursus arctos) in Wapusk National Park. Other ursids, polar bears (Ursus maritimus), are well known predators of waterfowl nests in the area, and grizzly bears could feasibly make use of such resources. However, since the arrival of polar bears on land in the spring is largely dependent on date of sea-ice breakup, the timing of predation by each bear species may differ. We investigated the timing of bear predation in common eider (Somateria mollissima sedentaria) and lesser snow goose (Anser caerulescens caerulescens) colonies from 2012 to 2018 using nest cameras. We observed grizzlies consuming eggs of both species in all years except 2013 and confirmed that at least two individual grizzlies occupied the park in 2016. In the 3 years when both grizzly and polar bears were detected, grizzlies were observed earlier in the year than polar bears and had greater overlap with an estimated availability index of incubating waterfowl. We hypothesize that grizzly bears could have earlier access to waterfowl eggs in the park, potentially reducing availability of these terrestrial foods to polar bears. [ABSTRACT FROM AUTHOR]

Hibernating brown bears, Ursus arctos, undergo extended periods of inactivity and yet these large hibernators are resilient to muscle disuse atrophy. Physiological characteristics associated with atrophy resistance in bear muscle have been examined (e.g., muscle mechanics, neural activity) but roles for molecular signaling/regulatory mechanisms in the resistance to muscle wasting in bears still require investigation. Using quantitative reverse transcription PCR (RT‐qPCR), the present study characterized the responses of 36 microRNAs linked with development, metabolism, and regeneration of skeletal muscle, in the vastus lateralis of brown bears comparing winter hibernating and summer active animals. Relative levels of mRNA of selected genes (mef2a, pax7, id2, prkaa1, and mstn) implicated upstream and downstream of the microRNAs were examined. Results indicated that hibernation elicited a myogenic microRNA, or "myomiR", response via MEF2A‐mediated signaling. Upregulation of MEF2A‐controlled miR‐1 and miR‐206 and respective downregulation of pax7 and id2 mRNA are suggestive of responses that promote skeletal muscle maintenance. Increased levels of metabolic microRNAs, such as miR‐27, miR‐29, and miR‐33, may facilitate metabolic suppression during hibernation via mechanisms that decrease glucose uptake and fatty acid oxidation. This study identified myomiR‐mediated mechanisms for the promotion of muscle regeneration, suppression of ubiquitin ligases, and resistance to muscle atrophy during hibernation mediated by observed increases in miR‐206, miR‐221, miR‐31, miR‐23a, and miR‐29b. This was further supported by the downregulation of myomiRs associated with a muscle injury and inflammation (miR‐199a and miR‐223) during hibernation. The present study provides evidence of myomiR‐mediated signaling pathways that are activated during hibernation to maintain skeletal muscle functionality in brown bears. [ABSTRACT FROM AUTHOR]

In order to investigate the detailed zoogeographical history of brown bears (Ursus arctos) in Bulgaria and their relationships with populations in neighboring regions of Europe and Asia, the amplified product length polymorphism (APLP) method for the mitochondrial DNA (mtDNA) haplogrouping was applied to ancient bone remains. The results showed that haplogroups for 12 of 31 samples (38.7%) were successfully classified using the APLP method, although partial sequences of the mtDNA control region were determined with PCR product-direct sequencing for only 6 samples (19.4%). Even among 25 samples, of which nucleotide sequences could not be determined, the APLP method successfully classified haplogroups of 6 samples (6/25, 24.0%), indicating an advantage of the APLP method. In Bulgaria, although both the Balkan/Italian lineage of mtDNA (clade 1b) and the Eastern European lineage (clade 3a1) have been identified from modern bears as reported in other studies, all bear remains examined in the present study had APLP haplogroup W. The mtDNA phylogenetic analysis showed that the ancient Bulgarian brown bears had clade 1b. This indicates that clade 1b was originally distributed in Bulgaria, whereas those with clade 3a1 could have entered from Romania to Bulgaria. In addition, the APLP and phylogenetic analysis of recent skin samples from Turkey showed that they have mtDNA of the Middle Eastern/Turkish lineage (referred to clade 7a). Therefore, Bulgaria on the Balkan Peninsula might have been located between two distribution borders: one is between clades 1b and 3a1, and the other is between clades 1b and 7. [ABSTRACT FROM AUTHOR]

Understanding the processes related to wildlife recoveries is not only essential in solving human – wildlife conflicts, but also for identifying priority conservation areas and in turn, for effective conservation planning. We used data from a citizen science program to study spatial aspects of the demographic and genetic recovery of brown bears in Greece and to identify new areas for their conservation. We visually compared our data with an estimation of the past distribution of brown bears in Greece and used a point process approach to model habitat suitability. We then compared our results with the current distribution of brown bear records and with that of protected areas. Our results indicate that in the last 15 years bears may have increased their range by as much as 100%, by occupying mainly anthropogenic landscapes and areas with suitable habitat that are currently not legally protected, thus creating a new conservation reality for the species in Greece. This development dictates the re‐evaluation of the national management and conservation priorities for brown bears in Greece by focusing in establishing new protected areas that will safeguard their recovery. Our conservation approach is a swift and cheap way of identifying priority conservation areas, while gaining important insights on spatial aspects of population recovery. It will help prioritize conservation actions for brown bears in Greece and may serve as a model conservation approach to countries facing similar financial and logistic constraints in the monitoring of local biodiversity or facing challenges in managing rapid population recoveries. Our conservation approach appeared to be particularly suited to identifying priority areas for conservation in areas with recovering wildlife populations and may therefore be used as an 'early‐warning' conservation system. [ABSTRACT FROM AUTHOR]

By the beginning of the twentieth century, many brown bear populations in Europe were on the brink of extinction due to relentless hunting pressure and habitat loss. The situation was critical also in Estonia, where in the 1920s the population went through a severe demographic bottleneck. Thanks to the protective measures implemented in the 1930s, the population started to recover. However, the process has been slow, especially in the western and southern areas of the country. To study the effects of the demographic bottleneck, we analysed 216 brown bear samples from throughout their main range in Estonia. In combination with widely used methods of population genetics, a recently developed spatially explicit analysis (distribution of residual dissimilarity, DResD) was also applied. Three genetic clusters were revealed, of which two were most likely founded by the survivors of the bottleneck. The DResD analysis revealed several contact zones near the Estonian-Russian border, suggesting that the third cluster was influenced by gene flow from the neighbouring population in Russia. The DResD analysis revealed also a male biased movement corridor along the forested south-north axis in the central part of Estonia. In comparison to other European populations, the genetic diversity of the Estonian population is relatively low and is comparable with other populations that have gone through a severe bottleneck. This work has important implications for brown bear conservation and highlights once again the dangers of excessive hunting. [ABSTRACT FROM AUTHOR]

Climate change poses a pervasive threat to humans and wildlife by altering resource availability, changing co-occurrences, and directly or indirectly influencing human-wildlife interactions. For many wildlife agencies in North America, managing bears (Ursus spp.) and human-bear interactions is a priority, yet the direct and indirect effects of climate change are exacerbating management challenges. Understanding the underlying ecological drivers of bear responses to climate variability and change, and the implications for conflict, will be critical for maintaining human-bear coexistence in North America. We synthesized 120 articles that identified direct and indirect mechanisms by which climate variability and change affect brown bears (Ursus arctos) and American black bears (Ursus americanus) in North America. The literature focused on examining climate impacts on bear diet, body size, habitat selection, space use, activity, denning chronology, and population demographics and dynamics. Across these categories, we summarized the documented and projected bear responses and resulting implications for human-bear interactions. Climate-driven changes in natural food availability were frequently implicated in influencing bear behavior and demography, and creating conditions under which interactions with humans are likely to increase. Bears in North America may face increased challenges as habitat and natural food availability continue to be altered by climate change. Our review provides a foundation upon which to identify climate drivers of bear ecology, conditions conducive to human-bear interactions, and adaptive management strategies. Given substantial evidence of climate impacts to bears, incorporating climate considerations into bear management can help managers strategically allocate resources and promote human-bear coexistence. • Synthesized 120 articles examining effects of climate variability and change on bears • Climate impacts bear habitat, diet, body size, movement, denning, and demographics • Climate-driven changes in natural food availability strongly affects bear ecology • Climate-driven changes increase risk of negative human-bear interactions • Adaptive management strategies can address challenges and promote coexistence [ABSTRACT FROM AUTHOR]

Cave bears (Ursus spelaeus) have been recognized as being predominantly herbivorous. However, Romanian Carpathian cave bears have displayed a flexible diet based on a wide range of δ15N values. In this work, we analyse 97 lower first molars of Ursus spelaeus and contemporaneous Ursus arctos from different sites in this region, using dental microwear analysis to reconstruct their pre-dormancy diets during MIS 3. Newly obtained radiocarbon dates of the individuals are also reported. The short-term diet of all populations studied is identified as omnivorous, with a preference for the consumption of hard objects. For the first time, the widespread presence of puncture pits on U. spelaeus populations has been observed, which could be linked to the intake of seeded and hard-shelled fruits from temperate broadleaf trees. Hence, the dietary patterns of Carpathian cave bears exhibit similarities to those of present-day brown bears inhabiting the same region and suggests that the Carpathians served as an ecological refuge for cave bear specimens. This is reinforced by an early 27.1 cal kyr B.P. date from an individual from Urşilor Cave, which sheds light on the potential dietary continuity of Romanian Carpathian cave bear populations even during the final phases leading up to their extinction. • Largest dental microwear study performed on cave bear from the Romanian Carpathians. • Evidence of an omnivorous diet for the cave bear from the Romanian Carpathians. • First evidence of bulk consumption of seed fruits by U. spelaeus. • New dating for an individual from Urşilor, close to species' extinction. • Different microwear patterns between cave and brown bear from the Carpathians. [ABSTRACT FROM AUTHOR]

Wild cherry (Prunus avium) is a climate-sensitive species of great ecological importance and has gained importance in the diet of the Cantabrian brown bear (Ursus arctos L.) in recent years. Understanding the potential impact of climate change on the distribution of wild cherry and the interactions with bears, specially dispersion to more suitable areas under future climate change scenarios, may help to improve the conservation of both species in the Cantabrian Mountains (NW Spain). We accurately modelled the current and future habitat suitability for wild cherry, constructing species distribution models (SDMs) based on true presence and absence data and environmental variables related to the species ecological limitations. Associated effects were assessed by intersecting the current and future distributions of both species. Seed dispersal by bears was assessed by examination of bear faeces collected between 1995 and 2020. The findings are fundamental for developing forestry plans and strategies and enabling timely and appropriate evidence-based actions to be taken for conservation of both species. We found that the impact of climate change will decrease the overall habitat suitability, with more suitable areas expected to occur at higher elevations, where cherry consumption by bears and associated seed dispersal due to the spatial use may favour upward dispersal of cherry, although success and adaptation will ultimately depend on whether the seeds will be deposited in the right places and their movement will overcome the effects of climate change. [Display omitted] • Wild cherry is a climate-sensitive species of great ecological importance. • The Cantabrian brown bear feed on cherry fruits at the early summer. • The current and future habitat suitability of wild cherry habitat was modelled. • Associated effects on brown bears reveal a win-win interaction. • The findings are important for the management and conservation of both species. [ABSTRACT FROM AUTHOR]

In September 2019, two gravid female brown bears (Ursus arctos) were captured and equipped with GPS/GSM collars in Paklenica National Park (Croatia). Home ranges during hyperphagia were analyzed to describe the spatiotemporal requirements. Mean seasonal home ranges were very small with 9.2 km2 and 7.5 km2 (Brownian Bridge Movement Model 95%). During the tracking period, both bears used different territories and showed little to no use of overlapping area. The bears in our study spent a considerable time in proximity of artificial feeding sites, indicating a probable use of these structures as a food resource (mean 15.7% and 30.7%). Furthermore, the bears approached very close to human structures such as 8.9 m and 4.4 m. As most encounters between humans and bears occur during hyperphagia, it is important to offer refugia from human disturbance, especially as the National Park is not only used by residents, but also by tourists. To adapt management according to the animal’s needs, further studies should include more individuals from different age and sex classes. Both females were gravid. It remains unclear whether gravidity has an effect on the home range and should be further investigated.

In northern Eurasia, large carnivores overlap with semi-domestic reindeer (Rangifer tarandus) and moose (Alces alces). In Scandinavia, previous studies have quantified brown bear (Ursus arctos) spring predation on neonates of reindeer (mostly in May) and moose (mostly in June). We explored if habitat selection by brown bears changed following resource pulses and whether these changes are more pronounced on those individuals characterised by higher predatory behaviour. Fifteen brown bears in northern Sweden (2010–2012) were fitted with GPS proximity collars, and 2585 female reindeers were collared with UHF transmitters. Clusters of bear positions were visited to investigate moose and reindeer predation. Bear kill rates and home ranges were calculated to examine bear movements and predatory behaviour. Bear habitat selection was modelled using resource selection functions over four periods (pre-calving, reindeer calving, moose calving, and post-calving). Coefficients of selection for areas closer to different land cover classes across periods were compared, examining the interactions between different degrees of predatory behaviour (i.e., high and low). Bear habitat selection differed throughout the periods and between low and high predatory bears. Differences among individuals’ predatory behaviour are reflected in the selection of habitat types, providing empirical evidence that different levels of specialization in foraging behaviour helps to explain individual variation in bear habitat selection.

Abstract Background Sex-biased dispersal is widespread among mammals, including the brown bear (Ursus arctos). Previous phylogeographic studies of the brown bear based on maternally inherited mitochondrial DNA have shown intraspecific genetic structuring around the northern hemisphere. The brown bears on Hokkaido Island, northern Japan, comprise three distinct maternal lineages that presumably immigrated to the island from the continent in three different periods. Here, we investigate the paternal genetic structure across northeastern Asia and assess the connectivity among and within intraspecific populations in terms of male-mediated gene flow. Results We analyzed paternally inherited Y-chromosomal DNA sequence data and Y-linked microsatellite data of 124 brown bears from Hokkaido, the southern Kuril Islands (Kunashiri and Etorofu), Sakhalin, and continental Eurasia (Kamchatka Peninsula, Ural Mountains, European Russia, and Tibet). The Hokkaido brown bear population is paternally differentiated from, and lacked recent genetic connectivity with, the continental Eurasian and North American populations. We detected weak spatial genetic structuring of the paternal lineages on Hokkaido, which may have arisen through male-mediated gene flow among natal populations. In addition, our results suggest that the different dispersal patterns between male and female brown bears, combined with the founder effect and subsequent genetic drift, contributed to the makeup of the Etorofu Island population, in which the maternal and paternal lineages show different origins. Conclusions Brown bears on Hokkaido and the adjacent southern Kuril Islands experienced different maternal and paternal evolutionary histories. Our results indicate that sex-biased dispersal has played a significant role in the evolutionary history of the brown bear in continental populations and in peripheral insular populations, such as on Hokkaido, the southern Kuril Islands, and Sakhalin.

Abstract Accurate population size estimates are important information for sustainable wildlife management. The Romanian Carpathians harbor the largest brown bear (Ursus arctos) population in Europe, yet current management relies on estimates of density that lack statistical oversight and ignore uncertainty deriving from track surveys. In this study, we investigate an alternative approach to estimate brown bear density using sign surveys along transects within a novel integration of occupancy models and home range methods. We performed repeated surveys along 2‐km segments of forest roads during three distinct seasons: spring 2011, fall‐winter 2011, and spring 2012, within three game management units and a Natura 2000 site. We estimated bears abundances along transects using the number of unique tracks observed per survey occasion via N‐mixture hierarchical models, which account for imperfect detection. To obtain brown bear densities, we combined these abundances with the effective sampling area of the transects, that is, estimated as a function of the median (± bootstrapped SE) of the core home range (5.58 ± 1.08 km2) based on telemetry data from 17 bears tracked for 1‐month periods overlapping our surveys windows. Our analyses yielded average brown bear densities (and 95% confidence intervals) for the three seasons of: 11.5 (7.8–15.3), 11.3 (7.4–15.2), and 12.4 (8.6–16.3) individuals/100 km2. Across game management units, mean densities ranged between 7.5 and 14.8 individuals/100 km2. Our method incorporates multiple sources of uncertainty (e.g., effective sampling area, imperfect detection) to estimate brown bear density, but the inference fundamentally relies on unmarked individuals only. While useful as a temporary approach to monitor brown bears, we urge implementing DNA capture–recapture methods regionally to inform brown bear management and recommend increasing resources for GPS collars to improve estimates of effective sampling area.

The goal of the present study was to monitor the physiological effects of a standardized balanced anesthetic protocol in brown bears (Ursus arctos) during routine dental procedures. Physiological parameters (rectal temperature, heart rate, respiratory rate and oxygen saturation) were evaluated in twelve brown bears, anesthetized with a balanced drug combination for 90 minutes during dental procedures. The animals were kept in the „Park for Dancing Bears“ Belitza, Bulgaria. A standardized premedication protocol of a combined intramuscular injection of tiletamine HCl and zolazepam HCl (Zoletil 100® Virbac, France) 1mg/kg, medetomidine HCl 0.003mg/kg and 0.05 mg/kg of butorphanol was administered intramuscularly. Anesthesia was induced intravenously with a combined bolus of ketamine at 2 mg/kg and propofol at 2 mg/kg, and maintained with a constant rate infusion (CRI) of ketamine at 0.8 mg/kg/h and propofol 0.04 at mg/kg/min. Rectal temperature decreased significantly during anesthesia, whereas: heart rate, respiratory rate and oxygen saturation were stable with no significant changes in these parameters for the duration of anesthesia. In conclusion, this anesthetic drug combination is suitable for oral surgery of medium duration in brown bears.

In framework of an international project of brown bear population monitoring, the bear population size and structure were analyzed on the Russian side of the Pasvik-Inari Trilateral Park (Russia, Norway, Finland) in 2015. The paper presents data gathered by two noninvasive methods: DNA analysis of hair samples and feces and the camera traps method. The material was obtained with 5 hair traps of made of barbed wire and scent lure and 4 Boskon Guard camera traps. In addition, feces were collected, as well as hair samples from national border fencing by staff of the Russian Border Authority. In total, 54 hair samples and 10 feces samples were collected. On the basis of the results the brown bear population size was estimated at 20 individuals in the study area: 13 individuals were detected by DNA analysis only, the remaining 7 animals – with the help of camera traps. The records include 9 females and 7 males; 13 adults, 4 yearlings and 3 cubs. The social structure consisted of three family groups, 10 singles, including 1 possible dominant male. Average brown bear density was 100 animals/1000 km². The combined usage of hair and feces collection, camera traps and GIS proved the techniques to be complementary in the analysis of the size and structure of the brown bear population.

Producer interest in using livestock guardian dogs (Canis lupus familiaris; LGDs) to protect domestic cattle (Bos taurus) is driven by expanding large carnivore predator populations and increased public concerns regarding lethal predator control in North America. However, few resources exist to guide livestock producers regarding the use of LGDs to protect cattle. This paper summarizes published information and personal ranch experiences regarding the use of LGDs to protect cattle, describes livestock-producer identified challenges to more widespread adoption of this method to deter predators, and provides guidelines for introducing pups to LGD-naïve cattle herds. I recommend more extensive research on the use of LGDs with cattle, increased development of programs to place LGDs with cattle herds, as well as educational efforts targeting resource managers, livestock producers, and the general public.

Habitat characteristics associated with species occurrences represent important baseline information for wildlife management and conservation, but have rarely been assessed for countries recently joining the EU. We used footprint tracking data and landscape characteristics in Romania to investigate the occurrence of brown bear (Ursus arctos), gray wolf (Canis lupus) and Eurasian lynx (Lynx lynx) and to compare model predictions between Natura 2000 and national-level protected areas (gap analysis). Wolves were more likely to occur where rugged terrain was present. Increasing proportion of forest was positively associated with occurrence of all large carnivores, but forest type (broadleaf, mixed, or conifer) generally varied with carnivore species. Areas where cultivated lands were extensive had little suitable habitat for lynx, whereas bear occurrence probability decreased with increasing proportion of built areas. Pastures were positively associated with wolf and lynx occurrence. Brown bears occurred primarily where national roads with high traffic volumes were at low density, while bears and lynx occurred at medium-high densities of communal roads that had lower traffic volumes. Based on predictions of carnivore distributions, natural areas protected in national parks were most suitable for carnivores, nature parks were less suitable, whereas EU-legislated Natura 2000 sites had the lowest probability of carnivore presence. Our spatially explicit carnivore habitat suitability predictions can be used by managers to amend borders of existing sites, delineate new protected areas, and establish corridors for ecological connectivity. To assist recovery and recolonization, management could also focus on habitat predicted to be suitable but where carnivores were not tracked.

Understanding mortality causes is important for the conservation of endangered species, especially in small and isolated populations inhabiting anthropized landscapes where both natural and human-caused mortality may hinder the conservation of these species. We investigated the mortality causes of 53 free-ranging brown bears (Ursus arctos) found dead between 1998 and 2023 in the Cantabrian Mountains (northwestern Spain), a highly human-modified region where bears are currently recovering after being critically threatened in the last century. We detected natural traumatic injuries in 52.63% and infectious diseases in 39.47% of the 38 bears for which the mortality causes were registered, with 21.05% of these cases presenting signs of both infectious diseases and traumas. More specifically, almost 30% of the bears died during or after intraspecific fights, including sexually selected infanticide (10.53%). In addition, primary infectious diseases such as infectious canine hepatitis, distemper, clostridiosis and colibacillosis caused the death of 15.79% of the bears. The number of direct human-caused deaths (i.e., shooting, poisoning, snare) decreased over the study period. This study also reveals three new mortality causes triggered by pathogens, two of which-Clostridium novyi and verotoxigenic Escherichia coli-not previously described in ursids, and the other one, canine distemper virus, never reported in brown bears as cause of death. New management strategies for the conservation of Cantabrian bears, which are urgently needed due to the rapid expansion of the population, should consider the mortality causes described in this study and must promote further research to elucidate how the high prevalence of infectious diseases may threaten the current recovery of the population., (© 2024. The Author(s).)

How organisms obtain energy to survive and reproduce is fundamental to ecology, yet researchers use theoretical concepts represented by simplified models to estimate diet and predict community interactions. Such simplistic models can sometimes limit our understanding of ecological principles. We used a polyphagous species with a wide distribution, the brown bear (Ursus arctos), to illustrate how disparate theoretical frameworks in ecology can affect conclusions regarding ecological communities. We used stable isotope measurements (δ 13 C, δ 15 N) from hairs of individually monitored bears in Sweden and Bayesian mixing models to estimate dietary proportions of ants, moose, and three berry species to compare with other brown bear populations. We also developed three hypotheses based on predominant foraging literature, and then compared predicted diets to field estimates. Our three models assumed (1) bears forage to optimize caloric efficiency (optimum foraging model), predicting bears predominately eat berries (~70% of diet) and opportunistically feed on moose (Alces alces) and ants (Formica spp. and Camponotus spp; ~15% each); (2) bears maximize meat intake (maximizing fitness model), predicting a diet of 35%-50% moose, followed by ants (~30%), and berries (~15%); (3) bears forage to optimize macronutrient balance (macronutrient model), predicting a diet of ~22% (dry weight) or 17% metabolizable energy from proteins, with the rest made up of carbohydrates and lipids (~49% and 29% dry matter or 53% and 30% metabolizable energy, respectively). Bears primarily consumed bilberries (Vaccinium myrtillus; 50%-55%), followed by lingonberries (V. vitis-idaea; 22%-30%), crowberries (Empetrum nigrum; 8%-15%), ants (5%-8%), and moose (3%-4%). Dry matter dietary protein was lower than predicted by the maximizing fitness model and the macronutrient balancing model, but protein made up a larger proportion of the metabolizable energy than predicted. While diets most closely resembled predictions from optimal foraging theory, none of the foraging hypotheses fully described the relationship between foraging and ecological niches in brown bears. Acknowledging and broadening models based on foraging theories is more likely to foster novel discoveries and insights into the role of polyphagous species in ecosystems and we encourage this approach., (© 2023 The Authors. Ecology published by Wiley Periodicals LLC on behalf of The Ecological Society of America.)

Wildlife managers conduct population inventories to monitor species, particularly those at-risk. Although costly and time consuming, grid-based DNA hair-snag sampling has been the standard protocol for grizzly bear inventories in North America, while opportunistic fecal DNA sampling is more commonly used in Europe. Our aim is to determine if low-cost, low-effort scat sampling along roads can replace the current standard. We compare two genetic non-invasive techniques using concurrent sampling within the same grid system and spatially explicit capture--recapture. We found that given our methodology and the present status of fecal genotyping for grizzly bears, scat sampling along roads cannot replace hair sampling to estimate population size in low-density areas. Hair sampling identified the majority of individual grizzly bears, with a higher success rate of individuals identified from grizzly bear samples (100%) compared to scat sampling (14%). Using scat DNA to supplement hair data did not change population estimates, but it did improve estimate precision. Scat samples had higher success identifying species (98%) compared with hair (80%). Scat sampling detected grizzly bears in grid cells where hair sampling showed non-detection, with almost twice the number of cells indicating grizzly bear presence. Based on our methods and projected expenses for future implementation, we estimated an approximate 30% cost reduction for sampling scat relative to hair. Our research explores the application of genetic non-invasive approaches to monitor bear populations. We recommend wildlife managers continue to use hair-snag sampling as the primary method for DNA inventories, while employing scat sampling as supplemental to increase estimate precision. Scat sampling may better indicate presence of bear species through greater numbers and spatial distribution of detections, if sampling is systematic across the entire area of interest. Our findings speak to the management of other species and regions, and contribute to ongoing advances of monitoring wildlife populations. [ABSTRACT FROM AUTHOR]

Railway networks contribute to the direct mortality of wildlife through collisions with trains, which can threaten vulnerable wildlife populations even in protected areas, including grizzly bears (Ursus arctos) in Banff and Yoho National Parks, Canada. Mitigation to reduce bear‐train collisions requires information about how grizzly bears use the railway spatially and temporally and how particular types of use might increase collision vulnerability. We used data from 27 grizzly bears fitted with global positioning system (GPS) collars between 2000 and 2016 to relate railway use by bears via resource selection functions to variables that described land cover, human use, and topography. We used the same suite of explanatory variables to distinguish pairs of 4 types of steps, in which 3 successive GPS points (with 2‐hr fix rates) included ≥1 within 30 m of the rail (hereafter on) and 2 others that defined locations where bears effectively entered the railway (first fix off rail, next 2 on), crossed it (only the middle fix on the rail), continued along the railway (all 3 fixes on), or exited the railway corridor (first 2 on, last off). We compared both sites of higher use and each of these 4 step types to the relative frequency of bear‐train collisions, predicting a positive correlation for continue step types. Relative to available locations, bears were more likely to use the railway close to railroad sidings (sections of twinned track where trains sometimes stop), at intermediate distances from human‐use features (e.g., town sites, highways, trails), in areas with lower values of the compound topographic index (a proxy for wetness; within 500 m), and within 90 m of rugged terrain. Seasonally, bears made greater use of the railway in spring and fall. Among 1,515 sequences of 3 steps, crossing locations comprised >50% and were most distinct from continue locations (about 20%), which occurred in areas with more rugged terrain (within 300 m), closer to railway sidings, in spring and fall, and with steps that were 60% shorter. Contrary to our prediction, past reports of bear‐train collisions were negatively correlated with continue locations and unrelated to overall use or any other movement type. Our results suggest that railway use by bears increased where it provided increased forage or easier travel, particularly in spring and fall, but more work will be needed to determine the mechanistic basis of bear‐train collisions. Meanwhile, mitigation efforts such as habitat alteration or warning systems might target locations where past strikes are concentrated for grizzly bears or other sensitive populations. © 2019 The Wildlife Society. Relative to available points, grizzly bears increased their use of a railway in areas that were at intermediate distances from areas of human use, closer to water bodies, with higher shrub cover, and with rugged topography. Among overall use and 4 movement types, designated as places where bears entered, exited, continued along, or crossed the railway, continue locations were unexpectedly negatively correlated with past locations of reported bear‐train collisions. [ABSTRACT FROM AUTHOR]

The understory vegetation of the Eurasian boreal forest is dominated by several ericaceous species (e.g. bilberry Vaccinium myrtillus). These species invest large amounts of energy in their sexual reproduction by producing seed-containing berries, which are apparent adaptations for endozoochory. Their seedlings are, however, almost never found in the wild, and they reproduce virtually exclusively through clones. Brown bears Ursus arctos consume enormous amounts of ericaceous berries (predominantly bilberry in central Scandinavia) during hyperphagia, and may facilitate sexual reproduction in such species. If ericaceous species would benefit from endozoochory by brown bears, one would predict that endozoochory would have no negative impacts on germination. We experimentally evaluated this prediction using germination trials under controlled conditions of bilberry seeds that were 1) extracted from brown bear feces, 2) extracted from ripe berries and 3) contained in berries. Using time-to-event analyses, we showed that passing the gut by itself did not stimulate or limit germination. However, seeds that were released from the berries germinated about one month earlier compared to seeds contained in berries. This implies that being released from a fruit, for example through endozoochory, can have a large temporal germination and growth advantage, especially in northern ecosystems a with short growing season. [ABSTRACT FROM AUTHOR]

A central challenge in animal conservation is to understand how a population may respond to different habitat characteristics, which may affect their growth and viability. At the beginning of the twentieth century, the Cantabrian brown bear Ursus arctos population (north-western Spain) was separated into western and eastern subpopulations. Today, brown bears in the Cantabrian Mountains are recovering and the two subpopulations are reconnected. However, the western portion of the population represents ca. 90% of the entire population, the number of females with cubs-of-the-year has also shown a more rapid increase in the western subpopulation than in the eastern one and mean litter size is significantly larger in the west. By comparing the characteristics of the landscape used by brown bears in the western vs. eastern sectors of the population, we intended highlighting focal elements of landscape composition and structure that may help explain the differences in numbers and fecundity of these two subpopulations. We suggest that habitat use alone might not have the expected role in potentially explaining differences between subpopulations. Both the current positive trend of the Cantabrian population and our results seem to show that the dynamics affecting these subpopulations might be more complex than previously believed and cannot be understood on the basis of habitat analyses only. Suspicions may arise around direct human influences (e.g. persistence of poaching and/or bad practices during hunting) on the different trends exhibited by the two sectors of this endangered bear population. [ABSTRACT FROM AUTHOR]

Conservation regulations are increasingly recognized as important elements of the available toolkit for effective biodiversity conservation. However, the full integration of evidence when designing these tools is still scarce, which limits the effectiveness of these legal instruments. Increasing concern is emerging on the compatibility between leisure activities and biodiversity conservation, which require a true integration of the best available evidence into policy-making. Managing authorities are required to take actions in order to ensure the compliance of international conservation commitments with species conservation. This is the case of applying spatio-temporal regulations on bear viewing activities in critical bear areas and periods, such as during the cub-rearing period. Here, we took advantage of a unique long-term dataset (>25 years) of observations of females with cubs in the endangered brown bear population in the Cantabrian Mountains, N Spain (>3000 observations from 329 females with cubs) to estimate monthly bear cub survival rates in the first sixteen months of cubs life. Overall, the monthly cub survival in this population was remarkable high, ranging from 0.839 to 0.994 monthly survival rates. The lower monthly cub survival rates were in May and June after the cubs left the den (mean ± SD: 0.839 ± 0.050 and 0.897 ± 0.023, respectively). Infanticide was estimated as the main mortality cause for cubs during the study period. Our results are practical because they can be used to inform conservation policies regarding the most appropriate periods to implement temporal regulations of human activities in bear breeding areas. The most appropriate period to implement such regulations here is the period between the time when the cubs leave the den (late March–April) until and including June; which should be considered in future temporal regulations adopted by Regional Governments in Spain. Accordingly, we also urge an update of the Spanish brown bear strategies considering the new scenario of bear conservation in Spain, including a set of measures related to bear viewing activities. • Integration of evidence when delineating regulations is a pending issue. • Bear conservation plans should provide a set of actions to reduce disturbance. • This may include temporally restricting human activities in bear breeding areas. • Critical periods for cub mortality were estimated for the endangered Cantabrian bears. • This information can be used to inform bear conservation policies. [ABSTRACT FROM AUTHOR]

Selection and use of dens is a critical behavioral adaption of bears (Ursus spp.) to survive extended periods of resource limitation. We analyzed selection of den sites by brown bears (Ursus arctos) in an arctic montane environment from 2014 to 2017.We used GPS data from 51 instrumented bears to physically locate, identify, and describe den sites (n = 33) and to quantitatively model the selection of denning habitat (n = 65 dens over 3 yr). We conducted an analysis of den-site selection at the home range (third order) scale using variables describing topographic, vegetative, and spatially-explicit fish and wildlife models. We hypothesized four main factors influence den-site selection by brown bears: (1) physiography, (2) proximity to food resources, (3) thermal insulation, and (4) den-area fidelity. We used kernel density estimates to define space use and conditional logistic regression to estimate den selection within individual home ranges. Brown bears selected den sites on steep slopes (>31°) with high snow load potential near their previously used den site. Our results supported our hypothesis that den selection by brown bears was related to thermal insulation, structural stability, drainage, and den-area fidelity. [ABSTRACT FROM AUTHOR]

Natal dispersal likely plays an important role in avoiding inbreeding among large carnivores. We tested the hypothesis that male-biased dispersal reduces close inbreeding by limiting the spatial overlap of opposite-sex pairs of close relatives in brown bears (Ursus arctos) in the Shiretoko Peninsula, Hokkaido, Japan. We genotyped 837 individuals collected in 1998–2017 at 21 microsatellite loci and performed parentage analysis. To calculate natal dispersal distance, we considered the site where the mother was identified as the birthplace of her offspring, and the site where the offspring were identified as their dispersed place. As predicted, we found that dispersal distances were significantly greater for males (12.4 km ± 1.0) than for females (7.7 km ± 0.9), and those for males increased from 3 years old, indicating that males begin to disperse around the time sexual maturation begins. Relatedness decreased with distance among pairs of females, and the mean relatedness was significantly higher between pairs of females than between pairs of males or between female–male pairs within 3 km. Closely related female–male pairs rarely (5–6%) resided in close proximity (< 3 km), compared with pairs of closely related females. Our study revealed that the potential for close inbreeding was low in Hokkaido brown bears because males are effective dispersers. [ABSTRACT FROM AUTHOR]

We collected blood and serum from 155 brown bears (Ursus arctos) inhabiting five locations in Alaska, US during 2013–16 and tested samples for evidence of prior exposure to a suite of bacterial, viral, and parasitic agents. Antibody seroprevalence among Alaska brown bears was estimated to be 15% for Brucella spp., 10% for Francisella tularensis, 7% for Leptospira spp., 18% for canine adenovirus type 1 (CAV-1), 5% for canine distemper virus (CDV), 5% for canine parvovirus, 5% for influenza A virus (IAV), and 44% for Toxoplasma gondii. No samples were seropositive for antibodies to Trichinella spp. Point estimates of prior exposure to pathogens among brown bears at previously unsampled locations generally fell within the range of estimates for previously or contemporaneously sampled bears in Alaska. Statistical support was found for variation in antibody seroprevalence among bears by location or age cohort for CAV-1, CDV, IAV, and T. gondii. There was limited concordance in comparisons between our results and previous serosurveys regarding spatial and age-related trends in antibody seroprevalence among Alaska brown bears suggestive of temporal variation. However, we found evidence that the seroprevalence of CAV-1 antibodies is consistently high in bears inhabiting southwest Alaska and the cumulative probability of exposure may increase with age. We found evidence for seroconversion or seroreversion to six different infectious agents in one or more bears. Results of this study increase our collective understanding of disease risk to both Alaska brown bear populations and humans that utilize this resource. [ABSTRACT FROM AUTHOR]

The European brown bear (Ursus arctos) shows a particular phylogeography that has been used to illustrate the model for contraction-expansion dynamics related to glacial refugia in Southern European peninsulas. Recent studies, however, have nuanced the once generally accepted paradigm, indicating the existence of cryptic refugia for some species further north. In this paper we collected available data on chronology and mitochondrial haplotypes from Western European brown bears, adding new sequences from present day individuals from the Cantabrian (North Iberia) area, in order to reconstruct the dynamics of the species in the region. Both genetics and chronology show that the Iberian Pleistocene lineages were not the direct ancestors of the Holocene ones, the latter entering the Peninsula belatedly (around 10,000 years BP) with respect to other areas such as the British Isles. We therefore propose the existence of a cryptic refugium in continental Atlantic Europe, from where the bears would expand as the ice receded. The delay in the recolonization of the Iberian Peninsula could be due to the orographic characteristics of the Pyrenean-Cantabrian region and to the abundant presence of humans in the natural entrance to the Peninsula. [ABSTRACT FROM AUTHOR]

The Arctic is generally warming with lengthening growing seasons that can influence individuals, populations, and communities. However, temperature data indicate that the changes are largely local and variable. We compared body size, body condition, and productivity among four Arctic brown bear (Ursus arctos) studies separated in time and space from 1977 to 2016. As body size, condition, and productivity varied among populations, local conditions, both biotic and abiotic, appear to influence the size, condition, and productivity of individual bears and, thus, bear populations. We conclude that current local studies are critical in informing management decisions, because extrapolations from concurrent adjacent studies or reliance on past local studies may not represent the present condition of an Arctic brown bear population. [ABSTRACT FROM AUTHOR]

The current phylogeographic pattern of European brown bears (Ursus arctos) has commonly been explained by postglacial recolonization out of geographically distinct refugia in southern Europe, a pattern well in accordance with the expansion/contraction model. Studies of ancient DNA from brown bear remains have questioned this pattern, but have failed to explain the glacial distribution of mitochondrial brown bear clades and their subsequent expansion across the European continent. We here present 136 new mitochondrial sequences generated from 346 remains from Europe, ranging in age between the Late Pleistocene and historical times. The genetic data show a high Late Pleistocene diversity across the continent and challenge the strict confinement of bears to traditional southern refugia during the last glacial maximum (LGM). The mitochondrial data further suggest a genetic turnover just before this time, as well as a steep demographic decline starting in the mid‐Holocene. Levels of stable nitrogen isotopes from the remains confirm a previously proposed shift toward increasing herbivory around the LGM in Europe. Overall, these results suggest that in addition to climate, anthropogenic impact and inter‐specific competition may have had more important effects on the brown bear's ecology, demography, and genetic structure than previously thought. [ABSTRACT FROM AUTHOR]

We conducted DNA capture-recapture monitoring of grizzly bears (Ursus arctos) from 5 to 17 years after hunting was stopped in two adjacent but genetically distinct populations in southwestern British Columbia, Canada. We used spatial capture-recapture and non-spatial Pradel robust design modelling to estimate population density, trends, and the demographic components of population change for each population. The larger population had 21.5 bears/1000 km2 and was growing (λ Pradel = 1.02 ± 0.02 SE; λ secr = 1.01 ± 4.6 × 10−5 SE) following the cessation of hunting. The adjacent smaller population had 6.3 bears/1000 km2 and was likely declining (λ Pradel = 0.95 ± 0.03 SE; λ secr = 0.98 ± 0.02 SE). Estimates of apparent survival and apparent recruitment indicated that lower recruitment was the dominant factor limiting population growth in the smaller population. Factors limiting reproductive rates and population density could include poor habitat quality, particularly the abundance of high-energy foods, genetic Allee effects due to a long period of population isolation, or demographic effects affecting infanticide rates. The cessation of hunting was insufficient to promote population recovery for the low density, isolated population. Our research highlights the importance of considering mortality thresholds in addition to small population effects and habitat quality when recovering large carnivore populations. [ABSTRACT FROM AUTHOR]

Understanding the breeding ecology of a species is essential for the appropriate conservation and management of wildlife. In brown bears, females occasionally copulate with multiple males in one breeding season, which may lead to multiple paternity in a single litter. In contrast, inbreeding, a potential factor in the reduction of genetic diversity, may occur, particularly in threatened populations. However, few studies have reported the frequency of these phenomena in brown bear populations. Here, we investigated the incidence of multiple paternity and inbreeding in a high-density brown bear population on the Shiretoko Peninsula in Hokkaido, Japan. A total of 837 individuals collected from 1998 to 2017 were genotyped at 21 microsatellite loci, and parentage analysis was performed. Out of 70–82 litters with ≥2 offspring, 14.6–17.1% of litters were sired by multiple males. This was comparable to the rate reported in a Scandinavian population, although population density and litter size, factors that potentially affect the incidence of multiple paternity, differed between the 2 populations. Out of 222 mother-father mating pairs, 6 litters (2.7%) resulted from matings between fathers and daughters. Additionally, 1 (0.5%) and 4 (1.8%) cases of mating between maternal half-siblings and between paternal half-siblings, respectively, were observed; however, no cases of mating between mothers and sons or between full siblings were observed. Our results suggest that male-biased natal dispersal effectively limits mating between closely related individuals (aside from fathers and daughters) in brown bears. [ABSTRACT FROM AUTHOR]