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In human‐dominated landscapes, rebounding bear populations share space with people, which may lead to bear–human conflicts and, consequently, a decrease in acceptance and an increase in bear mortality linked to human causes. Previous analyses of brown bear (Ursus arctos) movement data have shown that bears adopt a security‐food trade‐off strategy in response to variable human‐related risk. However, brown bear flexibility to cope with these risky situations may be reduced when resting, mating or stocking fat in preparation for hibernation. In this study, we measured the multi‐scale spatial response of brown bears to human‐related risk and food resource distribution in a highly heterogeneous human‐dominated landscape. We examined habitat selection both within the population range ('second‐order' selection) and at bedding site locations ('third‐order') for GPS‐tagged brown bears of a recently reintroduced population in the Italian Alps. We identified resting locations by field‐validated spatio‐temporal cluster analysis of telemetry locations. We mapped food availability and distribution using dynamic geographic layers of fruiting wild berries, and human‐related risk using human mobility data (Strava‐based Cumulated Outdoor activity Index). Brown bears appeared to compromise their need for food resources for avoidance of anthropogenic disturbance when selecting home ranges, as they utilized areas richer in wild berries less when human use of outdoor tracks was higher. Furthermore, selection of resting site locations strongly depended on the avoidance of human‐related risk only, with less frequented, more concealed and inaccessible sites being selected. We conclude that humans compete for space with bears beyond their infrastructural impact, that is, by actively occupying key areas for bear survival, thereby potentially restricting the bears' realized niche. We propose mitigating actions to promote bear–human coexistence by selectively restricting human access to key areas during sensitive annual physiological phases for bear survival. [ABSTRACT FROM AUTHOR]

Simple Summary: Fragmented habitats threaten animals by reducing genetic diversity. It is essential to understand the genetic composition and movement patterns of brown bears for effective conservation strategies and fostering coexistence with humans. This study analyzed 214 hair samples collected non-invasively from brown bears in the Trikala-Meteora area of Central Greece, revealing the genetic status and demographics of a local sub-population. Although the broader Central and South Pindos regions have not been examined in over ten years, findings indicate high genetic diversity, no signs of inbreeding, and an estimated effective population size of 99, suggesting a healthy conservation status. Additionally, a natural corridor facilitating bear movement between the western and eastern sections of the study area supports the population's sustainability. These results will aid in future conservation efforts aimed at maintaining natural corridors for brown bear habitats in Greece. Habitat fragmentation poses a significant threat to the existence and reproduction of large carnivores, such as brown bears, as it affects the genetic connectivity of populations and, consequently, their long-term viability. Understanding the genetic makeup and dispersal patterns in areas where brown bears live is crucial for developing effective conservation plans and promoting human-brown bear coexistence. In this study, 214 hair samples were collected non-invasively from brown bears and were genetically analyzed using fifteen specific microsatellite loci to shed light on the genetic status and demography of a sub-population residing in Central Greece (Trikala-Meteora area). The broader Central and South Pindos regions have not been studied for over a decade; however, high levels of genetic diversity, a lack of heterozygosity deficiency, and no signs of inbreeding, along with an estimated effective population size (Ne = 99), confirm the good conservation status of this sub-population. Moreover, the existence of a natural and apparently functional corridor in Central Pindos was demonstrated by bear movements between the western and eastern parts of the project area, enhancing the sustainability of the population. These findings will contribute to future efforts to conserve natural corridors that enable functional connectivity among large areas of brown bear territories in Greece. [ABSTRACT FROM AUTHOR]

Attempts to understand wildlife population dynamics and implement management practices benefit from understanding animal behavior traits. In Alaska, USA, grizzly bear (Ursus arctos) behavior is important to understand because the species is an apex predator, exerts top-down population effects, and is a cornerstone species across complex landscapes. Our objectives were to examine how environmental and anthropogenic factors affect behavior patterns in grizzly bears in south-central Alaska. We hypothesized that, for a given sex, the time spent by bears resting, foraging, and traveling are similar and show consistent seasonal shifts as resource availability changes throughout their nondenning season. Additionally, we hypothesized that males spend more time traveling than do females because of differences in home range sizes, metabolic needs, and the rearing of cubs associated with females. We used a hidden Markov model (HMM) to test our hypotheses and examine how various dynamic, static, and temporal variables affected bear (n = 12) behavior during the summers of 2021–2022. Males spent the most time foraging and the least time resting while females spent the most time resting and the least time foraging. These patterns shifted as the summer progressed with increases in traveling and foraging and decreases in resting for both sexes. Bears were found to be most likely in a resting state at hotter temperatures and more likely to be traveling at colder temperatures. Additionally, bear behaviors deviated depending on elevation, whereby bears were foraging at higher elevations and resting or traveling at lower elevations. Our findings indicate that male–female differences in behavior are seasonally dependent, being similar in autumn and opposite during the postdenning period. In addition, we see evidence that changes in environmental conditions, such as warming, can have direct effects on behavior. Further studies should explore how future environmental and anthropogenic factors such as predicted changes in climate and increases in land-use changes can affect bear behavior and subsequent demographic effects. [ABSTRACT FROM AUTHOR]

Survival of juvenile ungulates represents an important demographic parameter that influences population dynamics within ecosystems. In many ecological systems, the mortality of juvenile ungulates is influenced by various factors, including predation by large carnivores, human hunting activities and weather. While wolves Canis lupus are known to prey on moose Alces alces throughout all seasons, brown bears Ursus arctos primarily engage in predation during early summer, while human harvest primarily occurs in autumn and early winter. Hence, understanding the impacts of predation, harvest, and weather on the survival of juvenile moose is crucial for adaptive population management and the determination of sustainable harvest rates. To investigate the summer and autumn–winter survival of moose calves in relation to carnivore occurrence (wolf presence and bear density), summer habitat productivity, winter severity, human harvest, and migratory behaviour (migratory versus resident), we analysed data collected from 39 GPS‐collared female moose in south‐central Scandinavia. Our findings revealed significant interannual variation in summer survival rates, with areas with relatively higher bear densities exhibiting calf mortality rates twice as high as those in regions with low bear density. During the autumn–winter period, calf survival was lowest in the presence of wolves and deep snow, and it exhibited a negative correlation with the proportion of clearcuts and young forests within the mother's home range. Additionally, calf survival was negatively correlated with the risk of human hunting, and calves of stationary females displayed ten times higher survival rates compared to migratory individuals. Our study provides valuable insights into the survival of moose calves coexisting with two large carnivores and humans. Improving our understanding of the mechanisms causing calf survival to fluctuate has become increasingly important as many local moose populations in Scandinavia are declining and exposed to expanding predator populations, intense hunting pressure, and other threats associated with climate change. [ABSTRACT FROM AUTHOR]

Animal sociality, the extent and manner in which conspecifics associate with each other, ultimately affects an individual's survival and reproductive success. It is shaped by the spatiotemporal configuration and composition of the social units (e.g. individual, pair, group) in a population. Here, we assessed the formation and structure of social networks of a presumed nonsocial species with individual-based movement data of 153 GPS-marked brown bears, Ursus arctos. We explored changes in the frequency of dyadic associations in relation to distinct seasonal patterns (i.e. mating, hyperphagia and hunting seasons) that affect bear behaviour. We found seasonally distinctive frequencies in brown bear associations throughout their active period and that reproduction was the main driver for associations in the population, that is, the highest frequency of associations occurred during the mating season and male–female dyads during the mating season included the majority (73%) of observed associations. We also observed dyadic associations during the hyperphagia and hunting seasons, but found no significant changes in frequency during these seasons. In addition, we found that social structures during both the mating and nonmating periods were nonrandom, that is, dyadic associations occurred more often than expected. Animal sociality is commonly viewed as a classification of social versus nonsocial, but our results suggest that it is rather a dynamic continuum primarily influenced by variation in a species' spatiotemporal configuration (i.e. seasonal movements, social unit structure) and demographic composition (i.e. age, sex). Our results also support the contention that studies focusing on animal sociality should include a sociospatial perspective, as both components are tightly linked. Since sociality can affect individual fitness, and vice versa, advancing the knowledge on assumed 'solitary' species is paramount for the conservation and sustainable management of their populations. • Animal sociality is a dynamic continuum instead of a binary classification. • The sociospatial environment of a population is under constant change. • We performed a network analysis using a GPS location database from a solitary species. • In brown bears, a 'solitary species', sociality is driven by reproduction. • Brown bear social interactions are nonrandom outside the mating season. [ABSTRACT FROM AUTHOR]

In North America, polar bears (Ursus maritimus), grizzly bears (U. arctos), and American black bears (U. americanus) occasionally injure or kill humans. Although bear-inflicted human injuries are uncommon, they generate media attention that can lead to fear and unreasonable perceptions of the risk of bear attacks. Information on the behavioral responses of grizzly and black bears during interactions with people can provide a factual basis regarding the risks associated with recreating in bear habitats and assist land managers in developing and prioritizing bear safety messages. To address those objectives, we collected 17,171 reports of grizzly and black bear reaction behavior during interactions with people in Yellowstone National Park, USA, between 1991 and 2022. We used Bayesian Multinomial Logistic Regression models to examine the odds of attack, agitation and/or warning, flight, or curious behavioral reactions versus neutral responses in bear–human interactions. We found that reaction behavior depended on both the species involved and the location of the interaction. In developed areas and along roadsides, neutral responses were most likely for both species. On front-country trails, odds of curious or flee reactions were greater than neutral responses for both species. The odds of agitation and/or warning reactions from grizzlies were also greater in this setting. In backcountry campsites, there were marginally higher odds of black bears attacking; whereas, grizzlies had marginally higher odds of attacking during off-trail backcountry interactions. Although bear attacks were uncommon in all locations, grizzlies were ∼3.9× more likely than black bears to injure people in backcountry areas. Bear interactions with people were generally predictable; grizzly and black bears exhibited neutral behaviors or fled during most interactions. Curious approaches, agitation and/or warning behaviors, physical contact, and attacks were uncommon. Safety messages encouraging calm, confident responses during bear–human interactions are warranted, and may have better efficacy than those that generate fear and apprehension. [ABSTRACT FROM AUTHOR]

Prey must balance resource acquisition with predator avoidance for survival and reproduction. To reduce risk of predation, prey may avoid areas with high predator use, but if they are unable to due to resource acquisition requirements, they may instead change their habitat use or movement speed to mitigate predation risk. Prey risk response may depend on spatially or temporally varying forage availability as well as seasonal variation in prey vulnerability and availability of alternate foods for predators. To quantify how prey respond to spatial and temporal variation in risk of brown bear predation, we examined Roosevelt elk (Cervus canadensis roosevelti) spatiotemporal behavior responses to brown bear (Ursus arctos) habitat use on Afognak and Raspberry islands, Alaska, using Global Positioning System location data during elk parturition (20 May–15 June), summer (16 June–20 September), and autumn (21 September–10 November). During parturition and summer, elk used forest and shrub landcover in areas of higher brown bear probability of use. During parturition, elk used areas with lower forage productivity in areas of higher bear probability of use, and movement speed decreased with higher bear probability of use, especially in shrub landcover. During summer, elk used areas with higher forage productivity in areas of higher brown bear probability of use. During autumn, elk were less likely to use areas with higher bear habitat probability of use across landcover categories and forage productivity. During summer and autumn, elk movement speed increased with higher brown bear probability of use. Elk behavioral response to risk of brown bear predation could increase energy expenditure and decrease their ability to acquire forage, therefore negatively impacting survival and reproduction with spatiotemporal variation in risk response potentially amplifying these impacts. [ABSTRACT FROM AUTHOR]

For the first time in the Ukrainian Polissia and the Chornobyl Radiation and Ecological Biosphere Reserve (ChREBR), a concentrated linear distribution of bear-marked spruce trees was found at the abandoned estates of the village of Opachychi along the second terrace of the Prypiat River floodplain. Individual sightings of bears (Ursus arctos) in the Ukrainian Polissia have been known since the 1990s, but there are no reliable data on the reproduction of this species. The abundance of bears in Belarus has increased in recent years, which leads to the possibility of females coming to the Polissia from the north. Dried spruce trees without resin were not marked by the bear, and the animal moved on to live trees. Friction and more intensive marking of trees was recorded mainly in the eastern direction. Most of the marked spruce trees were upright with no branches to the height of the marking. The intensive marking behaviour of bears in 2023 in the ChREBR can be considered as the appearance of a female, as signalling to a female, and as a sign of dominance towards a male competitor. Two adult males were observed near one of the marked trees (data from amateurs). Special field surveys are needed to identify females with cubs to confirm or refute the hypothesis that the intensity of bear marking can be used in the event of the presence of a female bear in oestrus. Along the bear-marked trees in the village of Opachychi of the ChPEBR, an ecological trail and a visitor centre of large carnivores and herbivores should be created, which would be popular destinations. It is advisable to arrange a location for wildlife observations in an abandoned house for photo and video shooting, as is usually done in Sweden, Bulgaria, Romania, and Spain. In such tours, the effectiveness of the observation is not guaranteed and only preliminary statistics of wildlife encounters are provided. For this purpose, it is advisable to create two feeding areas for predatory mammals with dry food, as well as a salt marsh and a feeding trough for ungulates. The majority of the ChREBR territory has a low incidence of markings. The bear in the Polissia, as elsewhere in Europe, is expanding its range naturally, but at a slow pace due to the low intensity of female dispersal. Tree marking by bears was also observed in Chernihiv Oblast, in the Mizhrichynskyi Regional Landscape Park. It is advisable to release several bears in the ChEBR to create a reproductive centre for this species in the Polissia.

Hyperdontia refers to an excess number of teeth past the expected number of teeth for an individual located in the mandible or maxilla. These extra teeth are often referred to as "supernumerary." This condition is a relatively uncommon, infrequent phenomenon scarcely documented in Ursidae globally, with only a handful of examples documented in literature. In 2008, an indigenous hunter harvested a grizzly bear (Ursus arctos) in Smithers, British Columbia, Canada. The bear exhibited 7 maxillary incisors, with a supernumerary tooth present. This observation serves as the first-ever record of the supernumerary dentition of the incisors in brown bears. [ABSTRACT FROM AUTHOR]

Fertility control has traditionally been applied in zoos to control captive populations, and reversible contraception is important. However, contraceptive methods for male bears have not been reported. We aimed to establish a reversible contraceptive for male brown bears by investigating the effects of a gonadotropin‐releasing hormone (GnRH) vaccine (Improvac®) that was developed for the immune castration of pigs. We vaccinated six bears with two sequential doses of 400 (n = 2) or 600 μg Improvac® (n = 4) with a 1‐month interval during the pre‐breeding season (February to April). We compared the reproductive parameters (testosterone levels and semen parameters) of the six vaccinated and four non‐vaccinated (control) bears once during the breeding season (May or June). To investigate whether the reproductive performance could be restored in the following year of contraception, we also compared the reproductive parameters once during the breeding season in two bears between the year with GnRH vaccination and the following year without vaccination. Vaccination treatments suppressed reproductive parameters in 5 bears, although vaccination with 400 μg of Improvac® was not effective in one bear. Testosterone levels and the rate of progressive sperm motility were significantly lower, and total sperm count and testis size tended to be lower in vaccinated bears, compared with the controls. Blood biochemical findings and direct observations after Improvac® vaccination did not reveal side effects. Moreover, testosterone levels and spermatogenic scores of two bears were restored in the following year. We confirmed that the Improvac® vaccine elicited a reversible contraceptive effect in male brown bears. [ABSTRACT FROM AUTHOR]

During the reproductive period, mating strategies are a significant driver of adaptations in animal behaviour. For instance, for polygamous species, greater movement rates during the mating season may be advantageous due to the increased probability of encountering several potential mates. The brown bear Ursus arctos is a solitary carnivore that lives at low densities, with a polygamous mating system and an extended mating season of nearly 3 months. Here, we hypothesized that male brown bears may show changes in movement patterns and space‐use behaviour during their mating season. Using long‐term (2002–2013) telemetry data from the Finnish Karelia male population (n = 24 individuals; n = 10 688 GPS locations), we first analysed daily movement metrics, that is, speed, net and total distance with respect to the period (mating vs. post‐mating) and several environmental predictors. Then, we conducted a step‐selection analysis for each of these periods. Throughout the year, male bears selected forested/shrub habitats and increased movement rates near main roads. During the mating season, reproductive needs seem to trigger roaming behaviour in adult males to maximize encounter rates with potential receptive females. However, all movement metrics increased within areas of high human activity, suggesting a bear response to a higher risk perception while using those areas. During the post‐mating period, overlapping with the bear hyperphagia and the hunting season, males selected anthropogenic areas farther from main roads and trails, suggesting a trade‐off between foraging opportunities and risk avoidance. [ABSTRACT FROM AUTHOR]

Context: Large carnivores have faced severe extinction pressures throughout Europe during the last centuries, where human-induced disturbances reached unprecedented levels. In the late twentieth century, the Cantabrian brown bear population was on the verge of extinction, due to poaching. Yet, the end of the last century was a turning point for this population. Presence data on the western Cantabrian subpopulation was collected since the beginning of the century and insights provided by this long-term monitoring may be useful for brown bear conservation. Objectives: Here, we aim to: (i) identify the landscape features relevant to bears’ recovery; and (ii) understand if and how the landscape use patterns by bears changed over time. Methods: We tested the influence of landscape structure (i.e., composition and configuration) on bear occurrence patterns using MAXENT in three periods representative of land cover change. Results: Despite variation across the 19-year monitoring period, brown bears were more often detected near broad-leaf forests and bare rock areas and at lower to intermediate altitudes, but avoided arable lands, permanent crops, and burnt areas. Human population density or distance to roads—often used for modelling habitat suitability for Cantabrian brown bears—were not identified as relevant variables for this brown bear subpopulation. Artificial areas were identified as relevant landscape features, but not as disturbance. Conclusions: These findings reinforce the importance of preserving bears’ native habitats and provide new insights, namely on the use of humanized landscapes. [ABSTRACT FROM AUTHOR]

The polar bear (Ursus maritimus) is a species particularly vulnerable to the effects of climate change. As the climate warms, polar bears will be forced to move to more suitable habitats which are likely to shrink, adapt to the new conditions, or decline in population size. However, the genomic diversity within and among all 19 subpopulations of polar bears, and therefore their adaptive potential, is currently unknown. In addition, warmer climates are likely to result in more frequent contact between polar bears and grizzly bears (U. arctos), with which they can hybridize. Here we describe the development, quality control, and application of the Ursus maritimus V2 SNP chip. This 8 K SNP chip contains loci explicitly selected to assess both RAD-derived and transcriptome-derived loci, as well as SNPs to detect hybridization between species. A total of 7,239 loci (90.3% of those printed) were successfully genotyped, with over 99% genotype concordance for individuals typed in duplicate on this chip, and between individuals typed here and on the Ursus maritimus V1 SNP chip. Using simulations, we demonstrate that the markers have high accuracy and efficiency to detect hybridization and backcrosses between polar bears and grizzly bears. However, empirical analysis of 371 polar bears, 440 grizzly bears, and 8 known hybrids found no novel instances of recent hybridization. The Ursus maritimus V2 SNP chip provides a powerful tool for monitoring the adaptive potential of this species along with assessing population structure, quantitative genomics, and hybridization in polar bears. [ABSTRACT FROM AUTHOR]

Hibernation is a key adaptation for coping with unfavorable climatic conditions and low food availability in areas with severe winter conditions. While understanding the physiology and phenology of this adaptation has received considerable attention, comparatively little information is available on how hibernation will be affected by changing climate conditions. We used GPS telemetry data from 20 free‐ranging brown bears monitored over 31 winters between 2007 and 2022, to identify behavioral strategies of bears during winter. We applied behavioral change point analysis to quantify brown bears' hibernation phenology in a population close to the bear's southern latitudinal range limit in Europe where supplementary food is available to bears year‐round. We observed winter behavior patterns that varied across age and reproductive classes but also within individuals between winters. Among 31 winter events, we registered six cases in which bears exhibited a single hibernation/stationary period and 19 events where hibernation was split into up to five stationary periods. Moreover, six winter events did not show behaviors consistent with hibernation and individuals remained partly or completely active throughout winter. The movement of these active bears decreased with increasing snow depth. In addition, these winter‐active bears showed higher fidelity to supplementary feeding sites during the winter period compared to the rest of the year. Our data suggest that an abundance of human‐provided food resources during winter may facilitate the emergence of different wintering strategies in brown bears. Furthermore, supplemental feeding sites in combination with predicted mild winters and prolonged natural food availability suggest that the use of hibernation as an energy‐saving strategy to overcome severe environmental conditions may decrease in the future. [ABSTRACT FROM AUTHOR]

The Swedish brown bear Ursus arctos population is protected, but managed with legally defined hunting seasons. Management decisions (e.g., hunting quotas) are frequently changed and should be based on knowledge about demographic parameters, but collecting sufficient data in the field is time consuming and expensive. An efficient method to collect data on reproductive output could be counting placental scars in the uteri of female brown bears, because hunters in Sweden are required to collect samples (including reproductive organs) of harvested bears and submit them to the authorities. We assessed the reliability of placental scar counts to determine reproductive performance by counting the number of young with female radio-collared brown bears and comparing that with placental scar counts after those females had been harvested. We found that staining uteri improved the detection of placental scars. The differences between number of scars detected before and after staining the uteri, increased significantly with female age. The number of placental scars and number of observed cubs-of-the-year accompanying females corresponded well 2 and 3 years after birth; relatively small deviations between them might have occurred because of early cub mortality prior to the observations after leaving the den. Placental scar counts can provide accurate information on age of primiparity, evidence for reproductive aging (senescence), and reproductive productivity, and therefore inform decisions regarding adaptive management, sustainable hunting, and conservation. [ABSTRACT FROM AUTHOR]

В статье рассмотрен опыт использования различных средств, применяемых для отпугивания бурых медведей (Ursus arctos) от сотрудников геолого-геофизических отрядов, работающих в полевых условиях на п-ове Пьягина Ольского муниципального округа, в местности с одной из самых высоких плотностей бурого медведя. Выявлены наиболее и наименее эффективные средства и способы. Рассмотрено двадцать конфликтных ситуаций медведей с человеком в полевых условиях. Цель этой статьи — просвещение полевиков для максимально безопасной работы в ближайшем соседстве с таким грозным хищником, как бурый медведь, и их по возможности мирному сосуществованию, что необходимо для успешной реализации стратегии развития Крайнего Севера.

Long-term wildlife research and monitoring programs strive to maintain consistent data collections and analytical methods. Incorporating new techniques is important but can render data sets incongruent and limit their potential to discern trends in demographic parameters. Integrated population models (IPMs) can address these limitations by combining data sources that may span different periods into a unified statistical framework while providing a holistic view of population dynamics. We developed an IPM in a Bayesian framework for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. We coupled demographic data with multiple, independent population count data to link annual changes in abundance with vital rates over 4 decades (1983–2023). Abundance increased threefold from an estimated 270 individuals in 1984 to 1030 individuals in 2023. Parameter estimates indicated survival of bears ≥2 years of age was high, contributing to robust population growth during the 1980s (λ = 1.023 [50 % interquartile range = 0.993–1.082]) and 1990s (λ = 1.064 [1.023–1.103]). A slowing of population growth started around 2000 (2000s: λ = 1.030 [0.989–1.068]) and continued into the 2010s (λ = 1.021 [0.985–1.057]), due primarily to reductions in survival of bears

The co-existence between brown bears (Ursus arctos Linnaeus, 1758) and farmers in the Pyrenees has been a major concern for several decades. The bear's depredation on livestock has multiple implications for traditional practices of extensive grazing and calls for a better understanding of the various ways in which humans and non-humans interact across different territories. The present dataset stems from "The Pastoralism and Bears in the Pyrenees" research project led by the GEODE laboratory (UMR 5602 CNRS-UT2J) in partnership with the Association Dissonances. Focusing on three summer pastures as places of encounter, this project proposes to explore the definition of co-existence, based on context-dependent and constantly evolving relationships between bears and pastoralists. As part of an interdisciplinary approach combining animal geography and ecology, the spatio-temporal activity of the different species was explored using a network of 118 camera traps.The 118 camera traps were installed on the three summer pastures while livestock was present in the mountains between May and October, from 2021 to 2023 and were set in a 400 m ✕ 400 m grid covering a total area of around 2,000 ha. The present dataset contains 57,928 occurrences of 22 taxon categories, including 19 identified species, two family categories (equids and mustelids) and one class category (birds). As pastoral activity is significantly present in these areas, livestock (sheep (Ovis aries Linnaeus, 1758), equids, cows (Bos taurus Linnaeus, 1758) and goats (Capra hircus Linnaeus, 1758)) account for 16,207 occurrences across the three pastures. The three main wild species captured over the three years and three pastures were the red deer (Cervus elaphus Linnaeus, 1758; 9,517 occurrences), red fox (Vulpes vulpes Linnaeus, 1758; 9,400 occurrences) and wild boar (Sus scrofa Linnaeus, 1758; 4,016 occurrences).Data are aggregated at the grid scale. Nonetheless, the exact locations of each camera trap as well as the photos can be requested from us.

Foxes (Vulpes spp.) are small, solitary canids with relatively low social complexity compared to more gregarious canids, such as wolves and dogs. They are, therefore, expected to have a relatively simple vocal repertoire, with limited low-intensity sounds for close communication and many high-intensity sounds for long-distance communication. Arctic foxes (Vulpes lagopus), like many other foxes, are largely solitary outside of the breeding season. However, they have the largest litter size in the order Carnivora and may experience enhanced social complexity during the breeding season. In this study, we document the vocal repertoire of the Arctic fox during the breeding season, and how it changes before and after the emergence of pups. We also describe the relationship between vocalizations and other denning behaviours. Camera-traps captured six distinct sounds produced by breeding pairs of Arctic foxes and their young at dens: territorial barks, warning barks, alarm calls, cooing, whines and growling. Our study shows that although high-intensity sounds, such as territorial barks, are an important form of long-distance communication among Arctic foxes, low-intensity sounds and sound mixing are used on their dens following pup emergence. Thus, Arctic fox vocalization may be more complex than previously documented.

Harvest regulations commonly attenuate the consequences of hunting on specific segments of a population. However, regulations may not protect individuals from non‐lethal effects of hunting and their consequences remain poorly understood. In this study, we compared the movement rates of Scandinavian brown bears (Ursus arctos, n = 47) across spatiotemporal variations in risk in relation to the onset of bear hunting. We tested two alternative hypotheses based on whether behavioural responses to hunting involve hiding or escaping. If bears try to reduce risk exposure by avoiding being detected by hunters, we expect individuals from all demographic groups to reduce their movement rate during the hunting season. On the other hand, if bears avoid hunters by escaping, we expect them to increase their movement rate in order to leave high‐risk areas faster. We found an increased movement rate in females accompanied by dependent offspring during the morning hours of the bear hunting season, a general decrease in movement rate in adult lone females, and no changes in males and subadult females. The increased movement rate that we observed in females with dependant offspring during the hunting season was likely an antipredator response because it only occurred in areas located closer to roads, whereas the decreased movement rate in lone females could be either part of seasonal activity patterns or be associated with an increased selection for better concealment. Our study suggests that female brown bears accompanied by offspring likely move faster in high‐risk areas to minimize risk exposure as well as the costly trade‐offs (i.e. time spent foraging vs. time spent hiding) typically associated with anti‐predator tactics that involve changes in resource selection. Our study also highlights the importance of modelling fine‐scale spatiotemporal variations in risk to adequately capture the complexity in behavioural responses caused by human activities in wildlife. [ABSTRACT FROM AUTHOR]

Background: The co-existence between brown bears (Ursus arctos Linnaeus, 1758) and farmers in the Pyrenees has been a major concern for several decades. The bear's depredation on livestock has multiple implications for traditional practices of extensive grazing and calls for a better understanding of the various ways in which humans and non-humans interact across different territories. The present dataset stems from "The Pastoralism and Bears in the Pyrenees" research project led by the GEODE laboratory (UMR 5602 CNRS-UT2J) in partnership with the Association Dissonances. Focusing on three summer pastures as places of encounter, this project proposes to explore the definition of co-existence, based on context-dependent and constantly evolving relationships between bears and pastoralists. As part of an interdisciplinary approach combining animal geography and ecology, the spatio-temporal activity of the different species was explored using a network of 118 camera traps. New information: The 118 camera traps were installed on the three summer pastures while livestock was present in the mountains between May and October, from 2021 to 2023 and were set in a 400 m x 400 m grid covering a total area of around 2,000 ha. The present dataset contains 57,928 occurrences of 22 taxon categories, including 19 identified species, two family categories (equids and mustelids) and one class category (birds). As pastoral activity is significantly present in these areas, livestock (sheep (Ovis aries Linnaeus, 1758), equids, cows (Bos taurus Linnaeus, 1758) and goats ( Capra hircus Linnaeus, 1758)) account for 16,207 occurrences across the three pastures. The three main wild species captured over the three years and three pastures were the red deer (Cervus elaphus Linnaeus, 1758; 9,517 occurrences), red fox (Vulpes vulpes Linnaeus, 1758; 9,400 occurrences) and wild boar (Sus scrofa Linnaeus, 1758; 4,016 occurrences). Data are aggregated at the grid scale. Nonetheless, the exact locations of each camera trap as well as the photos can be requested from us. [ABSTRACT FROM AUTHOR]

We analyzed handedness of brown bears (Ursus arctos), which is the tendency to differentially use the right or left forelimb for dexterous actions. Handedness in mammals is hypothesized to be an outcome of lateralization of neocortex function, which serves to increase cognitive capacity by reducing redundancy of function between left and right hemispheres. Handedness in brown bears would give insight into brown bear capacity for cognition and innovative behavior. We tallied brown bear forelimb use from videography of bears foraging on anadromous sockeye salmon (Oncorhynchus nerka) while aggregated at the Brooks River within Katmai National Park, Alaska, USA, during autumn 2022. Brown bears exhibited a significant propensity for handedness, a result driven primarily by brown bears using their right forelimb more often than their left to swat at conspecifics during social interactions. Under the model that neocortex lateralization increases cognitive capacity, the right-handedness we observed in brown bears is consistent with their capacity for problem solving and behavioral innovation. [ABSTRACT FROM AUTHOR]

The brown bear (Ursus arctos L., 1758) is a widespread bear species inhabiting the forest zone of Eurasia, including the Republic of Yakutia. The association with forest habitats explains why the Pleistocene findings of U. arctos fossils are rare in the northern part of Eastern Siberia, where open steppe-tundra and steppefied landscapes prevailed during the Pleistocene. Fossils of U. arctos that have been found on the territory of Yakutia are dated since the beginning of the Middle Pleistocene. These are mainly the skulls and bones of the postcranial skeleton. In the present study, using comparative morphological analysis, computed tomography, and DNA sequencing, we describe a first mummified carcass of a brown bear individual that inhabited the New Siberian Islands (Northeast Siberia) in the Middle Holocene, approximately 3,500 years BP, which was found in the permafrost of Bolshoy Lyakhovsky Island, Russia, in 2020. [ABSTRACT FROM AUTHOR]

In recent years, Slovakia's brown bear (Ursus arctos arctos) population has expanded, accompanied by increased injuries, public fear of bear attacks, and the first bear-related fatality in recent decades. From 2000 to 2015, 54 brown bear attacks on humans were recorded in Slovakia with no fatalities. The authors report on a fatal bear attack from 2021, the first known bear-caused fatality in Slovakia since 1927. The victim was a 58-year-old male found dead with numerous injuries consistent with brown bear attack. The autopsy revealed a diffuse subarachnoid hemorrhage and fracture of the cervical spine with contusion and partial spinal cord tear, which ultimately led to death due to central nervous system failure. To avoid potential conflicts between humans and wild animals, wildlife management authorities must develop educational safety programs, and encourage behavioral changes among outdoor recreationists as well as responsible wildlife viewing practices. [ABSTRACT FROM AUTHOR]

Large carnivores have recently increased in number and recolonized in human‐dominated landscapes; however, their ecological roles in these landscapes have not been well studied. In the Shiretoko World Heritage (SWH) site, brown bears have recolonized a previously abandoned mosaic landscape of natural forests and conifer plantations after land abandonment. We previously reported that the bears had recently begun to dig for cicada nymphs in association with the creation of larch plantations. As a result, this digging activity decreased soil nutrients. To deepen the understanding of the novel ecological role of brown bears within human‐modified landscapes, we examined the impacts of brown bear digging on the growth of larch trees. We found that brown bear digging decreased fine root biomass of larch, soil water, and nitrogen availability. Brown bear digging negatively affected needle nitrogen content, but not carbon isotope ratios, a water stress index of trees. Tree ring data suggest that digging negatively affected the radial growth of larches. The results imply that digging decreases tree growth due to limited soil nitrogen uptake. Our findings indicate that the ecological roles of large carnivores may differ between natural and anthropogenic landscapes. [ABSTRACT FROM AUTHOR]

Assessing the seasonal changes in body condition (BC) of animals is important for understanding their reproduction and survival, as well as human–animal interaction. Visual or photographic assessment of BC has, however, been limited to species in open habitats or to specific times and locations. To noninvasively assess the seasonal changes in the entire local population of brown bears (Ursus arctos) inhabiting the forest habitat in eastern Hokkaido, Japan, we evaluated their BC using camera-trapping during 2015–2017. We assigned a 5-point BC score (BCS) for each individual based on the images, and examined seasonal changes in BCS by sex–age classes. Out of the 1,714 events in which brown bears were recorded, sex–age classes including adult males, subadults, females with offspring, and solitary adult females, could be determined in 887 events. Overall, BCS tended to decrease from spring to summer, with the lowest value in July, and tended to increase toward autumn, with the highest value in November. The BCS of adult male bears showed the highest seasonal variation, whereas that of subadults showed the least variation. Adult females, both solitary and those with offspring, showed intermediate seasonal variation in BCS compared with adult males and subadults. These seasonal changes were considered to be a general pattern and point to the amount of accumulated body fat. Adult males have a larger home range and, because of their social dominance, can exploit higher quality resources than can be exploited by other sex–age classes, which results in them being able to accumulate relatively more fat during hyperphagia. Females with offspring tended to have a lesser increase in BCS after August and lower BCS in autumn than did solitary adults. We were able to demonstrate the possibility of evaluating the BC of individuals and their seasonal changes by examining BCS based on the videos taken by camera traps. [ABSTRACT FROM AUTHOR]

The Cantabrian brown bear (Ursus arctos) population is threatened although in a constant process of recovery during the last 20 years. Since data on the parasitological status of this bear is still limited, the objective of the present study was to assess the diversity and prevalence of parasites in this population. Thus, 111 bear faecal samples were collected in north-western Spain and analysed for estimating the occurrence of gastrointestinal and bronchopulmonary parasites. Samples were processed by flotation in saline and sucrose solution, sedimentation and Baermann-Wetzel techniques. In addition, a commercial immunofluorescent assay was performed for detecting Giardia duodenalis and Cryptosporidium spp. Dicrocoelium dendriticum was the most prevalent parasite (58.6%), followed by Baylisascaris transfuga (43.2%) and nematodes of the Suborder Strongylida (18.9%) and Spirurida (2.7%). Mixed infections were detected in the 41.4% of the samples. The presence of D. dendriticum was significantly highest in bears from the autonomous region of Castile and León as well as in those in which grass or nuts/acorns were the predominant food item. Moreover, the risk of being positive to B. transfuga was significantly higher during autumn–winter, and in those, faecal samples were mainly composed of fleshy fruit. Some of the parasites detected could infect other wildlife and even humans, and therefore, the risk of pathogen transmission deserves further investigation. Since the impact of endoparasites in the health status of bears is poorly understood, the establishment of a disease surveillance protocol is strongly recommended in order to assess the potential risk of these infections for bears. [ABSTRACT FROM AUTHOR]

Abstract 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.

Habitat fragmentation poses a significant threat to the existence and reproduction of large carnivores, such as brown bears, as it affects the genetic connectivity of populations and, consequently, their long-term viability. Understanding the genetic makeup and dispersal patterns in areas where brown bears live is crucial for developing effective conservation plans and promoting human-brown bear coexistence. In this study, 214 hair samples were collected non-invasively from brown bears and were genetically analyzed using fifteen specific microsatellite loci to shed light on the genetic status and demography of a sub-population residing in Central Greece (Trikala-Meteora area). The broader Central and South Pindos regions have not been studied for over a decade; however, high levels of genetic diversity, a lack of heterozygosity deficiency, and no signs of inbreeding, along with an estimated effective population size (Ne = 99), confirm the good conservation status of this sub-population. Moreover, the existence of a natural and apparently functional corridor in Central Pindos was demonstrated by bear movements between the western and eastern parts of the project area, enhancing the sustainability of the population. These findings will contribute to future efforts to conserve natural corridors that enable functional connectivity among large areas of brown bear territories in Greece.

Avoiding humans will be more difficult and energetically costly for animals as outdoor recreation increases and people venture farther into wildland areas that provide high‐quality habitat for wildlife. Restricting human access can be an attractive management tool to mitigate effects of human recreation activities on wildlife; however, the efficacy of such measures is rarely assessed. In 1982, Yellowstone National Park identified areas important to grizzly bears (Ursus arctos) to help protect critical grizzly bear habitat and reduce the likelihood of human injuries by bears. Referred to as bear management areas (BMAs), human access is restricted in these areas for 2–8 months each year, with timing and type of restrictions varying by area. We examined 2 datasets to evaluate grizzly bear selection of BMAs and differences of bear density in BMAs and non‐BMAs. First, we used 17 years of recent global positioning system telemetry data for grizzly bears to assess their selection of BMAs during periods when human access was allowed, and when access was restricted. We used step‐selection functions to test the hypothesis that bears spend time in places that allow them to avoid people and select quality food sources. There was support that grizzly bears differentially select for BMAs regardless of whether human access was restricted at the time, compared with areas outside BMAs, and that selection changed with sex and season. Only males during the summer and hyperphagic seasons changed their selection of BMAs based on whether access restrictions were in place, and overall, male bears preferred unrestricted BMAs (BMAs without restrictions in place). Females preferentially selected BMAs regardless of whether the area had access restrictions in place only during the mating season. Individuals varied widely in their preference for BMAs and access restrictions. Bears likely choose to spend time in BMAs based on available food resources rather than restrictions to human access. Supporting this interpretation, our analyses indicated that a greater proportion of BMA in an area was associated with higher densities of grizzly bear. Thus, restrictions to human access likely help reduce the potential for human–bear interactions, accomplishing one of the original objectives for establishing the BMAs. [ABSTRACT FROM AUTHOR]

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 (δ13C, δ15N) 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. [ABSTRACT FROM AUTHOR]

Brown bears (Ursus arctos) were extinct in Portugal by 1843. In the spring of 2019, a male bear was officially confirmed in northern Portugal, and more bears will likely reach the country shortly. We surveyed participants in a workshop held in Bragança in October 2021 to understand the perceptions and attitudes of different stakeholder groups (Administration, Research, Nongovernmental Organizations, and Local Stakeholders) regarding the return of brown bears to Portugal. Results indicate that, generally, participants would feel safe in areas where bears are present, are positive toward the return of brown bears, and see it as an opportunity for local development rather than a threat. Results also indicate a high level of consensus among groups of stakeholders concerning the issues analyzed. These preliminary results provide a baseline for perceptions and attitudes to consider when planning the conservation of brown bears returning to Portugal. [ABSTRACT FROM AUTHOR]

American black (Ursus americanus) and grizzly bears (U. arctos) are sympatric throughout much of the grizzly bear's range, but information on how they share the landscape is lacking because distribution usually is not estimated simultaneously for both species. Here we analyze DNA data from noninvasively collected hair (using hair snags and rub trees) in a spatially explicit capture–recapture framework to study factors affecting the distribution of density for both black and grizzly bears in south Jasper National Park, Alberta, Canada, in 2014. Ninety-three black bears and 32 grizzly bears were detected. Black bears and grizzly bears showed different rates of detection for hair snags and rub trees, with hair snags being more effective in sampling both species. Female black bear density was greatest close to the town of Jasper, near roads, and in areas of higher amounts of closed canopy cover. Male black bear density was greatest at lower elevations with high canopy closure, and close to roads. Female grizzly bear density was greatest further from gravel roads, while male grizzly bear density was highest away from gravel roads and at medium canopy cover. We tested grizzly bears density as a predictor for black bear density and found that although habitat was the primary factor influencing black bear distribution, there was also a minor effect of grizzly bear density on male black bear density, and a slightly greater effect of grizzly bear density on female black bear density. The distribution of black bears within this study area puts them at a higher risk of conflict with humans. Our findings that grizzly bears prefer areas further from roads supports the use of habitat security thresholds to reduce human disturbance of grizzly bears. [ABSTRACT FROM AUTHOR]

Abstract Harvest regulations commonly attenuate the consequences of hunting on specific segments of a population. However, regulations may not protect individuals from non‐lethal effects of hunting and their consequences remain poorly understood. In this study, we compared the movement rates of Scandinavian brown bears (Ursus arctos, n = 47) across spatiotemporal variations in risk in relation to the onset of bear hunting. We tested two alternative hypotheses based on whether behavioural responses to hunting involve hiding or escaping. If bears try to reduce risk exposure by avoiding being detected by hunters, we expect individuals from all demographic groups to reduce their movement rate during the hunting season. On the other hand, if bears avoid hunters by escaping, we expect them to increase their movement rate in order to leave high‐risk areas faster. We found an increased movement rate in females accompanied by dependent offspring during the morning hours of the bear hunting season, a general decrease in movement rate in adult lone females, and no changes in males and subadult females. The increased movement rate that we observed in females with dependant offspring during the hunting season was likely an antipredator response because it only occurred in areas located closer to roads, whereas the decreased movement rate in lone females could be either part of seasonal activity patterns or be associated with an increased selection for better concealment. Our study suggests that female brown bears accompanied by offspring likely move faster in high‐risk areas to minimize risk exposure as well as the costly trade‐offs (i.e. time spent foraging vs. time spent hiding) typically associated with anti‐predator tactics that involve changes in resource selection. Our study also highlights the importance of modelling fine‐scale spatiotemporal variations in risk to adequately capture the complexity in behavioural responses caused by human activities in wildlife.

Hibernation is a period of metabolic suppression utilized by many small and large mammal species to survive during winter periods. As the underlying cellular and molecular mechanisms remain incompletely understood, our study aimed to determine whether skeletal muscle myosin and its metabolic efficiency undergo alterations during hibernation to optimize energy utilization. We isolated muscle fibers from small hibernators, Ictidomys tridecemlineatus and Eliomys quercinus and larger hibernators, Ursus arctos and Ursus americanus. We then conducted loaded Mant-ATP chase experiments alongside X-ray diffraction to measure resting myosin dynamics and its ATP demand. In parallel, we performed multiple proteomics analyses. Our results showed a preservation of myosin structure in U. arctos and U. americanus during hibernation, whilst in I. tridecemlineatus and E. quercinus, changes in myosin metabolic states during torpor unexpectedly led to higher levels in energy expenditure of type II, fast-twitch muscle fibers at ambient lab temperatures (20 °C). Upon repeating loaded Mant-ATP chase experiments at 8 °C (near the body temperature of torpid animals), we found that myosin ATP consumption in type II muscle fibers was reduced by 77–107% during torpor compared to active periods. Additionally, we observed Myh2 hyper-phosphorylation during torpor in I. tridecemilineatus, which was predicted to stabilize the myosin molecule. This may act as a potential molecular mechanism mitigating myosin-associated increases in skeletal muscle energy expenditure during periods of torpor in response to cold exposure. Altogether, we demonstrate that resting myosin is altered in hibernating mammals, contributing to significant changes to the ATP consumption of skeletal muscle. Additionally, we observe that it is further altered in response to cold exposure and highlight myosin as a potentially contributor to skeletal muscle non-shivering thermogenesis.

This study aimed to investigate the variations of parasites in the feces of brown bears Ursus arctos inhabiting the Cantabrian Mountains (NW Spain). A total of 248 bear fecal samples were collected throughout one year, spanning from August 2018 to September 2019, at an approximate frequency of 20 samples per month. The results were analyzed in relation to both the season and the biological activity of the brown bears, i.e., hibernation, mating and hyperphagia. Among the examined samples, eggs of Dicrocoelium dendriticum (32.2%; 95% Confidence Interval: 26.4–38.1), Baylisascaris sp. (44.8%; 38.5–50.9), ancylostomatids (probably belonging to Uncinaria spp.) (16.5%; 11.9–21.1) and Trichuris sp. (1.2%; 0–2.6) were observed. Significant seasonal differences were noted for Baylisascaris and ancylostomatids (χ2 = 21.02, P = 0.001 and χ2 = 34.41, P = 0.001, respectively). Furthermore, the presence of helminth eggs was correlated with the activity phase of the brown bears. Dicrocoelium attained the highest prevalence during the mating phase, while Baylisascaris and ancylostomatids were more frequent during hyperphagia. Notably, the highest egg-output counts for Dicrocoelium and Baylisascaris sp. were recorded during the mating phase and hibernation, respectively, whereas ancylostomatids eggs peaked during hyperphagia. Additionally, variations in egg-output counts were significant for all helminths concerning the season, with the exception of Trichuris sp., and for Dicrocoelium and Baylisascaris sp. According to bear activity. It is concluded that infection by gastrointestinal helminths depends on the season and the biological activity of the bears from the Cantabrian Mountains, and their health status could result influenced.

Trapping bears (Ursidae) with Aldrich leg snares has established itself as one of the most successful methods of trapping live animals with minimal injury. Most documented injuries are related to damage caused by the trap and prolonged exposure to it. Various physiological and behavioural responses have been observed, however self-eating of the toes of the captured foot has not been described so far. In November 2017 an adult male brown bear was caught with a standard Aldrich type leg snare. When the research team arrived, the bear teared off and swallowed phalanges of the first toe of its rear left foot before it could be sedated. The bear was measured and marked with GPS-GSM collar. Following the instalment of the collar, the animal was monitored for the duration of 23 months when the drop-off mechanism of the collar was activated. This rule out the possibility that a serious life threatening complications arised from the trauma.

In Japan, the recent series of sporadic outbreaks of human trichinellosis caused by Trichinella (Nematoda: Trichocephalida) has occurred owing to the consumption of raw or insufficiently cooked meat from wild bears. However, the infection status and molecular characteristics of Trichinella larvae in Japanese wild bears remain poorly understood. This study investigated the prevalence of Trichinella spp. in brown bears (Ursus arctos) from Hokkaido, and Japanese black bears (Ursus thibetanus japonicus) from three prefectures (Aomori, Akita, and Iwate) in northern Japan, between April 2019 and August 2022. Trichinella larvae were detected in 2.5% (6/236) of the brown bears and 0.9% (1/117) of the Japanese black bears. Sequence analysis using two genetic loci, the internal transcribed spacer region of nuclear ribosomal DNA and the mitochondrial cytochrome c oxidase subunit I gene, revealed that the larvae collected from the seven infected bears were identical to one of the two haplotypes of Trichinella T9. The prevalence of Trichinella T9 is low but is maintained in bears in the Hokkaido and Iwate prefectures suggesting that undercooked meat from these animals could cause human infection. Thus, continued health education campaigns are needed to raise awareness of the potential risk of trichinellosis among hunters, meat suppliers, consumers, and local governmental health agencies.

Brown bear (Ursus arctos) diet composition and seasonal food habits were examined in the Central Forest Nature Reserve (CFNR) in West-European Russia. This territory has 2 landscape types: (1) a mostly intact and strictly protected CFNR core area with southern taiga forests, and (2) a human-modified buffer zone around it. We collected 758 bear scats between March and November 2008–2021. Fleshy fruits were the most important food category in the bear diet and represented 30% of the annual estimated dietary energy content (EDEC). Among fruits, the most important food items were apples (Malus domestica; EDEC = 22%). Bears highly preferred bilberry (Vaccinium myrtillus) in the late summer and early fall seasons (EDEC = 9%). During the hyperphagia period, bears fed on apples, hazel nuts (Corylus avellana; EDEC = 17%), oat (Avena sativa; EDEC = 9%), rowan (Sorbus aucuparia; EDEC = 5%), and cranberry (V. microcarpum and V. oxycoccos; EDEC = 4%). Herbaceous plants were also important (EDEC = 6%) from late spring to early fall. Among insects, bears actively consumed ants (Formicidae; EDEC = 3%) and social wasps (Vespidae; EDEC = 3%). Ungulates, especially adult moose (Alces alces) and calves, comprised the most important food item for bears during spring, contributing 15% of the EDEC. The CFNR core area, which presents natural foods for bears, had a prevalence of bilberry in scat amount (Cliff's Delta = –0.20). The buffer zone had a prevalence of apples (Cliff's Delta = 0.19) and oat (Cliff's Delta = 0.14), whose distributions were associated with abandoned orchards and cultivated fields. Brown bear food habits in the CFNR are similar to those in southern and eastern Europe, with a great dietary contribution of plant materials (especially fleshy fruits and hard mast). However, at the same time, CFNR bears have a significant dietary impact associated with boreal ecosystems (high Vaccinium berry consumption and active moose hunting), which makes it similar to populations from northern Europe. [ABSTRACT FROM AUTHOR]

Although the advent of high‐resolution GPS tracking technology has helped increase our understanding of individual and multispecies behavior in wildlife systems, detecting and recording direct interactions between free‐ranging animals remains difficult. In 2023, we deployed GPS collars equipped with proximity sensors (GPS proximity collars) on brown bears (Ursus arctos) and moose (Alces alces) as part of a multispecies interaction study in central Sweden. On 6 June, 2023, a collar on an adult female moose and a collar on an adult male bear triggered each other's UHF signal and started collecting fine‐scale GPS positioning data. The moose collar collected positions every 2 min for 89 min, and the bear collar collected positions every 1 min for 41 min. On 8 June, field personnel visited the site and found a female neonate moose carcass with clear indications of bear bite marks on the head and neck. During the predation event, the bear remained at the carcass while the moose moved back and forth, moving toward the carcass site about five times. The moose was observed via drone with two calves on 24 May and with only one remaining calf on 9 June. This case study describes, to the best of our knowledge, the first instance of a predation event between two free ranging, wild species recorded by GPS proximity collars. Both collars successfully triggered and switched to finer‐scaled GPS fix rates when the individuals were in close proximity, producing detailed movement data for both predator and prey during and after a predation event. We suggest that, combined with standard field methodology, GPS proximity collars placed on free‐ranging animals offer the ability for researchers to observe direct interactions between multiple individuals and species in the wild without the need for direct visual observation. [ABSTRACT FROM AUTHOR]

Reduction in population size, with its predicted effects on population fitness, is the most alarming anthropogenic impact on endangered species. By introducing compatible individuals, genetic rescue (GR) is a promising but debated approach for reducing the genetic load unmasked by inbreeding and for restoring the fitness of declining populations. Although GR can improve genetic diversity and fitness, it can also produce loss of ancestry, hampering local adaptation, or replace with introduced variants the unique genetic pools evolved in endemic groups. We used forward genetic simulations based on empirical genomic data to assess fitness benefits and loss of ancestry risks of GR in the Apennine brown bear (Ursus arctos marsicanus). There are approximately 50 individuals of this isolated subspecies, and they have lower genetic diversity and higher inbreeding than other European brown bears, and GR has been suggested to reduce extinction risks. We compared 10 GR scenarios in which the number and genetic characteristics of migrants varied with a non‐GR scenario of simple demographic increase due to nongenetic factors. The introduction of 5 individuals of higher fitness or lower levels of deleterious mutations than the target Apennine brown bear from a larger European brown bear population produced a rapid 10–20% increase in fitness in the subspecies and up to 22.4% loss of ancestry over 30 generations. Without a contemporary demographic increase, fitness started to decline again after a few generations. Doubling the population size without GR gradually increased fitness to a comparable level, but without losing ancestry, thus resulting in the best strategy for the Apennine brown bear conservation. Our results highlight the importance for management of endangered species of realistic forward simulations grounded in empirical whole‐genome data. [ABSTRACT FROM AUTHOR]

A morphological description is provided for a unique find of a frozen mummified subfossil brown bear (Ursus arctos L., 1758), found for the first time ever. The find is a well-preserved bear carcass of approximately 3500 years in age. Results of computed tomography and DNA testing are discussed. [ABSTRACT FROM AUTHOR]

The influence of bottom‐up food resources and top‐down mortality risk underlies the demographic trajectory of wildlife populations. For species of conservation concern, understanding the factors driving population dynamics is crucial to effective management and, ultimately, conservation. In southeastern British Columbia, Canada, populations of the mostly omnivorous grizzly bear (Ursus arctos) are fragmented into a mosaic of small isolated or larger partially connected sub‐populations. They obtain most of their energy from vegetative resources that are also influenced by human activities. Roads and associated motorized human access shape availability of food resources but also displace bears and facilitate human‐caused mortality. Effective grizzly bear management requires an understanding of the relationship between habitat quality and mortality risk. We integrated analyses of bottom‐up and top‐down demographic parameters to understand and inform a comprehensive and efficient management paradigm across the region. Black huckleberry (Vaccinium membranaceum) is the key high‐energy food for grizzly bears in much of southeastern British Columbia. Little is known about where and why huckleberries grow into patches that are useful for grizzly bears (i.e., densely clustered fruiting shrubs that provide efficient access to high energy food) and how forage supply and mortality risk influence population vital rates. By following 43 grizzly bears tracked with global positioning system (GPS) collars (57 bear years) in a 14,236‐km2 focal area spanning the Selkirk and Purcell mountain ranges, we developed a model to identify huckleberry patches from grizzly bear use data. Over 2 years we visited 512 sites used by bears, identifying more than 300 huckleberry patches. We used boosted regression tree modeling associating geophysical, ecological, soil, climate, and topographical variables with huckleberry patches. We integrated this modeled food layer depicting an important pre‐hibernation resource, into broader bottom‐up and top‐down analyses. In addition to berries, we examined bottom‐up variables indexing vegetative productivity that were previously found to be predictive of bear use (e.g., alpine, canopy cover, greenness, riparian). We also examined top‐down variables including road presence, road density, distance‐to‐road, secure habitat (defined as 500 m away from a road open to vehicular access), highways, human development, and terrain ruggedness. We evaluated the relationship of these variables to female habitat selection, fitness, and population density, testing the predictability and interrelatedness of covariates relative to bottom‐up and top‐down influences. We estimated resource selection functions with 20,293 GPS telemetry locations collected over 10 years from 20 female grizzly bears. We modeled fitness using logistic regression of spatially explicit reproductive data derived from genetically identified family pedigrees consisting of a mother, father, and offspring. Data included 33 mothers and 72 offspring (1–8 offspring per female). We estimated density through spatial capture‐recapture analysis of 126 grizzly bears detected with hair‐sampled DNA 287 times between 1998 and 2005. In all 3 analyses (habitat selection, fitness, and density), huckleberry patches were the most influential bottom‐up factor and secure habitat was the most consistent top‐down variable (road density was similarly predictive). All of the best supported models contained bottom‐up and top‐down variables except the male density model, which only contained a top‐down variable (secure habitat). These results suggest that both bottom‐up and top‐down forces drive several population processes of grizzly bears in the region, especially for females. We found that 38% of huckleberry patches (235 km2) predicted by the top model were in non‐secure habitat and that these patches were associated with lower fitness and density relative to those in secure habitat. Grizzly bear density was 2.6 times higher in habitat with road densities <0.6 km/km2, supporting the use of this road density target for management. The models predict that applying motorized access controls to backcountry areas with huckleberry patches would increase grizzly bear abundance by 23% on average across the region and 125% in the lowest density portion of the study area (Yahk). Managing both bottom‐up and top‐down influences is necessary to best mitigate the expanding human footprint, which is affecting many carnivore species worldwide. We provide evidence that bottom‐up forces were more influential for female habitat selection, fitness, and density than top‐down effects. We also uncovered a critical pattern in the magnitude of top‐down and bottom‐up influences on behavioral (habitat selection) and demographic (population density and fitness) responses. We show that the relative influence of top‐down influences on habitat selection and fitness are relatively weak compared to bottom‐up influences, whereas top‐down pressures exert much stronger limiting forces on population density. Forming conservation decisions around behavioral responses alone may misdirect actions and have limited benefits to populations. This insight can facilitate more effective decision‐making for grizzly bear conservation. Our findings highlight the importance of considering both bottom‐up and top‐down influences, suggesting cautious interpretation of habitat selection models for any species. A comprehensive examination with population‐level metrics such as density, vital rates, and fitness may be needed for effective management. [ABSTRACT FROM AUTHOR]

Herbivorous animals tend to seek out plants at intermediate phenological states to improve energy intake while minimizing consumption of fibrous material. In some ecosystems, the timing of green‐up is heterogeneous and propagates across space in a wave‐like pattern, known as the green wave. Tracking the green wave allows individuals to prolong access to higher‐quality forage. While there is a plethora of empirical support for such behavior in herbivorous taxa, the green wave hypothesis (GWH) is nuanced based on factors such as body morphometrics and digestive capacity. Furthermore, little is known about whether other taxa, such as omnivores, track the green wave. Our objective was to assess whether the GWH can be extended to explain the movements of omnivores. Using GPS collar data from seven populations (n = 127 individuals) of brown bears Ursus arctos across their entire North American range, we first tested whether bears tracked the green wave. Using conditional resource selection functions (RSFs), we found that variation in proxies of vegetative forage quality better explained movement and habitat selection than proxies of forage biomass in over half of the bears in our study, providing evidence of green wave tracking. Second, we assess factors that explained variation in green wave tracking using linear mixed effects models. Green wave tracking in brown bears was explained by the variation in availability of green‐up within spring home ranges, and how green‐up transitioned across those home ranges. Our results demonstrate that the GWH can partially explain movement of a non‐migratory omnivorous species, extending the generality of the GWH as a broad predictor of animal space use. The green wave is another resource wave brown bears track, and our findings help predict brown bear space use, which can be used to guide conservation and habitat restoration efforts. [ABSTRACT FROM AUTHOR]

This paper presents the results of estimating the population density and abundance of Ursus arctos (hereinafter – brown bear) in the Southern Forestry of the Central Forest State Nature Biosphere Reserve (CFNR), West of European Russia, in 2021 based on the Random Encounter Model (REM) based upon data obtained from camera traps. Methods for obtaining parameters necessary for building a model are demonstrated. A total of 7970 camera trap nights were worked out at 46 stations, and 502 independent trap events were obtained. The average relative abundance index (RAI) was 6.28 ± 1.59. The total average brown bear population density was 0.086 ± 0.034 individuals per 1 km2. The approximate estimated abundance was 18.98 ± 7.54 individuals. The coefficient of variation was 38%. Population density estimates had a pronounced seasonal dynamics. The minimum value was recorded for the period from 24 June to 23 July (individuals feeding on meadows and ants outside the CFNR core area), and the maximum for the period from 24 July to 22 August (brown bears feeding by berries in the CFNR core area). We found a strong significant correlation between brown bear population density and its relative abundance index (r = 0.81, p < 0.05). It was found that with an increase in the sampling period duration, the estimate of the population density noticeably decreases (r = -0.53, p < 0.05). Parameters of the average travel speed and activity level are a subject to the greatest variability, which determines the significant variability of the day range. In general, the method of population density estimation using REM is highly promising to carry out the brown bear population size estimation in forests and mountain forests, where visual estimations are difficult or impossible.

Aggregated use along salmon‐bearing (Oncorhynchus spp.) streams is common for coastal brown bears Ursus arctos; however, it is much less common in non‐coastal (interior) environments, especially in the Arctic. A concurrent study of GPS‐collared brown bears in the interior Brooks Range mountains, northern Alaska, revealed that salmon‐bearing streams and their use by brown bears were more prevalent than previously known. Our goal was to estimate the number, gender, and species of bears (Ursus spp.) using anadromous streams while salmon were present in an area of northern, interior Alaska. We deployed single‐catch breakaway hair snares on heavily‐used bear trails along 7 km sections of two anadromous streams to identify individual animals through DNA genotypes. We collected 119 hair samples from August and September in 2016 and 2017 which revealed 31 unique brown bears and five American black bears Ursus americanus across both streams. Using a capture‐with‐replacement analysis, we estimated 24 (95% CI: 22–27) brown bears used 7 km of one stream and 15 (95% CI: 9–35) brown bears used 7 km of the other. Across both streams, we detected a higher proportion of females than males, more brown bears than black bears, and greater relatedness among bears that used the same stream. The high number of brown bears estimated along these streams belies their overall low densities in the region, while relatedness patterns suggests that bears obtain behavioral specialization through social learning. A 354 km industrial road is permitted to be constructed along the southern flanks of the Brooks Range, bisecting numerous streams and rivers, including the two sampled above. Given our findings, we identify potential mitigation measures to reduce human‐bear conflicts related to aggregated brown bear use along anadromous streams. [ABSTRACT FROM AUTHOR]

Understanding the density-dependent processes that drive population demography in a changing world is critical in ecology, yet measuring performance-density relationships in long-lived mammalian species demands long-term data, limiting scientists' ability to observe such mechanisms. We tested performance-density relationships for an opportunistic omnivore, grizzly bears (Ursus arctos, Linnaeus, 1758) in the Greater Yellowstone Ecosystem, with estimates of body composition (lean body mass and percent body fat) serving as indicators of individual performance over two decades (2000-2020) during which time pronounced environmental changes have occurred. Several high-calorie foods for grizzly bears have mostly declined in recent decades (e.g., whitebark pine [Pinus albicaulis, Engelm, 1863]), while increasing human impacts from recreation, development, and long-term shifts in temperatures and precipitation are altering the ecosystem. We hypothesized that individual lean body mass declines as population density increases (H1), and that this effect would be more pronounced among growing individuals (H2). We also hypothesized that omnivory helps grizzly bears buffer energy intake from changing foods, with body fat levels being independent from population density and environmental changes (H3). Our analyses showed that individual lean body mass was negatively related to population density, particularly among growing-age females, supporting H1 and partially H2. In contrast, population density or sex had little effect on body fat levels and rate of accumulation, indicating that sufficient food resources were available on the landscape to accommodate successful use of shifting food sources, supporting H3. Our results offer important insights into ecological feedback mechanisms driving individual performances within a population undergoing demographic and ecosystem-level changes. However, synergistic effects of continued climate change and increased human impacts could lead to more extreme changes in food availability and affect observed population resilience mechanisms. Our findings underscore the importance of long-term studies in protected areas when investigating complex ecological relationships in an increasingly anthropogenic world. [ABSTRACT FROM AUTHOR]

In Japan, the recent series of sporadic outbreaks of human trichinellosis caused by Trichinella (Nematoda: Trichocephalida) has occurred owing to the consumption of raw or insufficiently cooked meat from wild bears. However, the infection status and molecular characteristics of Trichinella larvae in Japanese wild bears remain poorly understood. This study investigated the prevalence of Trichinella spp. in brown bears (Ursus arctos) from Hokkaido, and Japanese black bears (Ursus thibetanus japonicus) from three prefectures (Aomori, Akita, and Iwate) in northern Japan, between April 2019 and August 2022. Trichinella larvae were detected in 2.5% (6/236) of the brown bears and 0.9% (1/117) of the Japanese black bears. Sequence analysis using two genetic loci, the internal transcribed spacer region of nuclear ribosomal DNA and the mitochondrial cytochrome c oxidase subunit I gene, revealed that the larvae collected from the seven infected bears were identical to one of the two haplotypes of Trichinella T9. The prevalence of Trichinella T9 is low but is maintained in bears in the Hokkaido and Iwate prefectures suggesting that undercooked meat from these animals could cause human infection. Thus, continued health education campaigns are needed to raise awareness of the potential risk of trichinellosis among hunters, meat suppliers, consumers, and local governmental health agencies. [Display omitted] • We demonstrated that Trichinella is maintained at low levels in wild bears. • The larvae in brown and Japanese black bears in Japan were identified as Trichinella T9. • Wild bears in Japan may have limited contact with infected animals. • Consuming bear meat in Japan can transmit Trichinella to other animals including humans. [ABSTRACT FROM AUTHOR]