Search

It has been suggested that the American black bear (Ursus americanus) may be responsible for a significant number of purported sightings of an alleged unknown species of hominid in North America. Previous analyses have identified a correlation between 'sasquatch' or 'bigfoot' sightings and black bear populations in the Pacific Northwest using ecological niche models and simple models of expected animal sightings. The present study expands the analysis to the entire US and Canada by modelling sasquatch sightings and bear populations in each state/province while adjusting for human population and forest area in a generalized linear model. Sasquatch sightings were statistically significantly associated with bear populations such that, on the average, every 1000 bear increase in the bear population is associated with a 4% (95% CI: 1–7%) increase in sasquatch sightings. Thus, as black bear populations increase, sasquatch sightings are expected to increase. On average, across all states and provinces in 2006, after controlling for human population and forest area, there were approximately 5000 bears per sasquatch sighting. Based on statistical considerations, it is likely that many supposed sasquatch are really misidentified known forms. If bigfoot is there, it could be a bear. [ABSTRACT FROM AUTHOR]

Anthropogenic pressure, such as urbanization and habitat loss, can wield many effects on wildlife that radiate through ecosystems. Large carnivores tend to experience these effects more severely than other species, diminishing their viability and altering ecosystem function by suppressing their role as an apex predator. Yet opportunistic carnivores that rely on an omnivorous diet can sometimes take advantage of anthropogenic food and improve their fitness prospects. We quantified the effect of phenotypic and ecological factors on female body mass of the American black bear (Ursus americanus) in New Jersey, USA. Habitat and reliable mast crops in New Jersey keep adult female black bear body mass and reproduction higher than many parts of the United States, and historically, female black bears in the mid‐Atlantic states tend to be larger than in other parts of their range. We used data collected from den surveys (n = 317) in northern New Jersey from 1984 to 2019 to examine the shared roles of climate, anthropogenic pressure (human food subsidies, harvest), habitat composition and configuration, natural food availability (hard mast production), and bear characteristics (age, history of human–black bear conflict) on female black bear body mass using generalized linear mixed models. Adult female body mass was heaviest with increased availability of cultivated crop and within low‐intensity developed land covers, suggesting anthropogenic food subsidies found in these 2 land cover types are contributing to female overall body mass. A history of conflict with humans explained heavier females, and a quadratic effect of age on body mass supported a senescent decline in adult female body mass later in life. Our results suggest that access to specific land cover types (i.e., crops, low‐intensity developments) that provide a diversity of food (e.g., corn, soft and hard mast) and support low human densities, explains female black bear body mass in a fragmented landscape. [ABSTRACT FROM AUTHOR]

Simple Summary: This research paper presents a comprehensive study of the patterns of conflicts between humans and Asiatic black bears (Ursus thibetanus) in the Guthichaur rural municipality, Jumla, Nepal. Through semi-structured interviews with villagers, focus group discussions, and key informant interviews, this study explores the extent of crop damage, livestock depredation, and human injuries caused by black bears from 2009 to 2019. It was found that crop damage was the most significant form of conflict, followed by livestock depredation and human casualties. This study identifies anthropogenic activities, such as human encroachment into bear habitats and agricultural practices near forests, as primary drivers of these conflicts. Importantly, this research proposes measures to mitigate these conflicts, including initiating compensation schemes for losses, establishing electric fences for crop protection, and launching educational programs. These recommendations, rooted in local practices and conservation efforts, show promise for managing conflicts in regions facing similar challenges with black bears. This paper fills a critical gap in understanding the dynamics of human–bear conflicts in Nepal, contributing valuable insights into wildlife management and conservation strategies. Its findings are significant for researchers, policymakers, and conservationists aiming to develop sustainable solutions for human–wildlife coexistence. Our study assessed patterns of Asiatic black bear (Ursus thibetanus)–human conflicts within the Guthichaur rural municipality, Jumla, Nepal. Through semi-structured interviews with villagers, focus group discussions (FGDs), and key informant interviews (KIIs), we gathered black bear–human conflict information from 2009 to 2019. We identified three primary types of black bear–human interactions: crop damage, livestock depredation, and human injuries. Of these, crop damage (77.03%) emerged as the most prevalent issue. Notably, peak occurrences were observed during autumn (September–October) typically between 9 PM and 3 AM. Livestock depredations were more frequent during nighttime in April–August, with cows/ox (70.12%) being the most depredated animal. Our data also revealed five recorded cases of black bear attacks on humans, which transpired from September to October, primarily in farmland areas in varying years. Despite a prevailing negative perception of bears, a notable level of support exists for their conservation efforts among local communities. Furthermore, these conflicts could be mitigated by reinforcing indigenous crop protection methods and implementing targeted mitigation strategies, as observed in other regions with successful black bear–human interaction management. [ABSTRACT FROM AUTHOR]

Estimating species distribution and abundance is foundational to effective management and conservation. Using an integrated species distribution model that combines presence‐only data from various sources with detection/non‐detection data from structured surveys, we estimated the distribution and expected abundance of three difficult‐to‐monitor mammals of management concern across New York State, namely, coyotes (Canis latrans), bobcats (Lynx rufus) and black bears (Ursus americanus). Three distinct landscape‐scale camera trap surveys provided detection/non‐detection data over 9 years between 2013 and 2021, and we augmented those data with incidental records of our focal species from public repositories. We used an inhomogeneous Poisson point process to construct an integrated model that fit both data types simultaneously. We demonstrate a simple application of spatial point density of all species records in the accessed public databases to inform the thinning process to account for unknown spatial sampling in the presence‐only data, often referred to as the ‘magic covariate’. Using this approach, we examine habitat associations and provide spatially explicit estimates in expected abundance across the entirety of New York State for all three focal species. As expected, coyotes were the most widely distributed and abundant species, with a strong positive association with agricultural land uses. Bobcats exhibited low expected abundance throughout the state and showed positive associations with deciduous forest and forest edge, and a negative association with road density. Finally, we observed considerable spatial variation in abundance of black bears with expected abundance increasing in association with various forest cover and composition covariates and decreasing with crop cover. We present insights into habitat associations and spatial variation in abundance, and provide management implications for each of the species of interest. Synthesis and applications. Our integrated modelling method allows for managers to use citizen sightings combined with detection/non‐detection surveys to estimate robust indices of abundance for both high‐ and low‐density, and wide‐spread versus patchily distributed species. Through comparison with previous studies, we highlight how broad‐scale programmes, such as the statewide efforts to estimate species distributions undertaken here, can benefit substantively from integrated models that leverage additional data (here, incidental records) from a larger region of space, and thus capture more landscape heterogeneity than is plausible within formalized surveys alone. [ABSTRACT FROM AUTHOR]

Rehabilitation and release back to the wild of orphaned American black bear (Ursus americanus) cubs is a wildlife management option used across North America. We reviewed the literature and surveyed wildlife managers and biologists within North America from August 2022 through March 2023 to gather information on their policies and practices regarding rehabilitation and release of orphaned black bear cubs. We define cubs as bears <1 year old but note that most releases happen when the animals are yearlings, typically 12–18 months of age. The literature suggests that when rehabilitation follows science-based protocols, it is a feasible management option, and rehabilitated cubs may survive at rates similar to those of their wild counterparts, die of similar causes, and generally have low rates of conflicts with humans. Repeatedly mentioned within both the literature and survey results was the importance of minimizing human contact and selecting appropriate release sites that consider habitat, food availability, proximity to humans, and the age structure, genetics, and density of black bears in the release area. We received 99 responses from 63 different jurisdictions. Rehabilitation of orphaned black bear cubs was allowed in 72.5% of surveyed jurisdictions with a breeding black bear population. In 82.3% of jurisdictions, a government agency was responsible for selecting release sites. The most common causes identified by our survey for cubs being orphaned were vehicle collisions (50 of 63 responses) and removal of mothers because of conflict behavior (35 of 63 responses). Almost all (96.9%) jurisdictions required rehabilitation centers to be licensed. On average, over the past 5 years (2018–2022), most (70.8%) jurisdictions rehabilitated <25 orphaned cubs. Lack of reliable and suitable rehabilitation centers following strict, science-based protocols was a frequently mentioned challenge, as was managing public perceptions and expectations. Despite these challenges, most (61%) survey respondents said rehabilitation of orphaned black bear cubs was either somewhat or very successful. [ABSTRACT FROM AUTHOR]

Although sleeping is essential for animals, little is known about the characteristics of Asiatic black bear (Ursus thibetanus) bed sites (resting sites). We studied bed-site selection of Asiatic black bears in the Central Alps, Japan, 2021–2022, by monitoring 12 GPS-collared bears and examining 56 bed sites. We assessed horizontal visibility, canopy openness, and dominant vegetation at both bed and control sites, accounting for season and time of day. Findings suggest bears prefer bed sites at the base of thick trees, such as Japanese red pines (Pinus densiflora) and Japanese larches (Larix kaempferi). Bed sites with low visibility were chosen during spring or autumn, corresponding with higher human activity, but not in summer. Proximity to foods, particularly in broad-leaved forests with abundant food such as buds, leaves, and acorn seeds, may influence bed-site selection during spring or autumn. Both sexes showed similar trends. This implies the interplay of safety and food access in Asiatic black bear bed-site selection. [ABSTRACT FROM AUTHOR]

In 2001 and 2002, 52 elk (Cervus canadensis; 21 males, 31 females), originally obtained from Elk Island National Park, Alberta, Canada, were transported and released into Cataloochee Valley in the northeastern portion of Great Smoky Mountains National Park (GRSM, Park), North Carolina, USA. The annual population growth rate (λ) was negative (0.996, 95% CI = 0.945–1.047) and predation by black bears (Ursus americanus) on elk calves was identified as an important determinant of population growth. From 2006 to 2008, 49 bears from the primary elk calving area (i.e., Cataloochee Valley) were trapped and translocated about 70 km to the southwestern portion of the Park just prior to elk calving. Per capita recruitment (i.e., the number of calves produced per adult female that survive to 1 year of age) increased from 0.306 prior to bear translocation (2001–2005) to 0.544 during years when bears were translocated (2006–2008) and λ increased to 1.118 (95% CI = 1.096–1.140). Our objective was to determine whether per capita calf recruitment rates after bear removal (2009–2019) at Cataloochee were similar to the higher rates estimated during bear removal (i.e., long‐term response) or if they returned to rates before bear removal (i.e., short‐term response), and how those rates compared with recruitment from portions of our study area where bears were not relocated. We documented 419 potential elk calving events and monitored 129 yearling and adult elk from 2001 to 2019. Known‐fate models based on radio‐telemetry and observational data supported calf recruitment returning to pre‐2006 levels at Cataloochee (short‐term response); recruitment of Cataloochee elk before and after bear relocation was lower (0.184) than during bear relocation (0.492). Recruitment rates of elk outside the removal area during the bear relocation period (0.478) were similar to before and after rates (0.420). In the Cataloochee Valley, cause‐specific annual calf mortality rates due to predation by bears were 0.319 before, 0.120 during, and 0.306 after bear relocation. In contrast, the cause‐specific annual mortality rate of calves in areas where bears were not relocated was 0.033 after the bear relocation period, with no bear predation on calves before or during bear relocation. The mean annual population growth rate for all monitored elk was 1.062 (95% CI = 0.979–1.140) after bear relocation based on the recruitment and survival data. Even though the effects of bear removal were temporary, the relocations were effective in achieving a short‐term increase in elk recruitment, which was important for the reintroduction program given that the elk population was small and vulnerable to extirpation. [ABSTRACT FROM AUTHOR]

Robust tick surveillance enhances diagnosis and prevention of tick-borne pathogens, yet surveillance efforts in the United States are highly uneven, resulting in large surveillance vacuums, one of which spans the state of New Mexico. As part of a larger effort to fill this vacuum, we conducted both active and passive tick sampling in New Mexico, focusing on the southern portion of the state. We conducted active tick sampling using dragging and CO₂ trapping at 45 sites across Hidalgo, Doña Ana, Otero, and Eddy counties between June 2021 to May 2022. Sampling occurred intermittently, with at least one sampling event each month from June to October 2021, pausing in winter and resuming in March through May 2022. We also conducted opportunistic, passive tick sampling in 2021 and 2022 from animals harvested by hunters or captured or collected by researchers and animals housed in animal hospitals, shelters, and farms. All pools of ticks were screened for Rickettsia rickettsii, Rickettsia parkeri, Rickettsia amblyommatis, Ehrlichia ewingii, and Ehrlichia chaffeensis. Active sampling yielded no ticks. Passive sampling yielded 497 ticks comprising Carios kelleyi from pallid bats, Rhipicephalus sanguineus from dogs, mule deer, and Rocky Mountain elk, Otobius megnini from dogs, cats, horses, and Coues deer, Dermacentor parumapertus from dogs and black-tailed jackrabbits, Dermacentor albipictus from domesticated cats, mule deer and Rocky Mountain elk, and Dermacentor spp. from American black bear, Rocky Mountain elk, and mule deer. One pool of D. parumapterus from a black-tailed jackrabbit in Luna County tested positive for R. parkeri, an agent of spotted fever rickettsiosis. Additionally, a spotted fever group Rickettsia was detected in 6 of 7 C. kelleyi pools. Two ticks showed morphological abnormalities; however, these samples did not test positive for any of the target pathogens, and the cause of the abnormalities is unknown. Passive surveillance yielded five identified species of ticks from three domestic and six wild mammal species. Our findings update tick distributions and inform the public, medical, and veterinary communities of the potential tick-borne pathogens present in southern New Mexico. [ABSTRACT FROM AUTHOR]

Conflict between humans and black bears (Ursus americanus) occurs throughout North America with increasing public demand to replace lethal management with non-lethal methods, such as aversive conditioning (AC). AC aims to teach animals to associate negative stimuli with humans or their infrastructure. We sought to test the efficacy of AC using radio-collared black bears in Whistler, British Columbia, by monitoring individuals and assigning those in conflict with people to control or treatment groups. We measured wariness using overt reaction distance, displacement distance, and reaction to researchers before, during and after executing 3–5-day AC programs that consisted of launching projectiles at bears in the treatment group. We also assessed predictors of successful AC events (i.e., leaving at a run), changes in bear use of human-dominated habitat during the day and at night, and the effects of including a sound stimulus to signal the beginning and end of AC events. Among treated bears, overt reaction distance increased by 46.5% and displacement distance increased by 69.0% following AC programs, whereas both overt reaction distance and displacement distance decreased over time among control group bears. Each additional AC event during the previous 30 days increased likelihood of bear departure in response to researcher presence by 4.5%. The success of AC events varied among individuals, declined with distance to cover, and increased with exposure to previous AC events. Projectiles launched from guns were slightly more effective at causing bears to displace compared to those launched from slingshots, and sound stimuli decreased the likelihood of a successful AC event. AC did not alter diurnal use by bears of human-dominated habitat. Our results suggest that AC effectively increases short-term wariness in black bears but does not alter bear use of human-dominated spaces, highlighting the importance of proactive attractant management and prevention of food conditioning. [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]

Having reproducible and transparent science‐based processes in wildlife management ensures the integrity of decision making. These processes are particularly important when establishing harvest frameworks, as guiding information in the peer‐reviewed literature is limited. We provide an example using multiple data sets, whose products guided aspects of the development of a harvest framework for a population of recolonizing American black bears (Ursus americanus) in Missouri, USA. To characterize the spatial distribution of harvest, we used 10 years (2010–2019) of black bear global positioning system (GPS) location data and 30 years (1991–2020) of sightings data to assess spatial vulnerability to harvest as the intersection among information on bear occurrence, bear sightings, and hunter land‐use tendencies (i.e., the avoidance of steep slopes, large distances from roads). We then used the spatial vulnerability assessment, information on the distribution of public and private lands, and easily discernable boundaries (i.e., major highways, rivers) to suggest boundaries for bear management zones. Additionally, to identify the timing of harvest that would limit female harvest bias, we assessed the temporal vulnerability of harvest using sex‐based changes in average daily step lengths and monthly utilization distribution sizes during fall. Black bear occurrence and sighting propensity was greater in southwestern Missouri, and potential hunter land use appeared pervasive across the landscape given the lack of landscape features that would disincentivize use. Given the influence of black bear occurrence and sighting propensity, spatial harvest vulnerability diminished from southern and southeastern to central portions of Missouri, with areas north of the Missouri River not a part of the established black bear range. We consequently divided areas south of the Missouri River into 3 black bear management zones: a small southwestern zone with primarily private lands and high harvest vulnerability, a southeastern zone that encompassed considerable public lands and moderate amounts of vulnerability, and a central zone that was composed mainly of areas of low vulnerability. Temporally, males did not exhibit movement‐based changes, but females became less active after the first week of October and used 63.9% less area through fall. Based on movements rates of males and females, a hunting season after the first week of October could reduce the likelihood of females being harvested. Harvests from the black bear harvest season in 2021 suggest that the proportion of bears harvested in each zone was similar in distribution to the proportion of permits allocated across zones with no harvest sex bias, which was aligned with agency goals. Animal movement and space use data products can guide harvest framework decision‐making. [ABSTRACT FROM AUTHOR]

The long‐term effects of intensive forest harvest on sensitive demographic stages of the American black bear (Ursus americanus) have been often overlooked. Much of Maine, USA, is covered in forests that are hospitable to bears and commercial timber harvest. To investigate the potential effects of differing intensities of disturbance on black bears, and on females with cubs particularly, we designed a large‐scale natural experiment with 197 motion‐sensitive camera sites dispersed over representative forest stands in northern and central Maine. Using multi‐state occupancy models, we distinguished the overall trends in space use by females with young versus adult bears without young. Forest disturbance at large spatial scales was positively associated with the probability of use for both demographic groups and the availability of hardwood trees was an additional important factor for habitat use by females with young. Our study illustrates the use of motion‐sensitive cameras to monitor and understand habitat use by distinct life‐history stages of animals living in human‐modified landscapes, and results indicate that managers can maintain black bear habitat in areas of active forest harvest by ensuring the availability of hardwood species. [ABSTRACT FROM AUTHOR]

The quality and availability of resources are known to influence spatial patterns of animal density. In Yellowstone National Park, relationships between the availability of resources and the distribution of grizzly bears (Ursus arctos) have been explored but have yet to be examined in American black bears (Ursus americanus). We conducted non‐invasive genetic sampling during 2017–2018 (mid‐May to mid‐July) and applied spatially explicit capture‐recapture models to estimate density of black bears and examine associations with landscape features. In both years, density estimates were higher in forested vegetation communities, which provide food resources and thermal and security cover preferred by black bears, compared with non‐forested areas. In 2017, density also varied by sex, with female densities being higher than males. Based on our estimates, the northern range of Yellowstone National Park supports one of the highest densities of black bears (20 black bears/100 km2) in the northern Rocky Mountains (6–12 black bears/100 km2 in other regions). Given these high densities, black bears could influence other wildlife populations more than previously thought, such as through displacement of sympatric predators from kills. Our study provides the first spatially explicit estimates of density for black bears within an ecosystem that contains the majority of North America's large mammal species. Our density estimates provide a baseline that can be used for future research and management decisions of black bears, including efforts to reduce human–bear conflicts. [ABSTRACT FROM AUTHOR]

The range of the Asiatic black bear (Ursus thibetanus) extends in its western limits to southeastern Iran where the species lives in arid mountainous landscapes in low densities. A better understanding of the adaptations of this threatened subspecies, the Baluchistan black bear (U. t. gedrosianus), to these harsh environmental conditions is necessary to devise conservation action. Here, we investigated the use and characteristics of Asiatic black bear dens in Hormozgan Province, one of the critical components of its life cycle. We detected 12 dens in caves and monitored them from 2012 to 2021 using camera traps (1,972 trap-nights). We obtained 138 bear detections, together with detections of 8 other wildlife species, in 12 dens. Our findings show that bears use dens as heat and probably anthropogenic refugia. Given the importance of dens for the Asiatic black bear, we suggest protecting these areas from human disturbances and expanding efforts to other areas with bear dens. [ABSTRACT FROM AUTHOR]

Global emergence of ciprofloxacin‐resistant ST198 Salmonella Kentucky poses an important public health threat. While conducting Salmonella surveillance among wildlife patients admitted to our veterinary medical teaching hospital in central New York, we isolated multidrug‐resistant (MDR) ST198 Salmonella Kentucky from an American black bear (Ursus americanus) in September 2020. The isolate was phenotypically resistant to numerous antimicrobial agents, including ceftriaxone and ciprofloxacin, and several antimicrobial resistance genes and mutational resistance determinants were detected. Between April and July 2021, the same strain of MDR ST198 Salmonella Kentucky was also isolated from seven other wildlife patients and multiple hospital environmental locations, suggesting nosocomial transmission. Ciprofloxacin resistance is conferred by triple point mutations in the quinolone resistance‐determining regions (QRDRs), a genotypic profile indicative of Clade ST198.2. To our knowledge, this is the first report of this ciprofloxacin‐resistant clade being identified in animals or animal products in the United States. Timely resolution of the outbreak was achieved following efforts to further enhance environmental disinfection protocols and biosecurity measures at the hospital, with no known cases or positive environmental samples after July 2021. [ABSTRACT FROM AUTHOR]

Previous studies have documented natural infections of SARS-CoV-2 in various domestic and wild animals. More recently, studies have been published noting the susceptibility of members of the Cervidae family, and infections in both wild and captive cervid populations. In this study, we investigated the presence of SARS-CoV-2 in mammalian wildlife within the state of Vermont. 739 nasal or throat samples were collected from wildlife throughout the state during the 2021 and 2022 harvest season. Data was collected from red and gray foxes (Vulpes vulples and Urocyon cineroargentus, respectively), fishers (Martes pennati), river otters (Lutra canadensis), coyotes (Canis lantrans), bobcats (Lynx rufus rufus), black bears (Ursus americanus), and white-tailed deer (Odocoileus virginianus). Samples were tested for the presence of SARS-CoV-2 via quantitative RT-qPCR using the CDC N1/N2 primer set and/or the WHO-E gene primer set. Surprisingly, we initially detected a number of N1 and/or N2 positive samples with high cycle threshold values, though after conducting environmental swabbing of the laboratory and verifying with a second independent primer set (WHO-E) and PCR without reverse transcriptase, we showed that these were false positives due to plasmid contamination from a construct expressing the N gene in the general laboratory environment. Our final results indicate that no sampled wildlife were positive for SARS-CoV-2 RNA, and highlight the importance of physically separate locations for the processing of samples for surveillance and experiments that require the use of plasmid DNA containing the target RNA sequence. These negative findings are surprising, given that most published North America studies have found SARS-CoV-2 within their deer populations. The absence of SARS-CoV-2 RNA in populations sampled here may provide insights in to the various environmental and anthropogenic factors that reduce spillover and spread in North American's wildlife populations. [ABSTRACT FROM AUTHOR]

Listeria monocytogenes is a facultative intracellular foodborne pathogen and the causative agent of the severe disease listeriosis. It is found ubiquitously in the environment and exhibits innate resistance to certain antimicrobials, but acquired antimicrobial resistance remains relatively uncommon. Given the potentially dire health outcomes associated with listeriosis, acquisition of antimicrobial resistance (AMR) by this pathogen is of considerable public health concern. AMR in L. monocytogenes has been surveyed frequently in strains of clinical and food origin, but much less commonly in wildlife. We analyzed 158 strains of L. monocytogenes and 27 of non-pathogenic Listeria spp. isolated from wild black bears (Ursus americanus) for resistance to a panel of antimicrobials. AMR was uncommon and noted mostly for tetracycline. Tetracycline resistance was more common in Listeria innocua than in L. monocytogenes. All tetracycline-resistant L. monocytogenes strains belonged to sequence type ST1039 and harbored the Tn916-like tet(M) transposon Tn916.1039 in a conserved chromosomal location. In contrast, three different tetracycline resistance elements, i.e., the tet(M) elements Tn5801.UAM and Tn5801.551 and the tet(S) element Tn6000.205, were ident ified among tetracycline-resistant strains of L. innocua. The greater prevalence and diversity of tetracycline resistance elements among bear-derived non-pathogenic Listeria strains suggest the potential of the latter to serve as reservoirs for retention and dive rsification of AMR determinants in this wildlife host and warrant their further monitoring and study. IMPORTANCE Listeria monocytogenes causes severe foodborne illness and is the only human pathogen in the genus Listeria. Previous surveys of AMR in Listeria focused on clinical sources and food or food processing environments, with AMR in strains from wildlife and other natural ecosystems remaining under-explored. We analyzed 185 sequenced strains from wild black bears (Ursus americanus) from the United States, including 158 and 27 L. monocytogenes and L. innocua, respectively. Tetracycline resistance was the most prevalent resistance trait. In L. monocytogenes, it was encountered exclusively in serotype 4b strains with the novel Tn916-like element Tn916.1039. In contrast, three distinct, novel tetracycline resistance elements (Tn5801.UAM, Tn5801.551, and Tn6000.205) were identified in L. innocua. Interestingly, Tn5801.551 was identical to elements in L. monocytogenes from a major foodborne outbreak in the United States in 2011. The findings suggest the importance of wildlife and non-pathogenic Listeria species as reservoir for resistance elements in Listeria. [ABSTRACT FROM AUTHOR]

Investigating spatial patterns of animal occupancy and reproduction in peripheral populations can provide insight into factors that form species range boundaries. Following historical extirpation, American black bears (Ursus americanus) recolonized the western Great Basin in Nevada from the Sierra Nevada during the late 1900s. This range expansion, however, has not continued further into the Great Basin despite the presence of additional habitat. We aimed to quantify whether reduced reproduction toward the range edge contributes to this range boundary. We analyzed black bear detections from 100 camera traps deployed across black bear distribution in western Nevada using a multistate occupancy model that quantified the probability of occupancy and reproduction (i.e., female bears with cubs occupancy) in relation to changes in habitat type and habitat amount toward the range boundary. We detected a strong effect of habitat amount and habitat type on the probability of black bear occupancy and reproduction. At similar levels of landscape‐scale habitat amount (e.g., 50%), estimated probability of occupancy for adult bears in piñon‐juniper woodlands near the range boundary was 0.39, compared to ~1.0 in Sierra Nevada mixed‐conifer forest (i.e., core habitat). Furthermore, estimated probability of cub occupancy, conditional on adult bear occupancy, in landscapes with 50% habitat was 0.32 in Great Basin piñon‐juniper woodlands, compared to 0.92 in Sierra Nevada mixed‐conifer forest. Black bear range in the western Great Basin conforms to the center–periphery hypothesis, with piñon‐juniper woodland at the range edge supporting ecologically marginal habitat for the species compared to habitat in the Sierra Nevada. Further geographic expansion of black bears in the Great Basin may be limited by lower occupancy of reproducing females in piñon‐juniper woodland. Center–periphery range dynamics may be common in large carnivore species, as their dispersal ability allows them to colonize low‐quality habitat near range edges. [ABSTRACT FROM AUTHOR]

Variance in reproductive success (sk2, with k = number of offspring) plays a large role in determining the rate of genetic drift and the scope within which selection acts. Various frameworks have been proposed to parse factors that contribute to sk2, but none has focused on age‐specific values of ϕ=sk2/k¯, which indicate the degree to which reproductive skew is overdispersed (compared to the random Poisson expectation) among individuals of the same age and sex. Instead, within‐age effects are generally lumped with residual variance and treated as "noise." Here, an ANOVA sums‐of‐squares framework is used to partition variance in annual and lifetime reproductive success into between‐group and within‐group components. For annual reproduction, the between‐age effect depends on age‐specific fecundity (bx), but relatively few empirical data are available on the within‐age effect, which depends on ϕx. By defining groups by age‐at‐death rather than age, the same ANOVA framework can be used to partition variance in lifetime reproductive success (LRS) into between‐group and within‐group components. Analytical methods are used to develop null‐model expectations for random contributions to within‐group and between‐group components. For analysis of LRS, random variation in longevity appears as part of the between‐group variance, and effects (if any) of skip breeding and persistent individual differences contribute to the within‐group variance. Simulations are used to show that the methods for variance partitioning are asymptotically unbiased. Practical application is illustrated with empirical data for annual reproduction in American black bears and lifetime reproduction in Dutch great tits. Results show that overdispersed within‐age variance (1) dominates annual sk2 in both male and female black bears, (2) is the primary factor that reduces annual effective size to a fraction of the number of adults, and (3) represents most of the opportunity for selection. In contrast, about a quarter of the variance in LRS in great tits can be attributed to random variation in longevity, and most of the rest is due to modest differences in fecundity with age estimated for a single cohort of females. R code is provided that reads generic input files for annual and lifetime reproductive success and allows users to conduct variance partitioning with their own data. [ABSTRACT FROM AUTHOR]

Simple Summary: Lameness scales are useful tools to identify and monitor potentially painful conditions in animals, such as acute bone, tendon, or tissue injuries as well as chronic arthritis. Pain assessment is an integral part of assessing animal welfare, especially in a zoo, aquarium, or sanctuary setting, where residents may acquire injuries or suffer from chronic conditions due to old age. While lameness scales have been developed for domestic animals, none are available for bears. Using existing scales, the Bear Lameness Scale was developed for Asiatic black bears (Ursus thibetanus) housed at their sanctuaries and can be used on other bear species. The scale was tested for reliability within different assessors and shown to be reliable regardless of previous experience working with bears. Having a reliable scale such as this improves the medical care given to bears in captivity, therefore improving their overall welfare. Lameness in animals is a welfare concern as it can be an indicator of pain. A standardized bear lameness scale would significantly improve the ability of facilities that house bears to monitor, manage, and treat lameness in their animals. The Animals Asia bear rescue center in Vietnam holds over 180 rescued bears with varying health and mobility conditions as a result of the illegal bear bile trade, and a reliable lameness assessment system was needed. Bear locomotion includes a lumbering gait, which differs from domestic animal locomotion, necessitating the modification of domestic animal lameness scales, and a five-point lameness scale was developed. Professionals from various veterinary-related backgrounds scored bear lameness videos to assess interobserver reliability and the intraclass correlation coefficient indicated good to excellent reliability. A 15-min training video with examples of lameness and grades was provided before assessment. The lameness scale developed herein addresses the lack of a published lameness scale for bears, and, due to the similar locomotion of the genus, can be used on any bear species. This scale is a consistent and reliable tool for evaluating and documenting lameness in addition to monitoring response to treatment. It will benefit bear welfare by indirectly characterizing the level of pain a bear is experiencing due to lameness as well as serving to document trends in pain status. [ABSTRACT FROM AUTHOR]

Understanding tolerance for wildlife requires accounting for the multiple cognitive antecedents of this concept and its contextual factors. We examined whether direct experience was associated with four antecedent dimensions of tolerance for black bears (antipathy, connection, lethal control [damage], lethal control [danger to self, pets, and economics]), both directly and indirectly via risk perception, self-assessed knowledge, and factual knowledge. We collected data using intercept surveys at trailheads in western Oregon, United States (n = 210). Risk perception was most strongly related to antipathy (cost-related beliefs) and connection (benefit-related beliefs) toward black bears. Self-assessed knowledge was most strongly associated with an individual's assessment that bears are a nuisance (lethal control [damage] and a safety concern [danger to self, pets, and economics]). Direct experience was related to all four antecedents, whereas factual knowledge was not related to any dimension. Identifying drivers of tolerance can inform actionable recommendations that promote tolerance for wildlife. [ABSTRACT FROM AUTHOR]

Ungulate neonates—individuals less than four weeks old—typically experience the greatest predation rates, and variation in their survival can influence ungulate population dynamics. Typical methods to measure neonate survival involve capture and radio-tracking of adults and neonates to discover mortality events. This type of fieldwork is invasive and expensive, can bias results if it leads to neonate abandonment, and may still have high uncertainty about the predator species involved. Here we explore the potential for a non-invasive approach to estimate an index for neonate survival using camera traps paired with decoys that mimic white-tailed deer (Odocoileus virginianus) neonates in the first month of life. We monitored sites with camera traps for two weeks before and after the placement of the neonate decoy and urine scent lure. Predator response to the decoy was classified into three categories: did not approach, approached within 2.5 m but did not touch the decoy, or physically touched the decoy; when conducting survival analyses, we considered these second two categories as dead neonates. The majority (76.3%) of the predators approached the decoy, with 51.1% initiating physical contact. Decoy probability of survival was 0.31 (95% CI = 0.22, 0.35) for a 30-day period. Decoys within the geographic range of American black bear (Ursus americanus) were primarily (75%) attacked by bears. Overall, neonate survival probability decreased as predator abundance increased. The camera-decoy protocol required about ½ the effort and 1/3 the budget of traditional capture-track approaches. We conclude that the camera-decoy approach is a cost-effective method to estimate a neonate survival probability index based on depredation probability and identify which predators are most important. [ABSTRACT FROM AUTHOR]

During a 6.5-year camera-trap study in Big Bend Ranch State Park (situated in the Trans-Pecos region of West Texas), we documented a persistent breeding population of American black bears (Ursus americanus) in the Solitario region of the park. The habitat in the Solitario, which is an isolated, eroded remnant of volcanic activity, is low-elevation Chihuahuan Desert scrub but includes significant and complex localized topography and prolonged water sources in the form of tinajas. From January 2016 to May 2022, camera traps captured 367,301 photographs. Of these, 868 contained one or more black bears, resulting in 1010 black bear images. Based on age class, size, color, body markings, facial patterns, presence of cubs, and dates of images, we determined that these images represent a minimum of 17 distinct individuals. Adult and subadult bears were identified during each year, yearlings were detected during 4 years, and cubs were noted during 3 years of the study. Based on these data, the Solitario black bears can be considered the westernmost reproductively viable population of American black bears in Trans-Pecos, Texas, and the only one that is situated exclusively in lowland desert habitat. Dietary resources of black bears from other Chihuahuan Desert localities in Texas and northern Mexico are also found in the current study area. This American black bear population is in an area spatially separated from other black bear populations in the region, and we discuss its relevance to the sky island metapopulation hypothesis of recolonization previously proposed for the species in northern Mexico and Trans-Pecos Texas. [ABSTRACT FROM AUTHOR]

Bear management in New Jersey is controversial. The Division of Fish and Wildlife's policies have not reassured factions who oppose their tools, namely hunting, despite being informed by science. This study applies qualitative content analysis to 43 policy documents to understand how actors pursue policy objectives, and how they are shaped. I find that actors pursue their policy objectives by making hybrid arguments that, in addition to science, involve history, values, and institutional power. Thus, they make scientific claims—or claims to what the science might mean—that are incompatible with each other. This study identifies four ways in which this occurs: science gets framed, science gets applied to certain ends, science gets weaponized, and science gets minimized. Comprehending the ways in which these factors supplement and frame science could reduce conflict, improve communication, and build consensus. [ABSTRACT FROM AUTHOR]

Wholly Eurasian highly pathogenic avian influenza H5N1 clade 2.3.4.4b virus was isolated from 2 free-ranging black bears with meningoencephalitis in Que-bec, Canada. We found that isolates from both animals had the D701N mutation in the polymerase basic 2 gene, previously known to promote adaptation of H5N1 viruses to mammal hosts. [ABSTRACT FROM AUTHOR]

Previous studies have documented natural infections of SARS-CoV-2 in various domestic and wild animals. More recently, studies have been published noting the susceptibility of members of the Cervidae family, and infections in both wild and captive cervid populations. In this study, we investigated the presence of SARS-CoV-2 in mammalian wildlife within the state of Vermont. 739 nasal or throat samples were collected from wildlife throughout the state during the 2021 and 2022 harvest season. Data was collected from red and gray foxes (Vulpes vulples and Urocyon cineroargentus, respectively), fishers (Martes pennati), river otters (Lutra canadensis), coyotes (Canis lantrans), bobcats (Lynx rufus rufus), black bears (Ursus americanus), and white-tailed deer (Odocoileus virginianus). Samples were tested for the presence of SARS-CoV-2 via quantitative RT-qPCR using the CDC N1/N2 primer set and/or the WHO-E gene primer set. Surprisingly, we initially detected a number of N1 and/or N2 positive samples with high cycle threshold values, though after conducting environmental swabbing of the laboratory and verifying with a second independent primer set (WHO-E) and PCR without reverse transcriptase, we showed that these were false positives due to plasmid contamination from a construct expressing the N gene in the general laboratory environment. Our final results indicate that no sampled wildlife were positive for SARS-CoV-2 RNA, and highlight the importance of physically separate locations for the processing of samples for surveillance and experiments that require the use of plasmid DNA containing the target RNA sequence. These negative findings are surprising, given that most published North America studies have found SARS-CoV-2 within their deer populations. The absence of SARS-CoV-2 RNA in populations sampled here may provide insights in to the various environmental and anthropogenic factors that reduce spillover and spread in North American's wildlife populations. [ABSTRACT FROM AUTHOR]

Tolerance for wildlife can be informed by a person's beliefs, attitudes, norms, or other characteristics. Although theoretical papers emphasize the interrelations of these multiple antecedents of wildlife tolerance, empirical studies have not tested them using a rigorous scale development process. We used psychometrics to characterize the cognitive antecedents of tolerance toward black bears (Ursus americanus). Proposed scale items were tested via web-hosted questionnaire (n = 240) and refined into 29 items representing five antecedent dimensions of tolerance for black bears. We then administered these items to a different sample of recreational trail users in western Oregon (n = 210). Second-order confirmatory factor analysis confirmed a 19-item measure representing four distinct yet related antecedent dimensions of tolerance: antipathy, connection, lethal control (damage), and lethal control (danger to self, pets, and economics). These dimensions help better explain why people may be more or less tolerant toward black bears and, potentially, other wildlife. [ABSTRACT FROM AUTHOR]

Ursus americanus (American Black Bear) and Alligator mississippiensis (American Alligator) are sympatric in areas of Florida. During summer, alligators build nest mounds for eggs on freshwater shores, shallow marshes, and tree islands. Biologists have speculated that bears might prey upon alligator nests because of their opportunistic and generalist diet, though such predation in Florida has not been documented in peer-reviewed literature. Herein, we report 3 photographed events of American Black Bear predation on American Alligator nests in Everglades National Park, Big Cypress National Preserve, and Dinner Island Ranch Wildlife Management Area, FL. During each event, bears dug into alligator nests and consumed egg contents. The predation events varied in duration from 36 minutes to nearly 5 hours. During 1 event, a female bear consumed alligator eggs alongside 2 cubs of the year. Future research might explore the extent and effect of nest predation on American Alligator populations and the benefits to American Black Bears. [ABSTRACT FROM AUTHOR]

Outdoor recreation is widespread, with uncertain effects on wildlife. The human shield hypothesis (HSH) suggests that recreation could have differential effects on predators and prey, with predator avoidance of humans creating a spatial refuge 'shielding' prey from people. The generality of the HSH remains to be tested across larger scales, wherein human shielding may prove generalizable, or diminish with variability in ecological contexts. We combined data from 446 camera traps and 79,279 sampling days across 10 landscapes spanning 15,840 km2 in western Canada. We used hierarchical models to quantify the influence of recreation and landscape disturbance (roads, logging) on ungulate prey (moose, mule deer and elk) and carnivore (wolf, grizzly bear, cougar and black bear) site use. We found limited support for the HSH and strong responses to recreation at local but not larger spatial scales. Only mule deer showed positive but weak landscape‐level responses to recreation. Elk were positively associated with local recreation while moose and mule deer responses were negative, contrary to HSH predictions. Mule deer showed a more complex interaction between recreation and land‐use disturbance, with more negative responses to recreation at lower road density or higher logged areas. Contrary to HSH predictions, carnivores did not avoid recreation and grizzly bear site use was positively associated. We also tested the effects of roads and logging on temporal activity overlap between mule deer and recreation, expecting deer to minimize interaction with humans by partitioning time in areas subject to more habitat disturbance. However, temporal overlap between people and deer increased with road density. Our findings highlight the complex ecological patterns that emerge at macroecological scales. There is a need for expanded monitoring of human and wildlife use of recreation areas, particularly multi‐scale and ‐species approaches to studying the interacting effects of recreation and land‐use change on wildlife. [ABSTRACT FROM AUTHOR]

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]

In the Southern Appalachian region of the United States, harvest data has indicated the occurrence of low deer densities while exposing a trend of declining white-tailed deer (Odocoileus virginianus) populations over the past several decades in northern Georgia. A triumvirate of increasing fawn predator populations reside in the Southern Appalachian Mountains including coyotes (Canis latrans), black bears (Ursus americanus) and bobcats (Lynx rufus). This region is also characterized by a homogenous landscape composed of mature forests and sparse understory vegetation, likely lacking adequate cover to offer fawns refugia from predators. Our objectives were to estimate survival and cause-specific mortality rates of fawns while assessing a possible link between mortality risk, intrinsic fawn characteristics (i.e., birth mass, Julian birth date, sibling status), and landscape features within fawn usage areas. During 2018–2020, we radio-collared 71 fawns within the Chattahoochee National Forest of northern Georgia, USA and monitored survival to 12 weeks of age. We observed low fawn survival (cumulative = 0.157, 95% CI = 0.091–0.273; vaginal implant transmitter = 0.196, 95% CI = 0.096–0.403) with predation as the leading cause of all known mortalities (45 of 55 mortalities; 82%) due primarily to coyotes (n = 22), black bears (n = 12), and bobcats (n = 7). Relationships between landscape features and fawn predation risk were minimal with only one informative covariate. Increasing amounts of early successional land cover within fawn usage areas decreased fawn mortality risk within the first 20 days of life, but elevated mortality risk thereafter. All fawns with any amount of early successional land cover in their usage areas died of predation (n = 13) at various time intervals, suggesting limited areas of potential fawning cover may be targeted by predators. However, fawn predation risk seemed to be high regardless of landscape covariates due to the limited number of surviving fawns. Coyote-caused mortality occurred over a longer period at a consistently higher magnitude than all other forms of mortality, indicating possible delayed prey-switching behavior and coyote predation as an important factor of fawn survival. The low recruitment of fawns influenced by high predation rates and homogenous habitat conditions is likely the cause of deer population declines in the region. [ABSTRACT FROM AUTHOR]

Supplemental food from anthropogenic sources is a source of conflict with humans for many wildlife species. Food-seeking behaviours by black bears Ursus americanus and brown bears Ursus arctos can lead to property damage, human injury and mortality of the offending bears. Such conflicts are a well-known conservation management issue wherever people live in bear habitats. In contrast, the use of anthropogenic foods by the polar bear Ursus maritimus is less common historically but is a growing conservation and management issue across the Arctic. Here we present six case studies that illustrate how negative food-related interactions between humans and polar bears can become either chronic or ephemeral and unpredictable. Our examination suggests that attractants are an increasing problem, exacerbated by climate change-driven sea-ice losses that cause increased use of terrestrial habitats by bears. Growing human populations and increased human visitation increase the likelihood of human–polar bear conflict. Efforts to reduce food conditioning in polar bears include attractant management, proactive planning and adequate resources for northern communities to reduce conflicts and improve human safety. Permanent removal of unsecured sources of nutrition, to reduce food conditioning, should begin immediately at the local level as this will help to reduce polar bear mortality. [ABSTRACT FROM AUTHOR]

During the Late Pleistocene, major parts of North America were periodically covered by ice sheets. However, there are still questions about whether ice‐free refugia were present in the Alexander Archipelago along the Southeast (SE) Alaska coast during the last glacial maximum (LGM). Numerous subfossils have been recovered from caves in SE Alaska, including American black (Ursus americanus) and brown (U. arctos) bears, which today are found in the Alexander Archipelago but are genetically distinct from mainland bear populations. Hence, these bear species offer an ideal system to investigate long‐term occupation, potential refugial survival and lineage turnover. Here, we present genetic analyses based on 99 new complete mitochondrial genomes from ancient and modern brown and black bears spanning the last ~45,000 years. Black bears form two SE Alaskan subclades, one preglacial and another postglacial, that diverged >100,000 years ago. All postglacial ancient brown bears are closely related to modern brown bears in the archipelago, while a single preglacial brown bear is found in a distantly related clade. A hiatus in the bear subfossil record around the LGM and the deep split of their pre‐ and postglacial subclades fail to support a hypothesis of continuous occupancy in SE Alaska throughout the LGM for either species. Our results are consistent with an absence of refugia along the SE Alaska coast, but indicate that vegetation quickly expanded after deglaciation, allowing bears to recolonize the area after a short‐lived LGM peak. [ABSTRACT FROM AUTHOR]

Characterizing patterns and drivers of dispersal is fundamental to our understanding of animal ecology and ultimately informing species conservation and management strategies. In this study, we used microsatellite data from 3941 individual black bears Ursus americanus occupying 73 spatially distinct sampling areas across a large heterogeneous landscape to characterize dispersal via gene flow directionality. We fit spatial models to quantified gene flow to test hypotheses regarding drivers of putative dispersal patterns. Specifically, we tested the relative influence of food productivity gradients, bear density, and bear harvest on dispersal. We also evaluated differences in gene flow patterns within and between sexes to assess sex‐biased dispersal. We found evidence suggestive of positive density‐dependent, male‐biased dispersal. Our data show evidence of a relationship between dispersal and broad food productivity gradients. Specifically, male bears displayed preferential dispersal towards mixed deciduous forests with higher food productivity relative to less productive boreal forests. Given the dense sampling scheme across a continuous population, occupying a large heterogeneous landscape, these results provide key insight as to the likely drivers of dispersal patterns in a wide‐ranging mammal. [ABSTRACT FROM AUTHOR]

Conservation biology is a mission‐driven discipline that must navigate a new relationship between conservation and science. Because conservation is a social and political as well as an ecological project, conservation biologists must practice interdisciplinarity and collaboration. In a comparative study of 7 cases (Jaguars in the Chaco, Grevy's zebra in Kenya, Beekeeping in Tanzania, Andean cats in Argentina, Jaguars in Mexico, Lobster fishing, and Black bears in Mexico), we examined motivations for collaboration in conservation, who can collaborate in conservation, and how conservation professionals can work well together. In 5 case studies, successful conservation outcomes were prioritized over livelihood benefits. In the other 2 cases, livelihoods were prioritized. All case studies employed participatory approaches. There were multiple external actors, including local and Indigenous communities, nongovernmental organizations, agencies, regional and national governments, and international organizations, which enhanced conservation and wider sustainability outcomes. Key collaboration aspects considered across the case studies were time (mismatch between relationship building and project schedules), trust required for meaningful partnerships, tools employed, and transformative potential for people, nature, and the discipline of conservation biology. We developed guidelines for successful collaboration, including long‐term commitment, knowledge integration, multiscalar and plural approaches, cultivation of trust, appropriate engagement, evaluation, supporting students, and efforts for transformation. [ABSTRACT FROM AUTHOR]

Wildlife species may shift towards more nocturnal behavior in areas of higher human influence, but it is unclear how consistent this shift might be. We investigated how humans impact large mammal diel activities in a heavily recreated protected area and an adjacent university-managed forest in southwest British Columbia, Canada. We used camera trap detections of humans and wildlife, along with data on land-use infrastructure (e.g., recreation trails and restricted-access roads), in Bayesian regression models to investigate impacts of human disturbance on wildlife nocturnality. We found moderate evidence that black bears (Ursus americanus) were more nocturnal in response to human detections (mean posterior estimate = 0.35, 90% credible interval = 0.04 to 0.65), but no other clear relationships between wildlife nocturnality and human detections. However, we found evidence that coyotes (Canis latrans) (estimates = 0.81, 95% CI = 0.46 to 1.17) were more nocturnal and snowshoe hares (Lepus americanus) (estimate = -0.87, 95% CI = -1.29 to -0.46) were less nocturnal in areas of higher trail density. We also found that coyotes (estimate = -0.87, 95% CI = -1.29 to -0.46) and cougars (Puma concolor) (estimate = -1.14, 90% CI = -2.16 to -0.12) were less nocturnal in areas of greater road density. Furthermore, coyotes, black-tailed deer (Odocoileus hemionus), and snowshoe hares were moderately more nocturnal in areas near urban-wildland boundaries (estimates and 90% CIs: coyote = -0.29, -0.55 to -0.04, black-tailed deer = -0.25, -0.45 to -0.04, snowshoe hare = -0.24, -0.46 to -0.01). Our findings imply anthropogenic landscape features may influence medium to large-sized mammal diel activities more than direct human presence. While increased nocturnality may be a promising mechanism for human-wildlife coexistence, shifts in temporal activity can also have negative repercussions for wildlife, warranting further research into the causes and consequences of wildlife responses to increasingly human-dominated landscapes. [ABSTRACT FROM AUTHOR]

Simple Summary: I trained an American black bear in human care to choose different response buttons when presented with an image of either a highly preferred or a less preferred food item. The bear learned to choose the appropriate response button when presented with the preferred food item at above chance levels and differentiated between the use of the buttons appropriately. However, she did not reach a high level of performance with the less preferred food item even after over 1000 trials, suggesting that performing a conditional discrimination on the basis of preferences may be challenging for black bears. However, the work presented here represents the first attempt to train a bear to indicate her relative preferences using something like a Likert scale commonly used with humans to indicate their preferences and could be a valuable welfare tool for animals in human care. Similar work with gorillas suggests that bears are as capable as great apes in learning such tasks and would also benefit from this type of technical enrichment. A preference scale for use by nonhuman animals would allow them to communicate their degree of liking for individual items rather than just relative preferences between pairs of items. It would also allow animals to report liking for images of objects that would be difficult to directly interact with (e.g., potential mates and habitat modifications). Such scales can easily be presented using touchscreen technology. Few zoos have used touchscreen technology for species other than nonhuman primates. I present a description of efforts taken to create such a scale for use with a single zoo-housed American black bear (Ursus americanus). Although the bear did not reach a high level of proficiency with assigning preferred and non-preferred food items to categorical responses of "like" and "dislike," she was able to learn how to use the like and dislike buttons differentially for a single preferred and less preferred food item and she selected the correct response button for the preferred item at above chance levels. These data contribute to our limited understanding of black bear cognition and suggest that conditional discriminations may be difficult for black bears. This finding can inform continued efforts to create a simpler tool for nonhumans to communicate their preferences to human caregivers in a more nuanced way than is currently possible. More generally, the current study contributes to the growing body of work supporting the use of touchscreen technology for providing enrichment to less studied species like bears. [ABSTRACT FROM AUTHOR]

American black bears (Ursus americanus) in Florida have increased in abundance from historically low numbers and currently number >4,000 across 7 subpopulations. Biologists monitor the range of black bears to track their recovery for conservation and management efforts. We estimated geographic range of black bears in Florida for historical (2001–2010) and contemporary (2011–2020) periods using 12 sources of occurrence data collected from wildlife professionals and the public. We reduced data sets by subsampling protocols to account for localized spatiotemporal biases and for possible differences in sampling effort from increases in the human population between modeling periods. We developed models at 2 levels: a generalized boundary (range extent) and a more detailed delineation (occupied range). We developed range extent using a concave hull model and occupied range using kernel density estimation with a corresponding 97.5% isopleth. Between modeling periods, range extent increased by 13.4% and occupied range increased by 11.3%, with both range levels expanding and contracting in certain areas. The ranges indicated improved connectivity among bear subpopulations. We also produced a range map for research, management, and public use built upon contemporary data that partitioned the state into 4 levels representing the relative frequency of bear use (frequent, common, occasional, and rare). Range map levels at the occupied range, and especially frequent use areas, help focus bear research efforts (e.g., placement of hair corrals), management efforts (e.g., assess varying levels of risk to the public of bear conflicts), and conservation efforts (e.g., focusing habitat protection in areas with high use by bears). [ABSTRACT FROM AUTHOR]

In this study, the pattern of myosin heavy chain (MHC) isoforms expression in skeletal muscles of the trunk, forelimb and hindlimb in Polar Bear (PB) Ursus maritimus; American Black Bear (AmBB), Ursus americanus and Asian Black Bear (AsBB), Ursus thibetanus was analysed by immunohistochemistry and SDS‐PAGE. Results showed that slow (MHC‐I) and fast (MHC‐II) isoforms exist in muscles of bears. Type II fibres were classified further into Type IIa and IIx in PB but not in AsBB and AmBB. The distribution of Type I and Type II fibres in the trunk, forelimb and hindlimb varied based on muscle type and animal species. The proportions of Type I fibres formed approximately one‐third of muscle composition in PB (trunk, 32.0%; forelimb, 34.7%; hindlimb, 34.5%) and a half in both AsBB and AmBB whereas Type IIa and IIx formed approximately two‐third in PB (trunk, 68.0%; forelimb, 65.3%; hindlimb, 65.5%) and a half of Type II in both AmBB and AsBB. PB is a good swimmer, lives in Arctic Ocean on slippery ice catching aquatic mammals such as seals and is larger in size compared to the medium sized AmBB (living in forest) and AsBB (arboreal). The results suggest that in bears, there is greater diversity in MHC isoforms II, being expressed in selected fast contracting skeletal muscles in response to variety of environments, weight bearing and locomotion. [ABSTRACT FROM AUTHOR]

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]

Human–wildlife conflict can cause major declines in wildlife populations and pose a threat to human safety and livelihoods. Large carnivores are among the most conflict‐prone species because they range widely, eat human‐associated foods, and can pose a risk to human safety. Legal harvest of carnivores by licensed hunters is an attractive method to attempt to reduce conflict; however, there is mixed evidence for its effectiveness. We leveraged a unique management project in Ontario, Canada in which a new spring American black bear (Ursus americanus) hunting season was implemented in selected wildlife management units in addition to the existing fall season. We examined human–bear interactions and incidents before (2012 and 2013) and after (2014 and 2015) this implementation in treatment and control areas. Further, using data from 2004–2019, we examined the longer‐term patterns of human–bear interactions and incidents before and after this management project when a spring season was implemented throughout the entire province beginning in 2016. Harvest increased significantly upon the implementation of the spring season in selected units, but there was no concomitant reduction in interactions or incidents, and these were higher in areas with the new spring season relative to control areas. Human–bear interactions, incidents, and harvest were strongly related to the availability of natural foods in all analyses. Regulated, presumably sustainable harvest was ineffective at reducing human–bear interactions and incidents in the near‐term and might have increased both. Our results support a long history of research showing that natural food availability is a primary driver of human–wildlife conflict. Programs promoting coexistence between people and wildlife, including education, capacity building, and management of unnatural food sources are likely to be the most successful at reducing conflicts between people and bears. [ABSTRACT FROM AUTHOR]

In the first 2 decades of the twenty‐first century, American black bear (Ursus americanus) populations rebounded with range expansions into areas where the species was previously extirpated. While there are a number of factors that limit range expansion, habitat quality and availability are among the most important. Such factors may be particularly important in western Nevada, USA, at the transition zone of the Sierra Nevada and the Great Basin Desert. We deployed a multi‐faceted data collection system including motion‐sensitive cameras, noninvasive hair sampling and genotyping, and global positioning system (GPS) tracking. We analyzed data using spatial capture‐recapture to estimate population density and dynamic occupancy models to estimate habitat use. Black bear habitat use and density were substantially higher in the Sierra Nevada than the Great Basin Desert and had strong positive relationships with the presence of conifer land cover in the transition zone. The average black bear density was >4 times higher in the mixed‐conifer forests of the Sierra Nevada (12.4 bears/100 km2) than in desert mountain ranges with piñon (Pinus monophylla)‐juniper (Juniperus spp.) woodland (2.7 bears/100 km2). The low‐elevation shrub and grassland portions of the study area had even lower estimated black bear density (0.6 bears/100 km2) and probability of use (0.03, 95% CI = 0.00–0.09). Across these spatially variable configurations in black bear density, we estimated the population size to be 418 individuals (95% CI = 239–740). Declining density towards the range edge, coupled with a relatively stable range of black bears in Nevada observed since 2000, suggests that further species range expansion into the western Great Basin may be limited by habitat quality and availability. [ABSTRACT FROM AUTHOR]

Fragmentation of the boreal forest by linear features, including seismic lines, has destabilized predator–prey dynamics, resulting in the decline of woodland caribou (Rangifer tarandus caribou) populations. Restoration of human‐altered habitat has therefore been identified as a critical management tool for achieving self‐sustaining woodland caribou populations. However, only recently has testing of the response of caribou and other wildlife to restoration activities been conducted. Early work has centered around assessing changes in wildlife use of restored seismic lines. We evaluated whether restoration reduces the movement rates of predators and their associated prey, which is expected to decrease predator hunting efficiency and ultimately reduce caribou mortality. We developed a new method for using cameras to measure fine‐scale movement by measuring speed as animals traveled between cameras in an array. We used our method to quantify speed of caribou, moose (Alces alces), bears (Ursus americanus), and wolves (Canis lupus) on treated (restored) and untreated seismic lines. Restoration treatments reduced travel speeds along seismic lines of wolves by 1.38 km/h, bears by 0.55 km/h, and caribou by 1.57 km/h, but did not reduce moose travel speeds. Reduced predator and caribou speeds on treated seismic lines are predicted to decrease encounter rates between predators and caribou and thus lower caribou kill rates. However, further work is needed to determine whether reduced movement rates result in reduced encounter rates with prey, and ultimately reduced caribou mortality. [ABSTRACT FROM AUTHOR]

The diet of predators can be highly variable, which is exemplified by their ability to acclimate to a wide range of ecological conditions. Such flexibility in foraging may be a key aspect of their performance in unpredictable environments such as at the edge of the range of a species or where food availability varies greatly in time and space. Gaining information on the diets of predators under such conditions could foster our comprehension of their ecological flexibility and the potential role of predation on the population dynamics of prey. We determined the diet of wolves (Canis lupus) and black bears (Ursus americanus) in northern Québec and Labrador (Canada) within the range of two migratory caribou (Rangifer tarandus) herds: the high-abundance Rivière-aux-Feuilles herd (RFH) and low-abundance Rivière-George herd (RGH). Worldwide, decline in caribou populations has become a concern, stressing the need to better understand the factors involved in these declines, including predation. In northern Québec (RFH range), caribou was the primary year-round prey of wolves while moose (Alces alces) and muskoxen (Ovibos moschatus) were consumed in some sectors. The diet of wolves in northern Labrador (RGH range) varied seasonally, with caribou, moose, and fish as main prey during different periods throughout the year. Black bear diets varied seasonally and regionally. Among the foods we analyzed, caribou was the main source of animal protein for bears in northern Québec and northern Labrador, except during a high abundance of Ungava collared lemming (Dicrostonyx hudsonius). Only bears in northern Québec ate caribou during late summer/fall. Our results highlight the diet flexibility of wolves and black bears in northern food webs, and how their diets change in relation to the distribution and abundance of prey. Our results will help quantify the potential impact of these predators on prey populations in northern systems. [ABSTRACT FROM AUTHOR]

Dispersal has important implications for population ecology and genetics of a species through redistribution of individuals. In most mammals, males leave their natal area before they reach sexual maturity, whereas females are commonly philopatric. Here, we investigate the patterns of natal dispersal in the Asian black bear (Ursus thibetanus) based on data from 550 bears (378 males, 172 females) captured or removed in Gunma and Tochigi prefectures on central Honshu Island, Japan in 2003–2018. We used genetic data and parentage analysis to investigate sex-biased differences in the distance of natal dispersal. We further investigated the age of dispersal using spatial autocorrelation analysis, that is, the change in the correlation between genetic and geographic distances in each sex and age group. Our results revealed that male dispersal distances (mean ± SE = 17.4 ± 3.5 km) were significantly farther than female distances (4.8 ± 1.7 km), and the results were not affected by years of mast failures, a prominent forage source for this population. Based on an average adult female home range radius of 1.8 km, 96% of the males and 50% of the females dispersed. In the spatial autocorrelation analysis, the changes in the relationship between genetic and geographic distances were more pronounced in males compared to females. Males seem to mostly disperse at age 3 regardless of mast productivity, and they gradually disperse far from their home range, but young and inexperienced males may return to their natal home range in years with poor food conditions. The results suggest that factors driving the dispersal process seem to be population structure-based instead of forage availability-based. In females, a significant genetic relationship was observed among all individuals in the group with a minimum age of 6 years within a distance of 2 km, which resulted in the formation of matrilineal assemblages. [ABSTRACT FROM AUTHOR]