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Increasing levels of human activity threaten wildlife populations through direct mortality, habitat degradation, and habitat fragmentation. Area closures can improve habitat quality for wildlife, but may be difficult to achieve where tourism or other economic drivers are a priority. Temporal closures that limit human use during specific times of day have potential to increase habitat quality for wildlife, while continuing to provide opportunities for human use. However, the effectiveness of daily temporal closures has not been tested. We assessed how implementation of a temporal road closure affected wildlife movements in Banff National Park. Parks Canada closed a popular 17 km stretch of road between 2000 and 0800 hours to improve habitat quality for wildlife. We assessed the effectiveness of the closure on nine mammal species using three sets of data: remote cameras, road surveys, and grizzly bear (Ursus arctos) GPS data. In all three analyses, wildlife detection rates on the road doubled during the closure while remaining unchanged in reference areas. Our strong and consistent results suggest temporal closures are an important conservation tool that can increase habitat quality for wildlife while minimizing effects on people.

We describe for the first time in the peer-reviewed literature observations of American black bear (Ursus americanus Pallas, 1780), grizzly bear (Ursus arctos Linnaeus, 1758), and polar bear (Ursus maritimus Phipps, 1774) at the same locations. Using remote cameras we documented 401 bear-visits of all three species at three camps in Wapusk National Park, Canada, from 2011–2017. These observations add to a growing body of evidence that grizzlies are undergoing a substantial range increase in northern Canada and the timing of our observations suggests denning locally. Polar and grizzly bears are of conservation concern regionally and internationally, so from the literature we assessed the potential effects on conservation efforts from interactions between these three species. In aggregate, those effects are likely to be positive for grizzlies and weakly negative for black and polar bears; further research is needed. Range overlap of these three species in this dynamic ecotonal region should not be viewed as a threat to any of them, but rather as an ecological response to environmental change that needs to be better understood.

Black huckleberries (Vaccinium membranaceum) provide a critical food resource to many wildlife species, including apex omnivores such as the grizzly bear (Ursus arctos), and play an important socioeconomic role for many communities in western North America, especially indigenous peoples. Remote sensing imagery offers the potential for accurate landscape-level mapping of huckleberries because the shrub changes colour seasonally. We developed two methods, for local and regional scales, to map a shrub species using leaf seasonal colour change from remote sensing imagery. We assessed accuracy with ground-based vegetation surveys. The high-resolution supervised random forest classification from one-meter resolution National Agricultural Imagery Program (NAIP) imagery achieved an overall accuracy of 75.31% (kappa = 0.26). The approach using multi-temporal 30-meter Landsat imagery similarly had an overall accuracy of 79.19% (kappa = .31). We found underprediction error was related to higher forest cover ...

Despite low numbers for the past century, black bear (Ursus americanus) populations in Alabama appear to be growing. There are often strong emotional reaction and public disagreement toward how wil...

Unspoiled wildlands of boreal landscapes provide critical habitats for wildlife. With the increase in resource development across Canada's boreal zone, woodland caribou (Rangifer tarandus caribou) and grizzly bears (Ursus arctos) are at risk of population declines. We used 4 planning scenarios with variants of these in decision-support software Marxan to allocate potential conservation priority areas for caribou and grizzly bears in boreal wildlands of the Muskwa-Kechika Management Area in northeast British Columbia, Canada. For caribou and grizzly bears across their seasonal habitats, priority areas allocated to preserve connectivity of habitat patches maintained more intact high-value habitats, with moderate opportunity cost for resource development, than those allocated under other scenarios. In winter when high-value habitats of caribou tend to coincide with resource-rich areas, priority areas allocated to preserve areas that are more vulnerable to development maintained more intact high-value habitats with higher opportunity cost (therefore greater adverse economic consequences) than those allocated in areas with lower resource potential. In growing-season (non-winter) habitats of caribou and grizzly bears, allocating priority areas toward either more vulnerable or less vulnerable areas did not substantially affect patch and landscape characteristics of conserved habitats. Priority areas intended to avoid predation risk for caribou were not effective in maintaining intact high-value habitats for caribou in these undeveloped wildlands. Conserving connectivity would best maintain most intact habitats for both species across seasons; conserving habitats most vulnerable to development also would discourage future development outside of the conserved areas in winter habitats of caribou. Findings from these conservation planning scenarios have implications globally to other areas where sensitive species are threatened by pending resource developments.

Habitat fragmentation caused by transportation infrastructure is an issue of growing concern worldwide. We show how secondary roads may affect landscape permeability for brown bears (Ursus arctos Linnaeus, 1758). We focused on identifying environmental variables that govern the selection of road-crossing zones by bears (crossing model). We also investigated whether variables that characterize road-crossing zones differ from those that are typical for bear–vehicle collision sites (collision model). The study area was located in north-central Slovakia. To identify road-crossing sites, we used the GPS fixes of 27 bears and identified 35 bear–vehicle collision sites from a different data set. We used mixed-effects logistic regression to model resource selection at road-crossing sites and to compare bear-crossing sites with bear-kill sites. The crossing model showed that the traffic volume with distance to forest and grassland were the most influential factors in bear selection of road-crossing sites. Results of the collision model indicated that successful road crossings by bears were located at different road sections from vehicle collisions, which differed by a traffic volume of 5000 vehicles/24 h. The outcomes of this study can facilitate improved mitigation measures on secondary roads.

Pregnancy-associated glycoproteins (PAGs) are abundant embryo-originated products expressed in the pre-placental trophoblast and, later, in the post-implantational chorionic epithelium of some mammalian species. This paper describes the identification and cellular immunolocalization of the chorionic PAG family in the discoidal-type placenta of the brown bear (Ursus arctos L. - Ua), in which the PAGs were named ‘UaPAG-Ls’. The study used: 1) Western blot for total placental glycoproteins; and 2) cross-species heterologous double fluorescent immunohistochemistry (IHC) for cellular immune-localization of the PAGs. This is the first study reporting the identification and immunolocalization of the UaPAG-L family in placental cells during early pregnancy in the brown bear. Our Western analysis revealed a dominant mature 72 kDa UaPAG-L isoform was expressed in all Ua placentas during early pregnancy. Various other UaPAG-L isoforms (16–66 kDa) were also identified. Using IHC, the UaPAG-L proteins were localized to trophectodermal cells (TRD), where signal intensity resembled intense TRD proliferation within developing placenta. The data increases our general knowledge of PAG proteins localized in discoidal-type placenta during early pregnancy in the brown bear.

The abundance and distribution of large carnivores in Europe have been historically reduced. Their recovery requires multilevel coordination, especially regarding transboundary populations. Here, we apply nuclear and mitochondrial genetic markers to test for admixture level and its impact on population genetic structure of contemporary brown bears (Ursus arctos) from the Eastern, Southern, and Western Carpathians. Carpathian Mountains (Europe). Nearly 400 noninvasive brown bear DNA samples from the Western (Poland) and Eastern Carpathians (Bieszczady Mountains in Poland, Slovakia, Ukraine) were collected. Together with DNA isolates from Slovakia and Romania, they were analyzed using the set of eight microsatellite loci and two mtDNA regions (control region and cytochrome b). A set of 113 individuals with complete genotypes was used to investigate genetic differentiation across national boundaries, genetic structuring within and between populations, and movement between populations. Transboundary brown bear subpopulations (Slovakia and Poland) did not show significant internal genetic structure, and thus were treated as cohesive units. All brown bears from the Western Carpathians carried mitochondrial haplotypes from the Eastern lineage, while the Western lineage prevailed in the brown bears from the Bieszczady Mountains. Despite similar levels of microsatellite variability, we documented significant differentiation among the studied populations for nuclear markers and mtDNA. We also detected male‐biased and asymmetrical movement into the Bieszczady Mountains population from the Western Carpathians. Our findings suggest initial colonization of the Western Carpathians by brown bears possessing mtDNA from the Eastern lineage. Genetic structuring among populations at microsatellite loci could be a result of human‐mediated alterations. Detected asymmetric gene flow suggests ongoing expansion from more abundant populations into the Bieszczady Mountains and thus supports a metapopulation model. The knowledge concerning this complex pattern can be implemented in a joint Carpathian brown bear management plan that should allow population mixing by dispersing males.

Resource waves—spatial variation in resource phenology that extends feeding opportunities for mobile consumers—can affect the behaviour and productivity of recipient populations. Interspecific diversity among Pacific salmon species (Oncorhynchus spp.) creates staggered spawning events across space and time, thereby prolonging availability to terrestrial wildlife.We sought to understand how such variation might influence consumption by terrestrial predators compared with resource abundance and intra‐ and interspecific competition.Using stable isotope analysis, we investigated how the proportion of salmon in the annual diet of male black bears (Ursus americanus; n = 405) varies with species diversity and density of spawning salmon biomass, while also accounting for competition with sympatric black and grizzly bears (U. arctos horribilis), in coastal British Columbia, Canada.We found that the proportion of salmon in the annual diet of black bears was ≈40% higher in the absence of grizzly bears, but detected little effect of relative black bear density and salmon biomass density. Rather, salmon diversity had the largest positive effect on consumption. On average, increasing diversity from one salmon species to ~four (with equal biomass contributions) approximately triples the proportion of salmon in diet.Given the importance of salmon to bear life histories, this work provides early empirical support for how resource waves may increase the productivity of consumers at population and landscape scales. Accordingly, terrestrial wildlife management might consider maintaining not only salmon abundance but also diversity., The species diversity of spawning salmon present in watersheds, not abundance, predicts the proportion of salmon in the annual diet of coastal black bears (Ursus americanus). Additionally, grizzly bear (Ursus arctos) presence reduces salmon consumption by ~40%, no matter the level of salmon diversity available.

The growth and sprawl of the American black bear (Ursus americanus) population have been observed and monitored in the past two decades, especially in south-central Kentucky. To better manage human-black bear interaction and develop informed policy and best practices, the current study sought to 1) understand south-central Kentucky residents’ current knowledge of and previous experience with black bears, 2) investigate residents’ attitudes toward black bears and regulated hunting in wildlife management; and 3) identify residents’ level of acceptance of various black bear related management actions in south-central Kentucky. From February to April 2017, residents of London and Stearns districts (southeastern regions) of the Daniel Boone National Forest, a black bear habitat, were invited to participate in this study. The results from 139 completed surveys showed that residents lacked sufficient knowledge about black bear populations in the region and received minimal information regarding black bear management efforts. In comparison to education efforts and relocation, regulated black bear hunting could be a cost-effective option to promote responsible use of wildlife resources and black bear population control. This study provided lessons and recommendations for black bear management in south-central Kentucky and may be of utilization for any other wildlife conservation areas.

This study presents a new database of dental microwear features for extant bear species, which is used to interpret palaeodiet in brown bear (Ursus arctos) from the late Middle Pleistocene site of Grays Thurrock, U.K. Applying light stereomicroscopy techniques in dental microwear analysis, we highlight, for the first time, that the talonid area of the first lower molar (m1) in extant ursids is most effective in the differentiation of dietary ecospaces. Extant bear species can be separated into different parts of a dietary ecospace revealing microwear features that mirror their dietary preferences. Of particular note is the differentation of ecospaces within modern brown bear populations from different geographical regions and the potential for identifying seasonal variation in diet. The results demonstrate that the diet of thelate Middle Pleistocene brown bear from the interglacial site of Grays Thurrock was closely comparable to that of the modern U. arctos from northern Europe, the American black bear (Ursus americanus), and the sun bear (Helarctos malayanus). This suggests the dietary importance of fibrous food, as well as soft fruits and invertebrates and a small vertebrate component. This finding is in agreement with climatic conditions and habitats inferred for the MIS 9 interglacial. The creation and testing of a dental microwear database for all modern bear species provides a foundation for subsequent application to other extinct Pleistocene bear populations.

Black bear (Ursus americanus) damage to trees in the Pacific Northwest is common, although volume and economic losses are unknown. Common measures to quantify bear damage to conifers at large scales rely solely on aerial estimates of red tree crowns (caused by complete girdling) and broad assumptions about stand characteristics. We surveyed 122 vulnerable stands in the Coast Range and western Cascades of Oregon using both aerial surveys and ground surveys. Then, we modeled 4 damage scenarios (Salvage; Total Loss; Root Disease; and Combined Damage) with the Forest Vegetation Simulator (FVS) growth and yield model and the Fuel Reduction Cost Simulator (FRCS). Damage polygons, digitized in real time from aerial surveys identifying red (dead or dying) tree crowns, overestimated bear damage by approximately 5-fold due to misclassification with root disease, and failed to detect partially peeled trees that contributed to economic loss. Damage polygons assessed from the air generally did not include red crowns, and were a mean distance of 58.8 m (SE = 8.8) from damage polygons’ outer edges to the nearest red crown. We accounted for mortality and volume losses from partially girdled trees that did not show red crowns in our Salvage scenario, whereas we assumed that all bear-peeled trees resulted in complete loss in the Total Loss scenario. At the landscape scale, economic loss was ≤0.35% of net present value under both damage scenarios, while processing bear damage trees (Salvage) was the most efficacious option. At the landscape scale, our worst-case scenario (Total Loss) resulted in an estimated loss of $56/ha to bear damage, 10-fold less than a previously reported estimate of $585/ha. Root disease was a more prevalent damage agent than bear damage but did not affect net present value at harvest. The majority (92%) of bear damage observed in ground surveys was older (>2 yrs) and existed at a low frequency (1.5 bear damaged trees/ha) and severity across the landscape. Our results suggest that black bear damage is not uniformly distributed and that perceived impact varies with spatial scale. On-the-ground monitoring of the status of bear damage across the western Oregon landscape will identify hot spots of severe peeling and provide an understanding of these changes over time.

On the territory of the south-east of Western Siberia (Tomsk Region), the features of the species biology are analyzed: abundance, dendroactivity, biotopic confinement, the device of a dens. Scuffs and scraps of bark left by the bear are marked on fir - 80 % and cedar -20 %. Bears were marked mainly by trees that are in the edge of the forest stand along the fringes, forest roads, winter roads and quarter walkways, animal paths. Traces of bear activity located at a height of 156 cm to 242 cm indicate the manifestation of food, comfortable and marking dendroactivity. The burlogs are confined to hard-to-reach places - forest heaps, cuttings, found in coniferous forests eaten by silkworms, on old garbage. The bergs are located beneath the roots of large trees: birches, cedar, less often under fallen trees, ovaries and fallen trees of cedar, aspen. The exit from the den is mainly directed to the south. The internal dimensions of the den often vary: length from 150 to 350 cm, height - 80-215 cm, width - 130-300 cm. In the litter - grass (33.3 %), moss (21.6 %), leaves (17, 6 %), branches (9.8 %), needles (7.8 %).

Global biodiversity is decreasing rapidly. Parks and protected lands, while designed to conserve wildlife, often cannot provide the habitat protection needed for wide‐ranging animals such as the American black bear (Ursus americanus). Conversely, private lands are often working landscapes (e.g., farming) that have high human footprints relative to protected lands. In southwestern Alberta, road densities are highest on private lands and black bears can be hunted year‐round. On protected lands, road densities are lowest, and hunting is prohibited. On public lands under the jurisdiction of the provincial government (Crown lands), seasonal hunting is permitted. Population estimates are needed to calculate sustainable harvest levels and to monitor population trends. In our study area, there has never been a robust estimate of black bear density and spatial drivers of black bear density are poorly understood. We used non‐invasive genetic sampling and indices of habitat productivity and human disturbance to estimate density and abundance for male and female black bears in 2013 and 2014 using two methods: spatially explicit capture–recapture (SECR) and resource‐selection functions (RSF). Land tenure best explained spatial variation in black bear density. Black bear densities for females and males were highest on parkland and lowest on Crown lands. Sex ratios were female‐biased on private lands, likely a result of lower harvests and movement of females out of areas with high male density. Synthesis and application: Both SECR and RSF methods clearly indicate spatial structuring of black bear density, with a strong influence based on how lands are managed. Land tenure influences the distribution of available foods and risk from humans. We emphasize the need for improved harvest reporting, particularly for non‐licensed hunting on private land, to estimate the extent of black bear harvest mortality.

Among Cetartiodactyla, cetaceans are the only obligate aquatic dwellers. Given morphological similarities between cetacean relatives such as Indohyus (the best represented Eocene raoellid artiodactyl) with other, later artiodactyls, any crown artiodactyl that engages in aquatic behaviors is of interest as an evolutionary model for the adaptations that accompanied the origins of cetaceans. The American moose (Alces alces) is the only non-cetacean artiodactyl to engage in aquatic foraging and, other than Hippopotamus, is distinctive in its diving behaviors. This study surveyed the soft and hard tissue nasal morphology of Alces alces to assess phylogenetic polarity and the presence of adaptations for diving and feeding in fresh water habitats. A fresh dissection of the facial musculature and nasal cavity was performed on one subadult male individual and osteological analyses were also performed on dry crania. This species was analyzed alongside fossil crania of Cervalces (its presumed ancestor), other cervids (e.g., Odocoileus virginianus, the white tail deer; Dama dama, the fallow deer), a bovid (Bos taurus, domestic cattle), and a carnivoran (Ursus americanus, the American black bear). A fresh dissection of the facial musculature and nasal anatomy of one fallow deer specimen was also performed for comparison with the moose. Results indicate that Alces alces exhibited a primitive configuration of maxillolabial muscles and, like Dama, exhibited a series of subcutaneous fibrous tissues connecting these muscles to skin. Alces and Dama, however, both exhibited autapomorphies in the soft tissue anatomy of the external nares. The former possessed a series of muscles that act to constrict the anterior nares, likely during diving. Extremely large fibrofatty pads that were perforated by muscle tendon supported their alar fold. Internally, a double-scrolled maxilloturbinal occupied nearly the entire volume of the anterior nasal cavity and protruded beyond the rim of the piriform aperture in dry crania. Dama had long, thin muscles taking origin on their nasal conchae and inserting onto the alar fold. Yet, despite these anterior nasal autapomorphies, the ethmoturbinal patterns of all observed cervids and the one bovid all appeared primitive with a posteroinferiorly oriented array of ethmoturbinals in close contact with a relatively straight cribriform plate, a macrosmatic condition. These differed from the curved cribriform plate of Ursus whose posterior nasal anatomy appeared hyper-macrosmatic. Indohyus exhibits no skeletal sign of a fleshy proboscis such as an enlarged piriform aperture or shortened nasal bones. Thus, there is little evidence that the early ancestors of cetaceans engaged in prolonged bouts of diving for aquatic foods but more probably were surface swimmers traveling between terrestrial food sources or fleeing predators. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 302:667-692, 2019. © 2018 Wiley Periodicals, Inc.

The Villafranchian ursids of Greece are scanty, represented by a few isolated teeth and bones. During our last field campaigns in the Mygdonia Basin (Macedonia, Greece) we discovered an almost complete cranium, as well as some cranial, dental and postcranial remains, which are presented in this article. The new material originates from the locality Tsiotra Vryssi (TSR), dated to the late Villafranchian (1.8–1.2 Ma). The specimens are described and compared with ursids from various European localities; their morphological characters and dimensions place it with Ursus etruscus Cuvier, 1823, while the dental features are most similar to the specimens from Pietrafitta (Italy). The TSR cranium was CT-scanned in order to create a 3D virtual model and study its internal anatomy. Its observed endocranial traits exhibit primitive conditions, confirming the basal position of U. etruscus among the Pleistocene European ursids. Most of these features are shared with U. arctos and clearly differ from U. deningeri and U. spelaeus. Finally, we provide a revision of the known Greek material of U. etruscus and the biostratigraphic distribution of the Miocene–Pleistocene ursids of Greece. The earliest secure appearance of Ursus etruscus in Greece is found in the locality Dafnero (Western Macedonia), dated to the end of the middle Villafranchian at ~2.0 Ma, whereas its probable last occurrence is known from the locality Apollonia 1 of the Mygdonia Basin, dated to the latest Villafranchian at ~1.2 Ma.

Coexistence between sympatric predators is achieved through a variety of behaviors that reduce competitive interactions. We examined fine-scale co-occurrence between sympatric apex predators across a large and highly variable landscape characterized by anthropogenic presence and related mortality in Idaho, USA. We analyzed data from 201 camera traps across 130,000 km2 to examine spatiotemporal associations between four apex predators: humans (Homo sapiens), wolves (Canis lupus), black bears (Ursus americanus), and cougars (Puma concolor). We hypothesized that the dominant competitors in our system would be associated with reduced detections of subordinate competitors (i.e., humans > wolves > black bears > cougars). Such a hierarchy proved true only when examining spatial associations between humans and wolves. We found a positive spatial association between black bear and cougars, suggesting that cougar kills may provide scavenging opportunities for bears. Although we found a slight positive spatial association between black bears and wolves, we found strong differences in temporal activity patterns between them. Mesic forest yielded higher detections of all predators (except humans) compared to xeric habitat. Cougars in particular appeared to be better predicted by habitat than presence of sympatric predators with more detections in mesic compared to mountain and xeric habitats. Understanding the co-occurrence of apex predators in a system is not a simple measure of their relative dominance cascading from one level to the next.

Large carnivores are among the most threatened species in the world because of their natural low densities and need for expansive habitats. The brown bear (Ursus arctos) is the largest carnivore in the southwestern Asia, and faces threats in much of its range from conflict with humans over shared resources and shrinkage of habitat. In this study, we surveyed for brown bear sign and scat during spring–autumn from April 2013 to November 2015 in 24 randomly selected, 25-km2 grid cells, and developed a model of potential brown bear occurrence in one of its globally southernmost distribution ranges in Iran. To better understand its conservation needs and management priorities at the landscape scale, we used a combination of field surveys to develop a Maximum Entropy (Maxent) model. The model was developed using 10 environmental and anthropogenic predictors. Potential brown bear occurrence was strongly influenced by availability of water resources (54.1%) as the most important variable; and distance to roads (16.1%), aspect (7.6%), and vegetation types (5.9%) were the other important factors. The model showed an area of 581 km2 (35%) within the study area has high to good bear-occurrence probability values; 86% of this area is located in 2 patches, each larger than the average bear home range. Identification of these patches may support establishment of a reserve in the area, which would ensure long-term survival of the brown bear and sustainable water use and resource extraction from Pistacia atlantica forests by resident and nomadic communities in the region.

Grizzly bears (Ursus arctos) are omnivore generalists that eat a wide array of plants and animals, including insects. Human-induced changes in climate may affect the species composition, abundance, range, and elevational distribution of the plants and animals consumed by grizzly bears. Therefore, determining the current food habits of grizzly bears is important for documenting future changes in food resources and how those changes may affect the nutritional ecology of grizzlies. In 2011, we observed grizzly bears in Yellowstone National Park (YNP) eating midges from the family Chironomidae along the shoreline of Yellowstone Lake. Midges are small, swarming aquatic insects that occasionally wash ashore in large numbers around the lake. To our knowledge, grizzly bear consumption of midges had not previously been reported in YNP despite extensive bear food-habits studies conducted there. We believe that midges are likely an opportunistic food for grizzlies, eaten only during sporadic periods of super-abundance.

—The diet of the brown bear (Ursus arctos) is described for the territory of the southern taiga subzone illustrated by the example of the Central Forest Nature Reserve (West-European Russia) and the protection zone surrounding it. Based on an analysis of 474 scat samples, we established the most commonly consumed food items and food groups and determined their proportions, nutritional value, and importance in the total diet of the species using basic techniques widely adopted abroad for processing the data. The investigation revealed 26 food items, including 18 plant (FO = 97.9%) and eight animal items (9.1%). Correction factors were used for each diet item. Food habits were assessed separately for the spring, summer, summer–autumn, and autumn periods. The frequency of scat occurrence per 10 km averaged 1.30. The most important in the bears’ diet were apples (EDEC = 31.1%), hazelnuts (19.1%), oats (12.5%), blueberries (6.8%), and forbs (4.3%). Mammal food had a certain value (EDEC = 11.1%), but mostly in the spring season. The width of the trophic niche decreased from spring to autumn. The diet composition varied greatly throughout the year, except for a hyperphagia period, which included summer and autumn. The territory of the moderately disturbed protection zone was more attractive to bears than the intact area of the reserve. Overall, scat analysis in the study area adequately reflects the basic preferences of the species, but underestimates the values of individual food groups, primarily insects, overestimates the value of apples, and poorly characterizes the feeding habits in the first half of the year.

During the years 1992–2013, we studied the relationship between Amur tigers and brown and Asiatic black bears in the Sikhote-Alin Nature Reserve and surrounding areas in the southern part of the Russian Far East. To determine the importance of bears in the diet of tigers, 763 kills were located and identified, and 430 tiger scat samples were collected and analyzed. To detect kills and scat samples, we used radio telemetry and satellite tracking, as well as snow-tracking. Relying on evidence revealed by tracks, as well as radio telemetry, we determined whether bears exploited tiger kills as a food resource and how the two may have interacted at kill sites. Thirty-two Asiatic black bear and 12 brown bear den sites were measured to define properties that might assist in protection from the threat of a tiger attack. We identified 641 instances of marking on trees by both tigers and bears, an indication of the complexity of their relationship. Bears are an important part of the tigers’ diet, representing 2.2% of all kills found. Bear remains were found in 8.4% of examined tiger scat. Bears exploited tiger kills after a tiger had left, by usurping a kill, or by “sharing” a kill at alternate times. The occurrence of den properties that provided some protection from tigers was dependent on the den type and location. Evidence of both tiger and bear marking was detected at 50.1% of marked trees. A review of the literature on the relationship of tigers and bears is provided.

Selection of den sites is a crucial aspect of American black bear (Ursus americanus) life history. High-quality dens provide thermal insulation, protection from disturbance, suitable environment for parturition and cub development, and proximity to available forage upon emergence. Black bears are increasingly coexisting with people in human-dominated landscapes; however, little is known about whether urban environments influence characteristics of dens and den site selection. Our objective was to determine the effect of housing density (a proxy for human activity and availability of anthropogenic resources) on selection of den sites in years of good and poor natural forage. We additionally compared size, shape, and location of dens of males and females to describe den characteristics and explore whether differences existed between males and females. We revisited 34 den locations detected during a 6-year (2005–2010) urban black bear study in Aspen, Colorado, USA, and measured den entrance and den volume. We fit a conditional logistic regression model using a resource selection function framework to determine the importance of housing density and other landscape variables (elevation, slope, aspect, and vegetation type) associated with den site selection. Slope was the best predictor of den site selection and there was no relationship between den selection and housing density, indicating that black bears were neither avoiding nor seeking urban areas for denning. Dens were smaller for females ( = 3.30 m3, SE = 1.94, n = 22) than for males ( = 7.56 m3, SE = 3.31, n = 8), supporting the idea that females have greater constraints in den characteristics, possibly related to cub development and security from predation or because females generally are smaller than males.

There is evidence that prey can perceive the risk of predation and alter their behaviour in response, resulting in changes in spatial distribution and potential fitness consequences. Previous approaches to mapping predation risk quantify predator space use to estimate potential predator-prey encounters, yet this approach does not account for successful predator attacks resulting in prey mortality. An exception is a prey kill-site, which reflects an encounter resulting in mortality, but obtaining these data can be expensive and requires time to accumulate adequate sample sizes. We illustrate an alternative approach using predator scat locations and their contents to quantify spatial predation risk for elk (Cervus canadensis) from multiple predators in Alberta, Canada. We combined predictions of scat-based resource selection functions for bears (Ursus arctos/U. americanus), cougars (Puma concolor), coyotes (Canis latrans), and wolves (C. lupus) based on scat-detection dog surveys with predictions for the probability that a predator-specific scat in a location contained elk. We evaluated our approach by comparing predictions to a predation risk model developed from elk kill sites and applied it to describing spatial patterns in predation risk that were consistent with changes in the distribution of elk over the past decade. We found a strong correlation between risk predicted by kill sites and risk predicted by our approach (r = 0.98, P < 0.001). There was a spatial pattern to predation risk, where elk that migrated east of their winter range were exposed to highest risk from cougars, non-migratory elk were exposed to high risk from wolves and bears, and risk to elk that migrated west of their winter range into protected areas was high only from bears. The patterns in predator risk were consistent with changes in the migratory tactics in this population. The scat-based approach we present permits broad-scale inferences on predation risk for prey.

Measuring the body mass of American black bears (Ursus americanus) can be challenging because of their large size, and if equipment to weigh individuals is undersupplied. Our purpose was to estimate body mass of Florida black bears (U. a. floridanus) by developing models (linear and non-linear) that use morphometrics that can be reasonably easy to obtain (e.g., chest girth and body length). We compared our models with a previously published model for Florida black bears to determine whether prediction of body mass could be improved. Our models were built with current data (2012–2018; n = 532) collected across Florida, USA, by the Florida Fish and Wildlife Conservation Commission. We partitioned the data into training and test subsets using 10-fold cross-validation with 100 iterations. Model fit was assessed by comparing root mean square error (RMSE), mean absolute error (MAE), and coefficient of determination (R2) of observed and predicted values. Based on RMSE, MAE, and R2, our optimal regression model for predicting mass (M) of both female and male bears used both chest girth (G) and total body length (L) as predictors in the non-linear form M = aGb × Lc. Our optimal model was a better fit than the previously published model when both were applied to the full data sets from the current and previous study and to an independent data set. We applied our optimal non-linear regression models built from live bear data to morphological data collected from bear carcasses (n = 544), mainly road mortalities. We found that the live-bear models acceptably estimated mass of dead bears for both sexes. Estimating the mass of live and dead bears can expedite handling time of individuals, fill in data gaps, and provide valuable information on the Florida black bear; our approach may be applicable to American black bears range-wide.

Ursus americanus (Pallas, 1780) Black Bear Figure 2H Material examined. MEXICO – Chihuahua • 1 Municipality of Namiquipa, Potrero Lajas, 28°46′34″N, 107° 27′34″W; elevation 2,180 m a.s.l.; 16 Jan. 2018; obs. F. Álvarez-Córdova. Identification. This is the only extant species of Ursus Linnaeus, 1758 in Mexico. It is a medium-sized bear with long, coarse, black or brown fur (Larivière 2001). Distribution. Canada, USA, and Mexico through the pine, pine-oak forests of the Sierra Madre Occidental and Sierra Madre Oriental (Larivière 2001). Recorded habitats in Chihuahua are sierras and valleys. Remarks. This species is now extirpated from most of northern Mexico. It only survives in small patches of forests in the Sierra Madre Occidental and Sierra Madre Oriental in central and northern Mexico (Scheick and McCown 2014). The record presented here is based on a single scat., Published as part of Álvarez-Córdova, Fernando & Fernández, Jesús A., 2021, Medium-sized and large mammals of the pine-oak forests and grasslands of the Rancho Experimental Teseachi in Chihuahua, Mexico, pp. 669-681 in Check List 17 (2) on page 677, DOI: 10.15560/17.2.669, {"references":["Lariviere S (2001) Ursus americanus. Mammalian Species 647: 1 - 11. https: // doi. org / 10.2307 / 0.647.1","Scheick BK, McCown W (2014) Geographic distribution of American Black Bears in North America. Ursus 25 (1): 24 - 33. https: // doi. org / 10.2192 / ursus-d- 12 - 00020.1"]}

Trichinella spp. nematodes are commonly found in bear species (Ursidae) and can pose severe health risks to humans when infective first-stage larvae are ingested in meat. Samples of tongue or masseter muscle from 22 male and 11 female American black bears (Ursus americanus; mean age 6.5 yr, range 1-16 yr) and 22 male, eight female, and one unknown sex grizzly bears (Ursus arctos; mean age 8.8 yr, range 2-28 yr), from Yukon, Canada, were tested to determine prevalence and intensity of Trichinella spp. infection. For black bears, prevalence was 20% and mean intensity was 401 larvae per gram of tissue (LPG), whereas for grizzly bears, prevalence was 71%, and mean infection intensity was 35 LPG. Isolates from all positive samples were identified as genotype Trichinella-T6 by multiplex PCR. For black bears, prevalence is the highest reported in Canada and infection intensity the highest recorded in North America. One black bear had a larval burden of 1,173 LPG, the second highest recorded in any host species. The prevalence in grizzly bears was the highest reported in Canada for this host. In total, 90% (27 of 30) of infected bears had infection burdens above the human food safety threshold of ≥1 LPG, reinforcing the importance of communicating the health risks to people consuming bear meat.

Archived serum samples taken between 1997 and 2017 from 170 American black bears (Ursus americanus) in the Lake Tahoe area between California and Nevada, US, were tested for Toxoplasma antibodies to assess the seroprevalence of this agent. Samples were screened using a commercial porcine Toxoplasma (enzyme-linked immunosorbent assay [ELISA]) modified with Protein A/G peroxidase and compared to a traditional fluorescent antibody test. Results were analyzed to determine if there were differences in seroprevalence based on the test used, sex of bears, or habitat usage (urban-suburban vs. wildland). No significant differences in seroprevalence were attributable to any of these parameters. The overall seropositivity for bears was 36% (62/170), with urban-suburban bears scoring lower (31%; 37/119) than rural-wildland bears (40%; 18/45). Our results strongly support the use of a Protein A/G-modified ELISA for determining Toxoplasma exposure in black bears. We found somewhat lower levels of Toxoplasma antibodies in black bears from this region than in several reports from populations in the eastern US.

Animal movements are major determinants of energy expenditure and ultimately the cost–benefit of landscape use. Thus, we sought to understand those costs and how grizzly bears (Ursus arctos) move in mountainous landscapes. We trained captive grizzly bears to walk on a horizontal treadmill and up and down 10% and 20% slopes. The cost of moving upslope increased linearly with speed and slope angle, and this was more costly than moving horizontally. The cost of downslope travel at slower speeds was greater than the cost of traveling horizontally but appeared to decrease at higher speeds. The most efficient walking speed that minimized cost per unit distance was 1.19±0.11 m s−1. However, grizzly bears fitted with GPS collars in the Greater Yellowstone Ecosystem moved at an average velocity of 0.61±0.28 m s−1 and preferred to travel on near-horizontal slopes at twice their occurrence. When traveling uphill or downhill, grizzly bears chose paths across all slopes that were ∼54% less steep and costly than the maximum available slope. The net costs (J kg−1 m−1) of moving horizontally and uphill were the same for grizzly bears, humans and digitigrade carnivores, but those costs were 46% higher than movement costs for ungulates. These movement costs and characteristics of landscape use determined using captive and wild grizzly bears were used to understand the strategies that grizzly bears use for preying on large ungulates and the similarities in travel between people and grizzly bears that might affect the risk of encountering each other on shared landscapes.

The prevalence of black bear (Ursus americanus) bark stripping in commercial redwood (Sequoia sempervirens (D. Don) Endl.) timber stands has been increasing in recent years. This stripping is a threat to commercial timber production because of the deleterious effects on redwood tree fitness. This study sought to unveil a remote sensing method to detect these damaged trees early and map their spatial patterns. By developing a timely monitoring method, forest timber companies can manipulate their timber harvesting routines to adapt to the consequences of the problem. We explored the utility of high spatial resolution UAV-collected hyperspectral imagery as a means for early detection of individual trees stripped by black bears. A hyperspectral sensor was used to capture ultra-high spatial and spectral information pertaining to redwood trees with no damage, those that have been recently attacked by bears, and those with old bear damage. This spectral information was assessed using the Jeffries-Matusita (JM) distance to determine regions along the electromagnetic spectrum that are useful for discerning these three-health classes. While we were able to distinguish healthy trees from trees with old damage, we were unable to distinguish healthy trees from recently damaged trees due to the inherent characteristics of redwood tree growth and the subtle spectral changes within individual tree crowns for the time period assessed. The results, however, showed that with further assessment, a time window may be identified that informs damage before trees completely lose value.

Global increases in human activity threaten connectivity of animal populations. Protection and restoration of animal movement corridors requires robust models to forecast the effects of human activity on connectivity. Recent advances in the field of animal movement ecology and step selection functions offer new approaches for estimating connectivity. We show how a combination of hidden Markov movement models and step selection functions can be used to simulate realistic movement paths with multiple behavioral states. Simulated paths can be used to generate utilization distributions and estimate changes in connectivity for multiple land use scenarios. We applied movement models to 20 years of grizzly bear (Ursus arctos) and gray wolf (Canis lupus) data collected in and around Banff National Park, Canada. These carnivores avoided areas near towns in all seasons, avoided areas of high trail density in most seasons, and campgrounds during summer and fall. We simulated movement paths for three landscape scenarios: reference conditions with no anthropogenic development, current conditions, and future conditions with expanded town footprints and trail networks. We counted the number of paths that crossed valley-wide, digital transects through mountain tourist towns of Banff and Canmore, Alberta. We divided current and future crossing rates by the reference crossing rates to estimate connectivity. Current connectivity rates ranged between 7 and 45% of reference values with an average of 21% for grizzly bears and 25% for wolves. Potential town expansion and increased development of trails further decreased connectivity an average of 6% in future scenarios. Anthropogenic developments reduced the amount of available high quality large carnivore habitat in the Bow Valley by an average of 14% under current conditions and 16% under future conditions. Our approach for estimating connectivity provides a robust and flexible method for combining movement models with step selection analyses to estimate connectivity for a variety of species.

Palaeogenomes provide the potential to study evolutionary processes in real time, but this potential is limited by our ability to recover genetic data over extended timescales.1 As a consequence, most studies so far have focused on samples of Late Pleistocene or Holocene age, which covers only a small part of the history of many clades and species. Here, we report the recovery of a low coverage palaeogenome from the petrous bone of a ∼360,000 year old cave bear from Kudaro 1 cave in the Caucasus Mountains. Analysis of this genome alongside those of several Late Pleistocene cave bears reveals widespread mito-nuclear discordance in this group. Using the time interval between Middle and Late Pleistocene cave bear genomes, we directly estimate ursid nuclear and mitochondrial substitution rates to calibrate their respective phylogenies. This reveals post-divergence mitochondrial transfer as the dominant factor explaining their mito-nuclear discordance. Interestingly, these transfer events were not accompanied by large-scale nuclear introgression. However, we do detect additional instances of nuclear admixture among other cave bear lineages, and between cave bears and brown bears, which are not associated with mitochondrial exchange. Genomic data obtained from the Middle Pleistocene cave bear petrous bone has thus facilitated a revised evolutionary history of this extinct megafaunal group. Moreover, it suggests that petrous bones may provide a means of extending both the magnitude and time depth of palaeogenome retrieval over substantial portions of the evolutionary histories of many mammalian clades.

Human–wildlife interactions (HWI) were frequent in the post-socialist period in the mountain range of Central European countries where forest habitats suffered transitions into built-up areas. Such is the case of the Upper Prahova Valley from Romania. In our study, we hypothesized that the increasing number of HWI after 1990 could be a potential consequence of woodland loss. The goal of our study was to analyse the effects of landscape changes on HWI. The study consists of the next steps: (i) applying 450 questionnaires to local stakeholders (both citizens and tourists) in order to collect data regarding HWI temporal occurrences and potential triggering factors, (ii) investigating the relation between the two variables through the Canonical Correspondence Analysis (CCA), (iii) modelling the landscape spatial changes between 1990 and 2018 for identifying areas with forest loss, (iv) overlapping the distribution of both the households affected by HWI and areas with loss of forested ecosystems. The local stakeholders indicate that the problematic species are the brown bear (Ursus arctos), the wild boar (Sus scrofa), the red fox (Vulpes vulpes) and the grey wolf (Canis lupus). The number of animal–human interactions recorded an upward trend between 1990 and 2018, and the most significant driving factors were the regulation of hunting practices, the loss of habitats, and artificial feeding. The landscape change analysis reveals that between 1990 and 2018, the forest habitats were replaced by built-up areas primarily on the outskirts of settlements, these areas coinciding with frequent HWI. The results are valid for both forest ecosystems conservation in the region, wildlife management, and human infrastructures durable spatial planning.

Camera traps are widely used to collect information on the distribution and abundance of multiple species simultaneously. However, we still lack important guidance for designing camera-trap surveys to monitor multiple species, and the consequences of species-specific responses to survey design strategies are often overlooked. Using camera-trap data collected on ten medium-to-large North-American carnivores in northern Minnesota, USA, between 2016 and 2018 (23 337 active trap-days), we evaluated: 1) two different survey-design frameworks (random- versus road-based), 2) two different lure types (salmon oil versus fatty acid scent oil), 3) two different placement strategies (completely random versus randomly-selected sites with feature-based placement), 4) survey timing (spring versus fall) and 5) temporal trends in daily encounter probabilities. Using generalized linear mixed models, we found evidence of differential responses to all of these design strategies. For 9 out of 10 species, we found strong responses to survey design frameworks: red foxes Vulpes vulpes, coyotes Canis latrans, bobcats, Lynx rufus, striped skunks Mephitis mephitis, wolves C. lupus and gray foxes Urocyon cinereoargenteus, had estimated encounter frequencies that were 9- to 106-fold higher at unlured sites along secondary roads; black bears Ursus americanus, martens Martes americana and fishers Pekania pennanti had estimated encounter frequencies that were 15- to > 3600-fold higher at lured, randomly selected sites. For six species, salmon oil provided 2- to 4-fold more encounters than fatty acid scent oil, but feature-basedplacement only improved detections of fishers. Daily encounter probabilities differed between spring and fall for all species, and usually decreased slightly within each sampling period Our study confirms that even similar-sized or closely-related species respond differently to survey-design choices. To maximize encounter frequencies, we recommend that multi-species camera-trap studies use a mix of survey-design strategies and include these design features during statistical analysis.

Skull specimens from: southern sea otter (Enhydra lutris nereis), Eastern Pacific harbor seal (Phoca vitulina), California sea lion (Zalophus californianus), northern fur seal (Callorhinus ursinus), walrus (Odobenus rosmarus), polar bear (Ursus maritimus), North American brown bear (Ursus arctos), American black bear (Ursus americanus), California mountain lion (Puma concolor couguar), California bobcat (Lynx rufus californicus), gray fox (Urocyon cinereoargenteus), kit fox (Vulpes macrotis), and gray wolf (Canis lupus) (n = 5,011) were macroscopically examined for dental and temporomandibular joint (TMJ) pathology. The presence of temporomandibular joint osteoarthritis (TMJ-OA) varied across species: 4.1% of southern sea otter, 34.5% of harbor seal, 85.5% of California sea lion, 20% of northern fur seal, 60.5% of walrus, 9.2% of polar bear, 13.2% of North American brown bear, 50% of American black bear, 20.9% of California mountain lion, 0% of California bobcat and gray fox, 6.3% of kit fox, and 11.6% of gray wolf specimens had lesions consistent with TMJ-OA. TMJ-OA was significantly more prevalent in males than females in walrus, North American brown bear, polar bear, American black bear, and California mountain lion (p < 0.001, p = 0.005, p = 0.005, p = 0.002, and p = 0.004, respectively). No other species showed a sex predilection. Adult specimens were significantly more affected with TMJ-OA than young adults in the harbor seal, fur seal, walrus (all p < 0.001), and kit fox (p = 0.001). Gray wolf and American black bear young adults were significantly (p = 0.047 and p < 0.001) more affected by TMJ-OA than adults. Of the 13 species analyzed, only three species, namely the harbor seal, northern fur seal, and polar bear, had a significant increase in the prevalence of TMJ-OA if their teeth had attrition and abrasion (p < 0.001, p < 0.001, and p = 0.033, respectively). TMJ-OA can lead to morbidity and mortality in wild animals, but its etiology is not yet fully understood.

8 páginas, 2 tablas, 1 figura., Canine adenovirus type 1 (CAdV-1) causes infectious canine hepatitis (ICH) and has recently been described as a cause of death among endangered populations of European brown bear (Ursus arctos arctos) in the Cantabrian mountain range in Asturias, Spain. Sympatric wild and domestic carnivores can act as reservoirs of the virus and likely spread it into the environment and subsequently transmit it to brown bears. The present work investigates the prevalence and geo-temporal distribution of CAdV-1 among free-ranging wolves (Canis lupus) in Asturias from 2009 to 2018, during which three fatal cases of ICH were reported among brown bears in the region. A total of 149 wolves were analysed in this study, of which 21 (14%) were found to have CAdV-1 DNA based on real-time polymerase chain reaction (RT-PCR) of spleen samples. Prevalence of the virus was similar between males and females. All but one of the 20 CAdV-1-positive animals of estimable age were younger than 2 years, and only one of the 46 adult animals (>2 years) tested positive. Prevalence was highest in the western area of Asturias and during 2010 and 2011. Our results confirm that CAdV-1 is circulating in Asturian free-ranging wolves, supporting their possible role as virus reservoirs and sentinels in the region of this emerging disease in brown bears., This work is a contribution to the agreement between Principado de Asturias and SERPA for the establishment and maintenance of a Wildlife Sanitary Surveillance Program in Asturias. We would like to thank the rangers at the game reserves (especially Francisco Alonso Mier) for their help in field work and carcasses submission, and our colleagues from SERIDA (Rosa Casais and J. Miguel Prieto) for their assistance in necropsy and laboratory work. This work was funded by Government of Asturias (PCTI 2018–2020, GRUPIN: IDI2018-000237) and FEDER.