| comparative development of the canine teeth in wild and captive black bears, ursus americanus pallas. | | 1967 | 5588104 |
| growth rate of newborn black bear cubs (ursus americanus). | | 1966 | 6008237 |
| analysis of the blood of american black bears. | | 1966 | 5968944 |
| [squamous cell epithelioma in the american black bear (euarctos americanus)]. | | 2014 | 13341516 |
| cranial injuries in prehistoric animals; with special notes on a healed wound of the skull in the dire wolf (canis [aenocyon] dirus [leidy] and a mortal wound in the california black bear (ursus americanus). | | 1953 | 13094266 |
| short notes on the myology of the american black bear (ursus americanus). | | 1883 | 17231502 |
| a combined human case of dirofilaria ursi infection in dorsal subcutaneous tissue and anisakis simplex sensu stricto (s.s.) infection in ventral subcutaneous tissue. | dirofilaria ursi is a filarial nematode that parasitizes the subcutaneous tissues of the american black bear (ursus americanus) and japanese black bear (ursus thiabetanus japonicus). d. ursi that has parasitized black bears has the potential to subsequently infect humans. in addition, extra-gastrointestinal anisakiasis is less common in japan. | 2017 | 29118653 |
| climate change can alter predator-prey dynamics and population viability of prey. | for many organisms, climate change can directly drive population declines, but it is less clear how such variation may influence populations indirectly through modified biotic interactions. for instance, how will climate change alter complex, multi-species relationships that are modulated by climatic variation and that underlie ecosystem-level processes? caribou (rangifer tarandus), a keystone species in newfoundland, canada, provides a useful model for unravelling potential and complex long-ter ... | 2018 | 29167983 |
| nowhere to hide: effects of linear features on predator-prey dynamics in a large mammal system. | rapid landscape alteration associated with human activity is currently challenging the evolved dynamical stability of many predator-prey systems by forcing species to behaviourally respond to novel environmental stimuli. in many forested systems, linear features (lfs) such as roads, pipelines and resource exploration lines (i.e. seismic lines) are a ubiquitous form of landscape alteration that have been implicated in altering predator-prey dynamics. one hypothesized effect is that lfs facilitate ... | 2018 | 28940254 |
| widespread distribution of ticks and selected tick-borne pathogens in kentucky (usa). | the geographical distribution of ixodes scapularis and amblyomma maculatum ticks is poorly understood in kentucky. we conducted a convenience survey of wildlife species (white-tailed deer (odocoileus virginianus), elk (cervus canadensis) and black bears (ursus americanus)) for ticks from october 2015 to january 2017. we detected four tick species including amblyomma americanum, dermacentor albipictus, i. scapularis and a. maculatum. although the former two tick species were previously known to b ... | 2018 | 29502988 |
| pathogen prevalance in american black bears (ursus americanus amblyceps) of the jemez mountains, new mexico, usa. | informed management of american black bears (ursus americanus) requires knowledge of the distribution and pathology of diseases affecting the species. little information is available on pathogen prevalence from black bear populations in the southwest, us, and it is unknown how these infections may influence black bear populations or disease transmission. we captured new mexico black bears (ursus americanus amblyceps) during 2016-17 as part of a long-term monitoring project and opportunistically ... | 2019 | 31112469 |
| spatial representation of magnitude in humans (homo sapiens), western lowland gorillas (gorilla gorilla gorilla), and american black bears (ursus americanus). | the spatial-numerical association of response codes (snarc) effect is the tendency for humans to respond faster to relatively larger numbers on the left or right (or with the left or right hand) and faster to relatively smaller numbers on the other side. this effect seems to occur due to a spatial representation of magnitude either in occurrence with a number line (wherein participants respond to relatively larger numbers faster on the right), other representations such as clock faces (responses ... | 2018 | 29728786 |
| a tissue digestion protocol for measuring sarcoptes scabiei (astigmata: sarcoptidae) density in skin biopsies. | sarcoptic mange is a parasitic skin disease caused by the burrowing mite sarcoptes scabiei that affects a diversity of mammals, including humans, worldwide. in north america, the most commonly affected wildlife includes wild canids, such as coyotes and red foxes, and more recently american black bears in the mid-atlantic and northeast united states. currently, surveillance for sarcoptic mange in wildlife is syndromic, relying on detection of clinical signs and lesions, such as alopecia and crust ... | 2020 | 33135750 |
| artificial night light helps account for observer bias in citizen science monitoring of an expanding large mammal population. | the integration of citizen scientists into ecological research is transforming how, where, and when data are collected, and expanding the potential scales of ecological studies. citizen-science projects can provide numerous benefits for participants while educating and connecting professionals with lay audiences, potentially increasing the acceptance of conservation and management actions. however, for all the benefits, collection of citizen-science data is often biased towards areas that are ea ... | 2020 | 32895962 |
| listeria monocytogenes at the human-wildlife interface: black bears (ursus americanus) as potential vehicles for listeria. | listeria monocytogenes is the causative agent of the foodborne illness listeriosis, which can result in severe symptoms and death in susceptible humans and other animals. l. monocytogenes is ubiquitous in the environment and isolates from food and food processing, and clinical sources have been extensively characterized. however, limited information is available on l. monocytogenes from wildlife, especially from urban or suburban settings. as urban and suburban areas are expanding worldwide, hum ... | 2020 | 31713354 |
| identifying archaeological bone via non-destructive zooms and the materiality of symbolic expression: examples from iroquoian bone points. | today, practical, functional and symbolic choices inform the selection of raw materials for worked objects. in cases where we can discern the origin of worked bone, tooth, ivory and antler objects in the past, we assume that similar choices are being made. however, morphological species identification of worked objects is often impossible due to the loss of identifying characteristics during manufacture. here, we describe a novel non-destructive zooms (zooarchaeology by mass spectrometry) method ... | 2019 | 31363122 |
| black bears alter movements in response to anthropogenic features with time of day and season. | with the growth and expansion of human development, large mammals will increasingly encounter humans, elevating the likelihood of human-wildlife conflicts. understanding the behavior and movement of large mammals, particularly around human development, is important for crafting effective conservation and management plans for these species. | 2019 | 31338195 |
| a review of sarcoptic mange in north american wildlife. | the "itch mite" or "mange mite", sarcoptes scabiei, causes scabies in humans and sarcoptic mange in domestic and free-ranging animals. this mite has a wide host range due to its ability to adapt to new hosts and has been spread across the globe presumably through human expansion. while disease caused by s. scabiei has been very well-studied in humans and domestic animals, there are still numerous gaps in our understanding of this pathogen in free-ranging wildlife. the literature on sarcoptic man ... | 2019 | 31304085 |
| bears habituate to the repeated exposure of a novel stimulus, unmanned aircraft systems. | unmanned aircraft systems (uas; i.e. 'drones') provide new opportunities for data collection in ecology, wildlife biology and conservation. yet, several studies have documented behavioral or physiological responses to close-proximity uas flights. we experimentally tested whether american black bears (ursus americanus) habituate to repeated uas exposure and whether tolerance levels persist during an extended period without uas flights. using implanted cardiac biologgers, we measured heart rate (h ... | 2019 | 30680216 |
| land tenure shapes black bear density and abundance on a multi-use landscape. | 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, ro ... | 2019 | 30680097 |
| diversity of anaplasma and ehrlichia/neoehrlichia agents in terrestrial wild carnivores worldwide: implications for human and domestic animal health and wildlife conservation. | recently, the incidence and awareness of tick-borne diseases in humans and animals have increased due to several factors, which in association favor the chances of contact among wild animals and their ectoparasites, domestic animals and humans. wild and domestic carnivores are considered the primary source of tick-borne zoonotic agents to humans. among emergent tick-borne pathogens, agents belonging to family anaplasmataceae (order rickettsiales) agents stand out due their worldwide distribution ... | 2018 | 30533417 |
| hourly movement decisions indicate how a large carnivore inhabits developed landscapes. | the ecology of wildlife living in proximity to humans often differs from that in more natural places. animals may perceive anthropogenic features and people as threats, exhibiting avoidance behavior, or may acclimate to human activities. as development expands globally, changes in the ecology of species in response to human phenomena may determine whether animals persist in these changing environments. we hypothesize that american black bears (ursus americanus) persist within developed areas by ... | 2019 | 30506304 |
| genome assembly and gene expression in the american black bear provides new insights into the renal response to hibernation. | the prevalence of chronic kidney disease (ckd) is rising worldwide and 10-15% of the global population currently suffers from ckd and its complications. given the increasing prevalence of ckd there is an urgent need to find novel treatment options. the american black bear (ursus americanus) copes with months of lowered kidney function and metabolism during hibernation without the devastating effects on metabolism and other consequences observed in humans. in a biomimetic approach to better under ... | 2019 | 30395234 |
| foxes (vulpes vulpes) as sentinels for parasitic zoonoses, toxoplasma gondii and trichinella nativa, in the northeastern canadian arctic. | outbreaks of toxoplasma gondii and trichinella spp. have been recurring for decades among inuit of nunavik, northeastern canada. contact with wildlife has been identified as a risk factor for inuit exposure to t. gondii, but reservoirs have yet to be confirmed based on direct detection of dna or organism. similarly, little is known about the occurrence of trichinella spp. in wildlife species of nunavik other than walrus (odobenus rosmarus) and bears (ursus americanus, ursus maritimus). foxes (vu ... | 2018 | 30370219 |
| combining stable isotopes, morphological, and molecular analyses to reconstruct the diet of free-ranging consumers. | accurate estimates of animal diet composition are essential to untangle complex interactions in food webs. biomarkers and molecular tools are increasingly used to estimate diet, sometimes alongside traditional dietary tracing methods. yet only a few empirical studies have compared the outcomes and potential gains of using a combination of these methods, especially using free-ranging animals with distinct foraging preferences.we used stable isotopes, morphological, and molecular analyses to inves ... | 2020 | 32724540 |
| boreal predator co-occurrences reveal shared use of seismic lines in a working landscape. | interspecific interactions are an integral aspect of ecosystem functioning that may be disrupted in an increasingly anthropocentric world. industrial landscape change creates a novel playing field on which these interactions take place, and a key question for wildlife managers is whether and how species are able to coexist in such working landscapes. using camera traps deployed in northern alberta, we surveyed boreal predators to determine whether interspecific interactions affected occurrences ... | 2020 | 32076543 |
| the importance of considering multiple interacting species for conservation of species at risk. | conservation of species at risk of extinction is complex and multifaceted. however, mitigation strategies are typically narrow in scope, an artifact of conservation research that is often limited to a single species or stressor. knowledge of an entire community of strongly interacting species would greatly enhance the comprehensiveness and effectiveness of conservation decisions. we investigated how camera trapping and spatial count models, an extension of spatial-recapture models for unmarked p ... | 2019 | 30306635 |
| are pumas subordinate carnivores, and does it matter? | interspecific competition affects species fitness, community assemblages and structure, and the geographic distributions of species. established dominance hierarchies among species mitigate the need for fighting and contribute to the realized niche for subordinate species. this is especially important for apex predators, many of which simultaneous contend with the costs of competition with more dominant species and the costs associated with human hunting and lethal management. | 2018 | 29379688 |
| clinical crenosomosis in a black bear (ursus americanus). | an orphaned black bear (ursus americanus) cub, estimated to be 9 months-of-age was presented to a wildlife rehabilitation facility in december of 2016. the cub was afebrile, under-weight (6.8 kg) and had a cough condition. centrifugal sugar fecal flotation examination failed to detect any gastrointestinal helminth or protozoan parasites, but revealed the presence of first-stage nematode larvae (l1). large numbers of l1 (>8000 l1/g) identified as crenosoma sp. based on morphology were recovered u ... | 2020 | 32448529 |
| picture recognition of food by sloth bears (melursus ursinus). | pictures are often used in cognitive research to represent objects and many species have demonstrated the ability to recognize two-dimensional pictures as representations of their three-dimensional counterparts. however, for ursids picture recognition has been reported in only one study of a single 11-year-old female american black bear (johnson-ulrich et al. 2016). we tested the picture recognition abilities of an additional species, the sloth bear. after a food preference test by which the bea ... | 2020 | 31630346 |
| multiscale consensus habitat modeling for landscape level conservation prioritization. | globally, wide-ranging carnivore populations are imperiled due to human-caused habitat fragmentation. where populations are fragmented, habitat quantification is often the first step in conservation. presence-only species distribution models can provide robust results when proper scales and data are considered. we aimed to identify habitat for a fragmented carnivore population at two scales and aid conservation prioritization by identifying potential future habitat fragmentation. we used locatio ... | 2020 | 33082467 |
| polytrauma from a north american black bear attack. | bear attacks, although rare, can inflict life-threatening injuries. we present the case of a 50-y-old woman from rural pennsylvania who was attacked by a north american black bear, ursus americanus. she sustained multiple complex injuries including near-complete scalp avulsion, bilateral ear avulsions, and fractures of the face, ribs, and pelvis. these injuries are similar to those sustained in other bear maulings reported in the literature and required both acute intervention and a multidiscipl ... | 2020 | 33032933 |
| a translational model for venous thromboembolism: microrna expression in hibernating black bears. | hibernating american black bears have significantly different clotting parameters than their summer active counterparts, affording them protection against venous thromboembolism during prolonged periods of immobility. we sought to evaluate if significant differences exist between the expression of micrornas in the plasma of hibernating black bears compared with their summer active counterparts, potentially contributing to differences in hemostasis during hibernation. | 2020 | 32858321 |
| population reduction by hunting helps control human-wildlife conflicts for a species that is a conservation success story. | among the world's large carnivores, american black bears (ursus americanus) are the foremost conservation success story. populations have been expanding across north america because the species is adaptable and tolerant of living near people, and because management agencies in the u.s. and canada controlled hunting and other human-sources of mortality. as a result, human-black bear conflicts (damage to property, general nuisance, threat to human safety) have dramatically increased in some areas, ... | 2020 | 32780755 |
| unraveling the mystery of the glacier bear: genetic population structure of black bears (ursus americanus) within the range of a rare pelage type. | glacier bears are a rare grey color morph of american black bear (ursus americanus) found only in northern southeast alaska and a small portion of western canada. we examine contemporary genetic population structure of black bears within the geographic extent of glacier bears and explore how this structure relates to pelage color and landscape features of a recently glaciated and highly fragmented landscape. we used existing radiocollar data to quantify black bear home-range size within the geog ... | 2020 | 32760555 |
| staphylococcus ursi sp. nov., a new member of the 'staphylococcus intermedius group' isolated from healthy black bears. | six staphylococcus strains were isolated from healthy black bears (ursus americanus) in the great smoky mountains national park, tennessee, usa. phylogenetic analysis based on complete genome, 16s rrna, dnaj, hsp60, rpob and soda genes, and maldi-tof-ms main spectral profiles revealed that the strains belonged to one species and showed the closest relatedness to members of the 'staphylococcus intermedius group' (sig), which include staphylococcus intermedius, staphylococcus pseudintermedius, sta ... | 2020 | 32672529 |
| behavior in free-living american black bear dens: parturition, maternal care, and cub behavior. | denning behavior has long remained the least observed aspect of bear behavior. during 2010-2013, we used webcams, microphones, the internet, and 14,602 h of archived video to document the denning behaviors of two adult wild black bears (ursus americanus) as they gave birth and cared for four litters through six winters in northeastern minnesota. observations included types of dens, labor, pre-parturient genital swelling, birthing positions, post-partum vocalizations, mothers removing amniotic ti ... | 2020 | 32630255 |
| clinical challenge: yew toxicosis in black bears (ursus americanus). | | 2020 | 32549580 |
| retinal cone photoreceptor distribution in the american black bear (ursus americanus). | the distribution of cone photoreceptor subtypes (important for color vision and vision quality) varies widely in different carnivore species, but there have been limited studies on bear (ursid) cone distribution. a previous behavioral study suggests that american black bears (ursus americanus) are dichromatic, indicating that they possess two cone subtypes, although the retinal distribution of cones is unknown. the purpose of this study was to examine the subtype and topography of cones in ameri ... | 2020 | 32510783 |
| mortality of a large wide-ranging mammal largely caused by anthropogenic activities. | with efforts to restore large mammal populations following extirpations, it is vital to quantify how they are impacted by human activities and gain insights into population dynamics in relation to conservation goals. our objective was to characterize cause-specific mortality of black bears (ursus americanus) throughout their range. we first quantified cause-specific mortality for 247 black bears in one harvested and two non-harvested populations. we then simulated a small recolonizing population ... | 2020 | 32444633 |
| tissue residue levels of the tranquilizer combination of butorphanol, azaperone, and medetomidine, and the antagonists, naltrexone, atipamezole, and tolazoline, in black bears (ursus americanus) postimmobilization. | the tranquilizer combination of butorphanol, azaperone, and medetomidine (bam) has shown good efficacy for immobilization of wildlife, including black bears (ursus americanus). bam is antagonized with a combination of naltrexone and atipamezole. we immobilized 19 adult captive wild caught black bears and, except for three bears that were euthanized immediately, bears were recovered with naltrexone and atipamezole. tissue residues (≥0.01 ppm) for the tranquilizers butorphanol, azaperone, and mede ... | 2020 | 32348204 |
| seroprevalence, dna isolation, and genetic characterization of toxoplasma gondii from black bear (ursus americanus) sera collected in eastern oklahoma. | black bears (ursus americanus) are commonly exposed to toxoplasma gondii. however, there are no reports of exposure or infection with t. gondii in black bears from oklahoma. the purpose of our project was to determine the seroprevalence of t. gondii antibodies in black bears collected in oklahoma. additionally, since only serum was available from these bears, we sought to determine if dna extraction and pcr amplification for t. gondii was possible on serum samples from bears with positive titers ... | 2020 | 32086592 |
| serologic survey of toxoplasma gondii in black bears (ursus americanus) from eastern tennessee, usa. | the modified agglutination test was used to study toxoplasma gondii exposure in 70 eastern tennessee, us, black bears (ursus americanus) from 2015 to 2017. overall, 74% (52/70) of bears were seropositive, and t. gondii was more prevalent in adults than subadults. | 2020 | 32053414 |
| chemical structures of oligosaccharides in milks of the american black bear (ursus americanus americanus) and cheetah (acinonyx jubatus). | the milk oligosaccharides were studied for two species of the carnivora: the american black bear (ursus americanus, family ursidae, caniformia), and the cheetah, (acinonyx jubatus, family felidae, feliformia). lactose was the most dominant saccharide in cheetah milk, while this was a minor saccharide and milk oligosaccharides predominated over lactose in american black bear milk. the structures of 8 neutral saccharides from american black bear milk were found to be gal(β1-4)glc (lactose), fuc(α1 ... | 2020 | 31828568 |
| draft genome sequence of multidrug-resistant listeria innocua strain uam003-1a, isolated from a wild black bear (ursus americanus). | there is currently limited knowledge of the genome sequences of nonpathogenic listeria species, especially strains from wildlife. here, we report the draft genome sequence and associated genome information of an antibiotic-resistant listeria innocua strain, uam003-1a, isolated from the feces of a black bear in california, usa. | 2019 | 31753950 |
| serology as a tool to investigate sarcoptic mange in american black bears (ursus americanus). | black bears (ursus americanus) have historically been considered an uncommon host for sarcoptic mange. however, over the last 25 yr, sarcoptic mange has been increasingly reported in black bears in the northeastern us. syndromic monitoring is the most common surveillance approach for mange in bears, but tools to monitor exposure to sarcoptes scabiei in bear populations have not been thoroughly evaluated under field conditions. in this study, we validated a commercially available enzyme-linked im ... | 2020 | 31743065 |
| ursaplex: an str multiplex for forensic identification of north american black bear (ursus americanus). | ursaplex is a forensic quality 5-dye multiplexed tetranucleotide str and sex identification panel for individual genetic identification of north american black bears (ursus americanus). the panel is validated for the identification of black bears involved in human-wildlife conflict events and poaching investigations. this is the first single multiplex panel composed solely of tetranucleotide strs derived from black bear and bear-specific sex markers. ursaplex produces complete genetic profiles f ... | 2020 | 31677443 |
| sertoli cell tumor (sct) in a captive black bear (ursus americanus). | a black bear of 29-year-old (ursus americanus) died unexpectedly in captivity without any gross lesions or clinical signs. we identified a firm, lobulated, yellowish tan, and well-circumscribed mass embedded inside the testicular tissue at the time of necropsy. the tumor sections exhibited soft necrotic and hemorrhagic areas beneath its capsule. histologically, the tumor comprised sertoli cells arranged in tubules and solid sheets supported by prominent fibrous connective tissues. the sertoli ce ... | 2019 | 31561583 |
| a serosurvey of multiple pathogens in american black bears (ursus americanus) in pennsylvania, usa indicates a lack of association with sarcoptic mange. | infectious diseases, particularly of wildlife, are intrinsically linked to human and domestic animal health. reports of sarcoptic mange in black bears (ursus americanus) are increasing in multiple states in the usa and while the reason is unknown, mange in other species has been associated with immunosuppression from multiple causes. serum from bears across pennsylvania were collected to determine the seroprevalence of five pathogens important for animal and/or human health: canine distemper vir ... | 2019 | 31547006 |
| effects of temperature on the survival of sarcoptes scabiei of black bear (ursus americanus) origin. | for two decades, the incidence and range of sarcoptic mange in black bears (ursus americanus) in pennsylvania has increased. the causative agent, sarcoptes scabiei, can be directly or indirectly transmitted; therefore, data on environmental persistence is important for guiding management and public communications. the objective of this study was to determine the survival of s. scabiei at different temperatures. full section skin samples and superficial skin scrapes were collected from bears imme ... | 2019 | 31388786 |
| the emergence and expansion of sarcoptic mange in american black bears (ursus americanus) in the united states. | mange was historically rare in american black bears (ursus americanus). since the 1990s, however, sarcoptic mange has become more widespread in black bears with hundreds of reports in 2018 from eight states. this emerging disease has potential implications regarding human and animal health and on future black bear management. | 2019 | 31303232 |
| polar bear evolution is marked by rapid changes in gene copy number in response to dietary shift. | polar bear (ursus maritimus) and brown bear (ursus arctos) are recently diverged species that inhabit vastly differing habitats. thus, analysis of the polar bear and brown bear genomes represents a unique opportunity to investigate the evolutionary mechanisms and genetic underpinnings of rapid ecological adaptation in mammals. copy number (cn) differences in genomic regions between closely related species can underlie adaptive phenotypes and this form of genetic variation has not been explored i ... | 2019 | 31209046 |
| incorporating citizen science data in spatially explicit integrated population models. | information about population abundance, distribution, and demographic rates is critical for understanding a species' ecology and for effective conservation and management. to collect data over large spatial and temporal extents for such inferences, especially for species with low densities or wide distributions, citizen science can be an efficient approach. integrated models have also emerged as an important methodology to estimate population parameters by combining multiple types of data, inclu ... | 2019 | 31168779 |
| systemic tuberculosis by mycobacterium bovis in a free-ranging marsican brown bear (ursus arctos marsicanus): a case report. | mycobacterium bovis is known to have a wide host range and has been isolated from numerous free-ranging wildlife species, carnivores included. in bears, m. bovis has been previously reported only from a culture of pooled lymph nodes of a black bear (ursus americanus) in the absence of lesions. the aims of this study were to describe gross and microscopic pathological findings of m. bovis tuberculosis in a deceased marsican brown bear (ursus arctos marsicanus). | 2019 | 31101105 |
| the effect of sex, age, and location on carnivory in utah black bears (ursus americanus). | ungulates are important to the diet of bears because they are high in protein, and the level of dietary protein strongly influences bear size. the size a bear obtains as an adult influences important life history characteristics, such as age of reproduction and reproductive success; therefore, it is important to know what foods are available to bears and how they are utilizing them. we tested hypotheses concerning the effect of age, sex, and location on black bear carnivory. we collected hair an ... | 2019 | 30989360 |
| the cascading effects of human food on hibernation and cellular aging in free-ranging black bears. | human foods have become a pervasive subsidy in many landscapes, and can dramatically alter wildlife behavior, physiology, and demography. while such subsidies can enhance wildlife condition, they can also result in unintended negative consequences on individuals and populations. seasonal hibernators possess a remarkable suite of adaptations that increase survival and longevity in the face of resource and energetic limitations. recent work has suggested hibernation may also slow the process of se ... | 2019 | 30792484 |
| detection and prevalence of babesia spp. in american black bears (ursus americanus) from eastern and western north carolina, usa. | blood samples collected from american black bears (ursus americanus) in eastern and western north carolina, us, were analyzed for piroplasms. piroplasmids were detected in 17% (23/132) of the animals surveyed. we detected a babesia spp. previously identified in north american raccoons (procyon lotor) and a maned wolf (chrysocyon brachyurus); prevalence was 22% (14/64) and 13% (9/68) in the mountain and coastal black bear populations, respectively. the presence of the same babesia species in blac ... | 2019 | 30694717 |
| salmonid species diversity predicts salmon consumption by terrestrial wildlife. | 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 i ... | 2019 | 30618046 |
| scale-dependent home range optimality for a solitary omnivore. | spatial and temporal heterogeneity are fundamental mechanisms structuring home ranges. under optimality, an individual should structure their space use economically to maximize fitness. we evaluated support for three hypotheses related to range optimality in american black bears (ursus americanus), predicting (a) range location on a landscape will correspond with high vegetation productivity, (b) increasing forest fragmentation will result in larger ranges, and (c) increasing proportion of fores ... | 2018 | 30598817 |
| the nasal complex of a semiaquatic artiodactyl, the moose (alces alces): is it a good evolutionary model for the ancestors of cetaceans? | 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, oth ... | 2019 | 30422388 |
| identification of gammaherpesvirus infection in free-ranging black bears (ursus americanus). | herpesvirus infection was investigated in black bears (ursus americanus) with neurological signs and brain lesions of nonsuppurative encephalitis of unknown cause. visible cytopathic effects (cpe) could only be observed on days 3-5 post-infection in hrt-18g cell line inoculated with bear tissue extracts. the observed cpe in hrt-18g cells included syncytia, intranuclear inclusions, and cell detachments seen in herpesvirus infection in vitro. herpesvirus-like particles were observed in viral cultu ... | 2019 | 30385363 |
| leptospirosis in urban and suburban american black bears ( ursus americanus) in western north carolina, usa. | american black bear ( ursus americanus) populations in north carolina, us have recovered significantly in recent decades and now occupy much of western north carolina, including urban-suburban areas. we used the black bear as a potential sentinel for leptospirosis, a bacterial zoonotic disease caused by leptospira spp., which is maintained by domestic and wild mammals. we determined whether leptospira spp. were present across a gradient of housing densities in the urban and suburban black bear p ... | 2019 | 30222487 |
| female american black bears do not alter space use or movements to reduce infanticide risk. | infanticide occurs in a variety of animal species and infanticide risk has large implications for the evolution of behavior. further, the sex hypothesis of sexual segregation predicts that for species in which infanticide occurs, females with dependent young will avoid males to reduce risk of sexually-selected infanticide. infanticide risk-avoidance behavior has been studied primarily in social species, but also occurs in some solitary species. we used generalized linear mixed models to determin ... | 2018 | 30216386 |
| canine adenovirus type 1 (cadv-1) in free-ranging european brown bear (ursus arctos arctos): a threat for cantabrian population? | canine adenovirus type 1 (cadv-1) is responsible for infectious canine hepatitis. the disease has been described in captive american black bear (ursus americanus) and european brown bear (ursus arctos arctos), with just one recently reported case in a cub of a free-ranging brown bear (ursus arctos horribilis) from alaska. the aim of this work is to summarize findings related to presence and associated mortality of cadv-1 in 21 free-ranging cantabrian brown bears (ursus arctos arctos) submitted t ... | 2018 | 30179311 |
| beyond the snapshot: landscape genetic analysis of time series data reveal responses of american black bears to landscape change. | landscape genetic studies typically focus on the evolutionary processes that give rise to spatial patterns that are quantified at a single point in time. although landscape change is widely recognized as a strong driver of microevolutionary processes, few landscape genetic studies have directly evaluated the change in spatial genetic structure (sgs) over time with concurrent changes in landscape pattern. we introduce a novel approach to analyze landscape genetic data through time. we demonstrate ... | 2018 | 30151035 |
| a bayesian state-space model using age-at-harvest data for estimating the population of black bears (ursus americanus) in wisconsin. | population estimation is essential for the conservation and management of fish and wildlife, but accurate estimates are often difficult or expensive to obtain for cryptic species across large geographical scales. accurate statistical models with manageable financial costs and field efforts are needed for hunted populations and using age-at-harvest data may be the most practical foundation for these models. several rigorous statistical approaches that use age-at-harvest and other data to accurate ... | 2018 | 30127405 |
| treatment of sarcoptic mange in an american black bear ( ursus americanus) with a single oral dose of fluralaner. | sarcoptic mange in american black bears ( ursus americanus) is a recent topic of concern in the mid-atlantic us as accounts of affected bears have increased in recent years. we describe a black bear with sarcoptic mange that was successfully treated with one oral dose of fluralaner. the outcome of this case has positive implications for the treatment options available for free-ranging black bears. | 2019 | 30016212 |
| evaluation of chemical immobilization in captive black bears ( ursus americanus) receiving a combination of nalbuphine, medetomidine, and azaperone. | to assess potential seasonal differences in responses to immobilization, we sedated eight orphaned yearling black bears ( ursus americanus) being held for rehabilitation at a wildlife facility in colorado, us, using a premixed combination of nalbuphine (40 mg/ml), azaperone (10 mg/ml), and medetomidine (10 mg/ml; nalmed-a) in october (autumn) prior to hibernation and again after emergence in may (spring) prior to their release. we dosed all bears at 1 ml nalmed-a per estimated 45 kg body mass (1 ... | 2019 | 30016210 |
| accounting for age structure and spatial structure in eco-evolutionary analyses of a large, mobile vertebrate. | the idealized concept of a population is integral to ecology, evolutionary biology, and natural resource management. to make analyses tractable, most models adopt simplifying assumptions, which almost inevitably are violated by real species in nature. here, we focus on both demographic and genetic estimates of effective population size per generation (ne), the effective number of breeders per year (nb), and wright's neighborhood size (ns) for black bears (ursus americanus) that are continuously ... | 2018 | 29668993 |
| the use of ketamine-xylazine or butorphanol-azaperone-medetomidine to immobilize american black bears ( ursus americanus). | wildlife anesthetic protocols must offer rapid inductions and recoveries, be physiologically safe, and be minimally regulated. with this in mind, we evaluated differences in induction and recovery times and physiological parameters in 33 american black bears ( ursus americanus) anesthetized with ketamine-xylazine (kx) or immobilized with a commercial drug combination of butorphanol, azaperone, and medetomidine (bam). dose was based on mass estimated from field observations. bears were housed at ... | 2018 | 29616881 |
| assays for detection and identification of the causative agent of mange in free-ranging black bears ( ursus americanus). | three mite species ( demodex ursi, ursicoptes americanus, and sarcoptes scabiei) have been associated with mange in black bears ( ursus americanus). since the early 1990s, the number and geographic distribution of mange cases in black bears in pennsylvania, us has increased; however, the causative mites have yet to be completely defined. we evaluated several diagnostic approaches for detection and identification of mites in 72 black bears with severe lesions consistent with mange. sarcoptes scab ... | 2018 | 29498895 |
| spatiotemporal heterogeneity in prey abundance and vulnerability shapes the foraging tactics of an omnivore. | prey abundance and prey vulnerability vary across space and time, but we know little about how they mediate predator-prey interactions and predator foraging tactics. to evaluate the interplay between prey abundance, prey vulnerability and predator space use, we examined patterns of black bear (ursus americanus) predation of caribou (rangifer tarandus) neonates in newfoundland, canada using data from 317 collared individuals (9 bears, 34 adult female caribou, 274 caribou calves). during the carib ... | 2018 | 29450888 |
| estimating population extinction thresholds with categorical classification trees for louisiana black bears. | monitoring vulnerable species is critical for their conservation. thresholds or tipping points are commonly used to indicate when populations become vulnerable to extinction and to trigger changes in conservation actions. however, quantitative methods to determine such thresholds have not been well explored. the louisiana black bear (ursus americanus luteolus) was removed from the list of threatened and endangered species under the u.s. endangered species act in 2016 and our objectives were to d ... | 2018 | 29360863 |
| spatial genetic structure in american black bears (ursus americanus): female philopatry is variable and related to population history. | previously, american black bears (ursus americanus) were thought to follow the pattern of female philopatry and male-biased dispersal. however, recent studies have identified deviations from this pattern. such flexibility in dispersal patterns can allow individuals greater ability to acclimate to changing environments. we explored dispersal and spatial genetic relatedness patterns across ten black bear populations-including long established (historic), with known reproduction >50 years ago, and ... | 2018 | 29234157 |
| genetic health and population monitoring of two small black bear (ursus americanus) populations in alabama, with a regional perspective of genetic diversity and exchange. | one of the major concerns in conservation today is the loss of genetic diversity which is a frequent consequence of population isolation and small population sizes. fragmentation of populations and persecution of carnivores has posed a substantial threat to the persistence of free ranging carnivores in north america since the arrival of european settlers. black bears have seen significant reductions in range size from their historic extent, which is most pronounced in the southeastern united sta ... | 2017 | 29117263 |
| viruses in unexplained encephalitis cases in american black bears (ursus americanus). | viral infections were investigated in american black bears (ursus americanus) from nevada and northern california with and without idiopathic encephalitis. metagenomics analyses of tissue pools revealed novel viruses in the genera circoviridae, parvoviridae, anelloviridae, polyomaviridae, and papillomaviridae. the circovirus and parvovirus were of particular interest due to their potential importance as pathogens. we characterized the genomes of these viruses and subsequently screened bears by p ... | 2020 | 33332429 |