| isolation and genetic characterization of toxoplasma gondii from raccoons (procyon lotor), cats (felis domesticus), striped skunk (mephitis mephitis), black bear (ursus americanus), and cougar (puma concolor) from canada. | viable toxoplasma gondii was isolated by bioassay in mice from tissues of 2 feral cats (felis domesticus), 2 raccoons (procyon lotor), a skunk (mephitis mephitis) trapped in remote locations in manitoba, canada, and a black bear (ursus americanus) from kuujjuaq, northern quebec, canada. genotyping of these t. gondii isolates using polymorphisms at 10 nuclear markers including sagi, sag2, sag3, btub, gra6, c22-8, c29-2, l358, pk1, and an apicoplast marker apico revealed 4 genotypes. none of the i ... | 2008 | 18372620 |
| sarcoptic mange and pelodera dermatitis in an american black bear (ursus americanus). | an adult female free-ranging american black bear (ursus americanus) was presented in poor body condition, with advanced skin disease. skin changes included hair loss, lichenification, crusting, and focal erosions. skin scrapings and histopathology identified two distinct parasitic conditions that were contributing to this animal's dermatitis. large numbers of larvae, nymphs, and adults of sarcoptes scabiei were present in the superficial epidermis, and nematodes consistent with pelodera strongyl ... | 2008 | 18634219 |
| use of empirically derived source-destination models to map regional conservation corridors. | the ability of populations to be connected across large landscapes via dispersal is critical to long-term viability for many species. one means to mitigate population isolation is the protection of movement corridors among habitat patches. nevertheless, the utility of small, narrow, linear features as habitat corridors has been hotly debated. here, we argue that analysis of movement across continuously resistant landscapes allows a shift to a broader consideration of how landscape patterns influ ... | 2009 | 19016821 |
| ticks and tick-borne pathogens and putative symbionts of black bears (ursus americanus floridanus) from georgia and florida. | ticks were collected from 38 black bears (ursus americanus floridanus) from northwestern florida (n = 18) from 2003 to 2005 and southern georgia (n = 20) in 2006. five species (amblyomma americanum, a. maculatum, dermacentor variabilis, ixodes scapularis, and i. affinis) were collected from florida bears, and 4 species (a. americanum, a. maculatum, d. variabilis, i. scapularis) were collected from bears in georgia. ixodes scapularis was the most frequently collected tick, followed by d. variabil ... | 2009 | 19413369 |
| sport hunting, predator control and conservation of large carnivores. | sport hunting has provided important economic incentives for conserving large predators since the early 1970's, but wildlife managers also face substantial pressure to reduce depredation. sport hunting is an inherently risky strategy for controlling predators as carnivore populations are difficult to monitor and some species show a propensity for infanticide that is exacerbated by removing adult males. simulation models predict population declines from even moderate levels of hunting in infantic ... | 2009 | 19536277 |
| grizzly bears (ursus arctos horribilis) and black bears (ursus americanus) prevent trabecular bone loss during disuse (hibernation). | disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. in contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. here we investigated the effects of hibernation on bone remodeling, architectural properties, and mineral density of grizzly bear (ursus arct ... | 2009 | 19703606 |
| identification and phylogenetic analysis of dirofilaria ursi (nematoda: filarioidea) from wisconsin black bears (ursus americanus) and its wolbachia endosymbiont. | dirofilaria ursi is a filarial nematode of american black bears (ursus americanus pallas, 1780) that is vectored by black flies (simuliidae) in many parts of the united states. in northwestern wisconsin, the prevalence of microfilaremic bears during the fall hunting season was 21% (n = 47). unsheathed blood microfilariae from wisconsin bears possess characters consistent with the original description of d. ursi, as do adult worms observed histologically and grossly. immunohistochemistry was used ... | 2010 | 19916630 |
| genomic analysis of expressed sequence tags in american black bear ursus americanus. | species of the bear family (ursidae) are important organisms for research in molecular evolution, comparative physiology and conservation biology, but relatively little genetic sequence information is available for this group. here we report the development and analyses of the first large scale expressed sequence tag (est) resource for the american black bear (ursus americanus). | 2010 | 20338065 |
| a new atypical highly mouse virulent toxoplasma gondii genotype isolated from a wild black bear in alaska. | most strains of toxoplasma gondii isolated in north america and europe are grouped into 3 (types i, ii, iii) genotypes and are considered clonal. recent evidence suggests that illness due to toxoplasmosis in immunocompetent persons may be related to infection with an atypical genotype; these strains are mouse virulent. in the present study, a new mouse-virulent atypical t. gondii genotype was isolated from an asymptomatic black bear ( ursus americanus ) from alaska. the bear had a titer of 1rati ... | 2010 | 20486739 |
| extreme respiratory sinus arrhythmia enables overwintering black bear survival--physiological insights and applications to human medicine. | american black bears survive winter months without food and water while in a mildly hypothermic, hypometabolic, and inactive state, yet they appear to be able to return to near-normal systemic function within minutes of arousal. this study's goal was to characterize the cardiovascular performance of overwintering black bears and elicit the underlying mechanisms enabling survival. mid-winter cardiac electrophysiology was assessed in four wild black bears using implanted data recorders. paired dat ... | 2010 | 20559779 |
| the phylogenetic roots of cognitive dissonance. | we presented 7 old world monkeys (japanese macaques [macaca fuscata], gray-cheeked mangabey [lophocebus albigena], rhesus macaques [macaca mulatta], bonnet macaque [macaca radiate], and olive baboon [papio anubis]), 3 chimpanzees (pan troglodytes), 6 members of the parrot (psittacinae) family, and 4 american black bears (ursus americanus) with a cognitive dissonance paradigm modeled after egan, santos, and bloom (2007). in experimental trials, subjects were given choices between 2 equally prefer ... | 2010 | 20836593 |
| fatal epizootic equine herpesvirus 1 infections in new and unnatural hosts. | in a zoological collection, four black bears (ursus americanus) died from neurological disease within six months. independently in a geographically different zoo, two thomson's gazelles (eudorcas thomsoni) and 18 guinea pigs (cavia porcellus f. dom.) suffered from neurological disorders. in addition, guinea pigs showed abortions and stillbirths. all affected animals displayed a non suppurative meningoencephalitis with intranuclear inclusion bodies. immunohistology demonstrated equine herpes viru ... | 2010 | 21167662 |
| fatal hepatic sarcocystosis in a captive black bear (ursus americanus) associated with sarcocystis canis-like infection. | fatal hepatic sarcocystosis was diagnosed in a 13-year-old captive black bear (ursus americanus) with a history of acute onset of vomiting, polyuria, polydipsia, and bilirubinuria. gross lesions included severe icterus, multisystemic hemorrhage, and gall bladder edema. the most significant microscopic lesion was severe necrotizing hepatitis with intralesional protozoa that reproduced by endopolygeny consistent with a sarcocystis spp. infrequent microglial nodules were randomly scattered within t ... | 2011 | 21398469 |
| paleozoological data suggest euroamerican settlement did not displace ursids and north american elk from lowlands to highlands. | the hypothesis that euroamerican settlement displaced some populations of large mammal taxa from lowland plains habitats to previously unoccupied highland mountain habitats was commonly believed in the late nineteenth and early twentieth centuries. by the middle twentieth century biologists had come to favor the hypothesis that euroamerican colonization resulted in the extirpation of populations of large mammal in lowland habitats and those taxa survived in pre-existing relict populations in the ... | 2011 | 21544707 |
| characterization of aβpn3 deposition in the brains of dogs of various ages and other animal species. | senile plaques (sp) are characteristic histopathological manifestations of alzheimer's disease (ad), but are also found in normal aging (na). recent studies have demonstrated that beta amyloid (aβ) proteins that have been truncated at the n-terminal position 3 (aβpn3) are the predominant component of sp in ad, but not in na. the present study revealed that aβpn3 was deposited in an age-dependent manner in canine brains. moreover, aβpn3 was the main component of the sp that developed in very old ... | 2011 | 21557687 |
| neonatal mortality of elk driven by climate, predator phenology and predator community composition. | 1. understanding the interaction among predators and between predation and climate is critical to understanding the mechanisms for compensatory mortality. we used data from 1999 radio-marked neonatal elk (cervus elaphus) calves from 12 populations in the north-western united states to test for effects of predation on neonatal survival, and whether predation interacted with climate to render mortality compensatory. 2. weibull survival models with a random effect for each population were fit as a ... | 2011 | 21615401 |
| prevalence of trichinella spp. in black bears, grizzly bears, and wolves in the dehcho region, northwest territories, canada, including the first report of t. nativa in a grizzly bear from canada. | samples of muscle from 120 black bears (ursus americanus), 11 grizzly bears (ursus arctos), and 27 wolves (canis lupus) collected in the dehcho region of the northwest territories from 2001 to 2010 were examined for the presence of trichinella spp. larvae using a pepsin-hcl digestion assay. trichinella spp. larvae were found in eight of 11 (73%) grizzly bears, 14 of 27 (52%) wolves, and seven of 120 (5.8%) black bears. the average age of positive grizzly bears, black bears, and wolves was 13.5, ... | 2011 | 21719845 |
| seroprevalence of toxoplasma gondii from free-ranging black bears (ursus americanus) from florida. | abstract toxoplasma gondii is a significant worldwide parasitic protozoan. in the present study, prevalence of antibodies of t. gondii was examined from 29 free-ranging black bears (ursus americanus) from south-central florida where the host species was listed as state threatened during this project. overall t. gondii prevalence was found to be 44.8%, specifically 46.2% in male and 43.8% in female u. americanus, using a modified agglutination test (mat, 1:25 titer). seroprevalence differences ... | 2011 | 22150391 |
| arterial supply and venous drainage of the brain of the black bear (ursus americanus). ii. intracranial microvasculature. | a morphological study of the intracranial microvasculature of the black bear (ursus americanus) using vascular casts was undertaken. the object was to provide basic information regarding structural modifications of the microvasculature that might provide insight into the ability to cope with low blood flow states that occur during winter sleep. vascular casts were prepared from 6 animals. the microvasculature of the brain disclosed characteristic features of the small vessels in mammals, includi ... | 2009 | 2782025 |
| detection of human bacterial pathogens in ticks collected from louisiana black bears (ursus americanus luteolus). | there are 4 major human-biting tick species in the northeastern united states, which include: amblyomma americanum, amblyomma maculatum, dermacentor variabilis, and ixodes scapularis. the black bear is a large mammal that has been shown to be parasitized by all the aforementioned ticks. we investigated the bacterial infections in ticks collected from louisiana black bears (ursus americanus subspecies luteolus). eighty-six ticks were collected from 17 black bears in louisiana from june 2010 to ma ... | 2013 | 23415850 |
| trophic facilitation or limitation? comparative effects of pumas and black bears on the scavenger community. | scavenging is a widespread behaviour and an important process influencing food webs and ecological communities. large carnivores facilitate the movement of energy across trophic levels through the scavenging and decomposition of their killed prey, but competition with large carnivores is also likely to constrain acquisition of carrion by scavengers. we used an experimental approach based on motion-triggered video cameras at black-tailed deer (odocoileus hemionus columbianus) carcasses to measure ... | 2014 | 25010629 |
| diet and macronutrient optimization in wild ursids: a comparison of grizzly bears with sympatric and allopatric black bears. | when fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. in the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition. by visiting locations of 37 individuals during 274 bear-days, we documented foods consumed by grizzly (ursus arctos) and black bears (ursus americanus) in grand teton national park during 20 ... | 2016 | 27192407 |
| negative density-dependent dispersal in the american black bear (ursus americanus) revealed by noninvasive sampling and genotyping. | although the dispersal of animals is influenced by a variety of factors, few studies have used a condition-dependent approach to assess it. the mechanisms underlying dispersal are thus poorly known in many species, especially in large mammals. we used 10 microsatellite loci to examine population density effects on sex-specific dispersal behavior in the american black bear, ursus americanus. we tested whether dispersal increases with population density in both sexes. fine-scale genetic structure ... | 0 | 22822432 |
| prevalence of anaplasma phagocytophilum in north carolina eastern black bears ( ursus americanus ). | we detected anaplasma phagocytophilum by dna amplification in whole blood from free-ranging, hunter-killed american black bears ( ursus americanus ) from the east coast of north carolina, us. molecular prevalence for anaplasma phagocytophilum was 3% from 68 black bears. no dna of other anaplasma or ehrlichia spp. was identified. | 2016 | 27479929 |
| american black bears as hosts of blacklegged ticks (acari: ixodidae) in the northeastern united states. | ticks and whole blood were collected from american black bears (ursus americanus pallas) between october 2011 and october 2012 across four counties in northwestern new jersey, an area where blacklegged ticks (ixodes scapularis say) and their associated tick-borne pathogens are prevalent. adult american dog ticks (dermacentor variabilis say) were the most frequently collected tick species in late spring, whereas adult and nymphal blacklegged ticks were found in both the late spring and fall month ... | 2015 | 26336232 |
| demographic characteristics and infectious diseases of a population of american black bears in humboldt county, california. | american black bears (ursus americanus) are common, widely distributed, and broad-ranging omnivorous mammals in northern california forests. bears may be susceptible to pathogens infecting both domestic animals and humans. monitoring bear populations, particularly in changing ecosystems, is important to understanding ecological features that could affect bear population health and influence the likelihood that bears may cause adverse impacts on humans. in all, 321 bears were captured between may ... | 2015 | 25700042 |
| serosurvey for selected pathogens in free-ranging american black bears (ursus americanus) in maryland, usa. | american black bears (ursus americanus) in maryland, usa, live in forested areas in close proximity to humans and their domestic pets. from 1999 to 2011, we collected 84 serum samples from 63 black bears (18 males; 45 females) in five maryland counties and tested them for exposure to infectious, including zoonotic, pathogens. a large portion of the bears had antibody to canine distemper virus and toxoplasma gondii, many at high titers. prevalences of antibodies to zoonotic agents such as rabies ... | 2014 | 25075540 |
| bartonella rochalimae and b. vinsonii subsp. berkhoffii in wild carnivores from colorado, usa. | spleen samples from 292 wild carnivores from colorado, us were screened for bartonella infection. bartonella dna was detected in coyotes ( canis latrans ) (28%), striped skunks ( mephitis mephitis ) (23%), red foxes ( vulpes vulpes ) (27%), and raccoons ( procyon lotor ) (8%) but not in black bears ( ursus americanus ), gray foxes ( urocyon cinereoargenteus ), and mountain lions ( puma concolor ). two bartonella species, b. vinsonii subsp. berkhoffii and b. rochalimae, were identified. all 10 in ... | 2016 | 27529290 |
| helminths of the black bear in quebec. | twenty-one complete carcasses of black bears, ursus americanus , together with 34 intestinal tracts, 86 diaphragms and 168 faecal droppings collected between june, 1971 and november, 1972 in the province of quebec were examinel for helminths. species found and their prevalence were as follows: dirofilaria ursi in 57%; uncinaria yukonensis in 6%; baylisascaris transfuga in 21%; larvae of trichinella spiralis in less than 1%; diphyllobothrium ursi in 36%; and taenia krabbei and taenia hydatigena i ... | 1977 | 24228968 |
| blindness in a wild american black bear cub (ursus americanus). | an approximately six-month-old wild american black bear (ursus americanus) was found wandering in saskatchewan and was presented to the veterinary medical centre of the western college of veterinary medicine for apparent blindness. clinical examination confirmed an inability to navigate a photopic maze, bilateral tapetal hyper-reflectivity, fundi devoid of retinal vessels, and small pale optic nerve papillae. single-flash electroretinography revealed a and b-wave amplitudes of approximately 40 a ... | 2016 | 26302466 |
| genetic predictions of prion disease susceptibility in carnivore species based on variability of the prion gene coding region. | mammalian species vary widely in their apparent susceptibility to prion diseases. for example, several felid species developed prion disease (feline spongiform encephalopathy or fse) during the bovine spongiform encephalopathy (bse) epidemic in the united kingdom, whereas no canine bse cases were detected. whether either of these or other groups of carnivore species can contract other prion diseases (e.g. chronic wasting disease or cwd) remains an open question. variation in the host-encoded pri ... | 2012 | 23236380 |
| anaerobic oral flora in the north american black bear (ursus americanus) in eastern north carolina. | microbial flora can provide insight into the ecology and natural history of wildlife in addition to improving understanding of health risks. this study examines the anaerobic oral flora of hunter killed black bears (ursus americanus) in eastern north carolina. oral swabs from the buccal and lingual supragingival tooth surfaces of the first and second mandibular and maxillary molars of 22 black bears were inoculated onto brucella blood agar plates supplemented with hemin and vitamin k after trans ... | 2012 | 22503889 |
| seroprevalence of toxoplasma gondii in american black bears ( ursus americanus ) of the central appalachians, usa. | we assessed toxoplasma gondii seroprevalence in 53 free-ranging american black bears ( ursus americanus ) in the central appalachian mountains, us. seroprevalence was 62% with no difference between males and females or between juvenile and adult bears. wildlife agencies should consider warnings in hunter education programs to reduce the chances for human infection from this source. | 2017 | 28318381 |
| seroepidemiologic study on the prevalence of toxoplasma gondii and trichinella spp. infections in black bears (ursus americanus) in pennsylvania, usa. | the protozoan toxoplasma gondii and the metazoan trichinella spp. infect virtually all warm-blooded animals, including birds, humans, livestock, and marine mammals. both parasitic infections can cause serious illness in human beings and can be acquired by ingesting under-cooked meat harboring infective stages. approximately 3500 black bears (ursus americanus) are legally-harvested each year in pennsylvania, usa during the november hunting season. among animals found infected with t. gondii, the ... | 2016 | 27809983 |
| isolation and genetic characterization of toxoplasma gondii from black bears (ursus americanus), bobcats (lynx rufus), and feral cats (felis catus) from pennsylvania. | toxoplasma gondii infects virtually all warm-blooded hosts worldwide. recently, attention has been focused on the genetic diversity of the parasite to explain its pathogenicity in different hosts. it has been hypothesized that interaction between feral and domestic cycles of t. gondii may increase unusual genotypes in domestic cats and facilitate transmission of potentially more pathogenic genotypes to humans, domestic animals, and wildlife. in the present study, we tested black bear (ursus amer ... | 2015 | 25393429 |
| isolation and characterization of new genetic types of toxoplasma gondii and prevalence of trichinella murrelli from black bear (ursus americanus). | black bears (ursus americanus) are hosts for two important zoonotic parasites, toxoplasma gondii and trichinella spp. and bears are hunted for human consumption in the usa. little is known of the genetic diversity of t. gondii circulating in wildlife. in the present study, antibodies to t. gondii were found in juice from tongues of 17 (25.7%) of 66 wild black bear from maryland during the hunting season of 2010 and 2011. antibodies to t. gondii were assessed by the modified agglutination test. t ... | 2013 | 23537944 |
| morphological variability and molecular identification of uncinaria spp. (nematoda: ancylostomatidae) from grizzly and black bears: new species or phenotypic plasticity? | the hookworms uncinaria rauschi olsen, 1968 and uncinaria yukonensis ( wolfgang, 1956 ) were formally described from grizzly ( ursus arctos horribilis) and black bears ( ursus americanus ) of north america. we analyzed the intestinal tracts of 4 grizzly and 9 black bears from alberta and british columbia, canada and isolated uncinaria specimens with anatomical traits never previously documented. we applied morphological and molecular techniques to investigate the taxonomy and phylogeny of these ... | 2015 | 25548982 |
| high risk of lead contamination for scavengers in an area with high moose hunting success. | top predators and scavengers are vulnerable to pollutants, particularly those accumulated along the food chain. lead accumulation can induce severe disorders and alter survival both in mammals (including humans) and in birds. a potential source of lead poisoning in wild animals, and especially in scavengers, results from the consumption of ammunition residues in the tissues of big game killed by hunters. for two consecutive years we quantified the level lead exposure in individuals of a sentinel ... | 2014 | 25389754 |
| first report of taenia arctos (cestoda: taeniidae) from grizzly (ursus arctos horribilis) and black bears (ursus americanus) in north america. | the cestode taenia arctos was found at necropsy in the small intestine of a grizzly (ursus arctos horribilis) and a black bear (ursus americanus) from kananaskis country in southwestern alberta, canada. the autolysis of the tapeworm specimens precluded detailed morphological characterization of the parasites but molecular analysis based on mitochondrial dna cytochrome c oxidase subunit 1 gene confirmed their identity as t. arctos. this is the first report of t. arctos from definitive hosts in no ... | 2014 | 24382413 |
| responses of beaver (castor canadensis kuhl) to predator chemicals. | free-ranging beaver (castor canadensis) in two different beaver populations in new york state were exposed to predator chemicals to test feeding inhibition. solvent extracts of feces were applied to stem sections of aspen, the preferred food tree of beavers, permitting smelling and tasting the samples. predator odors were from wolf (canis lupus), coyote (canis latrans), dog (canis familiaris), black bear (ursus americanus), river otter (lutra canadensis), lynx (lynx canadensis), and african lion ... | 1995 | 24234632 |
| chemical and biological analysis of active free and conjugated bile acids in animal bile using hplc-elsd and mtt methods. | the aim of the present study was to determine the chemical composition and in vitro cytotoxic activity of seven bile samples and bile acids using the high-performance liquid chromatography (hplc)-evaporative light scattering detector (elsd) method. free and conjugated bile acid standards were used to identify and quantify the chemical components of the seven animal bile samples. the mtt assay was used to determine the cytotoxic effect of the animal bile samples and the free and conjugated bile a ... | 2011 | 22977479 |
| phase-dependent climate-predator interactions explain three decades of variation in neonatal caribou survival. | climate can have direct and indirect effects on population dynamics via changes in resource competition or predation risk, but this influence may be modulated by density- or phase-dependent processes. we hypothesized that for ungulates, climatic conditions close to parturition have a greater influence on the predation risk of neonates during population declines, when females are already under nutritional stress triggered by food limitation. we examined the presence of phase-dependent climate-pre ... | 2016 | 26529139 |
| evaluating noninvasive genetic sampling techniques to estimate large carnivore abundance. | monitoring large carnivores is difficult because of intrinsically low densities and can be dangerous if physical capture is required. noninvasive genetic sampling (ngs) is a safe and cost-effective alternative to physical capture. we evaluated the utility of two ngs methods (scat detection dogs and hair sampling) to obtain genetic samples for abundance estimation of coyotes, black bears and canada lynx in three areas of newfoundland, canada. we calculated abundance estimates using program capwir ... | 2015 | 25693632 |
| anthropogenic influences on macro-level mammal occupancy in the appalachian trail corridor. | anthropogenic effects on wildlife are typically assessed at the local level, but it is often difficult to extrapolate to larger spatial extents. macro-level occupancy studies are one way to assess impacts of multiple disturbance factors that might vary over different geographic extents. here we assess anthropogenic effects on occupancy and distribution for several mammal species within the appalachian trail (at), a forest corridor that extends across a broad section of the eastern united states. ... | 2012 | 22880038 |
| home range scaling: intraspecific and comparative trends. | intraspecific and intrasexual variation in home range size, body mass and ecological productivity is examined in three selected species of carnivora (felis rufus: canis latrans; ursus americanus), reflecting different diets. we then compare the intraspecific results with prior cross-species studies. home range size and body mass infelis rufus are positively and significantly correlated, similar to other comparative studies. for both intraspecific and intrasexual analyses of all three species, ho ... | 1991 | 28313260 |
| innate threat-sensitive foraging: black-tailed deer remain more fearful of wolf than of the less dangerous black bear even after 100 years of wolf absence. | anti-predator behaviors often entail foraging costs, and thus prey response to predator cues should be adjusted to the level of risk (threat-sensitive foraging). simultaneously dangerous predators (with high hunting success) should engender the evolution of innate predator recognition and appropriate anti-predator behaviors that are effective even upon the first encounter with the predator. the above leads to the prediction that prey might respond more strongly to cues of dangerous predators tha ... | 2014 | 24288079 |
| avoidance of roads and selection for recent cutovers by threatened caribou: fitness-rewarding or maladaptive behaviour? | the impact of anthropogenic disturbance on the fitness of prey should depend on the relative effect of human activities on different trophic levels. this verification remains rare, however, especially for large animals. we investigated the functional link between habitat selection of female caribou (rangifer tarandus) and the survival of their calves, a fitness correlate. this top-down controlled population of the threatened forest-dwelling caribou inhabits a managed forest occupied by wolves (c ... | 2012 | 22951736 |
| use of acepromazine and medetomidine in combination for sedation and handling of rocky mountain elk (cervus elaphus nelsoni) and black bears (ursus americanus). | we opportunistically evaluated a combination of acepromazine maleate and medetomidine hcl for use in sedating rocky mountain elk (cervus elaphus nelsoni) and black bears (ursus americanus) as an alternative to scheduled drug combinations. this combination was safe and effective with limitations inherent in its sedative rather than anesthetic properties. | 2014 | 25014907 |
| novel species interactions: american black bears respond to pacific herring spawn. | in addition to the decline and extinction of the world's species, the decline and eventual loss of species interactions is one of the major consequences of the biodiversity crisis. on the pacific coast of north america, diminished runs of salmon (oncorhynchus spp.) drive numerous marine-terrestrial interactions, many of which have been intensively studied, but marine-terrestrial interactions driven by other species remain relatively unknown. bears (ursus spp.) are major vectors of salmon into te ... | 2015 | 26013706 |
| effects of climate and exurban development on nest predation and predator presence in the southern appalachian mountains (usa). | in the eastern united states, land-use and climate change have likely contributed to declines in the abundance of neotropical migrant birds that occupy forest interiors, but the mechanisms are not well understood. we conducted a nest-predation experiment in southern appalachian mountain forests (north carolina, u.s.a.) during the 2009 and 2010 breeding seasons to determine the effects of exurban development and temperature on predator presence and the average number of days until eggs in an arti ... | 2012 | 22624665 |
| black bear reactions to venomous and non-venomous snakes in eastern north america. | bears are often considered ecological equivalents of large primates, but the latter often respond with fear, avoidance, and alarm calls to snakes, both venomous and non-venomous, there is sparse information on how bears respond to snakes. we videotaped or directly observed natural encounters between black bears (ursus americanus) and snakes. inside the range of venomous snakes in arkansas and west virginia, adolescent and adult black bears reacted fearfully in seven of seven encounters upon beco ... | 2014 | 25635152 |
| vampire bat, shrew, and bear: comparative physiology and chronic renal failure. | in the typical mammal, energy flux, protein metabolism, and renal excretory processes constitute a set of closely linked and quantitatively matched functions. however, this matching has limits, and these limits become apparent when animals adapt to unusual circumstances. the vampire bat and shrew have an extremely high protein intake, and the glomerular filtration rate (gfr) is not commensurate with the large urea load to be excreted. the vampire bat is chronically azotemic (blood urea concentra ... | 2002 | 12010738 |
| fatal disseminated blastomycosis in a free-ranging american black bear (ursus americanus). | an aged, free-ranging, female, radio-collared american black bear (ursus americanus) died after an approximately 5 month long period of weight loss. gross necropsy findings included severe diffuse pyogranulomatous bronchopneumonia, marked granulomatous lymphadenitis of tracheobronchial lymph nodes and multiple intra-abdominal lymph nodes, chronic focal jejunal ulceration, and widespread alopecia. histopathologic examination revealed abundant fungal organisms morphologically compatible with blast ... | 2012 | 23012379 |
| a new species of sarcocystis (apicomplexa: sarcocystidae) from the black bear (ursus americanus). | infection with sarcocystis species is common in herbivores but is rare in bears. histological sections of 374 black bears (ursus americanus) from pennsylvania were examined for sarcocysts. in total, 3 sarcocysts were found in 3 bears, with 1 sarcocyst per section. sarcocysts from 2 bears were considered a new species, sarcocystis ursusi. sarcocysts of s. ursusi n. sp. were microscopic and contained only bradyzoites. by light microscopy, the sarcocyst wall was thin (< 0.5 microm thick) and had mi ... | 2008 | 18564883 |
| purifying selection drives the evolution of surfactant protein c (sp-c) independently of body temperature regulation in mammals. | the pulmonary surfactant system of heterothermic mammals must be capable of dealing with the effect of low body temperatures on the physical state of the lipid components. we have shown previously that there is a modest increase in surfactant cholesterol during periods of torpor, however these changes do not fully explain the capacity of surfactant to function under the wide range of physical conditions imposed by torpor. here we examine indirectly the role of surfactant protein c (sp-c) in adap ... | 2007 | 20483290 |
| prouterina wescotti n. gen., n. sp. (trematoda: prouterinidae n. fam.) from the brain, lungs, and nasal sinuses of a black bear (ursus americanus) from idaho. | prouterina wescotti gen. n. and sp. n. (trematoda: prouterinidae n. fam.) is described from a free-ranging black bear (ursus americanus) which died in may 1995 in northern idaho (usa). adult digenetic trematodes were detected in brain, lungs, and nasal sinuses, and were likely responsible for the emaciated condition, copious nasal discharge, neurological signs, and death of the bear. mature trematodes recovered from the bear were conical with small spines on the tegument. the anterior end was br ... | 1996 | 8722259 |
| demodicosis in black bears (ursus americanus) from florida. | demodicosis was diagnosed in five black bears (ursus americanus) from north-central florida. the first bear examined, a 5-yr-old male, had severe alopecia except for the dorsal neck, paws, and ears. the skin was characterized by moderate orthokeratotic hyperkeratosis, and mild to moderate follicular hyperkeratosis. superficial dermatitis, follicular pustules, and epidermal pustules were present, but rare. specimens of demodex sp. were seen most commonly within hair follicles devoid of hair and a ... | 1993 | 8445774 |
| eimeria albertensis n.sp. and e. borealis n.sp. (sporozoa: eimeriidae) in black bears ursus americanus from alberta. | | 1970 | 5534085 |
| ambiguous results when using the ambiguous-cue paradigm to assess learning and cognitive bias in gorillas and a black bear. | cognitive bias tests are frequently used to assess affective state in nonhumans. we adapted the ambiguous-cue paradigm to assess affective states and to compare learning of reward associations in two distantly related species, an american black bear and three western lowland gorillas. subjects were presented with three training stimuli: one that was always rewarded (p), one that was never rewarded (n) and one that was ambiguous (a) because its reward association depended on whether it had been p ... | 2017 | 28792447 |
| social and nonsocial category discriminations in a chimpanzee (pan troglodytes) and american black bears (ursus americanus). | one captive adult chimpanzee and 3 adult american black bears were presented with a series of natural category discrimination tasks on a touch-screen computer. this is the first explicit comparison of bear and primate abilities using identical tasks, and the first test of a social concept in a carnivore. the discriminations involved a social relationship category (mother/offspring) and a nonsocial category involving food items. the social category discrimination could be made using knowledge of ... | 2014 | 24903598 |
| what is your diagnosis? blood film from a black bear (ursus americanus). | | 2017 | 28745834 |
| prevalence of babesia spp., ehrlichia spp., and tick infestations in oklahoma black bears (ursus americanus). | american black bears (ursus americanus) are commonly infested with ticks throughout their range, but there are few surveys for tick-borne disease agents in bears. to characterize tick infestations and determine the prevalence of current infection with babesia spp. and past or current infection with ehrlichia spp. in newly re-established populations of black bears in east central and southeastern oklahoma, we identified adult (n=1,048) and immature (n=107) ticks recovered from bears (n=62). we ev ... | 2017 | 28657860 |
| molecular genetic-distance estimates among the ursidae as indicated by one- and two-dimensional protein electrophoresis. | evolutionary relationships among eight species of ursidae (including the giant panda) relative to two procyonidae species (raccoon and red panda) were estimated based on the extent of electrophoretic variation of 289 radiolabelled fibroblast proteins resolved by two-dimensional gel electrophoresis and among 44 isozyme loci resolved by one-dimensional electrophoresis. allelic differences among these species were converted to genetic distances, and phenetic trees were constructed. in addition, the ... | 1989 | 28568545 |
| quantitative morphology of the panda brain in comparison with the brains of the raccoon and the bear. | the quantitative development of brain and brain components with respect to body-size is discussed comparatively for the chinese giant panda, the canadian raccoon and the american black bear. the panda ranks highest in encephalization as well as in relative volumes of neocortex, cerebellum and six other parts. the raccoon exhibits the strongest development of olfactory elements. the bear stays below the other species, showing but a single index that is superior to the corresponding index in one o ... | 1985 | 3989277 |
| genetic characterization of sarcoptes scabiei from black bears (ursus americanus) and other hosts in eastern united states. | since the early 1990s there has been an increase in the number of cases and geographic expansion of severe mange in the black bear (ursus americanus) population in pennsylvania. although there are 3 species of mites associated with mange in bears, sarcoptes scabiei has been identified as the etiologic agent in these pennsylvania cases. historically s. scabiei-associated mange in bears has been uncommon and sporadic although it is widespread and relatively common in canid populations. to better u ... | 2017 | 28639466 |
| differential habitat use or intraguild interactions: what structures a carnivore community? | differential habitat use and intraguild competition are both thought to be important drivers of animal population sizes and distributions. habitat associations for individual species are well-established, and interactions between particular pairs of species have been highlighted in many focal studies. however, community-wide assessments of the relative strengths of these two factors have not been conducted. we built multi-scale habitat occupancy models for five carnivore taxa of new york's adiro ... | 2016 | 26731404 |
| mitochondrial genome phylogeny among asiatic black bear ursus thibetanus subspecies and comprehensive analysis of their control regions. | the complete mitochondrial genome (16,824 bp) of an asiatic black bear ursus thibetanus ussuricus (mammalia, carnivora, ursidae) was newly sequenced and characterized in detail. it is the second mitochondrial genome from this subspecies which has been completely sequenced. the two u. t. ussuricus individuals were compared with each other and then with individuals from the other four u. thibetanus subspecies and the other nine ursid species, focusing especially on the control regions in the 14 mi ... | 2010 | 20795781 |
| phylogeny of the bears (ursidae) based on nuclear and mitochondrial genes. | the taxomic classification and phylogenetic relationships within the bear family remain argumentative subjects in recent years. prior investigation has been concentrated on the application of different mitochondrial (mt) sequence data, herein we employ two nuclear single-copy gene segments, the partial exon 1 from gene encoding interphotoreceptor retinoid binding protein (irbp) and the complete intron 1 from transthyretin (ttr) gene, in conjunction with previously published mt data, to clarify t ... | 2004 | 15223031 |
| techniques for application of faecal dna methods to field studies of ursids. | we describe methods for the preservation, extraction and amplification of dna from faeces that facilitate field applications of faecal dna technology. mitochondrial, protein encoding and microsatellite nuclear dna extracted and amplified from faeces of malayan sun bears and north american black bears is shown to be identical to that extracted and amplified from the same individual's tissue or blood. a simple drying agent, silica beads, is shown to be a particularly effective preservative, allowi ... | 1997 | 9394465 |
| oocyte recovery and maturation in the american black bear (ursus americanus): a model for endangered ursids. | a study was conducted to determine if meiotic maturation could be induced in ovarian oocytes of the american black bear (ursus americanus), a model for gamete "rescue" techniques for endangered ursids. ovaries obtained from 48 black bears yielded 2,403 oocytes (51.1 +/- 4.9/female), of which 777 (32.3%) were morphologically classified as excellent quality. more total oocytes were recovered from donors that were anestrous compared to luteal/pregnant (p < 0.05) at the time of ovarian excision. del ... | 1994 | 8207381 |
| bears in a forest of gene trees: phylogenetic inference is complicated by incomplete lineage sorting and gene flow. | ursine bears are a mammalian subfamily that comprises six morphologically and ecologically distinct extant species. previous phylogenetic analyses of concatenated nuclear genes could not resolve all relationships among bears, and appeared to conflict with the mitochondrial phylogeny. evolutionary processes such as incomplete lineage sorting and introgression can cause gene tree discordance and complicate phylogenetic inferences, but are not accounted for in phylogenetic analyses of concatenated ... | 2014 | 24903145 |
| some physiologic and pharmacologic observations in african lions and american black bears. | | 1962 | 13917573 |
| the comparative effects of large carnivores on the acquisition of carrion by scavengers. | pumas (puma concolor) and black bears (ursus americanus) are large carnivores that may influence scavenger population dynamics. we used motion-triggered video cameras deployed at deer carcasses to determine how pumas and black bears affected three aspects of carrion acquisition by scavengers: presence, total feeding time, and mean feeding-bout duration. we found that pumas were unable to limit acquisition of carrion by large carnivores but did limit aspects of carrion acquisition by both birds a ... | 2015 | 25996866 |
| not accounting for interindividual variability can mask habitat selection patterns: a case study on black bears. | habitat selection studies conducted at the population scale commonly aim to describe general patterns that could improve our understanding of the limiting factors in species-habitat relationships. researchers often consider interindividual variation in selection patterns to control for its effects and avoid pseudoreplication by using mixed-effect models that include individuals as random factors. here, we highlight common pitfalls and possible misinterpretations of this strategy by describing ha ... | 2017 | 28889201 |
| comparative coagulation studies in hibernating and summer-active black bears (ursus americanus). | | 2017 | 28783512 |
| consequences of severe habitat fragmentation on density, genetics, and spatial capture-recapture analysis of a small bear population. | loss and fragmentation of natural habitats caused by human land uses have subdivided several formerly contiguous large carnivore populations into multiple small and often isolated subpopulations, which can reduce genetic variation and lead to precipitous population declines. substantial habitat loss and fragmentation from urban development and agriculture expansion relegated the highlands-glades subpopulation (hgs) of florida, usa, black bears (ursus americanus floridanus) to prolonged isolation ... | 2017 | 28738077 |
| the evolutionary history of bears is characterized by gene flow across species. | bears are iconic mammals with a complex evolutionary history. natural bear hybrids and studies of few nuclear genes indicate that gene flow among bears may be more common than expected and not limited to polar and brown bears. here we present a genome analysis of the bear family with representatives of all living species. phylogenomic analyses of 869 mega base pairs divided into 18,621 genome fragments yielded a well-resolved coalescent species tree despite signals for extensive gene flow across ... | 2017 | 28422140 |
| determining causes of genetic isolation in a large carnivore (ursus americanus) population to direct contemporary conservation measures. | the processes leading to genetic isolation influence a population's local extinction risk, and should thus be identified before conservation actions are implemented. natural or human-induced circumstances can result in historical or contemporary barriers to gene flow and/or demographic bottlenecks. distinguishing between these hypotheses can be achieved by comparing genetic diversity and differentiation in isolated vs. continuous neighboring populations. in ontario, american black bears (ursus a ... | 2017 | 28235066 |
| detection and prevalence of four different hemotropic mycoplasma spp. in eastern north carolina american black bears (ursus americanus). | hemotropic mycoplasma spp. are globally emerging, obligate parasitic, epierythrocytic bacteria that infect many vertebrates, including humans. hemoplasma infection can cause acute life-threatening symptoms or lead to a chronic sub-clinical carrier state. hemotropic mycoplasma spp. transmission, prevalence, and host specificity are uncertain. the purpose of this study was to determine the molecular prevalence of mycoplasma species in blood from 68 free-ranging black bears from the eastern coast o ... | 2017 | 28131370 |
| six years in the life of a mother bear - the longest continuous heart rate recordings from a free-ranging mammal. | physiological monitoring of free-ranging wild animals is providing new insights into their adaptations to a changing environment. american black bears (ursus americanus) are highly adaptable mammals, spending up to half the year hibernating, and the remainder of the year attempting to gain weight on a landscape with foods that vary seasonally and year to year. we recorded heart rate (hr) and corresponding activity of an adult female black bear over the course of six years, using an implanted mon ... | 2017 | 28094804 |
| trichinella surveillance in black bears ( ursus americanus ) from the dehcho region, northwest territories, canada, 2002-15. | we used muscle digestion to test black bears ( ursus americanus ) from the southwestern northwest territories, canada, for trichinella. results showed a prevalence of 4.1%. some bears had infection intensities of more than one larva per gram of muscle tissue; this level in meat is considered to pose a human consumption safety risk. | 2017 | 28094606 |
| dental and temporomandibular joint pathology of the american black bear (ursus americanus). | museum specimens (maxillae and/or mandibles) from 371 american black bears (ursus americanus) acquired between 1889 and 2006 were examined macroscopically according to predefined criteria, and 348 were included in this study. of the 348 specimens, 126 (36.2%) were from male animals, 106 (30.5%) were from female animals and 116 (33.3%) were from animals of unknown sex. specimen ages ranged from young adult (n = 63, 18.1%) to adult (n = 285, 81.9%), with juveniles excluded from the study. the numb ... | 2017 | 27989366 |
| blood clotting behavior is innately modulated in ursus americanus during early and late denning relative to summer months. | remarkably, american black bears (ursus americanus) are capable of varying their heart rates to coincide with their breathing, creating pauses of 30 s or more, yet they do not appear to suffer from embolic events. we evaluated some features of the clotting cascade of black bears, providing novel insights into the underlying mechanisms they evoke for embolic protection during hibernation. we measured activated clotting time, prothrombin time and activated partial thromboplastin time during early ... | 2017 | 27885044 |
| hydrocephalus in three juvenile north american black bears (ursus americanus). | hydrocephalus has been reported in a variety of species, including the north american black bear ( ursus americanus ). this report describes three cases of hydrocephalus in this species from wild bears aged 3-4 mo considered retrospectively from necropsy records of one institution. clinical signs included cortical blindness and ataxia. primary gross findings were doming of the skull, gyri compression and flattening, and lateral ventricle dilation. two cases had severe bilateral ventricular dilat ... | 2016 | 27468040 |
| detecting black bear source-sink dynamics using individual-based genetic graphs. | source-sink dynamics affects population connectivity, spatial genetic structure and population viability for many species. we introduce a novel approach that uses individual-based genetic graphs to identify source-sink areas within a continuously distributed population of black bears (ursus americanus) in the northern lower peninsula (nlp) of michigan, usa. black bear harvest samples (n = 569, from 2002, 2006 and 2010) were genotyped at 12 microsatellite loci and locations were compared across y ... | 2016 | 27440668 |
| picture object recognition in an american black bear (ursus americanus). | many animals have been tested for conceptual discriminations using two-dimensional images as stimuli, and many of these species appear to transfer knowledge from 2d images to analogous real life objects. we tested an american black bear for picture-object recognition using a two alternative forced choice task. she was presented with four unique sets of objects and corresponding pictures. the bear showed generalization from both objects to pictures and pictures to objects; however, her transfer w ... | 2016 | 27342434 |
| isotopic incorporation and the effects of fasting and dietary lipid content on isotopic discrimination in large carnivorous mammals. | there has been considerable emphasis on understanding isotopic discrimination for diet estimation in omnivores. however, discrimination may differ for carnivores, particularly species that consume lipid-rich diets. here, we examined the potential implications of several factors when using stable isotopes to estimate the diets of bears, which can consume lipid-rich diets and, alternatively, fast for weeks to months. we conducted feeding trials with captive brown bears (ursus arctos) and polar bea ... | 2017 | 27153128 |
| spatial distribution of black bear incident reports in michigan. | interactions between humans and carnivores have existed for centuries due to competition for food and space. american black bears are increasing in abundance and populations are expanding geographically in many portions of its range, including areas that are also increasing in human density, often resulting in associated increases in human-bear conflict (hereafter, bear incidents). we used public reports of bear incidents in michigan, usa, from 2003-2011 to assess the relative contributions of e ... | 2016 | 27119344 |
| an evolutionarily young polar bear (ursus maritimus) endogenous retrovirus identified from next generation sequence data. | transcriptome analysis of polar bear (ursus maritimus) tissues identified sequences with similarity to porcine endogenous retroviruses (perv). based on these sequences, four proviral copies and 15 solo long terminal repeats (ltrs) of a newly described endogenous retrovirus were characterized from the polar bear draft genome sequence. closely related sequences were identified by pcr analysis of brown bear (ursus arctos) and black bear (ursus americanus) but were absent in non-ursinae bear species ... | 2015 | 26610552 |
| sex, diet, and the social environment: factors influencing hair cortisol concentration in free-ranging black bears (ursus americanus). | increasingly, measures of glucocorticoid levels (e.g., cortisol), key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (hpa) activity to index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. however, many intrinsic and extrinsic factors affect hpa activity in animals. using american black bears (ursus americanus; n = 116) as an ecological model and hair cortisol conce ... | 2015 | 26529405 |
| growth trajectories in the cave bear and its extant relatives: an examination of ontogenetic patterns in phylogeny. | the study of postnatal ontogeny can provide insights into evolution by offering an understanding of how growth trajectories have evolved resulting in adult morphological disparity. the ursus lineage is a good subject for studying cranial and mandibular shape and size variation in relation to postnatal ontogeny and phylogeny because it is at the same time not diverse but the species exhibit different feeding ecologies. cranial and mandibular shapes of ursus arctos (brown bear), u. maritimus (pola ... | 2015 | 26525575 |
| bears show a physiological but limited behavioral response to unmanned aerial vehicles. | unmanned aerial vehicles (uavs) have the potential to revolutionize the way research is conducted in many scientific fields. uavs can access remote or difficult terrain, collect large amounts of data for lower cost than traditional aerial methods, and facilitate observations of species that are wary of human presence. currently, despite large regulatory hurdles, uavs are being deployed by researchers and conservationists to monitor threats to biodiversity, collect frequent aerial imagery, estima ... | 2015 | 26279232 |
| when top predators become prey: black bears alter movement behaviour in response to hunting pressure. | the trade-off between predator avoidance and foraging is a key decision making factor that shapes an organism's adaptive behaviour and movement patterns. human hunters act as top predators to influence the behaviour of free-ranging mammals, including large carnivorous species such as black bears (ursus americanus). analysing the effects of hunting on animal behavioural patterns is essential for understanding the extent to which animals detect and respond to human-induced disturbances. to this en ... | 2015 | 26277059 |
| suppressed bone remodeling in black bears conserves energy and bone mass during hibernation. | decreased physical activity in mammals increases bone turnover and uncouples bone formation from bone resorption, leading to hypercalcemia, hypercalcuria, bone loss and increased fracture risk. black bears, however, are physically inactive for up to 6 months annually during hibernation without losing cortical or trabecular bone mass. bears have been shown to preserve trabecular bone volume and architectural parameters and cortical bone strength, porosity and geometrical properties during hiberna ... | 2015 | 26157160 |
| genomics of american black bears reveal surprising ancient migration patterns to aid conservation efforts. | | 2015 | 26137944 |
| linking gps telemetry surveys and scat analyses helps explain variability in black bear foraging strategies. | studying diet is fundamental to animal ecology and scat analysis, a widespread approach, is considered a reliable dietary proxy. nonetheless, this method has weaknesses such as non-random sampling of habitats and individuals, inaccurate evaluation of excretion date, and lack of assessment of inter-individual dietary variability. we coupled gps telemetry and scat analyses of black bears ursus americanus pallas to relate diet to individual characteristics and habitat use patterns while foraging. w ... | 2015 | 26132204 |
| social network analysis of mating patterns in american black bears (ursus americanus). | nonrandom mating can structure populations and has important implications for population-level processes. investigating how and why mating deviates from random is important for understanding evolutionary processes as well as informing conservation and management. prior to the implementation of parentage analyses, understanding mating patterns in solitary, elusive species like bears was virtually impossible. here, we capitalize on a long-term genetic data set collected from black bears (ursus ame ... | 2015 | 26113220 |
| the urothelium of a hibernator: the american black bear. | the american black bear undergoes a 3-5 month winter hibernation during which time bears do not eat, drink, defecate, or urinate. during hibernation renal function (gfr) is 16-50% of normal but urine is reabsorbed across the urinary bladder (ub) urothelium thus enabling metabolic recycling of all urinary constituents. to elucidate the mechanism(s) whereby urine is reabsorbed, we examined the ubs of five nonhibernating wild bears using light, electron (em), and confocal immunofluorescent (if) mic ... | 2015 | 26109187 |
| insights from the den: how hibernating bears may help us understand and treat human disease. | hibernating brown bears (ursus arctos) and black bears (ursus americanus) spend half of the year in a physically inactive state inside their winter dens without food intake and defecating and no or little urination. under similar extreme conditions, humans would suffer from loss of lean body mass, heart failure, thrombosis, azotemia, osteoporosis, and more. however, bears exit the den in the spring strong without organ injuries. translational animal models are used in human medicine but traditio ... | 2015 | 26083277 |
| surgical correction of bilateral patellar luxation in an american black bear cub (ursus americanus). | a wild orphaned male american black bear cub ( ursus americanus ) presented with hind limb gait abnormalities and was found to have bilateral grade 3 laterally luxating patellas. there were no other significant abnormalities detected on neurologic, radiographic, or hematologic examinations. the trochlear grooves were deepened with a chondroplasty, and the redundant soft tissues imbricated. there was a marked improvement in the bear's gait postoperatively, with an apparent full return to function ... | 2015 | 26056894 |