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Improper food storage fuels human-bear conflicts in parks and protected areas around the globe. Bear-resistant food storage canisters provide an extremely effective solution for reducing food-related human-bear conflicts, especially for overnight visitors in backcountry settings. However, the success of this intervention depends on recreationists' willingness to use and comply with such food storage methods. This study used internet-based surveys to identify Appalachian Trail backpackers' attitudes, norms, perceived behavioral control, and intentions regarding the use of bear canisters through an application of the Theory of Planned Behavior. Results indicate attitudes and subjective norms provide potential leverage points for messaging under voluntary conditions; messaging incorporating attitudes, subjective norms, and perceived behavioral control may help influence food storage behavior under required conditions. Specific recommendations for effective, theorybased interpretation strategies aimed at reducing human-black bear conflicts on the Appalachian Trail are provided. [ABSTRACT FROM AUTHOR]

Human-dominated landscapes contain fragmented natural land cover interspersed throughout an urban matrix. Animals that occupy human-dominated landscapes often grow and reproduce differently than conspecifics. Female American black bears (Ursus americanus) produce litters for the first time usually at age 4 years; 2-year-olds rarely give birth. We visited winter bear dens and trapped bears in spring and summer to compare the reproductive output and weight of female black bears within the city limits of Asheville, North Carolina, and three forested rural sites in North Carolina and Virginia representative of the undeveloped habitat of Asheville. Urban yearling females weighed nearly double (45.0 kg ± 8.1 [± SD ]; n = 36) that of yearling females from the three rural study sites (23.2 ± 8.5 [Pisgah], 23.6 ± 8.3 [Virginia SW], and 23.9 ± 9.7 [Virginia NW]; n = 95). Across all sites, hard mast production during the autumn, when females were cubs, did not affect their weights as yearlings. Seven of 12 (58%) 2-year-old urban bears produced 11 cubs (mean litter size = 1.6 ± 0.8), but no 2-year-old rural females produced cubs. Production of hard mast in the autumn, when females were yearlings, did not influence cub production by 2-year-old female bears at the urban site. We hypothesize that reproduction by 2-year-old bears is linked to the availability of anthropogenic food sources associated with urban environments. To inform population level management decisions, managers and researchers should quantify urban food sources and the effects on black bear life history. If high fecundity allows urban populations to sustain relatively high mortality rates, then urban bear populations may be source populations for surrounding, rural areas. Alternately, if reproduction in urban populations cannot match high time-specific or age-specific urban mortality rates, then urban populations may be sinks for the surrounding areas. [ABSTRACT FROM AUTHOR]

Gray wolf populations have exceeded anticipated recovery levels since they were first reintroduced to central Idaho in 1995. Although wolf predation on livestock is a relatively minor issue to the livestock industry as a whole, it can be a serious problem for some individual livestock producers who graze their stock in occupied wolf habitat. This paper compares Idaho population estimates for gray wolves with the available information on numbers of livestock killed by wolves in order to estimate numbers of livestock killed per wolf. This information is compared with similar analyses for other species most commonly implicated as predators of livestock in Idaho (coyotes, black bears, and mountain lions). Population estimates for coyotes, black bears, and mountain lions are based on review of available scientific literature and analyses in environmental assessments prepared by Wildlife Services, as well as estimates from the Idaho Department of Fish and Game. Wolf population estimates are based primarily on monitoring information provided by the Idaho Department of Fish and Game and the Nez Perce Tribe. Estimates of numbers of livestock killed by wolves, coyotes, black bears, and mountain lions are based on survey data compiled by the National Agricultural Statistics Service. Rationale for use of various data sets is provided, and limitations of the data are discussed. This analysis suggests that individual wolves are much more likely to prey on livestock than are individuals of any other predator species in Idaho.

Developing the capacity to predict black bear (Ursus americanus; bear) activity in a diversity of habitats will help conserve bear populations and their habitats and minimize human–bear conflicts. This capacity will be particularly important in areas that provide bear habitat and offer backcountry hiking and camping experiences. Bryce Canyon National Park (BRCA), located on the edge of the Paunsaugunt Plateau in southern Utah, USA, provides important bear habitat and offers visitors 12 backcountry campsites. To effectively manage these areas to minimize human–bear conflicts, park managers will need better information about black bear use of these campsites and other anthropogenic features in the BRCA. From 2014–2016, we studied the nature and frequency of bear activity within BRCA, with an emphasis on bear–campsite relationships, by analyzing bear activity data using radio-collared bears, remote camera monitoring of areas containing features of interest, campsite assessments, and analysis of human–bear interaction reports. We further assessed and ranked each backcountry campsite regarding its bear habitat quality, bear displacement potential, and human–bear conflict potential. Model selection showed bear preference for campsites and springs and avoidance of trails and roads. During site assessments, we identified a number of modifications to existing campsites that may help minimize human– bear interactions. Foremost among these changes is the relocation of campsites farther off-trail to avoid bears using trails. Specifically, we recommend that campsites be no closer than 200 m to permanent water sources. Finally, while the park requires the use of bear-resistant food containers, we recommend backcountry visitors also be encouraged to carry bear spray.

Developing the capacity to predict black bear (Ursus americanus; bear) activity in a diversity of habitats will help conserve bear populations and their habitats and minimize human--bear conflicts. This capacity will be particularly important in areas that provide bear habitat and offer backcountry hiking and camping experiences. Bryce Canyon National Park (BRCA), located on the edge of the Paunsaugunt Plateau in southern Utah, USA, provides important bear habitat and offers visitors 12 backcountry campsites. To effectively manage these areas to minimize human--bear conflicts, park managers will need better information about black bear use of these campsites and other anthropogenic features in the BRCA. From 2014-2016, we studied the nature and frequency of bear activity within BRCA, with an emphasis on bear--campsite relationships, by analyzing bear activity data using radiocollared bears, remote camera monitoring of areas containing features of interest, campsite assessments, and analysis of human--bear interaction reports. We further assessed and ranked each backcountry campsite regarding its bear habitat quality, bear displacement potential, and human--bear conflict potential. Model selection showed bear preference for campsites and springs and avoidance of trails and roads. During site assessments, we identified a number of modifications to existing campsites that may help minimize human--bear interactions. Foremost among these changes is the relocation of campsites farther off-trail to avoid bears using trails. Specifically, we recommend that campsites be no closer than 200 m to permanent water sources. Finally, while the park requires the use of bear-resistant food containers, we recommend backcountry visitors also be encouraged to carry bear spray. [ABSTRACT FROM AUTHOR]

In the 1980s, black bears (Ursus americanus) began expanding into historic habitats in northwestern Nevada, USA. Over a period of >30 years, black bears recolonized areas where human populations have also increased. Our research represents one of, if not the longest-running and earliest comparative studies of a black bear population at wildland–urban interface and wildland areas in North America. As the population increased, we observed: 1) increasing human–bear conflicts in areas where several generations of people had lived in almost total absence of bears (70–80+ years); 2) changes in attitudes by the public toward bears and in the social realm regarding garbage management; and 3) changes in the demographics, behavior, and ecology of this bear population, due to an increasing human footprint on the landscape. Herein, we discuss a few of the lessons learned from this long-term study and the value of a collaborative approach between a state agency, a university, and an international conservation organization. Our collaborative approach allowed us to better understand the ecological, demographic, and behavioral changes in a large, recolonizing carnivore that is a functional omnivore, often residing at the wildland-urban interface, and to use these data to impact conservation and management. Throughout the study, our data were used extensively by various media, emphasizing public education about human–bear conflicts. This media platform proved important because of the impact it had on wildlife conservation. For example, partly in response to media coverage of our data-based education efforts, 3 Nevada counties enacted garbage management ordinances, and the Nevada legislature passed a state law prohibiting the feeding of large game mammals. Further, several million dollars in bear-resistant garbage containers are now used in the region by the public and government entities. The end result of these conservation measures has been a recolonization of the Great Basin Desert by bears from the Lake Tahoe Basin and Sierra-Nevada Range into portions of Nevada where bears have been absent for >80 years.

Although bear-inflicted (Ursus spp.) human fatalities are rare in North America, human injuries, property damage, and bear mortalities occur wherever bears and humans commingle. We investigated the efficacy of portable electric fencing systems for bear deterrence under a variety of environmental conditions in the lab and field. Our results showed that the bear deterrent systems we evaluated were effective in protecting humans, their food, and property from bears >99% of the time. Herein, we discuss the benefits of using electric fencing, reasons why fences sometimes fail, and provide guidance regarding the most effective implementation of the systems we evaluated. Lastly, we also explore why this deterrent is not yet in widespread use. We encourage the use of electric fencing in bear country for protecting humans, their camping gear and food, and ultimately to promote bear conservation.

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 urbansuburban 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 population in and around Asheville, North Carolina using serologic and molecular surveys. We collected blood from captured black bears (n=94) and kidneys and bladders from carcasses (n=19). We tested a total of 96 (47 females, 47 males, and 2 unknown) serum samples by microscopic agglutination test (MAT) and had positive results (titer >1:100) for L. kirschneri serovar Grippotyphosa (L. Grippotyphosa) in 4 females (8%) and 5 males (10%). No other serovars showed elevated titers in MAT. We tested a total of 125 samples using PCR (n=96 serum, n=20 kidney, and n=9 bladders) and obtained positive results from one serum (1%), one kidney (5%), and one bladder (11%). The presence of Leptospira spp. in black bears occupying an urban and suburban landscape may indicate a more extensive occurrence of the bacteria among animals in the study region because black bears are the top carnivore in that ecosystem. Potential threats of widespread contamination during natural events such as flood or drought must be considered. [ABSTRACT FROM AUTHOR]

Although bear-inflicted (Ursus spp.) human fatalities are rare in North America, human injuries, property damage, and bear mortalities occur wherever bears and humans commingle. We investigated the efficacy of portable electric fencing systems for bear deterrence under a variety of environmental conditions in the lab and field. Our results showed that the bear deterrent systems we evaluated were effective in protecting humans, their food, and property from bears >99% of the time. Herein, we discuss the benefits of using electric fencing, reasons why fences sometimes fail, and provide guidance regarding the most effective implementation of the systems we evaluated. Lastly, we also explore why this deterrent is not yet in widespread use. We encourage the use of electric fencing in bear country for protecting humans, their camping gear and food, and ultimately to promote bear conservation. [ABSTRACT FROM AUTHOR]

In the 1980s, black bears (Ursus americanus) began expanding into historic habitats in northwestern Nevada, USA. Over a period of >30 years, black bears recolonized areas where human populations have also increased. Our research represents one of, if not the longest-running and earliest comparative studies of a black bear population at wildland- urban interface and wildland areas in North America. As the population increased, we observed: 1) increasing human-bear conflicts in areas where several generations of people had lived in almost total absence of bears (70-80+ years); 2) changes in attitudes by the public toward bears and in the social realm regarding garbage management; and 3) changes in the demographics, behavior, and ecology of this bear population, due to an increasing human footprint on the landscape. Herein, we discuss a few of the lessons learned from this long-term study and the value of a collaborative approach between a state agency, a university, and an international conservation organization. Our collaborative approach allowed us to better understand the ecological, demographic, and behavioral changes in a large, recolonizing carnivore that is a functional omnivore, often residing at the wildlandurban interface, and to use these data to impact conservation and management. Throughout the study, our data were used extensively by various media, emphasizing public education about human-bear conflicts. This media platform proved important because of the impact it had on wildlife conservation. For example, partly in response to media coverage of our databased education efforts, 3 Nevada counties enacted garbage management ordinances, and the Nevada legislature passed a state law prohibiting the feeding of large game mammals. Further, several million dollars in bear-resistant garbage containers are now used in the region by the public and government entities. The end result of these conservation measures has been a recolonization of the Great Basin Desert by bears from the Lake Tahoe Basin and Sierra-Nevada Range into portions of Nevada where bears have been absent for >80 years. [ABSTRACT FROM AUTHOR]

ABSTRACT Wildlife consumption of human foods is common and these subsidies can alter a species' behavior, demography, and interspecific interactions, and lead to conflicts with humans. Intentional food subsidies, including feeding or baiting of wildlife for viewing or hunting, can represent a large energy source. We studied consumption of bait for an American black bear ( Ursus americanus) population in northern Wisconsin. Given the state's liberal baiting regulations, we hypothesized that bear baits would be highly available, and that bears would readily consume such baits within a hunting season. We documented the abundance of bear bait on forestlands, and quantified the diets of harvested black bears using stable isotopes and Bayesian mixing models to determine the relative contribution of human foods to individual and population diets. Baits occurred at ≥0.25 bait stations/km2 on public lands, and bears ( n = 180) were subsidized by these baits, which contributed to >40% of their diet. Our analysis of multiple tissue types with different turnover rates revealed that harvested bears were relying on subsidies throughout their lifetimes. Patterns of bait consumption were primarily influenced by age-sex class; adult males were the most reliant on human foods, followed by adult females. We found a high level of food subsidization in this bear population. We posit that the high density of bears in northern Wisconsin may be partly due to subsidies. Our results reveal how baits used for hunting can become an important resource for free-ranging bears and highlight the importance of considering potential consequences when bait is used in harvest management. © 2017 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Demand for commercial bee (Apis mellifera) services recently has increased, resulting in greater use of mobile apiaries for crop pollination. When commercial apiaries are moved into areas occupied by black bears (Ursus americanus), conflicts between beekeepers and bears sometimes occur. Commercial pollination often involves moving apiaries among agricultural fields, and, thus, permanent fencing is not a viable option for reducing damage by bears. In 2010, we tested the effectiveness of 4 temporary electric fence designs for excluding black bears from bait sites in northern Michigan. We determined the effectiveness of each fence design by observing bear behavior obtained from 24-hour video surveillance. From >433 minutes of bear–fence interactions (BFI), we recorded 168 BFIs in 73 visits by an estimated 15 bears. The only fence design deemed 100% effective at excluding bears consisted of 3 polytape strands charged with 5,000 V and spaced 0.58, 0.39, and 0.23 m from the ground, respectively. Proper fence construction and maintenance are critical elements of effectiveness, and we provide guidance on each. Our results demonstrate that low-cost temporary fencing can be an effective tool for excluding bears from localized sites, such as apiaries.

Demand for commercial bee (Apis mellifera) services recently has increased, resulting in greater use of mobile apiaries for crop pollination. When commercial apiaries are moved into areas occupied by black bears (Ursus americanus), conflicts between beekeepers and bears sometimes occur. Commercial pollination often involves moving apiaries among agricultural fields, and, thus, permanent fencing is not a viable option for reducing damage by bears. In 2010, we tested the effectiveness of 4 temporary electric fence designs for excluding black bears from bait sites in northern Michigan. We determined the effectiveness of each fence design by observing bear behavior obtained from 24-hour video surveillance. From >433 minutes of bear-fence interactions (BFI), we recorded 168 BFIs in 73 visits by an estimated 15 bears. The only fence design deemed 100% effective at excluding bears consisted of 3 polytape strands charged with 5,000 V and spaced 0.58, 0.39, and 0.23 m from the ground, respectively. Proper fence construction and maintenance are critical elements of effectiveness, and we provide guidance on each. Our results demonstrate that low-cost temporary fencing can be an effective tool for excluding bears from localized sites, such as apiaries. [ABSTRACT FROM AUTHOR]

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 Blastomyces sp. within pyogranulomatous inflammatory lesions in the lungs, multiple lymph nodes, liver, kidneys, jejunum, and right adrenal gland. In addition, the haircoat had a mild infestation of chewing lice (Trichodectes pinguis euarctidos), and large numbers of rhabditid nematodes consistent with Pelodera sp. were histologically observed within hair follicles. [ABSTRACT FROM PUBLISHER]

We compiled, summarized, and reviewed 269 incidents of bear-human conflict involving firearms that occurred in Alaska during 1883-2009. Encounters involving brown bears ( Ursus arctos; 218 incidents, 81%), black bears ( Ursus americanus; 30 incidents, 11%), polar bears ( Ursus maritimus; 6 incidents, 2%), and 15 (6%) unidentified species provided insight into firearms success and failure. A total of 444 people and at least 367 bears were involved in these incidents. We found no significant difference in success rates (i.e., success being when the bear was stopped in its aggressive behavior) associated with long guns (76%) and handguns (84%). Moreover, firearm bearers suffered the same injury rates in close encounters with bears whether they used their firearms or not. Bears were killed in 61% ( n = 162) of bear-firearms incidents. Additionally, we identified multiple reasons for firearms failing to stop an aggressive bear. Using logistic regression, the best model for predicting a successful outcome for firearm users included species and cohort of bear, human activity at time of encounter, whether or not the bear charged, and if fish or game meat was present. Firearm variables (e.g., type of gun, number of shots) were not useful in predicting outcomes in bear-firearms incidents. Although firearms have failed to protect some users, they are the only deterrent that can lethally stop an aggressive bear. Where firearms have failed to protect people, we identified contributing causes. Our findings suggest that only those proficient in firearms use should rely on them for protection in bear country. © 2012 The Wildlife Society. [ABSTRACT FROM AUTHOR]

The American black bear (Ursus americanus) experienced a significant range contraction during the 19th and 20th centuries due to a variety of anthropogenic factors. Although previous molecular studies of black bears provided insight into historic and contemporary forces shaping phylogeographic patterns, none included black bears from the central part of the species distribution. Understanding the historical aspects of the connectivity and genetic differentiation of black bears in this region is important for proper management and conservation programs, but this understanding is confounded by poorly documented translocation efforts and population expansion. To address these issues, we generated mitochondrial DNA sequence data for 409 black bears from 15 populations in North America. Two sampling localities (Manitoba, Canada, and Minnesota) were source populations for translocation into western Arkansas and Louisiana. Major conclusions from our study include: black bears in western Arkansas were affected genetically by the translocation program; eastern Oklahoma has been repopulated by westward expansion of bears from Arkansas with a mixture of translocated bears and remnant individuals; black bears in Louisiana were not affected genetically by the translocation program; black bears in western Texas and northern Mexico dispersed there from the southeastern United States; and bears in White River National Wildlife Refuge (eastern Arkansas) share closer genetic affinities with U. a. luteolus than they do with the widespread U. a. americanus. [ABSTRACT FROM AUTHOR]

We present a comprehensive look at a sample of bear spray incidents that occurred in Alaska, USA, from 1985 to 2006. We analyzed 83 bear spray incidents involving brown bears (Ursus arctos; 61 cases, 74%), black bears (Ursus americanus; 20 cases, 24%). and polar bears (Ursus maritimus, 2 cases, 2%). Of the 72 cases where persons sprayed bears to defend themselves, 50 (69%) involved brown bears, 20 (28%) black bears, and 2 (3%) polar bears. Red pepper spray stopped bears' undesirable behavior 92% of the time when used on brown bears, 90% for black bears, and 100% for polar bears. Of all persons carrying sprays, 98% were uninjured by bears in close-range encounters. All bear-inflicted injuries (n = 3) associated with defensive spraying involved brown bears and were relatively minor (i.e., no hospitalization required). In 7% (5 of 71) of bear spray incidents, wind was reported to have interfered with spray accuracy, although it reached the bear in all eases. In 14% (10 of 71) of bear spray incidents, users reported the spray having had negative side effects upon themselves, ranging from minor irritation (11%, 8 of 71) to near incapacitation (3%, 2 of 71). Bear spray represents an effective alternative to lethal force and should be considered as an option for personal safety for those recreating and working in bear country. [ABSTRACT FROM AUTHOR]

We developed a snare for collection of black bear (Ursus americanus) hair that obtained a unique hair sample at each snare site, improved the quantity of collected hair compared to barbed-wire corrals, and was easy to deploy over a wide range of topographical features and habitat conditions. This device allowed us to implement intensive sampling methodology needed in mark-recapture experiments with minimal effort. By improving the quantity of hair collected, we also lowered the potential for bear identification errors at the lab. During 2003-2004, bears in 2 study areas triggered snares 1,104 times, which resulted in the collection of 981 hair samples. Of the samples we collected, 79% (775) produced valid genetic data. In 2003, 454 samples identified 79 genetically distinct individuals, and 321 samples identified 86 genetically distinct individuals in 2004. Analysis of capture-recapture data indicated that capture probabilities were affected by heterogeneity among individuals and behavioral responses, but showed little evidence of time effects. Consequently, we used the Pollock and Otto (1983) estimator for model Mbh to estimate abundance with reasonably good precision (CV: 12-14%). Density on the Steamboat and Toketee, Oregon, USA, study areas over the 2-year period averaged 19 bears/100 km² and 22 bears/100 km², respectively. Average capture and recapture probabilities over the 2 years of the study were 30% and 63%, respectively, indicating a trap-prone behavioral response. Knowledge of bear densities on the Steamboat and Toketee study areas will enable managers to set hunting quotas, advise land management agencies on habitat issues, and create a baseline database to assist in the long-term monitoring of bear trends in a changing landscape. [ABSTRACT FROM AUTHOR]

Negative human–black bear interactions in New York's Adirondack Park campgrounds pose risk management challenges. Communication is one tool available to modify human behavior and reduce associated risks, but knowledge of constructs influencing risk perception among key stakeholder groups is needed to design effective risk communication approaches. We interviewed managers (n = 14) and users (n = 40) at 7 Adirondack Park campgrounds to characterize risk perceptions between groups. We identified eight constructs influencing risk perceived by users and/or managers with three constructs congruent between groups, and five constructs divergent. We discuss how congruencies and shared understanding across groups, and explicit recognition by risk communicators of differences between groups, may offer opportunities to maximize successes of risk communication efforts in campgrounds. [ABSTRACT FROM AUTHOR]

New York State's Adirondack Park is home to an estimated 6,000 black bears (Ursus americanus), about 75% of the state's total population. Human-bear interactions at the Park's nearly 100 campgrounds are commonplace. Some interactions are conflicts that include risks to personal safety and property damage. Between 19 June 2003 and 18 August 2003, we interviewed 54 Adirondack Park campers and caretakers at 7 campgrounds to determine stakeholder-perceived risks. We structured interviews to assess 9 possible constructs influencing risks not yet reported in the literature for human-bear conflicts from campground stakeholders' perspectives: volition of exposure; certainty; feelings of dread; perceived frequency of exposure to risk; responsiveness of black bear managers; trust in black bear managers; familiarity of risk; natural causes of risk; and control over risk. Overall, perceived risk associated with human-bear conflict was low. Evidence-based analysis revealed 8 of 9 constructs to be salient. We characterized salient constructs according to camper and caretaker perspectives. Caretakers had a higher risk perception than campers. Using camper comments as a foundation, we classified groups of constructs as agency capacity/responsiveness (i.e., incorporating volition, trust, and responsiveness of wildlife managers), and individual capacity/knowledge (i.e., incorporating perceived certainty, dread, and frequency, control over exposure to risks associated with black bears, and magnitude or acuteness of exposure to risks associated with black bears). With additional confirmatory analysis, these constructs and methodology may have the potential to increase understanding of risk perceptions associated with human-bear conflict and inform the content and format of strategic management plans incorporating risk management and communication. [ABSTRACT FROM AUTHOR]

Indices of relative abundance allow managers and researchers to examine changes in population size over time or compare relative population sizes in different areas. In the Pisgah Bear Sanctuary, bait-station surveys were conducted in most years from 1983 to 2000 to follow trends over time in the black bear (Ursus americanus) population. Baited bear trapping also took place in the sanctuary during those years, and some trap lines coincided with bait-station lines. Because the same baits were used for both trapping and bait station lines, we hypothesized that visitation rates of bears to bait stations established in proximity to baited trap lines would differ from rates at bait stations that were not associated with baited trap lines. We modeled probability of bait stations being visited by bears on trapped and untrapped lines to estimate the effect baited trapping had on visitation rates. We found that population trends inferred from bait-station visits in areas that also were trapped with bait were biased high and that bias increased over time. Bears may have become habituated to the bait on trap lines and incorporated it as a regular food source. Bait-station indices should not be conducted near research sites that employ similar bait when both produce a tangible reward for the animals. [ABSTRACT FROM AUTHOR]

We estimated survival, fertility, and realized and asymptotic population growth rates from 1981 to 2002 for a protected population of black bears (Ursus americanus) in the southern Appalachian Mountains. We used Akaike's information criterion to assess the time interval for averaging observations that was best for estimating vital rates for our study, given our yearly sample sizes. The temporal symmetry approach allowed us to directly assess population growth and to address all losses and gains to the population by using only capture data, offering an alternative to the logistically intensive collection of reproductive data. Models that averaged survival and fertility across 5- and 7-year time intervals were best supported by our data. Studies of black bear populations with annual sample sizes similar to ours should be of at least 5 years in duration to estimate vital rates reliably, and at least 10 years in duration to evaluate changes in population growth rate (λ). We also hypothesized that survival would not track changes in λ because λ is influenced by both survival and fertility. The 5-year model supported our hypothesis, but the 7-year model did not. Where long-term dynamics of large, relatively stable bear populations are of interest, monitoring survival is likely to be sufficient for evaluating trends in λ. For rapidly changing, small populations, however, failure to incorporate fertility into assessments of λ could be misleading. [ABSTRACT FROM AUTHOR]

The general public often prefers nonlethality when dealing with problem black bears (Ursus americanus). We evaluated the efficacy of nonlethal deterrent techniques on 62 bears in the Lake Tahoe Basin of the Sierra Nevada range. We contrasted animals randomly assigned to a control (no treatment) group (n = 21), an experimental (treatment) group (n = 21), or a treatment + dog group (n = 20). Experimental bears were pepper-sprayed, shot with 12-gauge rubber buckshot and a rubber slug, and exposed to cracker shells. Bears in the treatment + dog group were chased by hounds in addition to the combination of other deterrents. We tested and modeled the effectiveness of deterrents and dogs using a survival analysis with Cox proportional hazards and ANOVA. Relative success was evaluated by the latency of time (days) between treatment and return to the urban patch (RUP). Predictor variables in the saturated model included age, weight, season, sex, distance moved, and treatment. Only treatment remained in the most parsimonious model. However, mean number of days until RUP did not vary among the 3 treatment levels (ANOVA, P = 0.55). In all but 5 of 62 cases, bears eventually returned to the urban patch in which they were captured; 33 of 62 bears (53%) returned within 1 month and 70% (n = 44) of all bears returned in ≤40 days. We conclude that in the Lake Tahoe Basin the most common nonlethal deterrents, used by agencies responsible for black bear management, are not very effective at altering bear behavior over periods of time <1 month. [ABSTRACT FROM AUTHOR]

Temperature sensors were placed in the abdominal cavity, on the neck, and outside the dens of 5 hibernating black bears (Ursus americanus) during early winter and removed at the end of winter before emergence of bears from their dens. Bears did not arouse from torpor throughout the winter test period. Abdominal temperature remained within a 1.5°C temperature range and did not appear to exhibit circadian rhythmicity. However, neck surface temperature of bears demonstrated elevated spikes from 2 to 30°C about 4 times each day. Adult students wearing the same neck sensors as bears exhibited similar spikes in body surface temperature when vigorously exercising in the cold. We suggest that bears engage in bouts of muscle activity during the winter denning period that may result in the retention of muscle strength without elevating their core body temperature and without arousing from torpor. [ABSTRACT FROM AUTHOR]