Nutritional Consequences of Experimentally Introduced Tourism in Brown Bears

Abstract: Although numerous studies have documented behavioral effects of nature-based tourism on wildlife populations, few studies have determined whether behavioral changes translate to effects on individual condition and population health. This issue is currently a concern for wildlife managers in Alaska, USA, and Canada where bear viewing is a rapidly growing industry expanding into previously undisturbed bear habitats. Rather than record observations at long established tourism sites, we experimentally introduced bear viewing into 2 relatively undisturbed brown bear (Ursus arctos) populations in south-central Alaska. We examined the nutritional consequences of behavioral changes induced by the presence and activity of bear viewers for bears feeding on early summer vegetation and late-summer salmon (Oncorhynchus kisutch and O. nerka). We used Global Positioning System collars, monitored food resource availability, and quantified individual resource use and condition for a year prior to and during the introduction of bear viewing. Though bear viewing altered spatiotemporal resource use in all treatments, total resource use declined only when we exposed bears to 24-hour daily human activity. Energy expenditure, indexed as daily travel distances, was significantly higher when bears responded by altering spatial rather than temporal resource use. However, body weight and composition were unaffected by all treatments as bears shifted their foraging to other locations or times. Managers can minimize nutritional impacts of bear-viewing programs by avoiding spatial displacement and providing predictable time periods when bears can access food resources free of human activity. Bears in this study exhibited a high degree of behavioral plasticity, which may be an important factor in identifying flagship species for sustainable ecotourism programs.     

Attitudes Toward Bile Extraction From Living Bears: Survey of Citizens and Students in Beijing

Bear bile is a traditional Chinese medicine that has been used for millennia. Several arguments support and oppose the use of bear farming in terms of conservation and nonhuman animal welfare. This study involved designing a questionnaire and surveying a random sample of general citizens and college students in Beijing to elicit their attitudes on bile extraction from living bears. Older people and people with lower education levels used more bear bile medicines. In total, 29.47% (n = 204) of citizens and 23.14% (n = 81) of students surveyed used bear bile medicine since 1990. Students were less willing to use bear bile medicines than citizens (p < .05). The level the respondents agreed with the blue side (against the extraction of bile from living bears; anti for short) was significantly higher than that for the red side (support the extraction of bile from living bears; pro for short; p < .05). Additionally, college students had a more distinct attitude toward the opposing views, which indicates they were more inclined to oppose bile extraction from living bears.     

Quantitative Support for a Subjective Fatness Index for Immobilized Polar Bears

ABSTRACT Adequate stores of body fat are essential for survival and reproduction of polar bears (Ursus maritimus). However, polar bear body fat levels can be difficult to quantify in the field. For >30 years, biologists have subjectively estimated relative fatness of immobilized polar bears by assigning individuals a rating from 1 to 5, with 1 being leanest and 5 most obese. Although previous studies suggested this fatness index (FI) rating accurately reflects large-scale differences in body condition, its relationship to more quantitative measures of condition has not been explored. We compared the FI rating of individual polar bears in western Hudson Bay and the Beaufort Sea to 2 quantitative measures of body condition: the Quetelet Index (ratio of mass to length²) and the relative lipid content of adipose tissue. We found a significant relationship between FI rating and both Quetelet Index values and adipose lipid content. Our data demonstrate that the FI rating accurately reflects overall body condition, regardless of polar bear age, sex, or nutritional phase. We suggest that continued field use of the FI rating could provide valuable information on ecological effects of large-scale environmental change on polar bear populations.     

Efficacy of Bear Deterrent Spray in Alaska

Abstract: 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 cases. 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. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):640–645; 2008)     

The Welfare of Bears in Zoos: A Case Study of Poland

The welfare of captive bears became a big issue of concern in Poland when a case of a bear being ill-treated became a high-profile case in the media. This case created a challenge to verify, study, and understand the main problems associated with bear keeping so that zoos could significantly improve the conditions in which they keep bears or ensure they keep bears at the minimum required standards. The results presented here are from 1 of the few countrywide studies of captive bear conditions conducted in all the captive institutions in Poland that keep bears. Thirteen institutions kept bears at the time of the study (2007–2009), including 54 individuals of 5 species. Major welfare problems were identified, and the results have been used to challenge zoos to address the changes required and focus the government's attention on areas that require legislative improvement.     

Efficacy of firearms for bear deterrence in Alaska

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.     

Distinguishing Asiatic Black Bears and Sun Bears by Claw Marks on Climbed Trees

Abstract: Asiatic black bears (Ursus thibetanus) and sun bears (Helarctos malayanus) are sympatric in mainland Southeast Asia and face similar threats of habitat loss and commercial poaching. They are rarely seen but leave distinct signs, especially claw marks on climbed trees. These markings, which are potentially valuable indicators of presence, population status, and behavior of black bears and sun bears, have limited usefulness if the 2 species cannot be differentiated. We measured 121 claw mark imprints on climbed trees from 43 known (mainly captive) individual black bears and sun bears of both sexes in Thailand and Cambodia. The span across the markings made by 3, 4, or 5 claws from the hind foot was significantly greater for black bears than sun bears. We developed discriminant function models with these variables and arranged them in a 3-step process that distinguished claw marks as either sun bear, black bear, or indeterminate. This procedure correctly classified 95% of claw marks from the experimental animals. Tested on wild bears (at sites where only one species occurred), the procedure correctly classified 91% of claw marks of black bears in China (n = 94) and 100% of claw marks of sun bears in Indonesia (n = 32). The main limitation of the method was in distinguishing young, small black bears (cubs and yearlings) from sun bears. Nevertheless, application of these findings will be valuable in bear research and monitoring programs throughout Southeast Asia, where sign surveys have, until now, been hampered by the inability to differentiate these 2 ecologically and behaviorally similar species. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):814–821; 2008)     

Individual Effects of Seasonal Changes,Visitor Density,and Concurrent Bear Behavior on Stereotypical Behaviors in Captive Polar Bears (Ursus maritimus)

Stereotypical behaviors in captive polar bears (Ursus maritimus) can be detrimental to their welfare. These behaviors can be reduced through enrichment programs but are often not completely eliminated, so identifying potential triggers is important. The present study investigated the influences of seasonal changes, visitor density, and concurrent bear activity on stereotypical behaviors exhibited by 3 captive polar bears at the Toronto Zoo. All bears exhibited these behaviors; however, individual differences were found in duration and form. The male exhibited less stereotypical behavior during spring, and the females exhibited less stereotypical behavior during winter. An increase in visitor density was associated with more stereotypical behavior in 1 female but less stereotypical behavior in the other 2 bears. All bears engaged in more stereotypical behaviors when the other bears were inactive, and 1 female engaged in more stereotypical behaviors when the other bears were out of sight. Further, when conspecifics were active, all bears engaged in less stereotypical behaviors. Given the variability among individual bears, future enrichment programs must be tailored to the needs of individuals to maximize efficacy.     

Retention Time of Telazol in Black Bears

ABSTRACT Telazol® (Fort Dodge Animal Health, Fort Dodge, IA) is an effective immobilization drug for American black bears (Ursus americanus), but concern exists regarding retention time of this drug in tissues relative to human consumption of bears. Therefore, we evaluated retention time of Telazol in captured American black bears immobilized with Telazol and held in captivity for 3 days, 7 days, 14 days, or 21 days. We detected Telazol in muscle and liver of one bear on day 7, in serum from 2 bears on day 7, and in urine of one bear each on day 3 and day 14. Our findings suggest Telazol is metabolized and eliminated quickly from the bear's system and should allow managers additional flexibility in mark-recapture studies and nuisance situations.     

Resource Selection by Recolonizing American Black Bears

American black bears (Ursus americanus) were extirpated from Oklahoma, USA, in the early twentieth century but have since recolonized eastern portions of the state after immigrating from Arkansas, where they were successfully translocated. Within the last 2 decades, a population of black bears was detected in the Oklahoma Ozark region, prompting studies to determine population size, growth rate, and genetic makeup. To understand how black bears were recolonizing the human-dominated landscape, we investigated resource selection at 2 scales. Between 2011 and 2016, we collected global positioning system collar spatial data for 10 males and 13 females. We calculated average kernel density home ranges on a seasonal scale for all collared bears. We used generalized linear mixed models to calculate resource selection functions at the study area, defined by locations of all radio-collared black bears (second order) and the scale of individual black bear home ranges (third order). Resource selection did not differ significantly by sex. Black bears across seasons and scales selected riparian forest and moist oak (Quercus spp.) forest land cover types and mostly selected against indicators of human activity (e.g., pasture-prairie, anthropogenic land cover types, roads, and areas of high human population density). Black bears also selected areas with rugged terrain at high elevations, although not consistently across seasons and scales. Black bear recolonization appeared to be negatively affected by areas and features characterized as human-altered. Further expansion of the range of black bears may be limited by anthropogenic disturbance in the region. © 2021 The Wildlife Society.     

Trends in intensive management of Alaska's grizzly bears, 1980–2010

Hunting regulations for grizzly bears (Ursus arctos) in much of Alaska since 1980 increasingly were designed to reduce bear abundance in the expectation such regulations would lead to increased harvests by hunters of moose (Alces alces) and caribou (Rangifer tarandus). Regulations were liberalized during 1980–2010 primarily in the area we termed the Liberal Grizzly Bear Hunting Area (hereafter Liberal Hunt Area) which encompassed 76.2% of Alaska. By 2010, these changes resulted in longer hunting seasons (100% of Liberal Hunt Area had seasons > 100 days, 99.7% > 200 days, and 67.8% > 300 days), more liberal bag limits (99.1% of the Liberal Hunt Area with a bag limit ≥ 1/yr and 10.1% with a bag limit ≥ 2/yr), and widespread waiver of resident tag fees (waived in 95.7% of the Liberal Hunt Area). During 1995–2010, there were 124 changes that made grizzly bear hunting regulations more liberal and two making them more conservative. The 4-year mean for grizzly bear kills by hunters increased 213% between 1976–1980 (387 grizzly bears) and 2005–2008 (823 grizzly bears). Since 2000, long-term research studies on grizzly populations in the Liberal Hunt Area have been terminated without replacement. Management of large predators by the State of Alaska is constrained by a 1994 state statute mandating “intensive management” in areas classified as important for human consumptive use of ungulates. Current grizzly bear management in the Liberal Hunt Area is inconsistent with the recommendations of the National Research Council's 1997 report on predator management in Alaska. Current attitudes, policies and absence of science-based management of grizzly bears in Alaska are increasingly similar to those that resulted in the near extirpation of grizzly bears south of Canada in the 19th and 20th centuries. If current trends continue, they increase risks to portions of the largest and most intact population of grizzly bears in North America. © 2011 The Wildlife Society.     

The acute physiological response of polar bears to helicopter capture

Many wildlife species are live captured, sampled, and released; for polar bears (Ursus maritimus) capture often requires chemical immobilization via helicopter darting. Polar bears reduce their activity for approximately 4 days after capture, likely reflecting stress recovery. To better understand this stress, we quantified polar bear activity (via collar-mounted accelerometers) and body temperature (via loggers in the body core [T_abd] and periphery [T_per]) during 2–6 months of natural behavior, and during helicopter recapture and immobilization. Recapture induced bouts of peak activity higher than those that occurred during natural behavior for 2 of 5 bears, greater peak T_per for 3 of 6 bears, and greater peak T_abd for 1 of 6 bears. High body temperature (>39.0°C) occurred in T_per for 3 of 6 individuals during recapture and 6 of 6 individuals during natural behavior, and in T_abd for 2 of 6 individuals during recapture and 3 of 6 individuals during natural behavior. Measurements of T_abd and T_per correlated with rectal temperatures measured after immobilization, supporting the use of rectal temperatures for monitoring bear response to capture. Using a larger dataset (n = 66 captures), modeling of blood biochemistry revealed that maximum ambient temperature during recapture was associated with a stress leukogram (7–26% decline in percent lymphocytes, 12–21% increase in percent neutrophils) and maximum duration of helicopter operations had a similar but smaller effect. We conclude that polar bear activity and body temperature during helicopter capture are similar to that which occurs during the most intense events of natural behavior; high body temperature, especially in warm capture conditions, is a key concern; additional study of stress leukograms in polar bears is needed; and additional data collection regarding capture operations would be useful.     

Contrasting Activity Patterns of Sympatric and Allopatric Black and Grizzly Bears

ABSTRACT The distribution of grizzly (Ursus arctos) and American black bears (U. americanus) overlaps in western North America. Few studies have detailed activity patterns where the species are sympatric and no studies contrasted patterns where populations are both sympatric and allopatric. We contrasted activity patterns for sympatric black and grizzly bears and for black bears allopatric to grizzly bears, how human influences altered patterns, and rates of grizzly-black bear predation. Activity patterns differed between black bear populations, with those sympatric to grizzly bears more day-active. Activity patterns of black bears allopatric with grizzly bears were similar to those of female grizzly bears; both were crepuscular and day-active. Male grizzly bears were crepuscular and night-active. Both species were more night-active and less day-active when ≤1 km from roads or developments. In our sympatric study area, 2 of 4 black bear mortalities were due to grizzly bear predation. Our results suggested patterns of activity that allowed for intra- and inter-species avoidance. National park management often results in convergence of locally high human densities in quality bear habitat. Our data provide additional understanding into how bears alter their activity patterns in response to other bears and humans and should help park managers minimize undesirable bear-human encounters when considering needs for temporal and spatial management of humans and human developments in bear habitats.     

A three-dimensional analysis of tooth-root morphology in living bears and implications for feeding behaviour in the extinct cave bear

ABSTRACT

The morphology of both crowns and tooth-roots reflects dietary specialisation in mammalian carnivores. In this article, we analyse the tooth-root morphology of maxillary teeth from CT scans of living bears (Ursus arctos, Ursus americanus, Ursus maritimus, Ursus thibetanus, Melursus ursinus, Helarctos malayanus, Tremarctos ornatus and Ailuropoda melanoleuca) in order to make inferences about the diet and feeding behaviour of the extinct cave bear (Ursus spelaeus sensu lato). Specifically, we investigate two major mitochondrial clades of extinct cave bears recognized by previous authors: Ursus ingressus and Ursus spelaeus (U. spelaeus spelaeus, U. spelaeus ladinicus, U. spelaeus eremus). Our results indicate a close association between tooth-root surface area and feeding behaviour in all living bear species. Tooth-root surface area values of cave bears suggest that they relied more on vegetative matter than living brown bears (Ursus arctos) but subtle differences between these species/subspecies could also indicate different feeding strategies among the members of cave bear complex.     

Unraveling the mystery of the glacier bear: Genetic population structure of black bears (Ursus americanus) within the range of a rare pelage type

Glacier bears are a rare grey color morph of American black bear (Ursus americanus) found only in northern Southeast Alaska and a small portion of western Canada. We examine contemporary genetic population structure of black bears within the geographic extent of glacier bears and explore how this structure relates to pelage color and landscape features of a recently glaciated and highly fragmented landscape. We used existing radiocollar data to quantify black bear home‐range size within the geographic range of glacier bears. The mean home‐range size of female black bears in the study area was 13 km² (n = 11), whereas the home range of a single male was 86.9 km². We genotyped 284 bears using 21 microsatellites extracted from noninvasively collected hair as well as tissue samples from harvested bears. We found ten populations of black bears in the study area, including several new populations not previously identified, divided largely by geographic features such as glaciers and marine fjords. Glacier bears were assigned to four populations found on the north and east side of Lynn Canal and the north and west side of Glacier Bay with a curious absence in the nonglaciated peninsula between. Lack of genetic relatedness and geographic continuity between black bear populations containing glacier bears suggest a possible unsampled population or an association with ice fields. Further investigation is needed to determine the genetic basis and the adaptive and evolutionary significance of the glacier bear color morph to help focus black bear conservation management to maximize and preserve genetic diversity.     

Effects of sea ice extent and food availability on spatial and temporal distribution of polar bears during the fall open-water period in the Southern Beaufort Sea

We investigated the relationship between sea ice conditions, food availability, and the fall distribution of polar bears (Ursus maritimus) in terrestrial habitats of the Southern Beaufort Sea via weekly aerial surveys in 2000–2005. Aerial surveys were conducted weekly during September and October along the Southern Beaufort Sea coastline and barrier islands between Barrow and the Canadian border to determine polar bear density on land. The number of bears on land both within and among years increased when sea-ice was retreated furthest from the shore. However, spatial distribution also appeared to be related to the availability of subsistence-harvested bowhead whale (Balaena mysticetus) carcasses and the density of ringed seals (Phoca hispida) in offshore waters. Our results suggest that long-term reductions in sea-ice could result in an increasing proportion of the Southern Beaufort Sea polar bear population coming on land during the fall open-water period and an increase in the amount of time individual bears spend on land.     

Survival and Conflict Behavior of American Black Bears after Rehabilitation

Wildlife agencies face difficult situations when orphaned or injured American black bear (Ursus americanus) cubs (<12 months old) or yearlings (≥12 and <24 months old) are captured. One option is bear rehabilitation, the care and feeding of cubs or yearlings in a semi-natural environment, followed by release. Unfortunately, the survival and movements of bears released from rehabilitation facilities are often poorly documented and the ultimate reasons for success or failure poorly understood. Our goal was to assess survival and post-release conflict of orphaned bear cubs and yearlings following release from a rehabilitation facility, Appalachian Bear Rescue (ABR), in Townsend, Tennessee, USA, from 2015–2016. We predicted that rehabilitated bears would survive at similar rates, die from similar causes, and engage in similar conflict behavior to wild conspecifics. We equipped 42 black bear cubs and yearlings from ABR with global positioning system-collars and released them in Great Smoky Mountains National Park or Cherokee National Forest, Tennessee and North Carolina, USA. Estimated annual survival using known-fate methods for all released bears was 0.93 ± 0.06 [SE]). Survival for 13 bears released as cubs was 0.64 ± 0.14, whereas none of the bears released as yearlings died within 1 year after release (n = 29). Survival of rehabilitated bears was similar to or higher than published rates for wild conspecifics. Three of 42 bears (7.1%) released from ABR engaged in conflict behavior up to 1 year following release, and those had spent time involved in conflict behavior with their mothers (e.g., approaching humans) prior to being orphaned. Despite not having the typical post-natal experience with their mothers, the bears in our study appeared to behave and survive similarly to their wild conspecifics. Rehabilitation is effective for managing orphaned or injured bears. Best survival occurred for bears released as yearlings; however, managers can maximize cub survival through fall releases when plentiful wild foods are available. © 2019 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.     

A Multiscale Assessment of Den Selection by Black Bears in Louisiana

ABSTRACT Understanding den selection for the federally threatened Louisiana black bear (Ursus americanus luteolus) will assist managers in effectively managing bear populations and the landscapes they inhabit. We assessed den selection of 72 female Louisiana black bears at multiple spatial scales in northern and central Louisiana, USA. We used 230 den-years to examine den type preference, microhabitat characteristics of dens, and effects of landscape characteristics on den selection. We also evaluated reuse of tree dens and their availability across several study areas. Bears selected tree dens more frequently (65%) than ground dens. Most (55%) ground dens were associated with standing or downed trees, and most tree dens were in baldcypress (Taxodium distichum; 86%) or surrounded by water (80%). Selection of ground dens was positively associated with landscape metrics related to presence of water, whereas selection of tree dens was positively associated with proximity to edge and greater proportions of swamp and areas containing water. Reuse of tree dens averaged 15% (range = 0–20%) across study areas and our estimates of tree-den availability indicated that tree dens were not a limiting resource for Louisiana black bears in the northern or central portions of Louisiana. Although Louisiana black bears demonstrated plasticity in den selection, we recommend managers use forest management practices that conserve appropriate tree dens and create ground-denning opportunities, because both would promote the recovery of Louisiana black bear populations.     

DNA-Based Population Demographics of Black Bears in Coastal North Carolina and Virginia

ABSTRACT Noninvasive genetic sampling has become a popular method for obtaining population parameter estimates for black (Ursus americanus) and brown (U. arctos) bears. These estimates allow wildlife managers to develop appropriate management strategies for populations of concern. Black bear populations at Great Dismal Swamp (GDSNWR), Pocosin Lakes (PLNWR), and Alligator River (ARNWR) National Wildlife Refuges in coastal Virginia and North Carolina, USA, were perceived by refuge biologists to be at or above cultural and perhaps biological carrying capacity, but managers had no reliable abundance estimates upon which to base population management. We derived density estimates from 3,150 hair samples collected noninvasively at each of the 3 refuges, using 6–7 microsatellite markers to obtain multilocus genotypes for individual bears. We used Program MARK to calculate population estimates from capture histories at each refuge. We estimated densities using both traditional buffer strip methods and Program DENSITY. Estimated densities were some of the highest reported in the literature and ranged from 0.46 bears/km² at GDSNWR to 1.30 bears/km² at PLNWR. Sex ratios were male-biased at all refuges. Our estimates can be directly utilized by biologists to develop effective strategies for managing and maintaining bears at these refuges, and noninvasive methods may also be effective for monitoring bear populations over the long term.