Black Bears Research Articles

Space Use and Habitat Selection by Female Louisiana Black Bears in the Tensas River Basin of Louisiana

Abstract:Studies of space use and habitat selection of endangered species are useful for identifying factors that influence fitness of individuals and viability of populations. However, there is a lack of published information regarding these behaviors for the federally threatened Louisiana black bear (Ursus americanus luteolus). We documented space use and habitat selection for 28 female black bears in 2 subpopulations of the Tensas River Basin population in northeast Louisiana, USA. The Tensas subpopulation inhabits a relatively large (>300‐km2) contiguous area of bottomland hardwood forest, whereas the Deltic subpopulation exists mainly in 2 small (<7‐km2) forested patches surrounded by an agricultural matrix. Females on Deltic maintained smaller seasonal and annual home ranges than females on Tensas (allP< 0.04), except for females with cubs during spring. On Tensas, females with cubs maintained smaller home ranges than females without cubs during spring (P= 0.01), but we did not detect this difference on Deltic or in other seasons. Females on Tensas and Deltic exhibited differences in habitat selection when establishing home ranges and within home ranges (P< 0.001). Deltic females selected mature bottomland hardwood forests and avoided agricultural habitats at both spatial scales. Tensas females selected a mixture of swamps, mature and regenerating forests, and exhibited variation in selection across scale, season, and reproductive status. We suggest that differences in space use and habitat selection between Tensas and Deltic are at least partially due to habitat differences at the landscape (i.e., amount of forested habitat) and patch (i.e., food availability) scales. Our results contribute to the understanding of factors that influence space use and habitat selection by black bears and provide specific information on habitat types selected by Louisiana black bears to agencies involved in habitat protection and restoration for this threatened subspecies.

Campground Manager and User Perceptions of Risk Associated with Negative Human–Black Bear Interactions

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.

Were Native People Keystone Predators? A Continuous-Time Analysis of Wildlife Observations Made by Lewis and Clark in 1804-1806

It has long been claimed that native people were conservationists who had little or no impact on wildlife populations. More recently, though, it has been suggested that native people were keystone predators, who lacked any effective conservation strategies and instead routinely overexploited large mammal populations. To test these hypotheses, I performed a continuous-time analysis of wildlife observations made by Lewis and Clark because their journals are often cited as an example of how western North America teemed with wildlife before that area was despoiled by advancing European civilization. This included Bison, Elk, Mule Deer, Whitetailed Deer, Blacktailed Deer, Moose, Pronghorn Antelope, Bighorn Sheep, Grizzly Bears, Black Bears, and Grey Wolves. I also recorded all occasions on which Lewis and Clark met native peoples. Those data show a strong inverse relationship between native people and wildlife. The only places Lewis and Clark reported an abundance of game were in aboriginal buffer zones between tribes at war, but even there, wildlife populations were predator, not food-limited. Bison, Grizzly Bears, Bighorn Sheep, Mule Deer, and Grey Wolves were seldom seen except in aboriginal buffer zones. Moose were most susceptible to aboriginal hunting followed by Bison and then Elk, while Whitetailed Deer had a more effective escape strategy. If it had not been for aboriginal buffer zones, Lewis and Clark would have found little wildlife anywhere in the West. Moreover, prior to the 1780 smallpox and other earlier epidemics that decimated native populations in advance of European contact, there were more aboriginal people and even less wildlife. The patterns observed by Lewis and Clark are consistent with optimal foraging theory and other evolutionary ecology predictions.

Ovulation Induction by Administration of Equine and Human Chorionic Gonadotropin in Captive Japanese Black Bears (<i>Ursus thibetanus japonicus</i>)

Ovulation Induction by Administration of Equine and Human Chorionic Gonadotropin in Captive Japanese Black Bears (<i>Ursus thibetanus japonicus</i>)

The Black Bear Hunt in New Jersey: A Constructionist Analysis of an Intractable Conflict

AbstractThe black bear hunt in New Jersey represents a symbolic clash of understandings about how human beings should live with nonhuman animals who typify intractable conflicts involving potentially dangerous mammals. Manifest and latent content analysis of newspaper editorial materials—written over a 10-year period, ending in 2005—document 2 findings. First, hunt supporters and opponents promote specific constructions of bears, hunters, and other actors in their letters and editorials. Second, these constructions are not only different but contradictory. Opponents and supporters portray bears as either menacing threats or benevolent and peaceful animals. The two groups see hunters as either bloodthirsty killers or defenders of wildlife. Contradictory constructions serve to de-legitimate other constructions and other actors. This finding highlights how public discourse has fed intractability over the conflict rather than provided common grounds for consensus about how New Jersey's residents should interact with their ursine neighbors.

妊娠ニホンツキノワグマ（ Urusus thibetanus japonicus ）における体脂肪量とレプチンの繁殖への関わりの検討

妊娠ニホンツキノワグマ（ Urusus thibetanus japonicus ）における体脂肪量とレプチンの繁殖への関わりの検討

Urban wildlife management

Urban wildlife management

Growth and Sustainability of Black Bears at White River National Wildlife Refuge, Arkansas

The black bear (Ursus americanus) population at White River National Wildlife Refuge is isolated and genetically distinct, but hunting occurs adjacent to refuge boundaries and females with cubs are removed annually for a reintroduction project. We trapped and radiotracked bears to determine level of exploitation and compare methods for estimating population growth and sustainability. We captured 260 bears (113 M:147 F), 414 times, from 1998 through 2003. Survival estimates based on radiotracking and mark–recapture indicated that hunting and translocations were significant sources of loss. Based on mark–recapture data (Pradel estimator), the annual population growth rate (λ) averaged 1.066 (SE = 0.077) when translocation removals occurred and averaged 0.961 (SE = 0.155) when both harvest and translocations occurred. Estimates of λ based on a population simulation model (program RISKMAN) averaged 1.061 (SD = 0.104) and 1.100 (SD = 0.111) when no removals occurred, 1.003 (SD = 0.097) and 1.046 (SD = 0.102) when translocations occurred, and 0.973 (SD = 0.096) and 1.006 (SD = 0.099) when both harvest and translocations occurred, depending on the survival rate estimates we used. The probability of population decline by >25% over a 10-year period ranged from 13.8 to 68.8%, given our estimated removal rates. We conclude that hunting and translocation losses are at or exceed the maximum the population is capable of sustaining. Although extinction risks of this important bear population are low over the near term, it should continue to be closely monitored by state and federal agencies. The mark–recapture method we used to estimate λ proved to be a reliable alternative to more costly population modeling methods.

Lessons From Black Bears About the Best Way to Regain Bone Lost to Inactivity

Lessons From Black Bears About the Best Way to Regain Bone Lost to Inactivity

Food Habits of Louisiana Black Bears (Ursus americanus luteolus) in Two Subpopulations of the Tensas River Basin

The Louisiana black bear (Ursus americanus luteolus) is listed federally as a threatened subspecies and current information about food habits is necessary for developing a sound conservation strategy. We collected and analyzed 251 scats from bears in the Tensas River Basin (TRB) population in northeast Louisiana. We compared diets of the two subpopulations (Tensas and Deltic) of the TRB and we observed differences during summer and fall. We suggest that the greater diversity of mast consumed by bears on Deltic may provide demographic stability to this small isolated subpopulation. Across the TRB, corn (Zea mays) made up the greatest percentage volume of scats and dominated summer and fall diet, whereas beetles (Coleoptera) were the food item found most frequently in scats. Other important food items included: blackberries and dewberries (Rubus spp.), acorns (Quercus spp.), palmetto fruit (Sabal minor), grasses/sedges (Poaceae or Cyperaceae), herbaceous vegetation and other species of soft mast.

Infectious Diseases of North American Black Bears (Ursus americanus): Parasites (Part 2)

Black bears (Ursus americanus) serve as an important keystone species within an ecosystem and can serve as sentinels for environmental health. Wildlife rehabilitators, biologists, and veterinarians working with these animals should familiarize themselves with infectious diseases commonly associated with these ursids. The purpose of this paper is to provide a literature review of the common endoparasites and ectoparasites associated with black bears.

Cost-Effectiveness of the Black Bear Supplemental Feeding Program in Western Washington

In 2004 I concluded that the black bear (Ursus americanus) supplemental feeding program was an effective, nonlethal damage control tool to protect conifers during the spring in western Washington, USA (Ziegltrum 2004). Consequently, I analyzed the costs of the supplemental feeding program, which is used for about 10 years from stand age 15 to 25 and the costs of accepting bear tree damage. One Douglas-fir (Pseudotsuga menziesii) stand with known yield data served as a model. I assumed 15, 25, and 35% tree damage by bears in this stand at age 15 and allowed the stand to grow to 35-, 40-, and 45-year rotations. I performed present value calculations (PV) for the costs of the feeding program to determine if it was the best expenditure for the Animal Damage Control Program (ADCP) in comparison. For the sensitivity analysis, I used 5, 6, and 7% interest rates. I found that the costs of feeding bears for 2.5 months annually were always lower than the costs of tree damage by bears. Therefore, I concluded that the supplemental feeding program was a cost-effective damage control tool.

A Shocking Device for Protection of Concentrated Food Sources from Black Bears

Conflicts with American black bears (Ursus americanus) are increasing in rural and suburban areas throughout the United States. Human encroachment on bear range has increased availability of garbage, bird feeders, beehives, and other food sources. Preventing bears from attaining food from anthropogenic sources could mitigate these conflicts. We tested a new shocking mechanism that is being marketed to deter black bears from attaining food from clumped anthropogenic food sources. The Nuisance Bear Controller (NBC) has two 6-volt batteries wired to an automobile vibrator coil/condenser that emits 10,000–13,000 volts through a disk that triggers the device. Activation of the NBC only occurs when a bear or other animal contacts the disk. We tested the NBC in a rural area of central Minnesota by placing both unprotected and protected simulated bird feeders at 10 independent sites during summer and autumn 2004 and measuring the fate of each feeder. During the test period no protected feeders were robbed or destroyed by black bears, whereas 40% of unprotected feeders were robbed or destroyed (P = 0.043, one-tailed Fisher's exact test). The NBC is an inexpensive ($200.00), portable, and adaptable system that potentially can be used in a variety of situations to deter bears from accessing concentrated food sources.

Effectiveness of a Regional Corridor in Connecting Two Florida Black Bear Populations

Corridors may mitigate the adverse effects of habitat fragmentation by restoring or maintaining connectivity between disjunct populations. The efficacy of corridors for large carnivores, however has rarely been evaluated objectively. We used noninvasive sampling, microsatellite analysis, and population assignment tests to evaluate the effectiveness of a regional corridor in connecting two Florida black bear (Ursus americanus floridanus) populations (Osceola and Ocala). Bear movement was predominantly unidirectional, with a limited mixing of individuals from the two populations in one area of the corridor We also documented bears in Osceola that were genetically assigned to Ocala and bears in Osceola that may be offspring from an Osceola-Ocala mating. Our results indicate that the Osceola-Ocala corridor is functional and provides a conduit for gene flow between these populations. Human development, however may hinder the use of the Osceola-Ocala corridor by bears. The noninvasive sampling and genetic methods we used provide a means of evaluating corridor effectiveness that can help identify linkages necessary for maintaining metapopulation structure and population viability.

Do Black Bears Respond to Military Weapons Training?

The primary function of military training areas is to support military missions; however, management of natural resources that is compatible with that function has become a focal issue on many military installations. We investigated the relationship between black bear (Ursus americanus) habitat use and weapons-firing exercises at 3 spatial scales on the western portion of U.S. Marine Corps Base Camp Lejeune (Camp Lejeune), North Carolina. In 2000 and 2001, we collected 1,494 telemetry locations for 14 bears (6 males, 8 females). We used spatial contours of human auditory disturbance levels based on the noise generated from firing activities to establish high-, medium-, and low-disturbance noise zones for each firing range. We used the multinomial logit form of discrete choice analysis to examine whether bears exhibited a spatial (i.e., general avoidance of areas associated with military activity) or temporal response (i.e., avoidance of military training areas but only when firing exercises occurred). Except for small areas near the firing positions, differences in bear use among the 3 noise zone areas was mostly a function of the prevalence of selected vegetation types and not a response to military activity. Our temporal analysis further suggested that bears did not respond to weapons exercises; the distance of bears to the nearest high-disturbance noise zone was not associated with the occurrence of weapons exercises.

Long-range Homing by an Adult Female Black Bear, <em>Ursus americanus</em>

An adult female Black Bear was repeatedly captured and relocated as a result of nuisance behaviour. The relocation distances ranged from 40 km to 389 km (mean = 152 km, n = 6). She homed successfully from all relocations, even when accompanied by young-of-the-year. Differential homing ability among bears may depend on first homing from a short relocation, facilitating subsequent responses to longer distance relocations.

Evaluation of Environmental Condition by Drug Resistant and Molecular Epidemiological Analysis of <i>Staphylococcus</i> Isolated from Raccoon Dogs and Japanese Black Bears

Evaluation of Environmental Condition by Drug Resistant and Molecular Epidemiological Analysis of <i>Staphylococcus</i> Isolated from Raccoon Dogs and Japanese Black Bears

ニホンツキノワグマの糞に飛来する食糞性コガネムシ

ニホンツキノワグマの糞に飛来する食糞性コガネムシ

Black Bears Wiped Out by Introduced Deer

Black Bears Wiped Out by Introduced Deer

Incidence of Ovulation without Coital Stimuli in Captive Japanese Black Bears (Urus thibetanus japonicus) based on Serum Progesterone Profiles

The purpose of this study was to ascertain whether or not Japanese black bears (Ursus thibetanus japonicus) are induced ovulators. The progesterone levels of female bears kept with a male and allowed to mate (n=2) and female bears allowed contact with a male through bars but not allowed to mate (n=6) during the mating season increased significantly in late October. Based on this result, the female bears were considered to have ovulated. Females isolated from males (n=3) were ovarioectomized after the mating season, and no corpora lutea were observed, indicating they had not ovulated. These findings suggest that Japanese black bears may be induced ovulators that ovulate with stimuli from males and without coitus at a high rate.