Wildlife management agencies in US states and Canadian provinces and territories routinely assess population trends of American black bears (Ursus americanus) and estimate population size. State or province-wide population estimates are often extrapolated from small, short-term studies or are based on other expert opinions. We compiled black bear population estimates provided by 51 states and provinces for the period 1988–2001. Only 57% of trends ascertained from these serial population estimates (or less, depending on the method for determining trend and what was considered a match) agreed with corresponding agency assessments of trend for the same period. That is, nearly half the management agencies felt that the trend in their bear population was different than indicated by the estimates they produced. Most mismatches were cases where agencies perceived their populations as increasing but their estimates showed no discernible trend. Pooling all population estimates for North America suggested that continent-wide black bear numbers had increased by about 2%/year, but this growth cannot be statistically corroborated because of the subjective nature of the individual estimates (guesstimates). State or province-wide black bear population estimates may aid in managing bear harvests, but for the most part, they are not precise or rigorous enough to provide useful information on population trend.

We review the state of knowledge regarding conflicts between the Andean bear (Tremarctos ornatus) and livestock. Information was gathered from the current known geographic range of the species (Venezuela, Colombia, Ecuador, Peru, and Bolivia). Andean bears are perceived as livestock predators where herding is common; bears are frequently blamed for any livestock disappearance or death. This negative perception often leads to the poaching of Andean bears by local residents and to a disregard of protected areas and conservation efforts. We found no systematic documentation of conflicts in any Andean country. Carcass dragging, feeding signs, and presence of tree and ground nests were common features of livestock depredation sites. Direct observation of cattle depredation by Andean bears was reported at 3 sites in Colombia and Ecuador. No seasonal or cyclic patterns of depredation were discerned, and evidence suggested that bear–livestock conflicts were restricted to particular sites and involved problem bears. The conservation of Andean bears requires research on rapid ways of dealing with problem bears, as well as mitigation techniques designed to reduce perceived and actual conflicts between bears and livestock.

From June 1993 to June 2003, 40 adult female brown bears (Ursus arctos) were captured, radiocollared, and tracked for 1 to 10 years in a previously unstudied population in southwest Alaska. Mean litter size upon emergence from dens was 2.0, decreasing to 1.5 at weaning. Mean age of offspring at weaning was 2.9. Mean age of primiparity was 7.2 years while first weaning was estimated at 9.5 years. Mean maximum age of a female weaning a litter was 27.3 years. Mean annual survival estimates were 90.1–97.2% for radiocollared females ≥5 years old, 48.2–61.7% for cubs of the year, and 73.3–83.8% for 1 and 2-year-old offspring combined. Of 129 offspring followed beginning with their first summer, 38 (29.5%) survived to be weaned. Hunters harvested at least 12 marked or radiocollared bears (9 males and 3 females). No defense of life and property (DLP) killings were reported within or near the study area, but illegal harvests of brown bears were known to have occurred in the general region. Harvests within or near the study area averaged 7.3–12.1 males/year and 4.8–5.2 females/year. This population's rate of increase (λ) was estimated as 1.035–1.047 for the first half of the study, 0.963–0.997 for the second half, and was found to be most sensitive to survival of females 5–14 years old.

The impacts of tourism, most notably food resource enrichment and harassment, have led to alterations in natural bear (Ursus sp.) behavior in many National Parks throughout the United States. Comprehensive efforts to reduce these impacts and restore natural activity patterns have been elements of US National Park management for decades. We described black bear (U. americanus) activity patterns during 2001 and 2002 to assess the influence of human activity centers on bear behavior in Yosemite National Park, California, USA. We found bear activity and movement patterns, habitat use, and the distance bears were located from developed areas continued to be influenced by human presence in the Yosemite Valley region of Yosemite National Park. We recommend continued use of educational campaigns, stronger law enforcement efforts, improvements to food storage containers, more effective waste management, and more aggressive aversive conditioning techniques to reduce the number of human–bear interactions and restore the natural behavioral elements of Yosemite's black bear population.

We examined factors that affect site selection by female American black bears (Ursus americanus) in coastal British Columbia, Canada, 1992–95. We monitored 9 radiocollared females and compared sites that were selected within their home ranges to those that were not selected using 1-1 matched logistic regression procedures. We used information-theoretic inference to assess the effect of 19 habitat, temporal, and spatial variables in 27 candidate models to explain selection of sites within home ranges. The model that best explained site selection was 50 times more likely to be the best model, given the data, than the second-best model. The best model suggested that the probability that a site would be used by female black bears increased with increasing values of phenologically adjusted berry value interacting with light levels, phenologically adjusted succulent forage value, and forest harvesting. Probability of use decreased with increasing distance from streams dependent upon salmon (Oncorhynchus spp.) availability and increasing distance from low-traffic roads. Although the best model included horizontal visibility and distance to high-traffic roads as variables, these factors had undetermined effects on the probability of use (95% confidence interval of odds ratio encompassed 1). Including phenological adjustments for abundance of berries and succulent foods greatly increased the support for the models by the data, compared to models based on cover of food plants alone. These results confirm that bears are cognizant of both temporal and spatial differences in food availability and that they modify their selection of sites based on these differences. Our results imply that site selection by female black bears involved a complex set of decisions about not only food availability, but also disturbance by humans. To increase the compatibility of timber production with conservation of black bear habitat, managers need to consider the spatial and temporal effects of the creation of food-rich openings and different types of roads on the suitability and effectiveness of habitats to support black bears.

Canada's newest territory, Nunavut, has experienced increasing human population and growing resource extraction and exploration activities. Interactions between polar bears (Ursus maritimus) and humans are very likely to increase in the future, and knowing where, when, and why they occur could aid in preventing these events. I examined age, sex, time of year, general location, distribution by polar bear population, community, and region of polar bears killed in defense of life and property (DLP) between 1 July 1970 and 30 June 2000. A total of 618 polar bear DLP kills were recorded. Most DLP kills (73%) were bears ≤6 years of age, of which the majority (71%) were males. Males represented 55% of all bears >6 years of age. Native camp types accounted for most (74%) DLP mortalities (settlements, 18%; industry type camps, 4%; and research related DLP kills, 4%). The difficulty in deterring bears from native camp types might be because of the type of attractants (seal [Phoca spp.] and whale [Delphinapterus leucas and Monodon monoceros] meat and blubber), which are food items for polar bears and humans alike. Good record keeping of bear–human interaction occurrences and their analyses can aid in understanding specific circumstances leading to these incidents, and possibly minimize future DLP kills.

The US Fish and Wildlife Service (USFWS) proposed delisting the Yellowstone grizzly bear (Ursus arctos horribilis) in November 2005. Part of that process required knowledge of the most current distribution of the species. Here, we update an earlier estimate of occupied range (1990–2000) with data through 2004. We used kernel estimators to develop distribution maps of occupied habitats based on initial sightings of unduplicated females (n = 481) with cubs of the year, locations of radiomarked bears (n = 170), and spatially unique locations of conflicts, confrontations, and mortalities (n = 1,075). Although each data set was constrained by potential sampling bias, together they provided insight into areas in the Greater Yellowstone Ecosystem (GYE) currently occupied by grizzly bears. The current distribution of 37,258 km² (1990–2004) extends beyond the distribution map generated with data from 1990–2000 (34,416 km²). Range expansion is particularly evident in parts of the Caribou–Targhee National Forest in Idaho and north of Spanish Peaks on the Gallatin National Forest in Montana.

In 1994, we studied predation on domestic sheep using mortality radiocollars in an area in central Norway inhabited by brown bears (Ursus arctos). The total loss among 234 radiocollared ewes in 3 herds released on summer pastures was 54, and 51 (94.4%) were due to bear predation. Among 337 radiocollared lambs, 37 were known to have died, 14 (42.4%) due to bear predation. Bears selected ewes over lambs, consistent with optimal foraging theory. Ewes with bells had a higher risk of being killed than ewes without bells. Selection of young ewes with male-dominated litters in spring and small lambs can partly be explained according to parental investment theory and selection for individuals that are last in the flock when attacked or chased by bears.

Education programs designed to reduce conflicts between American black bears (Ursus americanus) and humans are often implemented by diverse groups of wildlife practitioners who may devote significant resources to these programs, yet little has been done to characterize the content, structure, and effectiveness of these programs. We review 6 education programs in North America. We build on a common performance indicator used in 5 of 6 programs—a reduction in the number of bear–related complaints to wildlife authorities—and suggest that practitioners incorporate other explanatory variables such as human dimensions, weather, natural food, or number of bears harvested. Some of these explanatory variables draw on potentially existing databases; others require new databases. If education programs are to remain an integral part of bear conservation and management, evaluation is essential to understand the ability of such programs to reduce conflict and encourage coexistence between people and bears.

American black bears (Ursus americanus) are commonly captured for research purposes with Aldridge traps. Disadvantages of this method include the possibility of non-target species setting off traps or being captured, a lengthy installation time, the possibility of bears being captured by the toes, and hind-foot captures. Here, we describe the RL04 trap, used with rubber-padded snares and drags, designed to address these issues. The RL04 trap is built from sturdy PVC tubing, can only be triggered by a bear in most areas, requires 20 minutes of installation time for 2 people, rarely results in toe captures due to the distance between the trigger and the snare, and eliminates hind-foot captures. This trap design captured 38 bears in 2 study areas. Every trap triggered by a previously untrapped bear resulted in a capture, and all snares tightened proximal to the metacarpal pad. Between 2001 and 2005, we trapped 304 bears using rubber-padded snares in an effort to reduce cuts and swelling often caused by bare-wire snares. These snares, tightened around bear paws with various trap designs including ground sets, produced surface cuts smaller than 1 cm in only 12 bears. Rubber-padded snares were linked to custom-designed drags and shock absorbers to reduce the risk of shoulder injuries. We provide detailed design descriptions of the RL04 trap and the restraining mechanism, which includes the snare, shock absorber, and drag.