Timing of parturition and, to a lesser extent, estrus, are rarely explored aspects of American black bear (Ursus americanus) reproductive ecology. The Cooperative Alleghany Bear Study was an intensive 10-year multi-faceted research project conducted on 2 study areas in western Virginia. We examined timing of estrus based on 430 observations of 326 lone (without cubs at the time of capture) female bears from late May–August, 1994–2002. We estimated parturition date for 383 cubs from 150 litters born from 1996–2003 to 99 individual females ranging from 3–24 years old. Bears were documented in estrus from late May through August with a peak during early July. Parturition dates ranged from late December to mid February with most births occurring in mid January. Three- and 4-year olds gave birth, on average, 12 days later than older bears. We suggest parturition date likely affects den exit date and perhaps cub survival, an area requiring further inquiry.

We estimated American black bear (Ursus americanus) abundance across the Upper Peninsula of Michigan (41,984 km²) during 8 years between 1990–2004 using tetracycline-laden baits and hunter harvest in mark–recapture analyses with the Lincoln–Petersen estimator. We marked 179–251 bears during each of 8 summer marking sessions using a mean bait density of 1 bait/69 km². We examined teeth collected annually during bear registration for tetracycline marks in the year of marking and through 6 years post marking. From harvest samples, we recovered 6–25% of bears marked in the year of marking. Annual proportion of harvested bears with tetracycline marks from a given marking session through 6 years post marking ranged from 0.0–5.6%. Males with tetracycline marks were more prevalent in the harvest as were bears 3–4-years old. Placement of baits in aspen (Populus spp.) vegetation type and presence of recent bear activity increased bait consumption and consequently the number of bears marked. Simulation modeling suggested that observed rates of bears ingesting multiple baits, number of bears harvested, and proportion of teeth examined did not affect population estimates, whereas tetracycline detection rates, ingestion of baits by cubs, and marks by external tetracycline sources did. Additionally, legal restrictions against harvest of females with cubs resulted in a negative population bias. Bear population estimates generally increased from 1990–2000, then apparently declined in 2002 before increasing again in 2004, possibly influenced by natural food availability. Incorporating recoveries over multiple hunting seasons generally resulted in increasing population estimates with decreasing confidence intervals. We recommend using ≥2 years of recapture data, including the year of marking, to estimate black bear population size. Population estimates of bears in Michigan's Upper Peninsula using tetracycline can be improved by increasing bait density and bear ingestion rates of baits, and decreasing ingestion rates by cubs. Development of a correction factor for tetracycline marks from external sources would also increase precision of estimates.

The rate of population change through time (λ) is a fundamental element of a wildlife population's conservation status, yet estimating it with acceptable precision for bears is difficult. For studies that follow known (usually marked) bears, λ can be estimated during some defined time by applying either life-table or matrix projection methods to estimates of individual vital rates. Usually however, confidence intervals surrounding the estimate are broader than one would like. Using an estimator suggested by Doak et al. (2005), we explored the precision to be expected in λ from demographic analyses of typical grizzly (Ursus arctos) and American black (U. americanus) bear data sets. We also evaluated some trade-offs among vital rates in sampling strategies. Confidence intervals around λ were more sensitive to adding to the duration of a short (e.g., 3 yrs) than a long (e.g., 10 yrs) study, and more sensitive to adding additional bears to studies with small (e.g., 10 adult females/yr) than large (e.g., 30 adult females/yr) sample sizes. Confidence intervals of λ projected using process-only variance of vital rates were only slightly smaller than those projected using total variances of vital rates. Under sampling constraints typical of most bear studies, it may be more efficient to invest additional resources into monitoring recruitment and juvenile survival rates of females already a part of the study, than to simply increase the sample size of study females.

Illegal killings are a major threat to wildlife conservation worldwide. Combating illegal killings and understanding the motives behind them are among the top challenges for the conservation of controversial species such as large carnivores. In Europe, the Eastern Alps are a focal area for many active brown bear (Ursus arctos) conservation and restoration projects. The wider public generally has a positive attitude toward bears and bear restoration, but some hunters and farmers seem less supportive. The extent this opposition can reach was demonstrated by the well documented illegal killing of a bear in the three-country triangle of Slovenia, Italy, and Austria in June 2009. We provide detailed background information and discuss this case within the context of the lack of a northward expansion of the Dinaric–Pindos bear population and the failed bear re-introduction in central Austria.

Few attempts have been made to estimate numbers and densities of Andean bears (Tremarctos ornatus). It is understandable that the many challenges involved in these efforts have made it difficult to produce rigorous estimates. A crude estimate of ∼20,000 Andean bears was derived by extrapolating the lowest observed density of American black bears (Ursus americanus) across the range of Andean bears. A second estimate, based on rangewide genetic diversity, produced a wide range of values; however, the low end of the confidence interval roughly matched the population estimate based on minimum black bear density. A mark–recapture analysis of 3 camera-trapped bears in Bolivia also yielded a similar density (4.4–6 bears/100 km²), but overlapping home ranges of 2 radiocollared bears at that same site suggested a higher density (≥12 bears/100 km²). Neither of these estimates can be considered reliable or representative of the wider population because of the small sample sizes. Moreover, the effective sampling area for the camera-trapping study was uncertain. A DNA hair-trapping mark–recapture study in Ecuador sampled a greater number of bears (n  =  25) within a larger study area, but a male-biased sex ratio suggested that closure was violated, precluding a simple estimate of density based on the area of the trapping grid. Also, low capture rates in what was perceived (from incidence of bear sign) as prime bear habitat might be indicative of a sampling bias. These issues are not simply incorporated into confidence intervals (CIs): CIs only include uncertainty due to sampling error, not biased sampling or an ambiguous sampling area. Whereas these (low density) estimates may provide guidance for conservation, their greatest usefulness may be in providing directions for improvement of future studies of Andean bears, as well as bears in Asia, which also lack rigorous population estimates.

I estimated home ranges of 5 female and 4 male Andean bears (Tremarctos ornatus) inhabiting the Intag region in Ecuador between September 2001 and December 2006, using 1,439 and 412 telemetry locations for females and males, respectively. Multi-annual and seasonal home ranges were estimated using 2 methods: minimum convex polygon (MCP) and nearest-neighbor convex hull (k-NNCH) analyses. I considered k-NNCH analysis the best method for estimating Andean bear home ranges in fragmented landscapes such as those across the study site. Annual home range of males (59 km²) were larger than those for females (15 km²) using the k-NNCH method. During the rainy season home ranges of males were 23 km² versus 10 km² for females, and in the dry season, 27 km² versus 7 km². All bears in this study showed some degree of home range overlap, indicating intra-specific tolerance. The mean annual k-NNCH home range of males overlapped home ranges of females by 32%, and among females, overlap was 22%. No evidence of territorial behavior was observed in this study.

Human–black bear (Ursus americanus) interactions (HBI) have been increasing in frequency and magnitude in North America since the 1960s, and many wildlife management agencies are turning to proactive management actions to reverse this trend. Information and education efforts (IEE) are the most common proactive management actions used; however, few studies monitor behavior and attitudes of residents exposed to HBI and IEE. We used a case study in the Rattlesnake Valley of Missoula, Montana, USA to describe the diversity of anthropogenic attractants available to black bears based on self-reported human behaviors, and to test for changes in resident behavior and attitudes over a 4-year exposure to HBI and IEE. We identified >5 non-vegetative attractants, and >12 species of native and non-native vegetation available to black bears. Comparing the responses from mail questionnaires in 2004 (n  =  369, response rate  =  74%) and 2008 (n  =  560, response rate  =  60.1%), we found that the prevalence of 1 important behavior (outdoor garbage storage) decreased, and support for management actions used to deal with HBI increased, suggesting behavior and attitudes of residents changed from 2004 to 2008. We suggest that bear managers developing proactive management plans for HBI must incorporate (1) the varying effects of reducing the prevalence of 1 or numerous attractants, (2) the changing dynamics of human behavior and attitudes, and (3) the importance of incorporating monitoring and evaluation procedures.

We investigated the distribution of brown bears (Ursus arctos) with white pelage in Kunashiri and Etorofu Islands, Southern Kuril Islands; we here name this white pelage form the Ininkari bear. The fur color of the brown bear varies considerably throughout its range, and many pelage variations have been reported. Ininkari bears are unique in having white fur only on the upper half of the body. There are no reports of bears with the Ininkari-type markings in other regions of the world. According to literature and interview surveys, Ininkari bears have been recognized since at least the late 1800s on Kunashiri and Etorofu. We surmise the reasons that distribution of Ininkari bears is restricted to these islands are the lack of predators and the low hunting pressure on brown bears there; these factors may allow the bears to maintain such a unique pelage.

American black bears (Ursus americanus) are opportunistic omnivores and can be proficient predators of neonate ungulates, but predation of adult ungulates is rare. In November 2009 we investigated a probable black bear predation of a radiocollared, adult (7.5 years old) female white-tailed deer (Odocoileus virginianus) in a densely vegetated, lowland conifer forest in the Upper Peninsula of Michigan, USA. The deer carcass was 80% buried with puncture wounds and lacerations on the back and hindquarters. The hide was everted, the intestines and stomach partially eaten, the mammary glands were punctured, and the skeleton remained articulated. All woody vegetation <5.0 cm diameter within 5 m of the carcass was trampled and contained bear and deer hair. We found no evidence of other carnivores. Based on the condition of the carcass, physical evidence at the site, and the similarity of this predation to reported black bear predations, we suggest this deer was attacked and killed by a black bear.