The white-colored brown bears of the Southern Kurils
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 […]
Behavioral and attitudinal change of residents exposed to human-bear interactions
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 […]
Andean bear home ranges in the Intag region, Ecuador
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 […]
Andean bear density and abundance estimates – How reliable and useful are they?
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) […]
Illegal killings may hamper brown bear recovery in the Eastern Alps
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 […]
Study design and sampling intensity for demographic analyses of bear populations
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 […]
Improving large scale mark-recapture estimates for American black bear populations
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 […]
American black bear estrus and parturition in the Alleghany Mountains of Virginia
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 […]