Active American black bear dens adjacent to a marine beach used for foraging
Hibernation and denning are essential to American black bears (Ursus americanus) throughout much of their range. Although den structure varies, it is generally agreed that dens provide the important functions of shelter and safety (Davis 1996). In coastal Alaska, studies indicate that most black bears den in upland areas and largely relied on large or […]
Reported mating of Hokkaido brown bear in autumn
We describe an incident we investigated in which a photographer on the Shiretoko Peninsula, Hokkaido, Japan observed a pair of adult brown bears (Ursus arctos yesoensis) mating on 11 October 2009. After an interview and examination of photographs, we conclude that the mating did occur on the reported date. Copulation evidently lasted about 30 minutes […]
Nursing vocalization of a polar bear cub
We recorded the nursing vocalization of a wild polar bear (Ursus maritimus) cub in Svalbard, Norway and describe it with the term humming. From a 3-minute recording of the vocalization, we found the sounds composed of between 30-55 pulses with a mean of 0.05 (SE = 0.002) seconds in duration, a frequency with the greatest […]
Ecological investigations of grizzly bears in Canada using DNA from hair, 1995-2005: a review of methods and progress
Grizzly bears (Ursus arctos) occur across British Columbia and in Alberta in mostly forested, mountainous, and boreal ecosystems. These dense forests make sighting bears from aircraft uncommon and aerial census impractical. Since 1995, we have used genetic sampling using DNA from bear hair collected with barbed wire hair traps to explore a suite of ecological […]
A proposed lexicon of terms and concepts for human-bear management in North America
We believe that communication within and among agency personnel in the United States and Canada about the successes and failures of their human-bear (Ursidae) management programs will increase the effectiveness of these programs and of bear research. To communicate more effectively, we suggest agencies clearly define terms and concepts used in human-bear management and use […]
Estimating ages of bear claw marks in Southeast Asian tropical forests as an aid to population monitoring
Asiatic black bears (Ursus thibetanus) and sun bears (Helarctos malayanus) in Southeast Asia leave claw marks on climbed trees that provide a cumulative history of their presence and activities, but this record can be difficult to interpret without knowing the age of the marks. We conducted an experiment to estimate ages of bear claw marks […]
Do public complaints reflect trends in human-bear conflict?
Minimizing conflicts with humans is a necessary component of the management of American black bears (Ursus americanus) across most of their range. The number of complaints about conflicts with black bears is commonly used to infer trends in the actual frequency or severity of human-bear conflict, and even trends in bear population size. However, the […]
Are brown bears recovering in the Cantabrian Mountains? Reply to Fernández-Gil et al
We reply to the critique from Fernández-Gil et al. (2010) regarding our study on trends in female brown bears with cubs (F CUB ) in the Cantabrian Mountains, Spain (Palomero et al. 2007). We discuss the relationship between sampling effort and the number of F CUB , the methods used to collect the data, and […]
Are Cantabrian brown bears recovering?
The Cantabrian brown bear (Ursus arctos) population of northwest Spain has been monitored since 1982. Population trends have been estimated using counts of females with cubs-of-the-year (hereafter, F CUB ). A population viability analysis found a mean annual decrease of 4-5% for 1982-95, but with a stabilizing or even slightly increasing trend in the early […]
Hematological and serum biochemical values of Andean bears in Ecuador
We collected blood samples (n = 49) from 43 Andean Bears (Tremarctos ornatus) in Ecuador between September 1995 and May 2006 and analyzed them for 11 serum biochemical and 13 hematological parameters. Results were grouped and compared according to the bears’ life condition (captive or free-ranging), sex, age, and body mass. Free-ranging bears had higher […]
