Bonding behavior of sister brown bears with different-aged offspring
This paper documents and describes the behavior of 2 sibling female brown bears (Ursus arctos) and their cubs as they bonded at Brooks River in Katmai National Park, Alaska, USA. Between mid- August and October 2022 the adult female bears and their cubs behaved much like a single family. The same-aged mothers each had a […]
Harvest-based demographic estimation of a brown bear population on the Oshima Peninsula, Hokkaido
We constructed a population dynamic model using demographic parameters with uncertainties by using long-term harvest data and estimated population dynamics of brown bears (Ursus arctos) on the Oshima Peninsula, Hokkaido, Japan, from 1968 to 2021 with population trend indicators obtained by forest sign survey and an upper population limit calculated by extrapolating an estimated density […]
Documentation of an Asiatic black bear preying on a living sika deer caught in a leg-hold snare trap
Asiatic black bears (Ursus thibetanus) rarely prey on living adult deer. We report video documentation, obtained May 2024, of a bear subduing and killing a sika deer (Cervus nippon) that was captured in a leg-hold snare trap, then staying in the area for repeated feeding visits. Leg-hold snare traps for deer capture are widely used […]
Factors affecting body weight fluctuation in free-ranging Asian black bears
The Asian black bear (Ursus thibetanus) shows seasonal changes in body weight, activity level, and range use. However, there is little information available on these factors in individuals in the wild. We documented the body weights of free-ranging Asian black bears from spring to autumn, 2017 to 2019, in the Nikko-Ashio Mountains, Tochigi Prefecture, Japan, […]
Denning ecology of an at-risk American black bear population in a unique habitat on the Bruce Peninsula, Ontario, Canada
The American black bear (Ursus americanus) population on the Bruce Peninsula in southern Ontario, Canada, is small (∼300 bears), genetically isolated from the closest bears in other parts of Ontario because of geography and urban development, and it is at risk because of habitat loss. The Bruce Peninsula is underlain by dolostone, and soils over […]
Andean bears below the Andes
We lack many quantitative data on the current distributions of several bear species, and hypotheses about the mechanisms underlying those distributions. We raise this point by discussing visual detections of Andean bears (Tremarctos ornatus) in sampling from 14 September 2016 to 24 August 2017 in the Haramba Queros Wachiperi Ecological Reserve Conservation Concession in southeastern […]
Sea ice dynamics influence movement patterns of adult female polar bears in southern Hudson Bay
To access seals (Pinnipedia), polar bears (Ursus maritimus) move large distances over the sea ice in winter. Already documented declines in ice duration for Hudson Bay, Canada, are predicted to continue, likely affecting polar bear movement patterns. Using data from global positioning system (GPS) collars, 2007-2011, we describe movement patterns of adult female polar bears […]
Grizzly bear and American black bear interactions with people in Yellowstone National Park
In North America, polar bears (Ursus maritimus), grizzly bears (U. arctos), and American black bears (U. americanus) occasionally injure or kill humans. Although bear-inflicted human injuries are uncommon, they generate media attention that can lead to fear and unreasonable perceptions of the risk of bear attacks. Information on the behavioral responses of grizzly and black […]
Handedness of brown bears aggregating in Katmai National Park, USA
We analyzed handedness of brown bears (Ursus arctos), which is the tendency to differentially use the right or left forelimb for dexterous actions. Handedness in mammals is hypothesized to be an outcome of lateralization of neocortex function, which serves to increase cognitive capacity by reducing redundancy of function between left and right hemispheres. Handedness in […]
First description of a mummified Middle Holocene brown bear from the New Siberian Islands, Russia
The brown bear (Ursus arctos L., 1758) is a widespread bear species inhabiting the forest zone of Eurasia, including the Republic of Yakutia. The association with forest habitats explains why the Pleistocene findings of U. arctos fossils are rare in the northern part of Eastern Siberia, where open steppe-tundra and steppefied landscapes prevailed during the […]
