Grizzly bear behavior in south-central Alaska: Use of a hidden Markov model to assess behavior
Attempts to understand wildlife population dynamics and implement management practices benefit from understanding animal behavior traits. In Alaska, USA, grizzly bear (Ursus arctos) behavior is important to understand because the species is an apex predator, exerts top-down population effects, and is a cornerstone species across complex landscapes. Our objectives were to examine how environmental and […]
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, […]
Possible sexually selected infanticide by polar bears in western Hudson Bay
Infanticide occurs in a diversity of taxa and may provide benefits to the perpetrator through nutritional gain, reduced competition, or increased fitness from mating opportunities through sexually selected infanticide (SSI). Infanticide, however, is rarely observed. We documented a probable infanticide event by a 23-year-old adult male polar bear (Ursus maritimus) on a 3-month-old cub in […]
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 […]
A case of hyperdontia in grizzly bear in British Columbia
Hyperdontia refers to an excess number of teeth past the expected number of teeth for an individual located in the mandible or maxilla. These extra teeth are often referred to as ‘supernumerary.’ This condition is a relatively uncommon, infrequent phenomenon scarcely documented in Ursidae globally, with only a handful of examples documented in literature. In […]
Temporal segregation between female Asiatic black bears with unweaned offspring and solitary bears
Mammalian females with unweaned offspring often engage in spatial and temporal segregation to avoid encounters with conspecifics, reducing the risks of infanticide and resource competition. Such behavioral strategies have been reported in bears (Ursus spp.), but knowledge is limited in Asiatic black bears (U. thibetanus). Here, we investigated the temporal segregation of Asiatic black bears […]
Hand-rearing and developmental milestones of a Bornean sun bear
Understanding cub growth and developmental milestones is one crucial key in determining the success of conservation breeding of the endangered Bornean sun bear (Helarctos malayanus euryspilus). One Bornean sun bear was successfully hand-raised from 9 days old until weaning at the Bornean Sun Bear Conservation Centre, Malaysia in 2021. Maternal-cub interaction was recorded for the […]