Denning of grizzly bears in the Yellowstone National Park area

Steven L. Judd; Richard R. Knight; Bonnie M. Blanchard

doi:10.2307/3872814

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USGS · 70121243

Denning of grizzly bears in the Yellowstone National Park area

Steven L. Judd·Richard R. Knight·Bonnie M. Blanchard

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Abstract

Radiotelemetry was used to locate 101 grizzly bear ( Ursus arctos ) dens from 1975 to 1980; 35 dens were examined on the ground. Pregnant females denned in late October, and most other bears denned by mid-November. Duration of denning average 113, 132, and 170 days for males, females, and females with new cubs, respectively. Males emerged from mid-February to late March, followed by single females and females with yearlings and 2-year-olds. Females with new cubs emerged from early mid-April. Den sites were associated with moderate tree cover (26%-75% canopy cover) on 30°-60° slopes. Dens occurred on all aspects, although northerly exposures were most common. Grizzly bears usually dug new dens but occasionally used natural cavities or a den from a previous year. Males usually dug larger dens than females with young. Eight excavated and 2 natural dens of the 35 examined dens were used for more than 1 year.

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Source-reported bounding extent: 44.1324° to 45.109° latitude; -111.156° to -109.8242° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Steven L. Judd, Richard R. Knight, Bonnie M. Blanchard. 1986. Denning of grizzly bears in the Yellowstone National Park area. https://doi.org/10.2307/3872814

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