Bear feeding activity at alpine insect aggregation sites in the Yellowstone ecosystem

Canadian Journal of Zoology
By: , and 



Bears (Ursidae) were observed from fixed-wing aircraft on or near alpine talus in the Shoshone National Forest between 15 June and 15 September in 1981–1989. Bears fed on insect aggregations at 6 known and 12 suspected alpine talus sites, disproportionately more at elevations > 3350 m, on slopes > 30°, and on south- and west-facing aspects. While at these sites, bears almost exclusively ate invertebrates, typically army cutworm moths (Euxoa auxiliaris). Subadult grizzly bears (Ursus arctos horribilis) appeared to be underrepresented at the sites, and proportionate representation of adult females with young appeared to decrease between 15 June and 15 September. Overall, observations of bears at these sites increased between 1981 and 1989. We suggest that alpine insect aggregations are an important food source for bears in the Shoshone National Forest, especially in the absence of high-quality foraging alternatives in July and August of most years.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Bear feeding activity at alpine insect aggregation sites in the Yellowstone ecosystem
Series title Canadian Journal of Zoology
DOI 10.1139/z91-341
Volume 69
Issue 9
Year Published 1991
Language English
Publisher National Research Council
Publisher location Ottawa
Description 6 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Canadian Journal of Zoology
First page 2430
Last page 2435
Country United States
State Idaho;Montana;Wyoming
Other Geospatial Yellowstone National Park
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