Alternative foraging strategies among bears fishing for salmon: a test of the dominance hypothesis

• Published in: Canadian Journal of Zoology
• Main Authors: Gill, I.D., Helfield, J.M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2012
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Ursus arctos; Alaska
• Online Access: http://dx.doi.org/10.1139/z2012-045; http://www.nrcresearchpress.com/doi/full-xml/10.1139/z2012-045; http://www.nrcresearchpress.com/doi/pdf/10.1139/z2012-045

Previous studies of bears (genus Ursus L., 1758) fishing for Pacific salmon (genus Oncorhynchus Suckley, 1861) suggest that dominant individuals are the most efficient foragers owing to their ability to secure access to the most productive locations. We tested this hypothesis by observing brown bears ( Ursus arctos L., 1758) fishing for chum salmon ( Oncorhynchus keta (Walbaum in Artedi, 1792)) at McNeil River, Alaska. We did not observe strong relationships between the foraging efficiency of individual bears and the frequency with which they engaged in dominance-related behaviors (e.g., displacing competitors, stealing fish, using more popular or productive locations). Although some dominant individuals achieved high catch rates, other nondominant bears foraged with comparable or greater efficiency by developing alternative strategies adapted to specific locations. Our observations demonstrate that bears may employ a variety of fishing strategies, the success of which may be location-specific and frequency-dependent. These findings suggest that physical and cognitive skills may be as important as social dominance in determining foraging success among bears.