Monster Seminar Jam - Alternative Foraging Strategies and Social Dominance among Brown Bears at McNeil Falls, Alaska: Why do Some Bears Catch More Fish than Others?
Dr. Jim Helfield, Assistant Professor, Department of Environmental Sciences, Huxley College of the Environment, Western Washington University
Previous studies of bears (Ursus spp.) fishing for Pacific salmon (Oncorhynchus spp.) suggest that dominant individuals are the most efficient foragers due to their ability to secure access to the most productive locations. We tested this hypothesis by observing brown bears (U. arctos) fishing for chum salmon (O. keta) 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). While some dominant individuals achieved high catch rates, other non-dominant 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.
Date and Time:
October 27, 2011,
10:30 am - 1:00 pm