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Date Permissions Signed

3-18-2011

Date of Award

2011

Document Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Environmental Sciences

First Advisor

Helfield, James M.

Second Advisor

Bodensteiner, Leo R., 1957-

Third Advisor

Bunn, Andrew Godard

Fourth Advisor

Quinn, Thomas

Abstract

Previous research on the fishing behavior of bears (Ursus spp.) along salmon streams suggests that dominant individuals forage more efficiently than their competitors; specifically, large adult males are the most efficient foragers at a given stream due to their ability to dominate the most productive locations. I tested this hypothesis by observing 26 individual brown bears (U. arctos) fishing for chum salmon (Oncorhynchus keta) at McNeil River, Alaska, over 33 days during the summer of 2010. In contrast with previous findings I 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 productive locations). While some individuals seemed to employ dominance as a strategy to achieve high catch rates, other individuals achieved high foraging efficiency by employing alternative foraging strategies that did not involve dominance-related behaviors. My observations suggest that bears at McNeil River employ a variety of fishing strategies, of which dominance-related behavior is but one alternative. I suggest that where foraging efficiency is concerned, an individual bear's ability to develop an effective foraging strategy may be more important than its social dominance. My findings open the door to intriguing questions for future research into which physical or cognitive traits lead to the development of successful foraging strategies among brown bears fishing for salmon.

Type

Text

Publisher

Western Washington University

OCLC Number

727948404

Digital Format

application/pdf

Geographic Coverage

McNeil River State Game Sanctuary (Alaska)

Genre/Form

Academic theses

Language

English

Rights

Copying of this thesis in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this thesis for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.

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