Assessing Nutritional Parameters of Brown Bear Diets among Ecosystems Gives Insight into Differences among Populations.

摘要: Food habit studies are among the first steps used to understand wildlife-habitat relationships. However, these in themselves insufficient differences population productivity and life histories, because they do not provide a direct measure of energetic value or nutritional composition complete diet. Here, we developed dynamic model integrating food habits information assess parameters brown bear (Ursus arctos) diets three interior ecosystems North America. Specifically, estimate average amount digestible energy protein (per kilogram fresh diet) content diet across active season by bears living western Alberta, Flathead River (FR) drainage southeast British Columbia, Greater Yellowstone Ecosystem (GYE). As well, proportion contributed different items, thereby highlighting important resources each ecosystem. Bear Alberta had lowest levels through all seasons, which might help explain low reproductive rates this population. The FR similar recent male GYE during spring, but were lower late summer fall. Historic most protein, is consistent with their larger body sizes higher productivity. decrease consumption trout (Oncorhynchus clarki), whitebark pine nuts (Pinus albicaulis), ungulates, particularly elk (Cervus elaphus), has decreased patterns observed suggest that size densities influenced seasonal availability an energy, likely due part influences on mass gain success.