Seasonal foraging strategies of Alaskan gray wolves (Canis lupus) in an ecosystem subsidized by Pacific salmon (Oncorhynchus spp.)

Canadian Journal of Zoology, e-First Articles. Despite frequent observations of gray wolves (Canis lupus L., 1758) using nonungulate prey, the seasonal and interannual variation in the use and relative importance of alternative prey sources to gray wolf diets have not been studied at the individual scale. We used stable isotope analysis ( δ13C and δ15N) of guard hair and blood components (clot and serum) collected over 4 years to examine the occurrence, extent, and temporal variation of Pacific salmon (genus Oncorhynchus Suckley, 1861) as a food resource by both individual wolves and social groups in Lake Clark National Park and Pr eserve in southwestern Alaska, USA. Our results demonstrate substantial variability in the use of salmon over time. During summer, diets of five wolves consisted of at least 50% salmon, while the diets of 17 wolves consisted of primarily terrestrial prey. Over 3 years, one group of wolves consistent ly consumed salmon in summer and switched to terrestrial prey in winter. Prey choices were generally similar within social groups; however, the degree to which individuals consumed salmon was highly variable. The use of salmon as exhibited by wolves in Lake Clark is likely widespread where salmon ar e abundant and this finding should be taken into consideration in the conservation and management of wolves and their prey.
Source: Canadian Journal of Zoology - Category: Zoology Authors: Source Type: research