Thesis defense: Ashley Stanek, master's candidate in biological sciences - Jan. 30, 2014

Thursday, Jan. 30, 10-11 a.m. Rasmuson Hall, Room 110

Ashley Stanek, master's candidate in biological sciences, will defend her thesis, "Dietary ecology of Alaskan gray wolves: Variation in seasonal foraging strategies in a salmon subsidized ecosystem."

Abstract: While wolves (Canis lupus) are traditionally considered to rely on terrestrial prey, primarily ungulates, they are opportunistic feeders and have been observed to use alternative prey, including marine resources, such as salmon (Oncorhynchus spp.). Despite these observations of alternative resource use, the seasonal and inter-annual variation and the relative importance of different dietary components have not been studied at this scale in individual wolves. Stanek used stable isotope analysis (δ13C, δ15N) of wolf guard hair and blood components to assess the seasonal and inter-annual variation in the use of salmon by wolves over the course of a four-year study.

Lake Clark National Park and Preserve in Southwestern Alaska is an ideal location for such an examination because it provides wolves with multiple ungulate species and salmon as potential prey resources. Stanek's results demonstrate that wolves in the Lake Clark region differ in their use of marine resources (salmon) both spatially and temporally. During the summer, half of the diet of some wolves consisted of salmon while other wolves consumed primarily terrestrial prey. In each of three years, one group of wolves consistently consumed salmon in summer and switched to terrestrial prey in winter. Salmon may be an important food source for wolves during periods when the availability of ungulates is reduced. Diets were similar between individuals within social groups. However, the degree to which wolves consumed salmon was highly variable. Stanek discusses factors that potentially contribute to this variation. The use of salmon exhibited by wolves in Lake Clark is likely widespread in regions where salmon are abundant and should be taken into consideration in the management of wolves and their prey.

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