Analyzing the prevalence of the newly reintroduced sea otter in coyote and wolf diet

• Main Author: Garcia, Lani M.
• Other Authors: Levi, Taal, Dymit, Ellen, Painter, Luke, Oregon State University. Honors College
• Format: Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Canis lupus; Alaska
• Online Access: https://ir.library.oregonstate.edu/concern/honors_college_theses/xd07h2274

Following their extirpation due to the maritime fur trade, northern sea otter (Enhydra lutris kenyoni) reintroduction in the 1960s has facilitated their recolonization in southeast Alaska. Sea otters are now sympatric with wolves (Canis lupus), which are widespread in southeast Alaska, and a colonizing coyote population (Canis latrans). Recent studies of coastal wolf diet have detected substantial consumption of sea otters. Whether coyotes also regularly consume sea otters remains unknown. To determine the prevalence of sea otters in coastal coyote diets, we analyzed coyote scats from the Gustavus Forelands of southeast Alaska using DNA metabarcoding and compared these results to those of wolves in the same region. We found that sea otters are among the top three most consumed prey items for both canids, making up 7.4% of coyote diet and 12.2% of wolf diet. Coyote scats containing sea otters were isolated to the western shore of the Gustavus Forelands. Although sea otters do not appear to be the primary prey for this coyote population, coastal coyotes may receive substantial subsidies with potential consequences for alternative terrestrial prey. Competition for sea otters may additionally exacerbate interference competition between wolves and coyotes. Keywords: marine subsidies, wolf diet, coyote diet, marine-terrestrial linkages, sympatric carnivores