Comparative foraging ecology of lynx and coyotes in three Gulf of Alaska national parks

Abstract

Consumers exhibit varying degrees of dietary specialization, with foraging strategies shaped by both evolutionary history and local food availability. In boreal systems, Canada lynx are considered snowshoe hare specialists, whereas coyotes are classically generalist foragers capable of exploiting diverse resources. At the western periphery of the lynx's range in southwestern Alaska, these species co-occur across a mosaic of coastal and interior habitats that differ in prey community composition and landscape structure. We used fecal DNA metabarcoding to characterize and compare the diets of lynx and coyotes in three national parks containing both coastal and interior habitats. We quantified dietary diversity and feeding niche overlap to assess how habitat type influences foraging ecology, interspecific niche partitioning, and species occurrence. Lynx diets were consistently dominated by snowshoe hare, particularly in interior forests, but coastal lynx exhibited niche expansion to consume a wider variety of alternate prey including birds, rodents, and larger mammals, though notably not marine resources. Coyote diets were more diverse overall and included marine-associated prey in coastal areas. Coastal coyotes had the broadest dietary niche, with 55 unique prey taxa and the highest Shannon diversity (H′ = 3.14). Dietary overlap between lynx and coyotes was high in the interior (Pianka's O = 0.86) but lower in coastal habitats (O = 0.51), suggesting increased niche partitioning in coastal regions due to the higher diversity of available prey. These patterns are consistent with the facultative specialist hypothesis and indicate that coastal environments may incite dietary plasticity in both species, particularly in the typically specialized lynx. In addition, we observed highly patchy distributions of both predators in coastal habitats, suggesting that prey availability, dispersal barriers, and carnivore guild structure may constrain coastal occupancy. Our results highlight the importance of prey community structure and habitat context in shaping carnivore foraging strategies, range limits, and interspecific interactions across heterogeneous landscapes.