Widespread mesopredator effects after wolf extirpation

Abstract

Herein, we posit a link between the ecological extinction of wolves in the American West and the expansion in distribution, increased abundance, and inflated ecological influence of coyotes. We investigate the hypothesis that the release of this mesopredator from wolf suppression across much of the American West is affecting, via predation and competition, a wide range of faunal elements including mammals, birds, and reptiles. We document various cases of coyote predation on or killing of threatened and endangered species or species of conservation concern with the potential to alter community structure. The apparent long-term decline of leporids in the American West, for instance, might be linked to increased coyote predation. The coyote effects we discuss could be context dependent and may also be influenced by varying bottom-up factors in systems without wolves. We make recommendations for ecological research in light of ongoing wolf recovery in parts of the West. Strong ecological effects of wolf repatriation may not occur outside of large reserves where wolves are prevented from achieving ecologically effective densities because of wolf hunting or wolf control programs. Finally, we advocate for more studies relating to the management of coyotes that compare exploited and unexploited populations and evaluate the influence of anthropogenic food subsidies on coyote densities.