Nesting with an enemy: The abundance and distribution of preferred and secondary prey near nesting Cooper's hawks, Accipiter cooperii

Abstract

By nesting near their predators, birds may gain safe nest sites because predators defend a region around their own nests. For some species, this benefit comes at the potential cost of increased predation risk due to the predators. We hypothesized that birds less vulnerable to predation were more likely to associate with predatory birds. We surveyed different bird species near active Cooper's hawk, Accipiter cooperii, nests, 200 m from each hawk nest, and at control sites that did not contain Cooper's hawk nests. The birds surveyed were categorized by weight, foraging height, and nest type. Canopy foraging birds were found in relatively higher densities near the Cooper's hawk nests than at other sites, whereas ground and mid-level foragers were more common away from Cooper's hawk nests. The association with Cooper's hawks was most pronounced for those canopy foraging birds that were small and built cup nests. Birds less vulnerable to predation by Cooper's hawks are more likely to nest in association with these hawks than are more vulnerable birds.