Context-dependent costs and benefits of a heterospecific nesting association

Abstract

The costs and benefits of interspecific interactions can vary among spatial or temporal contexts. We studied interactions between breeding shorebirds and gulls and found that the nature of interactions varied with breeding stage. Hudsonian Godwits aggregated their nests near colonies of Mew Gulls, a protector species that reduced risk of predation that godwits experienced during incubation. However, the association changed post-hatching, when Mew Gulls became important predators of young chicks and were avoided by godwits.