Conspecific and Interspecific Nest Reuse by Wood Thrush (Hylocichla mustelina)

Abstract

We report one instance of conspecific nest reuse by Hylocichla mustelina (Wood Thrush) within the same breeding season, two instances of conspecific nest reuse in subsequent breeding seasons, and two instances of Wood Thrushes reusing nests originally constructed by Pheucticus ludovicianus (Rose-breasted Grosbeaks) during a three-year study in Ontario. Rates of nest reuse were higher than previously reported for Wood Thrush, with conspecific nest reuse accounting for 8–12% of the observed nesting activity, and interspecific nest reuse accounting for 8–9%. Nest reuse occurred following periods of colder minimum temperatures or greater precipitation than in other years. We suggest that instances of nest reuse within and between breeding seasons may occur in response to time or energy constraints on females resulting from unusual weather conditions. Documenting instances of nest reuse behaviour contributes to our understanding of some of the constraints experienced during breeding and may shed light on factors affecting annual reproductive success.