Understanding nest success and brood parasitism in the endangered Black-capped Vireo: comparisons with two sympatric songbirds

Abstract

Abstract Nest predation and brood parasitism likely cause declines in many songbird species, yet the rate of these declines varies among species. Simultaneously studying co-occurring species with overlapping territories provides an opportunity to identify differences among the species that may explain differential reproductive success. We monitored nests of three co-occurring songbird species to determine whether the federally endangered Black-capped Vireo (Vireo atricapilla) experienced lower reproductive success than Northern Cardinals (Cardinalis cardinalis) and White-eyed Vireos (V. griseus) on private lands with and without trapping of brood parasites. We assessed if habitat metrics and nesting phenology were associated with nest success and frequency of brood parasitism by Brown-headed Cowbirds (Molothrus ater) to determine if these characteristics explain poor reproductive success. We monitored 188 nests in shrubland and ecotones with woodlands in central Texas from 2006–2008. We found species-spec...