Evaluating exotic plants as evolutionary traps for nesting Veeries

Abstract

Human-induced rapid environmental change, such as the introduction of exotic species, can create novel species interactions that might be detrimental to native organisms. For birds, introduced plant species may represent potentially attractive, but dangerous, locations to place a nest. If the environmental cues that birds use to select safe nest sites are unreliable when they apply to nonnative plant species, these plants could act as evolutionary traps: preferred nest substrates that confer the poorest reproductive outcomes. We tested this possibility by assessing reproductive consequences of nest substrate preference in the Veery (Catharus fuscescens). We followed the fates of nests in native plants and in three nonnative plants associated with reduced nest success in previous studies (Amur honeysuckle [Lonicera maackii], multiflora rose [Rosa multiflora], and Japanese barberry [Berberis thunbergii]). Veeries preferred to locate nests in nonnative plants and in denser patches of vegetation more dominated by nonnative plants. Nests placed in nonnative plants were more visually concealed. We found no evidence that these preferences were maladaptive, as there was no difference in the daily survival probability of nests based on nest-site characteristics. Veeries were not victims of an 'oviposition trap' in this forest system during the period of our study, but rather were facultatively exploiting nonnative plants to their reproductive advantage.