Vinous-throated parrotbills breed in invasive smooth cordgrass habitat: Can native birds avoid the potential ecological trap?

Abstract

Native animals are facing long-term coexistence with invasive plants worldwide, the impacts of which on animal behavior remain poorly known. Potential ecological traps could threaten native birds breeding in invasive plant habitats, but behavioral strategies for birds to avoid such risks are few concerned. The invasion of Smooth Cordgrass (Spartina alterniflora) has seriously varied the vegetation landscape in the coastal wetlands of eastern China, and affected the habitat selection of native birds. Here, we investigated the nesting and breeding characteristics of a common native passerine, the Vinous-throated Parrotbill (Sinosuthora webbiana), in habitats dominated by native Common Reed (Phragmites australis) and exotic cordgrass. We found that parrotbills could complete their breeding cycle in cordgrass habitat. Most nest failure was attributed to predation in native habitat but tide inundation in cordgrass habitat. However, the nest success rate and daily survival rate (DSR) in cordgrass habitat were higher. Moreover, nest height was markedly higher in cordgrass habitat and was the most important influencing variable (positively correlated with the DSR). These results suggest that cordgrass habitat is a potential ecological trap due to the tide inundation, but some parrotbills seem to effectively avoid this risk by increasing nest height. Our study reveals that a native passerine changes its nesting behavior to accommodate invasive plant habitat and highlights that habitat changes caused by invasive plants may drive the adaptive evolution of native animal behavior. The limitation of these results must be acknowledged for the small sample size, and there is a need for a larger sample and long-term data for further verification.