The Eurasian Magpie Preys on the Nests of Vinous-throated Parrotbills in Invasive Smooth Cordgrass

Abstract

Native animals worldwide are experiencing long-term coexistence with invasive plants, leading to diverse behavioral changes. Invasive plants may create new habitat structures that affect the distribution or behavior of prey, which in turn might attract predators to these novel habitats, thereby altering predator–prey dynamics within the ecosystem. However, this phenomenon is rarely reported. Our previous research found that in the Yellow Sea wetlands of China, the native bird species, the vinous-throated parrotbill (Sinosuthora webbiana), has adapted to breeding in the invasive smooth cordgrass (Spartina alterniflora) by increasing its nesting height. Here, our observations indicate that in cordgrass habitats, the main nest predator of parrotbills was the Eurasian magpie (Pica pica), accounting for 75% of predation events. In contrast, in native habitats, the primary predators were mammals and snakes, accounting for 83% of predation events, with no nests being predated by magpies. We believe that changes in the breeding and nesting behavior of parrotbills may have attracted magpie predation in cordgrass habitats. Our findings may provide an empirical case of how behavioral changes induced by invasive plants can lead to dynamic shifts in predation relationships. We advocate for further research into this intriguing phenomenon, as it could enhance our understanding of changes in interspecific relationships and their ecological consequences within the context of biological invasions.