Behavioral plasticity in nest structure and placement is linked to nesting success in an insular songbird population
Cheek, Rebecca et al. (2022), Behavioral plasticity in nest structure and placement is linked to nesting success in an insular songbird population, Dryad, Dataset, https://doi.org/10.5061/dryad.5mkkwh777
Avian nest structure and the substrate where nests are placed tend to be highly conserved characters. However, orange-crowned warblers (Leiothlypis celata sordida) breeding on the California Channel Islands exhibit remarkable variation in their nest structure and placement compared to their mainland conspecifics. Here we show that the same individuals on Santa Catalina Island build both lighter, grass-dominated ground nests or heavier off-ground nests that contain more ridged materials and less grass, resulting in highly variable patterns of nest construction and placement. We suggest the observed behavioral plasticity could be driven by the lack of avian predators on Santa Catalina Island, which in turn allows the warblers to use a wide variety of nest sites that make it difficult for native predators to develop search images for nest sites.