Advancing our understanding of the non-breeding distribution of Cerulean Warbler (Setophaga cerulea) in the Andes
Recent population declines have prompted the International Union for the Conservation of Nature to list Cerulean Warbler (Setophaga cerulea: Parulidae) as a Vulnerable species. It is believed that this decline may be related to habitat loss through its entire range, mainly due to deforestation and degradation of its habitats. In response, members of El Grupo Cerúleo, a subcommittee of the Cerulean Warbler Technical Group that addresses wintering ground issues faced by the species, developed a predictive model of wintering habitat for Cerulean Warblers throughout the northern and central Andes. From 2006-2010, we conducted field surveys in Venezuela, Colombia, Ecuador and Peru to validate the winter habitat model. In this paper, we share new insights into the distribution of Cerulean Warblers and preview recent analyses of the ability of the habitat model to predict wintering range. First, our data show that Cerulean Warblers occupy a broader altitudinal range than previously thought. Second, wintering Cerulean Warblers utilize a wider variety of habitat types than formerly believed, including different successional stages and intensively-managed agroecosystems. Third, the species shows a strong association with mixed-species flocks, composed mostly of resident bird species. Collectively, these findings have important implications for conservation efforts in the Andes.