Social Information and Habitat Selection in the Vermivora Complex

Golden-winged Warblers (Vermivora chrysoptera) and Blue-winged Warblers (Vermivora cyanoptera) are closely related species that have received extensive research attention. The two species hybridize frequently and produce fertile offspring yet tend to mate assortively and can hold overlapping territories. Studies examining behavioral responses between the species have shown mixed results. Still lacking, however, is information on how conspecific and heterospecific interactions impact settlement and habitat selection for both species. The purpose of this study was to examine the role of social information in the habitat selection process of both Golden-winged and Blue-winged warblers. The first objective was to determine if conspecific social information can be used to induce settlement in both Golden-winged and Blue-winged warblers across their range. The second objective was to determine the response of each species to heterospecific cues (how BWWA respond to GWWA calls and vice versa) and whether or not their response differs in allopatric and sympatric populations.In order to address these questions, in the summer of 2017 we broadcast vocalizations of Golden-winged warblers and Blue-winged warblers in an area where only Golden-winged warblers breed (Vilas County, WI), where only Blue-winged warblers breed (Vermillion County, IL), and where both species breed (Monroe County, WI). Preliminary results suggest the strongest responses occurred in the northern allopatric population of Golden-winged warblers with equivocal results elsewhere. Data analysis is ongoing to determine impacts of cues on settlement patterns across all treatment combinations. Ultimately, our results will provide important insight into the relationship between these species and the role of social information on habitat selection, thereby potentially guiding future management practices.