Effectiveness of Artificial Song Playback on Influencing the Settlement Decisions of an Endangered Resident Grassland Passerine

Social information in the form of songs, calls, or other overt behaviors may assist birds in assessing the quality of potential breeding habitat by providing direct public information about a site's quality or by providing indirect cues (e.g., the presence of conspecifics) that may be used to infer its quality. Broadcast of song has been used to demonstrate the influence of conspecific cues on the decisions of migratory passerines to settle; however, there is currently a dearth of information regarding resident species. We tested the influence of conspecific attraction and the effectiveness of song playback on an endangered resident of grassland, the Cape Sable Seaside Sparrow (Ammodramus maritimus mirabilis). We broadcast recorded song over large areas of suitable breeding habitat in the Florida Everglades in an attempt to influence the settlement of male sparrows during territory establishment. Our analyses included the creation of a qualitative sound map that formed a basis for measuring the species' response to playback. Our results suggested that territory establishment by Cape Sable Seaside Sparrows was influenced by these artificial conspecific cues. Our findings have important conservation implications for the species in light of continuing large-scale efforts at habitat restoration in the Everglades ecosystem.