Geographic Variation in Song of The Bright-Rumped Attila (Tyrannidae: Attila Spadiceus): Implications for Species Status

Abstract

Bright-rumped Attilas (Attila spadiceus) have two song forms, one sung primarily at dawn, the other primarily during the rest of the day. Both songs consist of a main phrase and an optional terminal phrase. Our recordings of dawn and day songs in Costa Rica were very similar to those made elsewhere in Central America. However, Central American dawn songs were significantly different than dawn songs from South America, both in terms of quantitative features (temporal and frequency variables) and qualitative characteristics (note shape). Day songs from Central and South America were similar. Song differences suggest that the Bright-rumped Attila may be two species, one in Central America, the other in South America.