Seemingly simple songs: Black-capped chickadee song revisited

Our lab has been studying songbird communication from an integrative perspective for over 13 years. A significant part of this program involves conducting bioacoustic analyses of vocalizations that are critical to survival. Initially, black-capped chickadees and their chick-a-deecall were our main research focus. In more recent years, we have turned our attention back to the fee-bee song, intensely studied by Weisman, Ratcliffe, and colleagues. Our re-examination of the fee-bee song revealed several, previously unreported features of this seemingly acoustically simple vocalization. We showed that songs contain regionalized cues for dominance status, and that females respond differentially to dominant song playback irrespective of their geographic origin. Moreover, females themselves produce a fee-bee song not previously reported in the literature. Female song is acoustically distinct from male song, and we have used operant conditioning experiments to identify features that can be used to identify sex of the singer. Finally, we have begun to explore neural response to different vocalizations, including song, and found that responses vary by singer, listener, and vocalization type. Our current efforts are aimed at unraveling the acoustic basis of communication in this nearly ubiquitous North American species.