Meeting Abstract
Male Bachman’s sparrows (Peucaea aestivalis) have repertoires of 33-55 primary song types as well as repertoires of “warble songs” and call types. How are these large vocal repertoires used during territorial disputes? We quantified responses to simulated territorial intrusions (STI) and found that more aggressive males sang fewer high-amplitude primary songs and more low-amplitude ‘‘whisper songs.’’ On average males share 47% of their song types (range 28-81%) Song sharing is not higher among adjacent neighbors and does not decline significantly across a distance of 3.3 km. High song sharing suggests a role for song type matching during agonistic signaling. In a second STI experiment 16 of 22 (72%) males matched during playback of their own songs and 14 of 22 (64%) matched more than once but these rates do not exceed the chance matching rate. Markov-chain analysis of singing behavior (n=8) suggests that males deliver their songs in sequences with some song types grouped together in a predictable order. Playback of a bird’s own song sequence did not increase the likelihood of song matching for most birds, but 4 of 21 birds matched at high rates when played their own sequence. Birds that matched playback were not more aggressive than those that did not match suggesting that song matching is not an immediate threat signal in this species.
