Sequence of songs in repertoires of western meadowlarks (Sturnella neglecta)

Abstract

The male western meadowlark has a repertoire of 5–12 song types and produces a bout of repetition of one song type before switching to another. Songs of neighboring birds were played to three territorial males to investigate the effect of playback on choice of song types. In contrast to findings on some other species, there was no tendency for responding birds to choose a song type that matched the playback. However, birds did tend to switch songs whenever the playback started. There was equal response to all song types, and little evidence of habituation between playback sessions.The sequence of switches from one song type to another was compared with a random sequence generated by computer simulation. Both during spontaneous singing, and in response to playback, there was significant avoidance of low recurrence intervals (the number of switches between two bouts of the same song). Thus, birds tended to cycle through their repertoires. The sequence more closely approximates a second- than a first-order Markov process.Song repertoires may function to decrease rate of habituation of receivers to whom the signal is directed. The sequential organization of switches is interpreted within this functional framework.