The Singer and the Song: On the Receiving End of Bird Song

Summary Variation in singing behaviour between males can involve fixed differences such as the song type composition of repertoires, as well as more flexible effects such as matched counter‐singing (Krebs & Kroodsma, 1980; Section III. 4), differences in bout length (the number of songs in a period of song) and changes in strophe length. Short‐term strophe length changes seem to be related to the willingness and ability of males to respond strongly to playback. Whether this is because strophe length indicates motivation or the degree of exhaustion of the neuromuscular song‐production system, or both, is currently unclear.