Response of sparrows to songs of deaf and isolation-reared males: further evidence for innate auditory templates.

Adult song sparrows (Melospiza melodia) were tested for response to songs of conspecific males that had been reared in acoustic isolation or deafened early in life. Territorial males responded more aggressively to playback of songs of isolated males than to songs of deafened males but did not discriminate between songs of deafened males and heterospecific songs. Captive females showed an identical pattern when their response was measured in terms of the number and intensity of courtship displays evoked by song. The results support the auditory template theory of song development in demonstrating that species-identifying features are present in songs of isolates and in showing that males unable to hear their own song production do not incorporate these species-identifying features into their songs.