The timing of song memorization differs in males and females: a new assay for avian vocal learning.

We describe a new assay for measuring the acquisition phase of song learning in birds and compare it with the standard method of comparing a pupil's imitation to his tutor's song. Juvenile male and female white-crowned sparrows, Zonotrichia leucophrysgive call notes in response to playback of species-typical song. After 10-day periods of tape tutoring conducted in the first 50 days of life, subjects gave significantly more calls in response to tutor songs than to novel songs. An identical procedure conducted at a later age yielded a different result. Birds did not distinguish tutor from novel songs in winter, after the sensitive phase for song acquisition. Males gave significantly more calls to those tutor songs that they subsequently sang the next spring than to tutor songs they did not reproduce. Assuming that the call assay correlates with long-term storage of songs in females as it does in males, these results also indicate that the sensitive phase for song acquisition is shorter in females than in males of this species.1997The Association for the Study of Animal Behaviour