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 le arning 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 leucophrys, give call notes in response to playback of species-typical song. After 10-day periods of tape tut oring conducted in the first 50 days of life, subjects gave significan tly more calls in response to tutor songs than to novel songs. An iden tical procedure conducted at a later age yielded a different result. B irds did not distinguish tutor from novel songs in winter, after the s ensitive phase for song acquisition. Males gave significantly more cal ls to those tutor songs that they subsequently sang the next spring th an 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 m ales, these results also indicate that the sensitive phase for song ac quisition is shorter in females than in males of this species. (C) 199 7 The Association for the Study of Animal Behaviour.