The role of auditory feedback in the control of vocalization in the white-crowned sparrow

The song dialects of White-crowned Sparrows are maintained from generation to generation through learning of songs of the adult birds by the young. Songs are learned during a short critical time by young birds before they begin to sing. If the birds which have been exposed to a wild White-crowned Sparrow song during this critical period are deafened before they start singing, they cannot reproduce the heard song. Intact control birds produce a fair copy of the song. Regardless of whether birds have or have not learned a song during the critical period, they will develop similarly atypical songs if they are deafened before the onset of singing. Once birds have sung, the pattern of song can be maintained relatively unaltered after deafening. Although the final song patterns produced by the deaf birds were extremely abnormal, there was gradual progress toward the end forms during their development as in normal birds. However, the deaf birds failed to keep the fine structure of their songs stable. Individual differences in the general pattern of deaf birds' songs were maintained relatively unchanged at least throughout the study period. Induction of singing in the female White-crowned Sparrow by testosterone implantation revealed learning of song dialects by female individuals, which do not sing naturally in this species