Acoustic changes in the vocal signals of grasshopper sparrows, Ammodramus savannarum, during early development.

Grasshopper sparrows produce unusually high-pitched vocalizations for birds, with fundamental frequencies of species typical songs in the range of 7-9 kHz. The characteristics of vocalizations produced early in life, however, are relatively understudied in this and related species. In this study, the development of vocal signal structure and vocal behavior in grasshopper sparrows was investigated in the field immediately after birds hatched. Acoustic characteristics of nestling begging calls were measured throughout the course of the 8-9-day nestling period. Starting at day 6 post-hatch, nestling calls changed qualitatively, incorporating frequency-modulated elements that resembled some parts of the adult vocalizations....

Categories: Publication; Types: Citation, Journal Citation; Tags: Ammodramus savannarum, Journal of the Acoustical Society of America, grasshopper sparrow, song learning, vocal development