Now Rockefeller University scientists have found that young canaries can learn to accurately imitate a computer-generated song that sounds nothing like a canary. But as the birds mature, they edit their song, dropping some elements, rearranging others, and adding repetitions and phrasing typical of an adult canary melody. The results appear in the May 13 issue of Science.
"This kind of reprogramming is reminiscent of the flexibility of phoneme rearrangement in human speech and is an aspect of vocal prowess in birds that had not been described before," says Fernando Nottebohm, Ph.D., Rockefeller's Dorothea L. Leonhardt Professor and head of the Laboratory of Animal Behavior.
Young canaries normally learn their songs by closely copying a nearby adult, a process that takes six to eight months. However, even birds raised without a singing tutor develop a song with canary-like syllables and phrasing. Under those conditions the juveniles are thought to be guided by an innate program that leads to the development of normal adult song.
But Timothy Gardner, Ph.D., at the time a postdoctoral fellow in the Nottebohm lab, had heard anecdotal evidence of canaries singing outside the range of normal imitations, of canaries that imitated zebra finches, for example.
With the exception of well-known mimics, such as the mockingbird, songbirds in nature rarely imitate the song of other species; they only imitate older birds of their own kind. The researchers wondered whether this preference results from innate knowledge about what the adult song should sound like, and if so, how that innate knowledge steers the learning process. They also wanted to study h
Contact: Joseph Bonner