Kazuchika Manabe
Robert J. Dooling
Psych. Dept., Univ. of Maryland, College Park, MD 20742
Budgerigars (parakeets) are small, highly social, Australian parrots capable of vocal learning throughout adulthood. These birds readily produce short (200 ms), whistled, frequency-modulated contact calls when separated from one another. In this experiment, birds were trained twice daily in 10 min sessions to produce or modify contact-call-like vocalizations using food reward. Calls were analyzed in real time using serial FFTs and each production was compared to a digitally stored ``template.'' Call productions which exceeded a predetermined criterion of similarity were rewarded, while those below criterion were not. Results show that budgerigars can learn to modify the intensity and spectro-temporal pattern of their species-typical calls within several days. Aside from human language, bird vocalizations have provided the only other clear example of learning in the acquisition and maintenance of a vocal repertoire. While song learning in birds has led to a number of important insights into the neurobiology of learning, such learning typically occurs over a time frame of months to years. The present results demonstrating call learning over a period of several days more closely parallel the time course of other more common forms of vertebrate learning. [Work supported by NIH Grants DC00198 and MH00982.]