Songbirds learn to sing by listening to themselves and to other birds. Songbirds evolved specialized brain regions to carry this out, and these regions are interconnected to form a specialized "song control circuit." The diagram below shows the major elements of this circuit. The red arrows show the pathway responsible for SINGING. The purple arrows show a pathway that does not seem to be necessary for active singing, but IS necessary for learning to sing. For more info, see Clayton, 1997 (and other articles in that particular issue of the Journal of Neurobiology).