Bird song learning as an adaptive strategy

Parallels are often drawn between bird song learning and human language learning. The analogies include an early sensitive period for learning, separation of sensory and motor phases of learning, 'innate knowledge' of language or song, and specialized neural systems. Nevertheless, in distinction to human language learning, song learning is usually viewed as a purely auditory process. This view is implied in the typical experimental paradigm for studying song learning, in which the bird is isolated in a sound-proof chamber and exposed only to tape-recorded song. This paradigm remains the major method of studying song learning despite recent demonstrations of the importance of social variables, and it contains the implicit assumption that non-auditory variables, especially social and ecological variables, play only a minor role in this process. I will argue here that understanding the functions of song learning requires that we investigate it in the field, where social and ecological variables have full play. We have done just this for the song sparrow, and when viewed in this perspective song learning in the song sparrow takes on the clear outlines of an adaptive strategy.