Learning to communicate.
Of the few animal groups that learn their vocalizations, songbirds are uniquely amenable to molecular, physiological, and behavioral analyses of the neural features responsible for vocal learning. In order to communicate effectively as an adult, a young songbird recognizes and memorizes a model of his species-specific song during a developmentally critical period called sensory acquisition. Factors are now emerging that contribute to the length and strength of this learning phase. In a second critical period, known as sensorimotor learning, the young bird uses auditory feedback to perfect his motor performance, creating a match to the memorized model. New studies show that motor matching can persist beyond sensorimotor learning, and thus a role for the acquired model might also persist into adulthood. Fascinating in their own right, songbirds also provide optimism that mature brains have recourse to plasticity.