Juvenile zebra finches can use multiple strategies to learn the same song

Does the ontogeny of vocal imitation follow a set program that, given a target sound, unfolds in a predictable manner, or is it more like problem solving, with many possible solutions? We report that juvenile male zebra finches, Taeniopygia guttata, can master their imitation of the same song in various ways; these developmental trajectories are sensitive to the social setting in which the bird grows up. A variety of vocal developmental trajectories have also been described in infants. Are these many ways to learn unique to the vocal domain or a hallmark of advanced brain function?