Bird song’s genetic key

drj writes "Canary (Serinus canaria) songs consist of arranged phrases, themselves composed of repeated, shorter tonal whistles called syllables. Syllables are learned and then arranged into sequences that are unique to each species. This structure is found even in birds raised in isolation, though their repertoire of syllables is smaller. If tutored, isolated birds can instead learn songs without such structure. Gardner et al. now show that imitated songs are remixed into the innate canary song structure as tutored male birds develop into adults. Testosterone accelerated the song restructuring and sexual maturity. The authors provide this maxim: freedom in youth, rules in adulthood . The songs of the juveniles, adults, tutor, and tutored birds are in the on-line supplementary materials.
Gardner et al. Science 308:1046, 13 May 2005 "Freedom and Rules: The Acquisition and Reprogramming of a Bird's Learned Song"