Comparative approaches to the neurobiology of avian vocal learning.

Birdsong provides an opportunity to study sensorimotor learning in the context of brain evolution. Despite the vast diversity in song behavior across species, mechanistic understanding of birdsong comes primarily from the zebra finch, a closed-ended songbird that learns one simple and stereotyped song, which it keeps singing throughout adulthood. It remains unclear if neural mechanisms of finch song production and learning generalize with other species, including open-ended learners with more complex and variable vocalizations. Here we review finch communication alongside both closely and distantly related avian species. We propose that comparing songbirds and parrots, sister clades that diverged over 50 million years ago and those that exhibit both similarities and differences in behavior and neural circuits, will be particularly useful in distinguishing general principles from neural solutions to species-specific needs.