Why vocal learning has evolved in songbirds, parrots, and hummingbirds but not in other
avian groups remains an unanswered question. The difficulty in providing an answer stems
not only from the challenge of reconstructing the conditions that favored vocal learning
among ancestors of these groups but also from our incomplete knowledge of extant birds.
Here we provide multiple lines of evidence for a previously undocumented, evolutionarily
independent origin of vocal learning among the suboscine passerines. Working with …