CONICET | Buscador de Institutos y Recursos Humanos

While bird vocalizations (produced by the syrinx) havebeen the focus of countless studies, mechanical sounds (produced by externalbody structures) have received much less attention. In particular, theevolutionary interplay between these two modes of acoustic communication remainslargely unstudied. Here we present the first species-level molecular phylogenyof the doraditos (Pseudocolopteryx), reconstructthe evolutionary history of acoustic vocal and non-vocal characters, elucidate theirrelationship to feather modifications and aerial displays, and explore theinfluence of acoustics in the speciation of cryptic species. Our well resolved phylogeny using four genes (ND2,COI, MB and ODC), recovered the monophyly of Pseudocolopteryx, resolvingthe relationships among its five species: (P. sclateri (P.acutipennis (P. dinelliana (P. citreola, P. flaviventris)))).Repetitionand translocation of acoustic elements were commonplace in the evolution of Pseudocolopteryx. Songs were composed of introductory syllablesand a final flourish. Bill-snappingsounds of P. sclateri were functionallyhomologous to introductory vocal syllables of the other species. The song of P. dinelliana evolved to high levels of complexityand repetition, and is the syntactically most complex song in Pseudocolopteryx(and perhaps in the Tyrannidae). Aerial displays, mechanical wing sounds and modificationsof primary feathers coevolved in three species: P. sclateri, P. acutipennisand P. dinelliana. Wing sounds documentedfor P. acutipennis and P. dinelliana differed markedly, andtheir production mechanisms might differ. The two cryptic and sibling species P.flaviventris and P. citreoladiverged ∽60,000Ya, were not reciprocally monophyletic and are acase of extremely rapid evolutionary acoustic differentiation with morphological stasis.