BOSTWICK, K.S.: Sexual selection for wing-sounds associated with convergent wing shape evolution between three clades of manakins (Aves: Pipridae

Males of most of the ~40 species of Neotropical manakins (Aves: Pipridae) perform energetic courtship displays on lek territories. In nearly half of the speices, males produce mechanical wing sounds during these displays. Recent phylogenetic hypotheses indicate wing sound production may have evolved as many as three times independently in the family. Repeated evolution of mechanical sounds allows comparative analysis of wing morphology in relation to sound production. Specifically, this research addresses (1) if wing shape has been detectably modified in the mechanical sound producing lineages, and (2) if so, are there any commonalities in shape change between lineages. I measured the lengths and widths of 4 wing bones for 42 species of manakins and allies, including representatives from each of the three mechanical sound producing clades. Three measures of overall body size were also made. Wing shape was characterized by the second principle component of a PCA, and mechanical sounds were categorized according to complexity, loudness, and repertoire sizes of species. Independent contrast of species values of these variables were regressed to show that wing shape has changed convergently in mechanical sound producing lineages. Wings of mechanical sound producing clades have shorter, thicker ulna, shorter carpometacarpi, and thicker scapula blades then non-mechanical sound producing manakins. These result support the hypothesis that sexual selection has caused wing morphology to evolve in response to functional requirements for mechanical sound production.