Phylogenetic analyses of the evolution of behavior, wing morphology, and the kinematics of mechanical sound production in the neotropical manakins (Aves: Pipridae)

The Neotropical manakins (Pipridae) are a family of ∼40, sexually-dimorphic, lek-breeding birds found in Central and South America. Many male manakins produce unique wing sounds to court females. I use behavior, video and acoustic recordings, and museum skeletal and fluid specimens to study the production and evolution of manakin wing-sounds, also called mechanical sounds, or sonations.;Video-recordings of the Club-winged Manakin, Machaeropterus deliciosus , show that this species' unique wing sound (a sustained series of integer-related tones) is made by a unique pronating motion of the wing that causes secondary feathers to interact above the back. Phylogenetic analysis of M. deliciosus's display behaviors leads to the novel hypothesis that this genus is sister to or embedded within the genus Pipra.;High-speed video of two piprids, Manacus and Pipra mentalis, show (1) the first details of how birds move their wings to sonate, and (2) that acoustically similar sounds can be made in different ways both within and between species. Thus, manakins can produce sounds by secondary feather interactions (M. deliciosus above), clapping their wings together over the back (Manacus), flicking primary feathers laterally into the air (Manacus), clapping wings against the body (P. mentalis), knocking secondary feathers together by a lateral wing flick (P. mentalis), or rubbing wing feathers across tail feathers (P. mentalis).;Two morphological analyses are presented demonstrating how manakin wings have been modified for sonation. The first tests for a correlation between species' wing shape and wing-sound intensity by using the independent contrasts method (Felsenstein 1985). I find sonating species have shorter, stockier wing bones, but that different sound-producing clades have modified different wing elements. In the second morphological analysis I illustrate the myological details of morphological modification from dissection and comparison of sonating and non-sonating manakins. I find that the Pipridae have exceptionally diverse wing morphology, and that wing-sonating species have been modified both from non-sonating species, and from each other.;In conclusion, I find that the Pipridae manifest extreme morphological and behavioral diversity for sonation. The use of mechanical sounds in courtship displays implies sexual selection has driven the evolutionary of this extreme character diversification.