Meeting Abstract

83.4  Friday, Jan. 6  Unique Wing Morphology in Wingsnapping Manacus Manakins FRISCIA, A.R.*; SCHLINGER, B.A.; Univ. of California, Los Angeles; Univ. of California, Los Angeles

Manakins (Manacus spp.) have complex courtship displays with loud, whip-crack-like, wingsnaps and rollsnaps. During wingsnaps, the wings are forcefully lifted over the head to strike at the wrists creating a loud snapping sound. Previous work has confirmed that the sound of the snap comes from percussion of the wings against one another. Investigation of the osteology of the wing discovered a unique morphology of the radius that may facilitate this sound generation mechanism. The radii of Manacus are considerably flattened cranio-caudally and broad dorso-ventrally. Interestingly, this morphology is shown in both males and females, even though the latter do not normally wing-snap. Other piprids (Xenopipo, Corapipo, Chiroxiphia, and Pipra) have complex courtship displays, and some do show a similar flattened morphology, especially when compared to other Tyrannides (Cotinga, Sayornis), but not to the extent seen in Manacus. This may indicate that the morphology is autapomorphous for Pipridae, and hints at a possible functional mechanism. The broadened radius may allow for larger muscle attachments and longer lever arms to facilitate the complex motions associated with the courtship displays in this family, and may have been further modified for sound production in Manacus. Supported by NSF IBN 0213194.