BREWER, M.L.*; HERTEL, F.; California State University, Northridge; California State University, Northridge: Wing shape as correlated with flight behavior in pelecaniform seabirds.

Tropical seabirds often traverse great distances in search of prey, therefore selection on wing morphology is likely to be intense. Wing morphology of five species of pelecaniform seabirds from Johnston Atoll in the central tropical Pacific was analyzed to determine how wing size and shape correlate with observed foraging behavior. Digital photos of wings were used to compute aspect ratio and wing loading for a comparison among species. To explore more subtle differences in wing morphology, landmarks were created on the digital photos of the wings and analyzed using the Thin-Plate Spline-Relative Warps program. This analysis summarizes variation in the positions of each landmark into composite variables called relative warps, thereby providing a visualization of complex shape change throughout the entire wing. This method allowed for a more detailed view of wing shape and was used to look for differences among species, and in two cases, between sexes. Significant differences were found among species with regards to width of the wing base, curvature of the mid wing, and size/shape of the distal wing. Significant differences were found between sexes of the Great Frigatebird but not the Brown Booby. In the case of the Red-tailed Tropicbird, explanations are suggested that may help explain why this species deviates from predicted wing loading and aspect ratio. Differences in wing shape can be correlated with feeding and foraging ecology for most of these species. Future analyses incorporating more species will help us to understand the evolution of wing shape among seabirds as they radiated to utilize oceanic resources.