Abstract

Structural characteristics of bird feathers vary with flight style and feather type. Feather barbs, which branch off the central shaft, are predicted to be higher where greater force is exerted during flight. In Binghamton and Ithaca, NY, we collected 154 molted flight feathers of the American crow (Corvus brachyrhynchos), a generalist with continuous flapping flight, and measured barb density at the base, middle, and distal tip of the feather and on both the leading and trailing edges. We predicted barb densities would be greatest proximally, on trailing edges, and on wing feathers. Consistent with predictions, trailing edges and proximal points had significantly higher densities. Our results support aerodynamic models which suggest that greater force is directed against these areas during flight, emphasize the importance of studying variation within feathers, and can be compared to results in other species to better understand how feather structure is adapted to different flight styles.