Scaling of avian primary feather length

摘要: The evolution of the avian wing has long fascinated biologists, yet almost no work includes length primary feathers in consideration overall variation. Here we show that longest feather () contributing to scales with negative allometry against total arm (ta = humerus+ulna+manus). scaling exponent varied slightly, although not significantly so, depending on whether a species level analysis was used or phylogeny controlled for using independent contrasts: . different from predicted (0.86) by earlier work. It appears there is general trend birds contribute proportionally less, and ta more, wingspan as this dimension increases. Wingspan constrained close mass (M1/3) because optimisation lift production, which limits opportunities exterior morphological change. Within wing, variations underlying bone lengths nevertheless may, altering joint positions, permit range flight styles facilitating variation upstroke kinematics.