ALTSHULER, Douglas L.; DICKINSON, Michael H.; California Institute of Technology; California Institute of Technology: Detailed kinematics of hovering flight in hummingbirds

Although hovering flight is common among insects, hummingbirds are the only vertebrate group that perform sustained hovering. Hummingbirds are larger than most insects, operate at higher Re numbers, and thus experience the air as a less viscous medium. We studied hovering flight in hummingbirds using three orthogonally-positioned high speed cameras to characterize their flight kinematics for comparison with those of insects. Despite considerable size differences and vastly divergent musculoskeletal systems between hummingbirds and insects, the kinematics of hovering are remarkably similar. Both groups exhibit shallow angles of attack during translation and advanced rotation before the transitions between strokes. These results indicate that the aerodynamics governing hovering flight in animals are surprisingly similar across a wide range of body sizes.