Meeting Abstract
Turning in flight requires reorientation of force, which birds, bats, and insects accomplish either by shifting body position and total force in concert or by using left-right asymmetries in wingbeat kinematics. Although both mechanisms have been observed in multiple species, it is currently unknown how each is used to control changes in trajectory. We addressed this problem by studying hummingbirds tracking a revolving feeder. Comparing hovering and turning flight revealed that hummingbirds banked both their stroke plane and body into turns, supporting a body-dependent mechanism. However, several body-independent wingbeat asymmetries were present during turning, including a higher and flatter outer wing-tip path and a lower more deviated inner wing-tip path. We next varied the radius and velocity of the revolving feeder. Body and wing banking were significantly associated with changes in translational velocity, and four asymmetries in wingbeat kinematic variables were significantly associated with changes in turn radius. No kinematic variables were associated with both velocity and radius. These results indicate that hummingbirds use both body-dependent and body-independent mechanisms to reorient forces, and that these mechanisms can be used to control separate aspects of the same maneuver.
