Meeting Abstract

P3.166  Sunday, Jan. 6  Landing Performance of Anna’s Hummingbird (Calypte anna) in Variable Wind Conditions STEVES, I.D.; MEHRABANI, H*; ROSE, C; MOK, A; MCCLELLAND, Z; CHIRICO, J; DUDLEY, R; University of California, Berkeley; University of California, Berkeley; University of California, Berkeley; University of California, Berkeley; University of California, Berkeley; University of California, Berkeley; University of California, Berkeley hmehrabani5110@gmail.com

Hummingbirds are able to perform maneuvers that require precision, such as approaching feeders or landing on small perches, despite in-flight perturbations from real, windy environments. To measure how wind speed affects landing maneuvers, we filmed Anna’s Hummingbirds (Calypte anna) landing on a perch in a wind tunnel at constant wind speeds ranging from 0 to 9 m/s, and analyzed overall trajectory and detailed body kinematics. Landing consisted of three phases: (1) approach – horizontal movement to the perch ending in leg extension; (2) descent – vertical lowering with small horizontal adjustments; and (3) docking – a grasp onto the perch and the end of flapping. At different wind speeds, the largest variation in path was observed during approach, in some cases including 180 deg rotations and controlled backwards flight. Velocities of approach and of descent also changed with wind speed, with the slowest approach and descent speeds observed at the highest oncoming wind speed. Despite an 80% increase in oncoming wind relative to typical flight speeds, hummingbirds were still able to complete the maneuver with only small changes in trajectory despite large changes in body kinematics. This suggests further work to understand the mechanical and neuro-muscular controls underlying their robustness in more realistic environments, including those with time-varying gusts of wind.