How Hummingbirds Reorient Forces During Maneuvering Flight

Hummingbirds are among the most agile of birds with the unique ability to hover in flight. While their flight kinematics have been studied extensively, their aerodynamic forces have primarily been studied using indirect methods like inverse dynamics and particle image velocimetry, which are insufficient to capture the full weight support of the bird. Here we present in vivo force recordings of maneuvering Anna’s hummingbirds feeding from a moving flower using a novel 3D aerodynamic force platform. The pressure field generated by the maneuvering bird travels to the boundaries of the flight arena, and the six instrumented plates mechanically integrate the resulting pressure and shear distribution at a high enough sample rate to record wingbeat-resolved forces. With these data, we can determine the tracking effectiveness of hummingbirds as well as the control methods they employ during feeding from moving flowers as well as inflight prey capture. Unraveling how hummingbirds manipulate aerodynamic forces with their wings to maneuver has profound applications to the study of other flying animals and the development of more maneuverable aerial robots.