How hummingbirds hover

Doctoral student Rivers Ingersoll and engineering professor David Lentink describe their experiments on hummingbird hovering in a short new video by bioGraphic. Ingersoll and Lentink are providing the first direct measurements of how hummingbirds generate the lift necessary to keep their bodies aloft and stationary as their wings beat at a blurring forty times per second. Combining high-speed video and direct measurements of pressure waves on force plates, the researchers link hummingbird wing motion with lift generation, and in particular are able to quantify the force from the upstroke versus downsroke, and evaluate the role of elastic recoil in wingbeat efficiency. Their studies have included hummingbirds from Jasper Ridge and some measurements at the preserve. Ingersoll also presented his studies to the Jasper Ridge community in a taped seminar.