Dudley Lab -> People -> Chris Clark

I study hummingbird tails. I measured the morphology of approximately 330 species of hummingbird in museums, to examine patterns of hummingbird tail evolution in a phylogenetic context. Hummingbirds evolve elongated tails a number of times, and theory predicts that long tails increase drag. I've flown Anna's Hummingbirds (Calypte anna) in a wind tunnel and experimentally manipulated their tail length (using the long tails from the Jamaican Streamertail, Trochilus polytmus), to test whether a long tail increases the amount of energy necessary to fly, and also whether the top speed they can fly is reduced with a long tail. I have also tested to see whether a long tail affects the ability of the Jamaican Streamertail to maneuver.

Finally, male Anna's Hummingbird perform a spectacular display dive to females, in which they rise 30 to 50 m in the air, then dive headfirst towards the female, before pulling up at the bottom of the dive. At the bottom of the dive he emits a "dive-noise". Previous researchers thought that the dive-noise was vocal, but I have evidence suggesting that the noise is made with their tails!