Hummingbird Courtship Displays and Acoustics (Image 3)

A composite of an Anna's hummingbird (Calypte anna) diving to a female. The tail is spread to make a loud sound at the bottom of the dive. Chris Clark, a postdoc at the Peabody Museum of Natural History at Yale University, is studying how hummingbird feathers produce various sounds during their courtship displays.

When Clark attended graduate school, his Ph.D. work focused on the roles of sexual selection and flight performance in shaping hummingbird tail morphology. In 2008, he published a paper titled "The Anna's Hummingbird Chirps With It's Tail," which received wide publicity and helped launch his current research focus. Clark's paper described how Anna's hummingbirds (Calypte anna) make a loud sound with their tail feathers during courtship displays rather than vocally.

After completing his doctorate, Clark and his advisor, Richard Prum, were awarded a grant from the National Science Foundation to study the physics of the sounds feathers make. Clark traveled to Latin America, where he recorded the courtship displays of a number of hummingbird species that produce distinctive sounds with their tail feathers including sheartails and woodstars. He then took his research into the lab, where he used a wind tunnel to reproduce the sounds feathers make when the birds are in flight in the wild, and studied how feathers produce sounds over a range of air speeds. [Research supported by National Science Foundation grant IOS 09-20353.] (Date of Image: unknown)

Credit: Christopher Clark, Yale University