Meeting Abstract

S1-4.7  Jan. 5  Is the Anna�s Hummingbirds� dive-noise vocal or non-vocal? CLARK, C.J.; Univ. of Calif., Berkeley cclark@berkeley.edu

Male Anna�s Hummingbirds (Calypte anna) perform display dives in which they fly 30-50m up in the air, then dive head-first towards a perched female. At the bottom of the dive, they emit a loud noise called the dive-noise. Rodgers (1940) provides evidence that the dive-noise is produced by the tail, but Baptista and Matsui (1979) present acoustic evidence that the dive-noise is produced vocally. As neither hypothesis has strong support, the source of the dive-noise is an open question. I test the hypothesis that the tail produces the dive-noise using three methods: 1) high-speed kinematics of diving males, 2) sound-recordings of display dives before and after experimental manipulation of the tail, and 3) noises produced when tail-feathers of males and females are placed in a stream of air in the lab. I discuss the implications my results have on the evolution of wing and tail morphology in birds.