This entry was posted on 1/30/2008 11:17 AM and is filed under Articles by Scott.
Many of us here in the Pacific Northwest are familiar with the mating dive of the male Anna's Hummingbird. He flies up to a height of about 100' and then tips over into a high speed dive over the top of an available female. As he pulls out of the dive he makes a loud chirp. If you're like me you always assumed that the chirp was a vocalization. Recent studies have shown that is not true. The chirp is actually made by outer tail feathers that vibrate.
From the article...
Scientists have argued whether the sound is vocal or mechanical, that is, produced by feathers. In a short 1940 paper in The Condor,
UC-Berkeley's Thomas Rodgers described an experiment in which he
attached a plucked outer tail feather to a slender strip of bamboo. "By
whipping this through the air a note was produced, which was almost
identical with that produced by the bird," Rodgers wrote. "No other
feathers produced this note."
