Neotropical Bird “Sings” With Wings

July 29, 2005

Birds are justifiably known for their ability to communicate using a bewildering variety of songs, calls and other vocalizations, including imitations of human speech. The ACP’s Birds section contains many examples.

Now a research team from Cornell and Yale universities reports a novel means of producing a call, one more like that of crickets than of any vertebrate. Males of the new-world species the club-winged manakins (Machaeropterus deliciosus), produce a call using their wings and specialized feathers. Flipping their wings up over their backs, the birds rapidly tap the wings together. The sound, which Kimberly S. Bostwick of Cornell and Richard O. Prum of Yale describe “tick, tick ting,” arises from two mechanical mechanisms

On male manikin wings, some secondary feathers have swollen, hollow shafts. The shafts ring like a wind chime when feathers from a left wing and those from a right wing are tapped together. A male manakin produces a tick with two deliberate taps of his wings over his back. To produce the ting variation, the bird shivers his wings, tapping the wings together at about 106 cycles per second. Now another feather modification comes into play, causing two feathers to function as a pick-and-file mechanism, like that of the forewings of crickets (see Crickets). Each shake of a wing rubs the pick feather back and forth across the file feather. The net result is a high-pitched ting of about 1.5 kHz.

The whole tick, tick ting call is as loud as an average bird call, advertising the male’s presence to other birds in the area.

The authors write: “Based on hundreds of observations, the wing motions used to produce the wing sounds are unmistakable from other motions; the motions are (1) unique to sound production, (2) occur every time the sounds are produced, and (3) last for the duration of the sounds.”

“Courting Bird Sings with Stridulating Wing Feathers,” Kimberly S. Bostwick and Richard O. Prum, Science, July 29, 2005

Kimberly S. Bostwick, Cornell University, Ithaca, NY