Superfast vocal muscles help bats home in on prey

Oct 10, 2011, 12:14 GMT

Washington - Bats use 'superfast' vocal muscles to home in on flying prey at night by means of echo-location, report Danish and American researchers in the US journal Science. Previously, such muscles had been found only in rattlesnakes, some fish and birds. Now they have been discovered for the first time in mammals, wrote the team led by Coen Elemans from the University of Southern Denmark.

When bats approach their prey, the frequency of their echo-locating calls increases up to 190 calls per second. How the creatures do it had been a mystery. In their study of Daubenton's bats, the researchers found the answer in the bats' laryngeal muscles, which can contract at a rate 20 times faster than the fastest muscles in humans -- those that control eye movements.

The discovery of the superfast muscles in a mammal 'suggests that these muscles -- once thought extraordinary -- are more common than previously believed,' Elemans was reported as saying. Experiments on isolated muscle fibres showed that the laryngeal muscles could contract up to 200 times per second.

Daubenton's bats are fairly common in many countries. They hunt mosquitoes and other insects flying near the surface of ponds and lakes.

'Before the bats evolved more than 50 million years ago, the night skies were full of moths and other flying insects,' Elemans said. The authors of the study, among them biologists from the University of Pennsylvania, conclude that the development of superfast vocal muscles was decisive for bats' successful echo-location of erratically flying prey in the dark.