Daubenton’s Bats, Myotis daubentonii, Leaving a Roost
Some echolocating bats create a high-speed buzz for capturing prey using the fastest-known contracting muscle type in mammals, according to a new study published in the journal Science on Sept. 29.
Producing such a high call rate is not possible with a typical skeletal muscle. A team of Danish scientists found that certain bats’ vocal cords are controlled by a rare type of tissue called superfast muscles.
"We discovered that Daubenton’s bat (found throughout Eurasia) controls its echolocation calls with the fastest-contracting muscle type described," said study lead author Coen Elemans at the University of Southern Denmark in a press release.
This flying mammal can increase the echolocation call rate to 190 calls per second to form a "terminal buzz," just moments before capturing its target insect prey in the dark.
Superfast muscles are also used to produce sound in other animals, including rattle snakes and ray-finned-fish like oyster toadfish.
"But recently we also found them in birds who use them to sing their beautiful songs," said Elemans.
"And now we have discovered them in mammals for the first time, suggesting that these muscles—once thought extraordinary—are more common than previously believed."
It was unknown how the bats can generate calls so quickly. The researchers thought this rate would be limited by the bats’ ability to either produce the calls or process the returning echoes.
"Our data suggest that bats could theoretically produce calls much faster—up to 400 calls a second—before the returning echoes would become confusing to the bat," said co-author John Ratcliffe at the University of Southern Denmark in the release.
The scientists determined that it is actually the muscles that limit the maximum call rate during the buzz, and believe this ability allows the bats to better track the often erratic movements of insects in the dark.
