'Superfast' muscles help bats land their dinner

Bats are the only flying vertebrates that use echo-location to find their prey. To do that, they emit a sound called the terminal buzz. Until now, scientists have not been exactly sure how they do it, but a recent study appearing in Friday's edition of Science sheds light on how "superfast" muscles help bats emit calls at rapid rates and target moving prey.

Picture this: It is dusk. Your friendly neighborhood brown bat is flying around in search of dinner. It is making high-pitched squeaks and waiting for the echo to hear if there is a nearby house or tree to avoid. Then suddenly --- a bug! It zeroes in on the prey, and those calls? They speed up.

"As a bat flies closer and closer to an insect, it produces shorter and shorter and shorter calls," said Brock Fenton, a University of Western Ontario bat expert.

By the time a long call bounced off a bug and made it back to the bat, Fenton said the delicious morsel would have flown away. So the squeaks are quick, and close together--up to 190 separate calls per second.

Bats use throat muscles to produce sound, just like humans, but scientists had never found a mammal muscle that could turn on and off that quickly, said Andy Mead.

"You can tap your finger on a table, and you can try to tap your finger as fast as you possibly can," said Mead, a biology graduate student at the University of Pennsylvania.

"Eventually you seize up, you get stiff and you can't tap any faster ... you can probably tap five, six, seven times a second if you really try, but you certainly can't tap 190 times a second," he said.

As part of a research team based in Denmark led by Coen Elemans from the University of Southern Denmark, Mead found muscles in a bat larynx that could turn on and off in less than one one-hundredth of a second.

"It was instantaneously really shocking and exciting to see yes, this is a very, very fast muscle," Mead said.

It is a "superfast" muscle--the actual scientific term. They are responsible for the rattle of a rattlesnake and the mating call of a fish called the toadfish. This is the first time a superfast muscle has been found in a mammal, leading researchers to believe the muscles may be more common than previously thought.