In order to navigate and hunt for their prey in the dark, bats use echolocation, or biological sonar, through which they emit high-pitched sound and then listen to the echoes to identify and locate objects.
Echolocation is particularly crucial for these nocturnal animals when finding food at night because it allows them to find and track their prey even in complete darkness. Since they had to compete with other bats for food, these flying mammals have come up with an ingenious way to ward off competition for a prey.
Findings of a new research have revealed how bats vie for the same meal. In a new study published in the journal Science on Nov. 7, Aaron Corcoran, from Wake Forest University in North Carolina and William Conner from the University of Maryland, used high-speed infrared cameras and ultrasonic microphones to observe how the Mexican free-tailed bats (Tadarida brasiliensis) interacted with their prey, moths.
The researchers accidentally observed that the bats made a strange sound that they only produce when there is another bat making a "feeding buzz," which is produced when a bat homes in on a prey. It turned out that bats jam each other's sonar system so they can throw off competing bats away from the prey.
When a bat hears another bat going in for the kill, it produces a specialized jamming call to ward off its competitor from its prospective food; a behavior that the researchers believe could improve the bat's odds of getting its meal. Corcoran and Conner found that bats were 70 percent less likely to make their catch when they hear the jamming call while they were echolocating. The animals would also take turns jamming each other's sonar system until one of them finally gives up.
"Playbacks of the jamming call, but not of control sounds, caused bats to miss insect targets. This study demonstrates intraspecific food competition through active disruption of a competitor's sensing during food acquisition," the researchers wrote.
It appears that sonar jamming is not limited to bats. Scientists have also found that moths have their way of warding off bats. Brock Fenton, from the Western University in Canada, said that the behavior may also exist in other dolphins and other species that echolocate.
"This research changes our understanding of the possible ways animals compete with each other for food, which is one of the most basic biological needs," Corcoran said.
