As species that primarily navigate with their ears and not their eyes, bats are fairly amazing creatures. Their abilities to track predators, prey and hear sounds far beyond what humans can hear, makes these echolocators quite impressive specimens. But new research reveals that their sonar signals may have an additional function as well -- to jam up competitors, and steal their prey.
Utilizing sound waves to find their meals, bats can echolocate a tasty snack by judging the distance at which their high-frequency sonar bounces back to them -- the closer the target, the faster their calls resound. But herein lies bat species' largest competitive flaw: by using sonar location, they alert other bats nearby that they're on the verge of capturing their prey.
However, in spite of their echolating flaws, in a new study published in this week's issue of the journal Science, researchers from Wake University investigated the sonic weapon used by Mexican free-tailed bats to jam the signals of other bats and steal their resources.
"It's the same solution that sonar and radar engineers came to for jamming sonar and radar for military purposes" study co-author, William Conner says. "And the cool thing about it is, bats came up with this idea about 65 million years earlier than the engineers."
When a Mexican free-tailed bat hears a competitor diving in on a moth or another tasty morsel, it sends out a well-timed counter-call that researchers have now identified as a jamming signal. Used to confuse their competitors for a temporary instance in their search for food, the jamming signal matches the frequency range of the other bat's food-finding signal and just like that its competitor is flying "in-the-dark".
By jamming their competitors at their most vulnerable time, just as they're about to reach their target, the bat is confused enough that it loses its prey and the bat doing the jamming can come in to take the spoils.
"It's a form of competition" Conner says. "Make the other guy miss, and when he misses, you then go in and clean up, and take the insect."
But it's not just a simple one, two punch. The thieving behavior and competition created by this signal jamming technique can create a complex duel, as the bats' thwarting signals go back and forth. Several rounds can ensue, and if the prey doesn't escape in the process, then the bat with the stronger will can be called the victor.
