Battle Of The Bats

“Bats live in a world of acoustic warfare,” writes Ed Yong. He describes a study that investigated a type of bat call with an “antagonistic bent”:

It’s called the sinFM. The bats rapidly raise and lower the pitch of their call more than a dozen times over, in bursts or “syllables” that last just a tenth of a second. The bats only ever did this [under observation] when one of their peers was using its feeding buzz, and was about to snag an insect. And when these hunting bats heard the sinFM, they usually flubbed their strikes, missing their targets between 77 and 85 percent of the time.

Yong goes on to describe an experiment that tested whether “the bats use their sinFM calls to actively jam the sonar of their competitors”:

[The researchers] attached a thin line to a street light, and dangled a moth from it. Whenever a bat approached this bait, they played a recording of a sinFM call from a nearby speaker. Normally, bats capture the dangling moths around 70 percent of the time, and neither a loud tone nor burst of noise put them off. But a sinFM call slashed their success rate to below 20 percent. Even though the moths were hanging in place, the bats couldn’t hit them.

And critically, the sinFM only worked if it overlapped with the bats’ feeding buzz. If the team played it just before an attack, it had no effect. Clearly, this call isn’t an off-putting shout. It really does seem to be a way for bats to jam each other. It isn’t meant to overwhelm a target’s senses like, say, a bright light shone into another person’s eyes. It’s more subtle than that. I imagine it to be more like saddling an opponent with a set of goggles that makes their world fuzzier.

If [researchers Aaron] Corcoran and [William] Conner are right, they’ve discovered the first example of a non-human animal that competes with a rival by disrupting its senses.