Think your upstairs neighbors are loud? Be glad they aren’t bats. Researchers have discovered that the mouse-like mammals can emit sounds up to 140 decibels (dB), which is about the same level as a jet engine from 100 feet away or a gun blast right next to your ear. All from an animal that typically weighs in at around 1/3 of an ounce.
University of Southern Denmark biologist Annemarie Surlykke and University of Ulm (it’s in Germany) ecologist Elisabeth Kalko took on the less-than-soothing job of recording the calls of 11 bat species living on Barro Colorado Island in Panama. They found that, while all the bats emitted high-pitched calls at ultrasonic frequencies to echolocate prey, some species screeched at lower pitches than others. The higher the pitch, the less distance the sound traveled, meaning that the highest-pitched bats had to crank up the volume to astonishing levels in order to spot food from a distance.
Given that bats usually travel in groups, it’s worth asking how they manage to tolerate all the noise. A bat can muffle the sounds of its own calls by squeezing its ear muscles shut, but experts say that does nothing to drown out the din from its neighbors. Maybe they just get used to it—or become masters of meditation.
