The rivalry, documented in the latest issue of Biology Letters, reveals how relatively tiny moths can defend themselves against bug-hungry bats.
Researchers haven’t precisely deciphered the communications, but the function of the antagonistic hawkmoth sounds might include “defense and/or jamming of echolocation,” co-authors Jesse Barber of Boise State University and Akito Kawahara of the University of Florida write.
Barber and Kawahara point out that “bats and moths have been engaged in aerial warfare for nearly 65 million years.” Over that long period, hawkmoths evolved ultrasonic bat-detecting ears. But listening for the bats isn’t enough to avoid them.
The moths “produce entirely ultrasonic sounds” when they are near bats. This cool bit of natural high tech, as the authors determined, allows the moths to warn their predators that they taste awful.
Moths might also “scream” using ultrasound when bats approach, hoping to startle the would-be killer so that the moth can fly off in a speedy getaway.
The bat, in turn, is emitting attack mode biosonar. It enables the bat to navigate and locate prey. Bats also use ultrasound for direct communication with fellow bats.
In terms of mimicry, the moths may additionally try to emit bat-like sounds, in hopes that the bat hunters will think no tasty moths are around.
Image: Seth Tisue