Can Navy Ships Take Tips From Moths To Confuse Sonar?
by Michael Keller
Moths and bats have been competing in an evolutionary arms race for 60 million years–one preferring to eat while the other preferring not to be eaten. Over those eons, bats have developed an extremely sensitive sonar system that lets them locate and catch airborne prey in total darkness. This fine-tuned echolocation makes bat attacks a mortal danger to the insects the aerial mammals feed on.
But natural selection works tirelessly behind the scenes, with every moth generation seeing those that don’t escape a diving bat’s clutches unable to pass their genes on to the next generation. While this selection pressure has produced ears that many species of moth can use to detect oncoming bats and evade capture, such tools haven’t evolved in all species. Instead, some have acquired an entirely different and unexpected adaptation.
University of Florida and Boise State University researchers trained an infrared camera on big brown bats as they swooped in to nab luna moths, a species with long trailing tails extending from their wings. By slowing the video down, they realized that the insects’ fluttering tails lured the bat away from the moth’s body in more than half of all attacks.
“When you pit them against bats, bats can’t find the moths,” said Akito Kawahara, an assistant curator at UF’s Florida Museum of Natural History. “They go to the tail instead of the head of the moth.“