Bat Signal Precision

Imagine you’re singing the Batman theme song in a large chorus and you need to identify your own voice in the playback. Sounds difficult, but it is similar to what individual bats in colonies must do to navigate and find tiny morsels of food such as insects via echolocation. New research from a team at Tel Aviv University led by Yossi Yovel indicates they do this by modifying the volume and duration of the calls and then following the echo that exactly matches. If you did this in your chorus, you’d pick out your own voice by knowing whether you were singing “batman,” “batmaan,” or “batmaaan.” The finding dispels the previous assumption that the bats were modifying the pitch of their voices.

The researchers placed bats (Pipistrellus kuhlii) in a room and trained them to find a small perch, which the bats did by emitting short, infrequent calls. The researchers then played a recording of many bats in order to simulate the signal inference bats regularly experience. The subjects increased their calls’ volume and duration to continue to locate the perch.

The team hopes the research will lead to human technological advances. Imitating animals in technology is nothing new. The warped wings that lift airplanes were based on the Wright brothers’ observations of soaring birds, the winglets that improve fuel economy of aircraft such as 737s were inspired by eagle feathers, high-speed jet engines avoid stalls by adapting the nostril shape of falcons, and bullet trains move quietly from tunnels to open air by mimicking the shape of kingfishers, who move splashlessly from air to water. Future cars that navigate safely by radar among thousands of similar cars may owe their signal-coding precision to bats.

Source: Proceedings of the Royal Society B: Biological Sciences