Bats avoid collisions by calling less in a crowd

Date:  January 3, 2017
Source:  Society for Integrative and Comparative Biology (SICB)

In the warm summer months, bats go about their business each night, flying and gobbling up insects (a benefit to us). Using echolocation (making calls and listening for returning echoes to figure out where objects are) they can hunt and navigate around obstacles in total darkness, often in large groups. But if everybody is echolocating at once, how do bats pick out their own echoes?

This question has mystified scientists since the discovery of echolocation, but Dr. Amanda Adams and Dr. Michael Smotherman at Texas A&M University may have found part of the answer. Using wild-caught Mexican free-tailed bats, they study whether the bats adjust their echolocation calls in response to other bat calls.

When bats are flying in a cluttered environment they increase their call rates and listen for returning echoes. This gives them a detailed idea of the location of objects or even other bats. But if a bat's echo overlaps with another bat's call or echo, the information gets lost. This is "interference," and it can be a real problem for a bat because losing information could cause it to miss the insect it was trying to eat or even run into something.

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