When a group of bats fly together, how do you tell which echo is your own?

a paper published this week in the journal Communication-Biology
, the strategies bats have adopted to avoid interfering with each other's echo-positioning signals. This strategy may shed inspiration for sonar or radar research.the echo-positioning behavior of four bats as they flew together.
bats use echo positioning for hunting and navigation in the dark, they must be able to recognize their signals from the signals of other bats flying together. This auditory disturbance is called a "cocktail party problem" and it has not been fully possible to understand how bats can avoid auditory interference in such situations.
, at Doxa University in Japan, and colleagues placed small microphones on the backs of bats, directly measuring the echo-positioning behavior of Asian long-winged bats. The echo-positioning signal characteristics released by bats when flying alone are similar, but as they fly in groups, each bat changes one of its own echo-positioning signals, the end frequency, to reduce the similarity of the signals between them. They also make signal pulses longer and louder, just as a person may need to raise the volume at a noisy party to let others hear what they're saying.used different end frequencies for echo-positioning bats as they flew in groups.
the study, the authors tested only four bats in one group, so it remains to be known whether bats used the same strategy when flying in larger groups. (Source: Science.com)