Natures wonders: Bats unjam their group sonar (Introduction)

by David Turell , Friday, January 29, 2016, 01:35 (3009 days ago) @ David Turell

Bats use echolocation to find prey. In crowds they can jam each other:-http://www.sciencedaily.com/releases/2016/01/160128133301.htm-"Individual bats emit sonar calls in the dark, using the echo of their signature sounds to identify and target potential prey. But because they travel in large groups, their signals often "jam" each other, a problem resembling extreme radar interference. How do bats overcome this "cocktail party" cacophony to feed and survive in the wild?-"A new Tel Aviv University study published in Proceedings of the Royal Society B: Biological Sciences identifies the mechanism that allows individual bats to stand out from the crowd. The research, by Dr. Yossi Yovel of TAU's Department of Zoology, finds that individual bats manage to avoid noise overlap by increasing the volume, duration and repetition rate of their signals.-***-"In another paper, published in 2009, we trained bats to crawl toward one side or another, in the direction of another bat," Dr. Yovel explained. "This indicated that they indeed differentiated between the voice of one bat and another. This also proved they could identify their own calls.-"'In the current study, we trained bats to fly around a small room and land on a small object -- in the midst of a loud mixture of bat signals playing overhead. They found the object by increasing their emissions: crying louder and longer and shouting more frequently. They cried 'ahhhhhhh' instead of 'ah' twice as frequently -- every 50 milliseconds instead of the usual 100 milliseconds.'"-Comment: Could be a learned response to crowd noise.