From Nature, Dec 11 2014 pg 147
Some bat species unable to use sonar to sense their environment can instead navigate using echoes from clicking their wings – possibly an early, crude form of echolocation.
A team led by Arjan Boonman and Yossi Yovel at Tel Aviv University in Israel studies three species of wild, non-echolocating Old Worlf fruit bats. They found that individuals of two species emitted clicks more frequently in the dark than in the light, and could find and land on large objects, although they failed to detect small obstacles. When the researches taped the bats’ wings, the clicking stopped, but the exact clicking mechanism could not be determined.
The authors suggest that much can be learned about the evolution of echolocation from these fruit bats.; Curr. Biol http://doi.org/xmr (2014)