These results suggest that echolocation gives bats a huge evolutionary advantage, allowing them to track insects from further away and with greater accuracy at peak feeding time. Echolocation also, of course, allows bats to continue hunting into the night, when their competitors are blinded by darkness.
A one-two evolutionary punch
On the negative side, bat echolocation was poor at detecting large objects in the distance: Vision can detect large objects at distances several orders of magnitude greater than echolocation does. The researchers think that bats therefore use both senses in combination vision mostly for orientation, navigation, and avoiding large objects in the distance, and echolocation to search for small prey. Different species of bats probably combine the senses somewhat differently.
"We believe that bats are constantly integrating two streams of information one from vision and one from echolocation to create a single image of the world," said Dr. Yovel, also of TAU's Sagol School of Neuroscience. "This image has a higher definition than the one created by vision alone."
The combination of vision and echolocation opened up a large nocturnal advantage for bats in which they have multiplied and diversified bats account for 20 percent of all classified mammal species on earth today. The researcher
|Contact: George Hunka|
American Friends of Tel Aviv University