'Tutor' Bats Take Peers Under Their Wings

Do you ever decide what you want at a restaurant by peeking at the dishes on the next table and eavesdropping on what those diners say about their choices?

If you answered yes, you have something in common with bats.

Humans are far from alone in learning from one another, and new research has found that a species known as the fringe-lipped bat learns about new kinds of food by watching and listening to "tutor" bats.

These bats usually locate prey by the calls made by male frogs. They usually ignore the calls of the sympatric cane toad, which is poisonous and too large to serve as prey, but researchers found that once they taught one bat to associate the sound of this toad with food, other bats got the idea within half a dozen tries. Bats left on their own took nearly a hundred trials to figure out this was a new source of food.

To do the experiment, which was reported in the June 20 issue of the journal Current Biology, researchers Rachel Page and Michael Ryan from the University of Texas at Austin and the Smithsonian Tropical Research Institute in Panama didn't use real frogs. They played frog sounds on a notebook computer, using speakers concealed by leaves. When a bat landed on a speaker making the frog sounds, it was rewarded with bait fish.

When the researchers introduced a second bat into the same caged area, they found that the new bat quickly learned to seek out the cane toad sounds, presumably by connecting the dots between the computerized frog sounds and the subsequent chewing sounds of the tutor bat. Once the lesson had been learned, the new bat could serve as tutor to another neophyte.

-- Shankar Vedantam