Rachel Page and Mike Ryan of the Smithsonian Tropical Research Institute on Barro Colorado Island in Panama discovered that the fringe-lipped bat learn of an edible prey by eavesdropping on what their neighbors are eating.
To observe the cultural transmission of this new information in the bats, Page and Ryan captured wild fringe-lipped bats and tested them in large outdoor flight cages. They played the calls of large, poisonous cane toads through speakers and gave the bats that approached the speaker a reward of raw fish. Once a bat learned to associate the cane toad call with food, they became "tutor" bats.
Naïve bats were then allowed to observe the tutor bats. The naïve bats, on average, learned to associate the new frog call with food after observing their tutor five times. Page and Ryan believe the naïve bat observes the tutor's location through echolocation and then listens to it chewing on its prey.
This is the first study to show predators learning socially through acoustic, rather than visual or olfactory, prey cues.