When we think of animals that work together to hunt prey, we typically think of creatures such as wolves or orcas. Common bats may soon be added to that list, as a new study suggests that they show each other where the tasty insects can be found.
As most people already know, bats are able to locate flying insects in pitch black conditions via echolocation. More specifically, they emit ultrasonic waves that reflect off insects' bodies and back to the bats' big ears, letting them know how far away and in which direction those insects are located.
According to scientists from Germany's University of Potsdam and the Leibniz Institute for Zoo and Wildlife Research, this system can only locate insects within a range of 10 to 15 meters (33 to 49 ft) – if there's a swarm of insects any farther away, a bat won't be able to detect them. That said, because bats are considerably larger than insects, they can echolocate each other up to a distance of 160 m (525 ft) under ideal conditions.
In order to see how bats might use this fact to their advantage, the researchers glued small radio transmitters to the backs of 81 common noctule bats (Nyctalus noctula). An array of antennas in the bats' habitat received signals from those transmitters, allowing the scientists to track the flight patterns of each animal for a total of five sessions over a three-year period.
It was found that when hunting for insects, large groups of the bats fanned out far enough to cover as wide an area as possible while still remaining in echolocation range of one another.
If any one of those bats encountered a swarm of insects and began going after them, adjacent bats would be notified by detected changes in its flight movements, and by special echolocation calls it started using when actually attacking the insects. Those other bats would then proceed to the first bat's location, snagging some of the insects for themselves.
Using a computer model, the scientists determined that by "networking" in this fashion, bats required 40 percent less time to locate prey than they would if they ignored other bats. The researchers state that it is therefore important to protect the communal roosts in which many bats live, as the creatures may not be able to find enough food if living in small groups or own their own.
A paper on the study, which was led by U Potsdam's Dr. Manuel Roeleke, was recently published in the journal Proceedings of the National Academy of Sciences.
