When bats take wing looking for food, they're often at close quarters with one another, and a new study has determined how they maneuver at high speeds without crashing into each other.
In research published today in PLOS Computation Biology, University of Bristol, U.K., researchers concluded that bats avoid collisions thanks to one simple practice: listen in on a nearby bat and copy the route it has just taken.
To determine their surroundings bats use echolocation, or biosonar -- sending out high-pitched calls and then using the returning echoes to effectively map out what's up ahead. Marc Holderied, of Bristol's School of Biological Sciences, recorded video of the flight trajectories and interactions of these echolocating fliers -- specifically, pairs of Daubenton's bats (Myotis daubentonii) -- while they foraged for insects over low water. Holderied and his team then used modeling tools and mathematical functions to measure the calls of interacting pairs of bats and compare the flight headings of one bat vs. the other for select time intervals.
The team found that the bats were observing what they termed "traffic rules" -- slowing down to avoid collisions, swapping follower and leader roles, making tandem turns and chasing each other.
How did they do all of this precision flying without accidents? The scientists found that the bats copied each other's flight headings, taking readings that happened just 500 milliseconds prior -- or only slightly more time than it takes for a human eye to blink.
"The bats seem to have adopted a simple trick: once another individual is close enough for your biosonar to pick up its echo, copy this individual's flight direction within four to five of your own wingbeats," Holderied explained in a news release.
Research team member Luca Giuggioli, from Bristol's Center for Complexity Sciences, pointed out that a better understanding of bats' movement decisions during foraging had implications outside of animal science.
"By employing movement strategies that nature has optimized over millions of years, engineers may be able to improve the efficiency of search and rescue missions, monitoring tasks, and surveillance operations in the emerging market of flying drones and autonomous moving vehicles," Giuggioli said.
(Source: Discovery News)