Under the cover of darkness, a large number of mature and fast-moving bats fly into the sky every night to perform foraging tasks. How they move skillfully without collision has always been an unsolved mystery-but now it has been solved.
bat
A new study found that bats, which are nocturnal animals, will follow several simple "traffic rules" to avoid air collision: they will first use their own sonar system to grasp the positions of other bats, and then follow the route taken by the leading bat.
In a new experiment in Britain, scientists observed the flight pattern of Daubenton II, a wild water vole. This insect-eating bat is only about the weight of No.4 (AAA) battery, and it is distributed from the British Isles to Japan.
Rat-eared bats fly low over lakes and other water bodies, catching midges, moths and other insects, usually with their feet, just like eagles catch fish.
bat
With the naked eye, this kind of light may fly and pass over the water without any rules, but Marc Holderied, the co-author of this research paper and a behavioral biologist at the University of Bristol in the United Kingdom, said that after recording the data of 70,000 bat flights, scientists found that there was "amazing" coordination in bat flight.
"Sometimes they avoid collisions by speeding up one side and slowing down the other," Holdred said. His research paper was published in the American journal "Computational Biology in the Public Library of Science" on March 26th.
Dancing in the dark
Many bat species use echolocation, that is, they emit high-frequency sounds and then listen to the sound waves that bounce back from possible prey. After observing the flying mode of the mouse-eared bat, Holderied and his team used the collected data to simulate the bat's use of its sonar system during the flight. This model gives the research team a little understanding of how flying bats perceive the world.
As a result, the research team found that the water rat-eared bat used echolocation for another purpose: to understand the dynamics of other bats in its own airspace.
bat
This ultrasonic skill can help bats avoid collisions and concentrate on following the leading bat. Once the bat chooses the object to follow, it will start to imitate the other person's turn and dive. Because the reaction time is only about 500 milliseconds-almost in the blink of an eye-the movements of the two bats seem to be almost completely synchronized.
Interestingly, some bats in pairs will change their leading roles many times in one flight. In addition, because echolocation can provide information from all directions, the leading bats don't always fly ahead.
In other words, it is also possible to lead from the rear.
bat
Researchers admit that although they have developed an accurate model to explain how bats make sharp turns without collision, why they imitate remains an unsolved mystery.
One possibility is that the second bat can benefit from following, and perhaps catch the insects that the leader missed. It is also possible that flying in tandem is good for both bats, because listening to each other's hunting signals can expand their hunting range.
Finally, the authors said that they did not rule out witnessing the mother bat training the baby bat to fly.
Generally speaking, there are still many places for us to discover and understand about the flight of bats.