The Echolocation of bats is produced by projecting ultrasonic sounds from the mouth or nose And then detecting the ultrasounds that return from an object within the scope. Bats quickly produce these pulses in succession to receive an image periodically from their environment.
In other words, A single call offers the bat from a single snapshot of its environmentWhile a series of evokes offers a series of snapshots, in the same way that a strobe light offers us a series of staggered images. As the frequency of stroboscope light increases (or wrist frequency), individual images begin to be seen as a continuous image.
While the sound travels in the air at a constant speed, bats can measure how far an object isDetermining the difference between the moment when the call was issued and the time that the ultrasound returns. If an object is far, the sound waves take longer to return bat Then with a poet object.
Why don’t bats collide against each other?
See a herd of bats That simultaneously emerges from a cave is a typical image of the collective imaginary. Until recently, however, science did not know how they did not let each other crash, even if it is colonies of hundreds of thousands flying through a small opening. Now, one Study published in the magazine Pnashas solved the mystery: Avoid collisions Changing his way of echolocalizing.
Lots of species of bat They see the world through Echolocation: They shed a call and listen to the reflected ultrasound, which in turn allows them far What’s Near. But a lot bats At the same time, they echo out – such as when thousands of them leave a cave – the calls of the other animals will find the information about the environment they need to know where they are flying.
This Loss of acoustic information is called interferenceand it is expected to cause them bats They crash. And yet air accidents in these events are not common.
Previous studies in the laboratory have shown that each bat of a small group of echoloced on a slightly different frequency, which In theory you must reduce interference. But nobody had studied this mass events in action.
That is what the research researchers did, led by Aya Goldshtein, of the Max Planck Institute for Animal Behavior” Those Wild Bats data collected a cave every night.
Go to your sensory world
They used a high-resolution monitoring combination, ultrasonic recording and computer and motor computational modeling. This allowed researchers to Sensory world Of the bats when they left the cave and flew in search of food.
For two years, They marked dozens of bats with trackers who registered their location every second. Some of these markers also include ultrasonic microphones that acoustic atmosphere From the point of view of each bat. Every year the data was collected in the same night when the bats.
A Restriction was that clear bats were released outside the cave when the herd came outWhich meant that real data from the principle of the output was missing when the density is greater. The team compensated for this restriction with a computer model that simulated this situation.
He Model has collected the data collected by the trackers and the microphones, To re -create the order of complete behavior, start with the entrance of the cave and end after the bats They would have flown two kilometers through the valley.
“The Simulation enabled us to verify our hypotheses about how bats solve this task So complex during the night room, “says Omer Mazar, a researcher at the University of Tel Aviv and one of the work authors.
Interference -Reduction
According to the results, when leaving the cave, the bat. In the five seconds of leaving the cave, the bats They considerably reduced the interference of Echolocation.
They also introduced two important changes in their behavior: first, They spread Of the dense core of the colony, maintaining the group structure; And secondly they spent shorter and more weak calls more often.
The researchers suspected that bats They reduced the interference that quickly spread from the cave. But why bats They have changed their echolocation with a higher frequency? Would the calls of interference and therefore the risk of collision increase the call? To understand that result, The authors had to concentrate the scene From the point of view of a bat.
“Imagine you have a bat That flies for a messy space. The most important object you need to know is it bat It is immediately through. So You must reflect it in such a way that you get the most detailed possible information about that bat”, Says Mazar.” You may miss the most available information because of the traffic jams, but it doesn’t matter, because you only enough details that don’t crash”The researcher adds.
In other words, what the study has revealed, that is Bats change their way of ultrasound to obtain detailed information about their nearby neighborsA strategy that ultimately helps them to maneuver successfully and to avoid collisions.
The authors underline that solving this mystery was possible thanks to the Study of bats in their natural environment. “The theoretical and laboratory studies from the past have enabled us to present the possibilities. But only as close to us as possible, in the skin of an animal we can understand the challenges that they are confronted with and what they do to resolve them,” concludes Aya Goldshtein, leader of the study.