Study reveals how bats use echolocation and vision to navigate long distances

A new study published in the journal Science shows that Kuhl’s pipistrelle bats can navigate long distances using echolocation and vision. The study describes how these bats can determine their location even after moving or moving. The study was carried out by a team of researchers from the Max Planck Institute for Animal Behavior, the Center for Advanced Research in Collective Behavior at the University of Konstanz in Germany, Tel Aviv University and the Hebrew University of Jerusalem in Israel. .

Scientists conducted experiments with 76 Kuhl’s pipistrelle bats, tracking them near their roost and moving them within a three-kilometre radius. Each bat was tagged with an innovative lightweight reverse GPS tracking system called ATLAS, which provided high-resolution, real-time tracking. Some bats were equipped exclusively with the ATLAS system, while others were further manipulated to assess how their vision, smell, magnetic sense and echolocation affected their ability to return to their habitats.

The research team sought to highlight echolocation as a potential navigation tool. To achieve this, they first had to find the right kind of bat. They decided to study Kul’s pipistrelle bats, which weigh six grams and are common in the Hula Valley in Israel. These bats are known for their ability to combine thousands of sound signatures into acoustic maps.

Remarkably, even using echolocation alone, 95 percent of Kuhl’s bats returned to their positions within minutes, demonstrating their ability to navigate on a kilometer scale using echolocation alone. Bats use environmental features with characteristic acoustic signals as landmarks and cues. They can use acoustic information to distinguish between environmental objects such as a tree and a road, and thus use them as acoustic cues.

During the localization phase after movement, Kuhl’s pipistrelle bats perform a meandering flight, which at a certain point changes to a directed flight towards their destination, suggesting that they already know where they are. The model showed that they tend to fly near environmental features with higher “echoic entropy”, i.e. areas that provide richer acoustic information that can complement what they can see with their echolocation.

In addition to the field experiments, the team created a detailed map of the entire Hula Valley to understand what each bat experienced during flight and how they used acoustic information to navigate. The study shows that bats can use echolocation to navigate maps over long distances, and the sound map can help navigate distances of up to 1.8 miles.

The study also found that when given vision, Kuhl’s pipistrelle bats improve their navigation performance by combining both senses. Aja Goldstein, a researcher at the Max Planck Institute for Animal Behavior in Konstanz, Germany, said: “We were surprised to find that these bats also use vision. This was not what we expected. It was incredible to see this, even with such small eyes, in such conditions they can rely on vision,” ScienceDaily reports.

Bats have long been known to use echolocation to avoid obstacles and navigate, using this technique to find food and roosting sites. Echolocation is the ability of some animals to recognize their environment by making sounds and interpreting the echoes they generate. Many species of bats use echolocation to avoid obstacles such as tree branches and to hunt small insects while flying in the dark.

However, navigation using echolocation was not obvious because the range of echolocation is limited. Bats can use echolocation to sense objects no more than a few tens of meters away. Echolocation is not omnidirectional; The cone of coverage that bats get from echolocation is usually a maximum of 120 degrees. Despite these limitations, Kuhl’s pipistrelle bats can travel several kilometers using echolocation alone, as shown by experiments in which nearly 100 bats were moved three kilometers from their roost.

The ability of bats to create acoustic maps suggests that they possess an acoustic mental map of their home range. They use these acoustic maps to successfully navigate several kilometers across their hunting grounds. Kuhl’s skybats fly close to environmental objects, receiving more acoustic information and making navigational decisions. They use environmental agents with characteristic acoustic signals as landmarks.

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The study concluded that Kuhl’s pipistrelle bats can travel several kilometers using echolocation alone. When they have vision, they improve navigational performance by combining both senses. After moving, bats first determine their new location and then fly home, using environmental features with characteristic acoustic signals as landmarks.

Bats using echolocation are tasked with recognizing their location and finding their way home from any random point within a three-kilometer radius in complete darkness using only echolocation. The research team showed that bats can use echolocation to know where they are and how to navigate over distances of several kilometers, demonstrating navigational abilities even after moving. This study shows that echolocation for bats is much more than just a system for avoiding close-range obstacles and targeting prey.

Sources: Page/12, Ars Technica, ScienceDaily.

This article was written in collaboration with generative artificial intelligence company Alchemiq.