Imagine being dropped in complete darkness three kilometers from home with only a flashlight to guide you.
Could you find your way back?
For echolocating bats, this is a routine challenge they solve using their built-in ability to navigate with sound.
A new study reveals that bats have an “acoustic cognitive map” of their home area, allowing them to travel over long distances with precision, even in the dark.
The research, published in Science, was conducted by scientists from the Max Planck Institute of Animal Behavior in Germany, Tel Aviv University, and the Hebrew University of Jerusalem.
They discovered that bats don’t just use echolocation to avoid obstacles—they also rely on it to recognize their surroundings and navigate back to their roosts over several kilometers.
To investigate, researchers studied Kuhl’s pipistrelle bats, which weigh just six grams, in Israel’s Hula Valley.
Over several nights, they tracked 76 bats using a lightweight GPS tracking system called ATLAS.
The bats were moved to random locations within a three-kilometer radius of their home range, and their journey back was monitored.
Some bats relied solely on echolocation, while others had their vision, sense of smell, or magnetic sense tested.
Remarkably, 95% of the bats returned home quickly, proving that echolocation alone is enough for kilometer-scale navigation. However, when bats had the option to use their vision, they navigated even more effectively.
“We were surprised to learn that bats also use vision,” says researcher Aya Goldshtein. “Their eyes are so small, yet they rely on vision in certain conditions.”
The team created a detailed 3D map of the valley to better understand how bats use sound to navigate.
They found that bats often fly near landmarks that provide rich acoustic information, such as trees or roads. These areas, called “echoic entropy” zones, help the bats identify where they are.
During their flights, the bats first move in a zigzag pattern to locate themselves. Once they recognize their surroundings, their flight path becomes more direct, showing they know where they are and where they need to go.
“Bats can distinguish between different environmental features using sound,” says Xing Chen from Tel Aviv University. “They use these acoustic landmarks to find their way.”
The study concludes that bats have an acoustic mental map of their home range, allowing them to recognize specific features and navigate efficiently. While echolocation is their primary tool, they enhance their performance by combining it with vision when possible.
This discovery highlights the incredible abilities of bats, showing how their unique sensory systems allow them to thrive in challenging environments.
