Orientating yourself in the darkness of a cave seems like a difficult task. But some bats may have an ingenious solution: using their tails.
Greater mouse-tailed bats (Rhinopoma microphyllum) live in groups inside small caves where flying is challenging, so they hang from the cave鈥檚 walls and move deeper into it by crawling backwards. They manoeuvre this way in many situations, such as in response to the appearance of a predator, or when they want to find a better position in the cave.
Biologists have long wondered whether these bats might use their unusually long tails as a 鈥渟ensor鈥� to navigate inside the caves, and so at Tel Aviv University in Israel and his colleagues designed two experiments to put the bats鈥� tails to the test.
Advertisement
In the first experiment, the researchers recreated a setup that mimicked the interior of a cave, creating a maze with obstacles similar to the uneven, rocky terrain the bats would encounter naturally. The team measured how long it took for the bats to climb the wall while crawling backwards, and how smoothly they were able to do so, first naturally and then with their tails anaesthetised.
The bats moved their tails back and forth to sense the obstacles and find their way through the maze. But when the researchers anaesthetised the bats鈥� tails, the flying mammals navigated the maze less smoothly and around 10 per cent more slowly. They still made it through, however, suggesting they also use other body parts to sense obstacles. 鈥淲hen you walk backwards, you can still feel with your body and with your legs,鈥� says Yovel. 鈥淚t鈥檚 clear that they can do it. But there was a significant reduction in performance.鈥�
In the second experiment, the researchers designed a Y-shaped maze that presented two corridors with different ridged textures that the bats could feel and choose between. They used textural differences between the two corridors to teach the bats that one corridor led to a reward, while the other didn鈥檛. Even though the textural differences were subtle 鈥� one corridor had gratings every 1.5 centimetres and one had gratings every 1 cm 鈥� the animals were able to distinguish between them.
While other bat species have long tails, the researchers say this is so far the only one known to find its way in the darkness using this distinctive strategy. 鈥淚 don鈥檛 think this is the general for bats with long tails,鈥� says Yovel. But 鈥渦ntil we test the other bats, we don鈥檛 really know鈥�.
iScience
