What’s new: Some bats, like birds, migrate long distances. But these long-distance bat migrations have been somewhat of a mystery to researchers, especially since only a few species embark on them. Now, in a new study, researchers have mapped the odyssey of common noctule bats (Nyctalus noctula) using innovative tiny trackers. And the results have surprised them: the trackers reveal that the noctule travels far across Europe by “surfing” warm winds that precede storms.
What the study says:
- For long, bat migration has been “poorly understood” because researchers lacked the tools to follow multiple bats over long periods of time, Edward Hurme, the study’s lead author from the Max Planck Institute of Animal Behavior (MPI-AB) in Germany, said in a video statement. To address this, Hurme and his colleagues designed specialized tags that weigh just over a gram each that can be attached to bats. The tags use what’s called the Internet of Things technology, relying on a large wireless network of devices connected to the internet that communicate with each other.
- The team tracked the movements of 71 female common noctules they tagged in Switzerland over the course of three years. The common noctule is a widespread insectivorous and migratory bat species in Europe. The researchers chose to tag female bats as they were more migratory than males.
- The study revealed that the bats traveled up to 1,116 kilometers (693 miles) across Central Europe, moving hundreds of kilometers in a single night. But the bats didn’t follow a main migration corridor like migrating birds do; rather, they moved in many different directions. “We had assumed that bats were following a unified path, but we now see they are moving all over the landscape in a general northeast direction,” study co-author Dina Dechmann, a staff scientist at MPI-AB, said in a statement.
- The study also found that the bats migrated during specific weather conditions. They usually left just before storms came, taking advantage of incoming warm fronts that pushed the bats forward, allowing them to save energy. The bats’ movements also showed a “hopping pattern,” suggesting the bats were frequently stopping to refuel throughout their journey.
What this means:
Charlotte Roemer, a conservation biologist at the National Museum of Natural History in France, who wasn’t involved in the study, told Science that the new technology “revolutionizes the tracking of bat movements and will surely help researchers answer many questions about migration.”
Hurme added that greater understanding of bat migration can help prevent collisions with wind turbines, which is a major problem.
“More studies like this will pave the way for a system to forecast bat migration. We can be stewards of bats, helping wind farms to turn off their turbines on nights when bats are streaming through,” Hurme said in the video statement.
Banner image of a common noctule courtesy of Kamran Safi/Max Planck Institute of Animal Behavior.