Bats Hang Out with Their Pals This Halloween

It turns out that bats like to hang out with their friends. Scientists have found that despite moving house frequently, bats will choose to roost with the same social network, even when they shift locations.

In order to learn more about bat social groups, the scientists examined two different but closely related species living in the same woodland. One species, Natterer's bat, forms mixed-sex social groups. The second species, the Daubenton's bat, has largely separate male and female groups.

The researchers fitted the bats with small aluminum arm bands. In addition, four bats were tagged with tiny lightweight radio-transmitters to allow the scientists to track them. The radio tracking revealed that the bats changed roost site frequently-about once every two days.

While the bats changed roost site, though, they didn't change social group. In fact, each social group occupied a home patch in the wood. Although the two bat species occupied the same area of woodland, the home patches of the different social groups within the species didn't overlap.

"This work has really important practical implications for bat conservation," said Fiona Mathews, one of the researchers, in a news release. "We now realize that although social groups of woodland bats 'move house' every few days, they remain within a very small geographical range. This means that even quite small-scale tree felling may destroy all the roosts potentially available to a group."

The findings are important for learning about how best to protect bat populations in the wild. That said, this story is only the beginning. Scientists need to conduct further studies in order to better understand what steps need to be taken.

"The social networks of animals are poorly understood," said Mathews. "Yet they are fundamentally important to processes ranging from information transfer to the spread of disease. Just as some types of people are super-connected on Facebook, this work shows that in animal systems, two very closely related species living in the same habitat can have very different kinds of social network."

The findings are published in the journal PLOS One.