Vampire bats socially distance when they fall ill

Oct. 27 (UPI) -- New research suggests vampire bats are better at following CDC guidelines than some humans.

When a vampire bat gets sick, they spend less time around other members of the colony, helping to slow the spread of disease, according to a new study published Tuesday in the journal Behavioral Ecology.

Scientists had previously observed vampire bats practicing social distancing in captivity, but the latest research suggests wild bats also work to flatten the curve.

For the study, researchers captured 31 adult female vampire bats from a roost located in a hollow tree in Belize. To simulate the influence of illness, scientists injected half the bats with lipopolysaccharide, an immune-challenging substance. The control bats were injected with saline.

After attaching proximity sensors to the bats, researchers released them back into the wild.

The data revealed shifting interaction patterns among the different bats during the six-hour treatment period -- before the effects of the injection wore off. The sick bats interacted with fewer members of the colony and spent less time their peers.

In the hours following their release back into the wild, the data showed a control bat had a 49 percent chance of interacting with another control bat, but only a 35 percent of interacting with a sick bat. Sick bats also spent 25 fewer minutes with their partners than control bats.

"The sensors gave us an amazing new window into how the social behavior of these bats changed from hour to hour and even minute to minute during the course of the day and night, even while they are hidden in the darkness of a hollow tree," lead study author Simon Ripperger said in a news release.

"We've gone from collecting data every day to every few seconds," said Ripperger, an ecologist at Ohio State University.

For most species, illness symptoms, such as lethargy and sleep, or reduced movement and sociality, prevent infected individuals from interacting with the rest of the community -- a kind of involuntary social distancing. But the latest research suggests bats are part of a minority group of animals that purposefully self-isolate in cooperation with their colony mates.