Vampire bats practice social distancing when they get sick: study
Last updated on: 30 October,2020 09:23 pm
Animals often isolate to avoid spreading disease in their communities
(Web Desk) - While social distancing during a pandemic may feel unnatural to many people, it’s actually quite common in the natural world.
Birds do it, bees do it — and even vampire bats do it.
A new paper published in Behavioral Ecology on Tuesday finds that diseased wild vampire bats spend less time near other bats in their colony — including other sick bats — which slows how quickly the infection spreads through their community.
U.S. researchers noticed that sick vampire bats (Desmodus rotundus) kept their distance from other bats in laboratory settings, and they wanted to see whether the bats would also exhibit this behavior in the wild.
So they captured 31 adult female vampire bats from a colony roosting in a hollow tree in Lamanai, Belize. They simulated sickness in the bats by injecting a random half of them with an immune-challenging substance (lipopolysaccharid, or LPS), while the control group of bats was injected with saline. The researchers also attached proximity sensors to the bats, and released them all back into their hollow tree to track any changes in their movements and interactions with other bats.
Their findings: the “sick” bats associated with fewer bats in the group; they spent less time with other bats; and they were less socially-connected to healthy groupmates. “Sick” bats interacted with four fewer bats, on average, compared with the healthy control bats. And “sick” bats spent 25 fewer minutes associating per partner. The healthy bats had a 49% chance of associating with each control bat, but only a 35% chance of associating with each “sick” bat.
And these limited interactions weren’t just because the “sick” bats were all clustered together; in fact, associations between two “sick” bats were even lower than between a “sick” bat and a control bat. The “sick” bats generally self-isolated to avoid being in close proximity with any other bats. The researchers concluded that this helps “slow the spread of a pathogen that is transmitted at higher probability with higher rates of physical contact (e.g., grooming) or closer proximity.”