Vampire bats may come with a notorious reputation, but they’re not that far off from other animal species in terms of forming relationship bonds. When it comes to finding friendship, new research suggests that vampire bats form connections in the lab that can persist even after being released into the wild.
When kept in captivity, bats become highly cooperative and are more likely to share their food – aka regurgitate blood – and groom one another, even with unrelated adults. But do these relationships last in the wild?
“In other words, are we experimenting with real social bonds that would persist in nature?" said Gerald Carter, a research associate at STRI and professor at Ohio State University, in a statement. Carter and his research team have been studying female vampire bats and their captive-born offspring in the lab for nearly two years.
"For several years, we have been doing experiments on food sharing in kin and non-kin vampire bats in captivity, but we also wondered if these stable cooperative relationships were largely an artifact of being in captivity," Carter added.
To find out who bats would associate with and where they would go, researchers designed a specially equipped bat-pack and headed out to the field. Each captive-held bat was outfitted with tiny tracking devices with proximity sensors and miniaturized computers that weigh less than a penny. These same devices were put on a random control group of bats from the same colony before all were released to their natural colony in a hollow Panamanian tree. For over eight days, these backpack computers logged every time a bat came into close proximity with another peer.
Bats that were previously held in captivity chose to associate with the same bats as they did during captivity, but not all the friendships survived the graduation.
"Living in close contact is really important for building social relationships, but it's not everything," Carter said. "If you go to college, you tend to become friends with the other kids in your dorm. But after college, some of those friendships may go on but others will fade away, and that will depend on your personality and the kinds of experiences you shared."
The findings suggest that social bonds aren’t just a result of being in captivity, but rather from preferences that are influenced by one’s external environment and circumstances.