The social life of a vampire bat
When you think of vampire bats feasting on blood, friendship and cooperation might not be among the qualities that come to mind, but maybe they should.
Scientists have shown how bats that have forged “friendships” with others find these friends while searching for a meal.
Studying female bats
Researchers attached small devices to 50 vampire bats to track nighttime foraging in Panama, when these flying mammals drink blood from wounds they inflict on cattle in pastures. The study looked at female bats, known to have stronger social relationships than males.
Among the bats were 23 wild-born individuals who had been held in captivity for about two years during related research on the social behavior of bats. Social links had already been observed between some of them. After being released into the wild, bats would often join a “friend” while foraging, possibly coordinating the hunt.
“Each bat maintains its own network of strong cooperative social bonds,” said behavioral ecologist Gerald Carter of Ohio State University and the Smithsonian Tropical Research Institute, who led the research published in PLoS biology.
Social bonds between vampire bats when roosting in trees include grooming and regurgitating blood meals for hungry friends. The study showed that the social bonds formed in the dormitories extended to hunting.
Researchers suspect that bats, although they hardly ever go foraging with their “friends”, do connect with them while hunting for mutual benefit. They hypothesize that bats could exchange information about the location of prey or access to an open wound for food.
Living in colonies
Vampire bats, which inhabit warmer parts of Latin America and have a wingspan of around 18cm, are the only mammals that have a blood-only diet. They reside in colonies of thousands.
“Even outside of their social life, vampire bats are quite special: specializing in a 100% blood diet is already quite rare in vertebrates,” said co-author Simon Ripperger, post-doctoral researcher at the Smithsonian Tropical Research Institute. “They are incredible runners that you wouldn’t expect with a bat. They have heat sensors in their snouts that help them find a place to grab a bite.