On 29th August 2019, Lilith, a vampire bat housed in the Smithsonian Tropical Research Institute in Panama, died, leaving behind a pup. Curiously, for Gerry Carter and Imran Razik — the scientists studying these bats — BD, another bat in the colony, whom Lilith had met only two months ago, adopted her pup. In that two-month span, BD and Lilith had evidently formed a close bond. While this is not the first instance of adoption exhibited by vampire bats (or in the animal kingdom), it does raise a peculiar question: if natural selection is about maximizing one's genetic legacy, what does a bat get out of raising the children of an unrelated bats?
Vampire bats are highly social animals, for whom "blood relative" takes on a whole new meaning. Roosting in groups, they spend a large portion of their waking time grooming each other, and even regurgitating food — i.e., blood — for the benefit of a few special friends. Gerry Carter, an assistant professor at Ohio State University, is trying to unravel the mysteries of vampire bat friendships. Carter's findings get us closer to understanding how and why cooperative friendships form in social animals, including humans.
