Vampire bats form cooperative, friendship-like social relationships

  • Vampire bats form cooperative, friendship-like social relationships

Vampire bats form cooperative, friendship-like social relationships

To study how social bonds between vampire bats persist across radically different contexts, researchers collected 23 wild bats from western Panama and brought them back to the lab.

This is significant because it's often hard to tell whether "partner fidelity" in animal relationships is due to the immediate costs and benefits of helping each other, or due to some shared relationship history.

To test the strength of relationships in female common vampire bats (Desmodus rotundus), which often groom and share food (normally the blood of livestock) with one another, researchers caught 17 bats from a wild colony and kept them-and their six offspring-in captivity for almost 2 years. The idea, boiled down, was to see if the partnerships these bats would form in the lab were "genuine" or simply the best available at the time (in which case they would break down as the bats started to associate with other individuals).

"The social relationships in vampire bats that we have been observing in captivity are pretty robust to changes in the social and physical environment - even when our captive groups consist of a fairly random sample of bats from a wild colony", Simon Ripperger, researcher at the Leibniz-Institute for Evolution and Biodiversity Science in Germany, said in a news release. This kind of cooperation is particularly rare between vampire bats that aren't related because they have to pay a cost to help their peers - to feed each other, they have to regurgitate their own meals.

Not all bats maintained their relationships, but in a press release, co-lead author Gerald Carter equated this to the human experience of friendship after graduating high school.

The test bats remained closer with each other than with the wild bats, and their bonds were stronger than bonds wild bats had with one another. You may stay in touch with some people but not others, depending on personality and shared experiences. In particular, the captive-born offspring had bite marks after returning to the wild colony, and they eventually left the roost.