Vampire bats are social animals that live in large communities. In fact, zoologists have known for a long time that these mammals native to the tropical and subtropical regions of America usually behave altruistically, sharing their food with those of their peers who have not been able to obtain it on their own . It has been observed that eight out of ten times it is the females that manifest this behavior. However, until now it was not clear why they did it even with those vampires who were not part of their relatives or their closest group.
In a study published recently in the journal Proceedings of the Royal Society B , scientists from the Smithsonian Tropical Research Institute, in Panama, and the University of Maryland, in the United States, point out that, in this way, they establish a link with other specimens over time . That is, when a vampire regurgitates blood in the mouth of others, he does so with the intention that they will do the same when he is the one who needs the food.
To determine this, they established a mini-community similar to the one that could occur in their natural environment, in which they included specimens related to each other with others obtained from different zoological parks, and they recorded their way of acting when they prevented some from accessing food. Thus, they observed that vampires tended to share their blood with those who had previously shared it with them.
In the opinion of the signatories of the trial, this practice not only broadens and strengthens the social relationships of these blood-sucking animals, but could also constitute an essential survival mechanism , since they can die when they go more than two days without feeding.
