Mommy Bat Dies Giving Birth, Her Bestfriend Bat Steps in to Adopt Baby

A mother bat died a few days after giving birth, and her best friend adopted her baby.

Since establishing a strong social connection with the baby's mother before she died, a female vampire bat adopted the orphaned baby bat and began breastfeeding it.

While female bats live in "maternity colonies," often consisting of hundreds of bats, they tend to raise their young individually rather than as a group.

According to Imran Razik at Ohio State University, this unusual discovery of a bat adopting an unrelated child provides more insight into the dynamics of social interactions between individual bats.

"The cool thing about vampire bats is that these long-term social relationships are formed with each other, comparable in some ways to human friendships," Razik says. "We have had the opportunity to contextualize this event very easily with this adoption, something we usually do not see, by having it documented, long-term history of the social interactions [leading up to the adoption]."

The social activity of common vampire bats (Desmodus rotundus) at the time of adoption was observed by Razik and his colleagues at the Smithsonian Tropical Research Institute in Panama.

They collected 23 female adult bats from three wild colonies distributed hundreds of kilometers from each other. They put them together to see if they established relationships with strangers in a single captive colony. By licking each other's mouths, female vampire bats will form social ties with other bats, grooming each other and sharing food.

During the study, one bat became ill and died within weeks of giving birth. Another bat adopted the child, says Razik, to the delight and relief of the researchers.

BD adopts Lilith's Baby

The researchers could thoroughly trace the creation of the relationship between the ill mother bat ('Lilith') and the adoptive bat ('BD'), who was not pregnant or breastfeeding, by viewing hundreds of hours of video clips of their social interactions. Initially, they had shown a lot of mutual grooming, indicating they were bonding, Razik says.

The healthier bat shared food even more frequently than Lilith did, a pattern that intensified with what the researchers suspect was stomach disease as Lilith grew sicker.

Although she did not have a daughter, BD also helped take care of Lilith's baby, clean it, and even feed it.

BD officially adopted the baby when Lilith died 19 days after giving birth and raised it as her own. I moved BD's nipple milk manually, and I said, 'wow, she's actually breastfeeding this pup,' and I knew it was a pretty great story," Razik says."

In the colony, the other 21 females did not support Lilith or her pup to precisely the same degree.

We set out to research partner selection, and why bats engage in each other, and how these relationships are created," says Razik." "This adoption was truly an interesting contribution to that."

Adoption In The Animal Kingdom

According to Jenny Holland, author of the 2011 book Unlikely Friendships, such adoptions are comparatively common among domestic animals and rarely seen in the wild, this makes BD's case even more special.

Some cases include a dog that, as part of her own litter, nursed a baby squirrel, captive apes who handled cats like newborn apes, and a dog who watched over a baby owl, Holland said.