Researchers Shocked After Capturing a ‘Very Rare’ and Weird Behavior of Monkey

A female drill monkey named Kumasi, residing in a European zoo, recently displayed a distressing behavior after her baby died. Instead of immediately accepting the loss, Kumasi carried the lifeless infant’s body around her enclosure for nearly two days, refusing to allow keepers to remove it.

Tragically, on the second day, Kumasi resorted to consuming her own deceased offspring. This unusual act, though horrifying from a human perspective, may actually enhance her prospects of having another child in the future, according to experts.

In August 2020, Kumasi, a female drill monkey (Mandrillus leucophaeus), gave birth to a son at the Dvůr Králové safari park in the Czech Republic. However, only eight days later, the infant passed away, with the cause of death remaining undetermined. It’s worth noting that the baby was not deemed to be in poor health at birth.

Kumasi’s behavior during those agonizing days was recorded by researchers studying the drill troop. The team documented the grim event in a recently published study in the journal Primates, which includes distressing video clips of Kumasi carrying and consuming her deceased child. (Warning: Some people may find these clips distressing.)

Infant cannibalism is an extremely rare phenomenon, with only anecdotal reports found in scientific literature, according to Elisabetta Palagi, a primate biologist at the University of Pisa in Italy and co-author of the study. Hence, this recent incident of infant cannibalism becomes one of the most thoroughly studied cases to date.

Following her baby’s death, Kumasi remained close to the lifeless body while other members of the troop inspected it. The mother may have been grieving, but the researchers suspect that she was uncertain or unwilling to accept the baby’s demise.

Kumasi repeatedly positioned herself in front of the corpse’s eyeline, as if trying to engage her baby’s gaze. This behavior is common among monkeys and apes who inspect the faces of their deceased offspring, possibly in an attempt to perceive eye movements. When mothers receive no response from their babies, it often indicates that something is wrong, as per Palagi.

As time passed without any response, Kumasi grew restless and began dragging and throwing the corpse around the enclosure. While this might seem horrific from a human standpoint, researchers believe that Kumasi had a valid reason to consume her deceased son.

“If we consider the incredible reproductive energy investment of primate mothers, cannibalism can be considered an adaptive evolutionary trait that helps the mother to recover energy after gestation,” Palagi remarked.

This behavior, according to the expert, may increase the mother’s chances of future reproductive success.

The fact that Kumasi did not share the carcass with other group members supports the hypothesis that cannibalism provides nutritional benefits, as the others did not require additional nutrients, according to the author.

This incident is not the first time cannibalism has been explained as a means to enhance reproductive success. In 2019, researchers studying white-faced capuchin monkeys in a national park in Costa Rica observed a female eating the remains of an infant that had fallen from a tree. Although not the infant’s mother, this female gave birth two weeks later, suggesting that cannibalism was a strategy to acquire extra nutrients for her own offspring.

The researchers also speculate that the age of the baby drill could have influenced its consumption.

“The younger the baby, the less likely the mother-infant attachment has become sufficiently strong to prevent maternal cannibalism on the dead infant,” Palagi added.

The researchers do not believe that the monkeys’ captivity played a role in the infant’s death or the mother’s cannibalism, as the zoo makes efforts to provide engaging lives for the monkeys.

In fact, the zoo’s dedication to enriching the lives of primates extends to other species as well. For instance, in 2021, keepers installed a large screen in the chimp enclosure to enable the apes to interact with other chimps residing in a different Czech zoo via video calls. This virtual meeting aimed to compensate for the lack of social interactions with visitors due to the COVID-19 pandemic and was highly appreciated by the chimps.

Image Credit: Shutterstock