Image: YouTube

While chimpanzees are often prone to excessive violence, it is rare to see a family member brutally murdered — and eaten afterward. 

Fongoli chimpanzees are among the most human-like chimps on the planet and reside in wooded areas of Senegal, West Africa. They are capable of brandishing tools and weapons and performing technical tasks involving the use of spears, including termite fishing and hunting. In addition, Fongoli chimps are known for bathing in water and understanding temperature differentiation, including the physiology of fire — without fearing it.

Jill Pruetz out of Iowa State University has been observing these Fongoli chimps for more than fifteen years and maintains a keen understanding of their familial tendencies. Chimpanzees prefer to live in groups containing more female members than males in order to maintain an optimal hierarchy based dominance while providing for sufficient reproduction options for all male members.

The increasingly imbalanced gender numbers of chimpanzee groups around the world can be partially attributed to human presence, specifically poaching — with females being the most desirable in terms of pet trade.

Image: Ryan Summers, Flickr

While having enough females in a community of chimps is important, alliances between male members are also predominant factors in lethal behavior.

One chimp called Foudouko was a former alpha leader of this particular Fongoli hierarchy until a five-year exile that left him wandering the outskirts of the community. When he finally attempted to return to his family, he was warmly welcomed by his older male friends, but the younger chimpanzee males were threatened by his return.

One morning, Pruetz’s team rushed to the source of erratic movement and rampant uproar and found Foudouko’s mutilated dead body lying in the dirt. He had sustained massive injuries to his foot, anus, and fingers, but what was most disturbing were the chunks of flesh eaten away from his neck and genitals.

The team and other chimpanzee behavior experts concluded the disturbing event was a result of competition over mates and limited resources.

The findings are published in the International Journal of Primatology