07/13/2026
Earth’s largest chimpanzee community split — and is now locked in a deadly civil war.
For thirty years, scientists have closely monitored the Ngogo chimpanzee community in Uganda's Kibale National Park—a massive group of around 200 chimps that was famously featured in the Netflix documentary series Chimp Empire.
For the first two decades of study, these primates coexisted peacefully, grooming each other, foraging together, and defending their borders from outsiders.
However, a groundbreaking study published in the journal Science reveals that this once-unified group has permanently fractured. Triggered by a series of events starting in 2015—including the deaths of key elder males, changes in the social hierarchy, and a devastating disease outbreak—the community completely split into distinct Western and Central factions by 2018.
What followed is being described by researchers as an unprecedented, slow-motion civil war of shocking brutality. Members of the smaller Western group began launching coordinated, lethal raids into the territory of their former companions in the Central group. Between 2018 and 2024, researchers documented at least 24 killings, including seven adult males and 17 infants. Since chimpanzees are among our closest living evolutionary relatives, this rare event—estimated to occur naturally only once every 500 years—offers a sobering look into the origins of collective violence. Scientists note that because these primates began killing former friends with whom they once held hands, it demonstrates that deep-seated group dynamics and polarization can drive lethal conflict even in the absence of human-like political or religious ideologies.
source: Sandel, A. A., et al. (2026). Lethal conflict after group fission in wild chimpanzees. Science, 392(6794), 216.