A 30-year study documents a rare split within a chimpanzee community in Uganda’s Kibale National Park — one that sparked a deadly war.Two rival chimp groups have staged coordinated raids that killed both adult males and infants.Researchers recorded at least 24 attacks between 2018 and 2024, suggesting unusually intense violence.The findings show how shifting social ties can fracture animal societies and trigger collective violence.
A chimpanzee community in Uganda’s Kibale National Park that split into rival factions later attacked former allies in what researchers are describing as a rare chimpanzee “civil war.”
The new study, published in the journal Science, draws on nearly three decades of observations at the Ngogo chimpanzee research site, led by primatologist Aaron A. Sandel of the University of Texas at Austin, in the U.S. He and his colleagues say this is a rare event that may occur only once every 500 years. It’s only been observed once before by humans.
Before the split, the Ngogo community was unusually large, with roughly 150 to 200 chimpanzees (Pan troglodytes), making it one of the largest chimp groups ever recorded in the wild. After the rupture, the community divided into two factions, which researchers call the Central and Western groups — named after the areas of forest they occupied.
