Researchers studying the Ngogo chimpanzees at Uganda’s Kibale National Park have revealed that the world’s largest wild chimp group has been locked in a blood‑shed civil war for eight years. Since 2018 the community split into Western and Central factions, sparking 24 killings, including 17 infants, as former allies turn lethal.

The split began in June 2015 when the Western group fled after a chase by the Central chimps, triggering a six‑week avoidance period and more aggressive encounters. By 2018, the factions had hardened, and the Western side launched targeted attacks, killing at least seven adults and many infants, a pattern the team links to resource competition and dominance shifts.

Sandel, an anthropologist from the University of Texas, attributes the rupture to three catalysts: the 2014 deaths of five adult males and one female that disrupted social bonds, a 2015 alpha‑male change that heightened aggression, and a 2017 respiratory epidemic that killed 25 chimps, including key connectors between the groups.

The findings echo human conflict dynamics, suggesting that group identity alone can spark lethal violence when hierarchy and resources shift. As researchers note, even the closest kinship bonds can erode without social cohesion, underscoring the need to study primate behavior to better understand the roots of tribal warfare.