A new study has documented what may be the first known case of a "civil war" among wild chimpanzee, revealing a level of internal conflict previously thought to be uniquely human.
The research, published in Science, focuses on a long-studied chimpanzee community in Kibale National Park. Once a cohesive group, the chimps split into two factions around 2015, forming what scientists later identified as the "western" and "central" groups.
Over the following years, the western group carried out at least 24 coordinated attacks against their former companions, killing multiple adult males and infants. Researchers say the scale and organisation of the violence resembles patterns seen in human civil conflicts.
Primatologist Aaron Sandel, who observed early signs of the split, noted that the chimpanzees initially behaved as if encountering strangers rather than familiar group members. Changes in social hierarchy, the death of key individuals and even disease outbreaks may have contributed to the breakdown of group cohesion.
While chimpanzees have long been known to attack rival groups, this kind of sustained in-group violence is very rare. Scientists also warn that environmental pressures such as deforestation or climate change could increase the likelihood of similar conflicts in the future.