Overview
- The peer-reviewed study, published Thursday in Science, details a permanent 2018 split of the Ngogo chimps into Western and Central groups followed by years of lethal raids.
- Researchers report at least seven adult males and 17 infants from the Central group killed between 2018 and 2024, and they say unexplained disappearances likely mean the true toll is higher.
- All recorded attacks were carried out by the smaller Western group, whose population grew as the Central group declined, and field teams say the conflict is still ongoing.
- The findings draw on three decades of demographic records, a decade of GPS data, and 24 years of close behavioral observation to track the rupture and its consequences.
- The authors outline possible drivers—an unusually large community, the deaths of key “bridge” males, a new alpha male, and rising competition—but stress that causes remain unresolved, and they note such splits are estimated to occur only about once every 500 years.