Overview
- Researchers writing in Science in April 2026 report that a once cohesive Ngogo community in Kibale National Park, Uganda, divided into western and central groups that now carry out coordinated raids.
- The break first showed in 2015 as the groups began to avoid each other, then by January 2018 observers recorded the first confirmed killing and further lethal attacks followed.
- The study estimates the western group killed about 24 central chimpanzees, including 17 infants, which has driven a steep decline in the central subgroup.
- The authors point to several pressures that likely fed the rupture, including an unusually large community size, fiercer feeding and mating competition, deaths of key elder connectors in 2014, and a shift in the dominance hierarchy.
- Researchers say the violence is ongoing and unusually rare in long‑studied chimps, drawing comparisons to the 1970s Gombe conflict and raising concern that the central faction could disappear from the area.