A violent territorial conflict has broken out between two rival chimpanzee groups in Kibale National Park in western Uganda. Scientists believe the clash is unlike anything they have seen before.
Researchers have been studying the Ngogo chimpanzee community since 1995. The group, once numbering over 100 individuals, is among the largest ever recorded in the wild, according to The NY Times.
About a decade ago, the large community split into two separate factions. Since then, these groups have been locked in a violent battle over territory.
"The Ngogo chimps were victims of their own success. The group continued to grow and grow and grow, and it reached the size that individuals couldn't pull together anymore," said John Mitani, a primatologist at the University of Michigan.
Male chimpanzees in Ngogo group formed strong alliances over the years. They hunted in teams and guarded their territory as one unit. Over time, the chimpanzee group grew to around 200 animals. Instead of staying together all the time, they moved around the forest in smaller sub-groups to find food.
When these smaller groups met, they didn't fight. Instead, they behaved in a friendly way such as grooming each other, relaxing together, and acting like one big family again. A chimpanzee could even move from one group to another multiple times in a single day but each chimpanzee still had a "main group".
Scientists divided these into three clusters, Western, Central, and Eastern, based on where the chimpanzees spent most of their time. But in 2015, when Central cluster met with Western cluster, they became aggressive almost instantly.
"The chimpanzees started screaming loudly and attacking each other. The Western group eventually ran away, while the Central group chased them," said Dr Mitani. At first, scientists thought this was just a one-time fight. But in the following years, such clashes became more frequent. By 2018, the fights had become deadly, with chimpanzees being killed.
Researchers saw chimpanzees from the Western group kill at least seven adult males and 17 babies from the Central group between 2018 and 2024.
During the same period, 14 teenage or adult males from the Central group went missing. Their bodies were never found. Scientists say these chimpanzees were healthy before they disappeared, so it's likely that some of them were also killed in these attacks.
"All of a sudden, yesterday's friend becomes today's foe," said Dr Mitani.
In the White House's proposed 2027 budget, funds for the National Science Foundation would be reduced by more than half. The agency supports many research projects, including studies on animal behaviour and human cognition.
Scientists warn that if these cuts actually happen, long-running research sites like the Ngogo chimpanzee project could be lost.
