Chimpanzees in Uganda Engaged in Brutal 'Civil War'

Fri Apr 10 2026 19:55:00 GMT+0000 (Coordinated Universal Time)

Research reveals the alarming split of the Ngogo chimpanzee community in Kibale National Park, resulting in violence and killings among members.

For the past eight years, the Ngogo chimpanzees in Uganda have been embroiled in a violent conflict, leading to the death of several individuals, including infants. The study highlights how shifts in dominance and social disruptions may provoke intense territorial aggression, shedding light on the implications for understanding human conflict.

The world's largest known group of wild chimpanzees has split and been locked in a vicious civil war for the last eight years, according to researchers.

It is not clear exactly why the once close-knit community of Ngogo chimpanzees at Uganda's Kibale National Park are at loggerheads, but since 2018 the scientists have recorded 24 killings, including 17 infants.

These were chimps that would hold hands, lead author Aaron Sandel said. Now they're trying to kill each other. The study, published in the journal Science, says the intensity and duration of the violence may inform how early human conflict developed.

Sandel, an anthropologist from the University of Texas in the US, and co-director of the Ngogo Chimpanzee Project, says chimpanzees are very territorial and have hostile interactions with those from other groups. [It's] like a fear of strangers, he told the Science podcast.

Despite this, Sandel noted that the nearly 200 Ngogo chimpanzees had lived in harmony for decades, being divided into two sets known as Western and Central, yet they existed overall as a cohesive group. The divide, he observed, began in June 2015, when the Western chimpanzees fled and were pursued by the Central group.

Following the 2015 dispute, researchers observed that a six-week avoidance period ensued between the two sets, with interactions becoming increasingly infrequent and aggressive.

Since the split, the Western group has launched targeted attacks on the Central chimpanzees, leading to the deaths of at least seven adult males and 17 infants. The researchers suggest that various factors contribute to the conflict, including increased competition for resources and mating opportunities.

Three major events are believed to have catalyzed the violence: the unexplained deaths of five adult males and one female in 2014, a change in alpha male the following year, and a respiratory epidemic in 2017 that decimated the population.

Sandel and his colleagues believe these findings challenge existing notions of human conflict and warfare, noting that chimpanzees can exhibit lethal group aggression without constructs such as religion or politics. Researcher James Brooks emphasized the relevance of these studies for understanding human society, urging a perspective that considers the impactful nature of group divisions.