Chimpanzee ‘Civil War’ in Uganda: Chimpanzees Enter Prolonged Conflict After Group Breaks Apart, Scientists Don’t Have Answers

A long-term study of wild chimpanzees in Uganda has documented an unusual and prolonged wave of lethal conflict after a large social group fractured into two rival factions. Researchers report that the violence, described as a form of “civil war,” has resulted in multiple killings, infanticide, and continued attacks over several years in Kibale National Park.

The findings, published in the journal Science, are based on decades of observation of the Ngogo chimpanzee community, once numbering around 200 individuals. Scientists say the split and subsequent conflict offer rare insight into how social breakdown within animal groups can escalate into sustained violence. ‘Pink’ Elephant Photoshoot in Jaipur by Russian Artist Julia Buruleva Triggers Outrage, Animal Died a Month Ago.

A Rare Split in a Large Chimpanzee Community Leads to 'Civil War'

The Ngogo chimpanzee community, one of the most extensively studied groups of Pan troglodytes, had long been observed forming fluid sub-groups that interacted across a shared territory. Over time, however, researchers noted the emergence of tighter cliques, particularly among certain adult males.

By around 2015, the once-unified group began dividing into two distinct factions that gradually reduced cooperation. Although some social ties initially remained, by 2018 most interactions between the groups had broken down, and aggression during territorial patrols became more frequent. Is Jonathan the Tortoise Dead? Fact Check Debunks the Death Hoax Going Viral on Social Media.

Escalation Into Lethal Violence

Following the split, researchers recorded a sustained period of attacks between the two factions. These included coordinated raids that resulted in the deaths of adult males and, starting in 2021, cases of infanticide. Scientists involved in the study say the true number of deaths is likely higher than recorded, as some individuals disappeared without confirmation of their fate.

Researchers have continued to observe aggressive encounters beyond the formal study period, with reports of further attacks extending into 2025 and 2026.

Possible Triggers Behind the Conflict

Scientists have not identified a single cause for the breakdown, but several contributing factors have been proposed. These include the unusually large size of the community, competition over resources, leadership changes, and the impact of disease outbreaks that reduced population stability.

One notable disruption was a respiratory epidemic in 2017 that killed multiple individuals, followed by shifts in dominance among adult males. Researchers suggest these pressures may have weakened long-standing social bonds.

What Researchers Say About 'Civil War' Label

Lead researcher Aaron Sandel said the term “civil war” is used cautiously to describe violence between individuals that previously belonged to the same social group. He emphasised that chimpanzees do not form political or national identities, but the conflict reflects a breakdown of long-standing social networks.

Other primatologists note that while similar fission events have been observed before, most famously in studies by Jane Goodall in Gombe, Tanzania, such prolonged and lethal internal conflict remains rare.

Experts say the findings highlight how group dynamics can shift rapidly under environmental and social stress, even among highly intelligent species. However, researchers caution against drawing direct parallels with human conflict. While chimpanzees and humans share evolutionary traits, scientists note that closely related species such as bonobos exhibit more stable and less lethal intergroup behavior.

(The above story first appeared on LatestLY on Apr 10, 2026 09:39 AM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).