{"id":400109,"date":"2026-04-15T17:35:11","date_gmt":"2026-04-15T17:35:11","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/400109\/"},"modified":"2026-04-15T17:35:11","modified_gmt":"2026-04-15T17:35:11","slug":"the-unprecedented-civil-war-of-the-ngogo-chimpanzees","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/400109\/","title":{"rendered":"The Unprecedented Civil War of the Ngogo Chimpanzees"},"content":{"rendered":"

\"Group<\/a>Some Ngogo chimps. Credit: Aaron Sandel<\/p>\n

For twenty years, researchers watched the Ngogo chimpanzees of Uganda hold hands, groom each other, and share the forest as a single, massive community of nearly 200 apes. Then, something happened that tore their social fabric. Former companions splintered into two distinct, hostile factions, tracking down and killing their old friends in a brutal, years-long conflict.<\/p>\n

In a new study, researchers describe this permanent, violent split as an exceedingly rare event that complicates our understanding of primate aggression. While animal skirmishes over territory are common, a lethal \u2018civil war\u2019 among previously affiliated individuals has never been clearly documented outside of humans. <\/p>\n

The sheer scale of the bloodshed suggests the evolutionary roots of collective violence require no modern constructs like religion, ethnicity, or political ideology to ignite. <\/p>\n

The Day the Truce Broke<\/p>\n

\"Wild<\/a>Western group chimps surround and attack Basie (facing the camera), a 36-year-old male who belonged to the Central group. The encounter later killed Basie. His death was the second documented death within the \u2018civil war\u2019. RIP Basie. Credit: Aaron Sandel<\/p>\n

Chimpanzees normally adhere to a dynamic lifestyle that scientists call fission-fusion. Small parties drift apart to travel only to smoothly reunite later, often with joyous grooming and embracing. Like other large chimpanzee groups, the Ngogo community contained distinct subgroups, known as the Western, Central, and Eastern clusters, but individuals frequently crossed these invisible lines to mingle.<\/p>\n

On June 24, 2015, the Ngogo fractured definitively. A group of Western chimpanzees approached members of the Central cluster deep in the forest. Instead of their usual friendly mingling, the apes erupted into a screaming brawl. The Western chimpanzees broke rank and fled in panic, relentlessly pursued by the Central group.<\/p>\n

Watching the chaos unfold from the undergrowth, University of Michigan primatologist John Mitani told the New York Times<\/a> that \u201call hell broke loose.\u201d His colleague on the observation team, Aaron Sandel, a primatologist at the University of Texas, realized immediately that the fundamental social contract of the apes was failing. \u201cNothing like that had been observed before,\u201d Sandel told Scientific American<\/a>.<\/p>\n

A tense, six-week period of total avoidance followed. Usually, chimpanzee disputes end quickly. \u201cChimpanzees are sort of melodramatic,\u201d Sandel noted to the BBC<\/a>, explaining that typical fights involve \u201cscreaming and chasing\u201d followed by grooming and reconciliation. But this was not the case.<\/p>\n

By 2018, the rift became permanent. The two factions settled into separate territories. What was once the shared heart of their forest transformed into what looks to us like a militarized border. The Western group began conducting coordinated patrols into Central territory.<\/p>\n

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The ensuing violence shocked the observing scientists. Between 2018 and 2024, Western chimpanzees executed a string of brutal attacks, killing at least seven adult males and 17 infants from the Central group. Those are just the casualties that the researchers know of. The killers often outnumbered their victims in these ambushes, mercilessly dispatching apes they had known for years.<\/p>\n

Echoes of Human Warfare<\/p>\n

A huge ambush. Credit: Aaron Sandel.<\/p>\n

Jane Goodall reported a comparable split at Gombe in the 1970s, but because those chimpanzees were provisioned and observations were more limited, researchers say the case left key questions unresolved<\/a>.<\/p>\n

Researchers suspect Ngogo\u2019s massive population stretched its social networks to the breaking point. \u201cIf you\u2019re not engaging in those daily practices holding everything together, the social glue starts to fall apart,\u201d Catherine Hobaiter, a primatologist at the University of St. Andrews, told National Geographic<\/a>. <\/p>\n

A cascade of tragedies accelerated the collapse. Several deaths in 2014, including the loss of adult males that may have been linked the clusters, weakened social bridges. A respiratory outbreak in 2017 then killed 25 chimpanzees, mostly infants, further destabilizing the community.<\/p>\n

These grim events unfolding in the Ugandan canopy force us to confront uncomfortable questions about human nature. Anthropologists frequently attribute the brutality of human warfare to cultural divides, such as religion, language, or political ideology. The Ngogo conflict suggests that the social dynamics underlying collective violence may run deeper in our evolutionary history than cultural explanations alone can capture.<\/p>\n

But if raw relational dynamics drive conflict, then mending those relationships holds the key to averting war. \u201cHumans must learn from studying the group-based behavior of other species, both in war and at peace, while remembering that their evolutionary past does not determine their future,\u201d wrote James Brooks, a researcher at the German Primate Center, in an accompanying Perspective <\/a>for the journal Science.<\/p>\n

Sandel shared a similar outlook with Discover Wildlife<\/a>: \u201cIf relational dynamics alone can drive polarization and lethal conflict in chimps without language, ethnicity, or ideology, then in humans, those cultural markers might be secondary to something more basic.\u201d He concluded, \u201cIf that\u2019s true, then we may have the potential to reduce societal conflicts in our personal lives, and that gives me hope. It may be in the small, daily acts of reconciliation and reunion between individuals that we find opportunities for peace.\u201d<\/p>\n

The study was published in the journal Science<\/a>.<\/p>\n

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