https://www.bbc.com/news/articles/cr71lkzv49po Skip to content Watch Live * Home * News * Sport * Business * Technology * Health * Culture * Arts * Travel * Earth * Audio * Video * Live * Documentaries * Home * News + US & Canada + UK o UK Politics o England o N. Ireland # N. Ireland Politics o Scotland # Scotland Politics o Wales # Wales Politics + Africa + Asia o China o India + Australia + Europe + Latin America + Middle East + In Pictures + BBC InDepth + BBC Verify * Sport * Business + World of Business + Technology of Business + NYSE Opening Bell * Technology + Watch Documentaries + Artificial Intelligence + AI v the Mind * Health + Watch Documentaries * Culture + Watch Documentaries + Film & TV + Music + Art & Design + Style + Books + Entertainment News * Arts + Watch Documentaries + Arts in Motion * Travel + Watch Documentaries + Destinations o Africa o Antarctica o Asia o Australia and Pacific o Caribbean & Bermuda o Central America o Europe o Middle East o North America o South America + World's Table + Culture & Experiences + Adventures + The SpeciaList * Earth + Watch Documentaries + Science + Natural Wonders + Climate Solutions + Sustainable Business + Green Living * Audio + Podcast Categories + Radio + Audio FAQs * Video + Watch Documentaries + BBC Maestro + Discover the World * Live + Live News + Live Sport * Documentaries [ ] Home News Sport Business Technology Health Culture Arts Travel Earth Audio Video Live Documentaries Weather Newsletters Watch Live Chimpanzees in Uganda locked in vicious 'civil war', say researchers 6 hours ago ShareSave Add as preferred on Google Hafsa Khalil [grey-place]Aaron Sandel via Reuters A chimpanzee bearing its teeth at other chimpanzees with their backs to the camera in a forested area. Aaron Sandel via Reuters This shows adult male chimpanzees of one group attacking a male chimpanzee of another group in 2019 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. Wild chimpanzees filmed using forest 'first aid' 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. But over several decades, Sandel said the nearly 200 Ngogo chimpanzees had lived in harmony. There were divided into two sets - known to researchers as Western and Central - but they had existed overall as a cohesive group. Sandel said he first noticed them polarising in June 2015, when the Western chimpanzees ran away and were chased by the Central group. "Chimpanzees are sort of melodramatic," he said, explaining that following arguments there would ordinarily be "screaming and chasing" and then later, they would grooming and co-operating. But following the 2015 dispute, the researchers saw that there was a six-week avoidance period between the two sets, with interactions becoming more infrequent. When they did occur, Sandel said they were "a little more intense, a little more aggressive". Following the emergence of the two distinct groups in 2018, members of the Western group started attacking the Central chimpanzees. In 24 targeted attacks since the split, at least seven adult males and 17 infants from the Central chimps have been killed, the study found, although the researchers believe the actual number of deaths are higher. The researchers believe many factors such as the group size and subsequent competition of resources, and "male-male competition" for reproducing may be to blame. But they say there were three likely catalysts: * The first, were the deaths of five adult males and one adult female - for reasons unknown - in 2014, which could have disrupted social networks and weakened social ties across the subgroups * The following year, there was a change in the alpha male, which the study says coincided with the first period of separation between the Western and Central groups. "Changes in the dominance hierarchy can increase aggression and avoidance in chimpanzees," it explained * The third factor was the deaths of 25 chimpanzees, including four adult males and 10 adult females, as a result of a respiratory epidemic, in 2017, a year before the final separation. One of the adult males who died was "among the last individuals to connect the groups", the research paper said. Sandel and his colleagues said their findings encourage people to rethink what they know of human conflict and warfare. "In the case of the Ngogo fission, individuals who lived, fed, groomed and patrolled together for years became targets of lethal attacks on the basis of their new group membership," they wrote in the paper. If chimpanzees - one of the species closest to humans genetically - could do so without human constructs of religion, ethnicity and political beliefs, then "relational dynamics may play a larger causal role in human conflict than often assumed", they added. James Brooks, a researcher at the German Primate Center in Germany, said it was a "reminder of the danger that group divisions can present to human societies". Commenting on the study in Science, he wrote: "Humans must learn from studying the group-based behaviour of other species, both in war and at peace, while remembering that their evolutionary past does not determine their future." You may also be interested in: Chimpanzees 'self-medicate' with healing plants Forty years after the last one was poached, rhinos are back in the wild in Uganda [grey-place]Getty Images/BBC A woman looking at her mobile phone and the graphic BBC News AfricaGetty Images/BBC Go to BBCAfrica.com for more news from the African continent. Follow us on Twitter @BBCAfrica, on Facebook at BBC Africa or on Instagram at bbcafrica BBC Africa podcasts Focus on Africa This Is Africa Chimpanzees Animals Uganda Africa --------------------------------------------------------------------- Related Chimp rescued as a baby from circus abuse turns 30 Watch: Baby chimp doing 'really well' at zoo Zoo welcomes first newborn chimpanzee in 17 years --------------------------------------------------------------------- More from the BBC 5 hrs ago [grey-place]Footage shows the runaway wolf walking on a road in Daejeon, South Korea South Korea deploys thermal imaging cameras in search for escaped zoo wolf The male wolf, named Neukgu, escaped a zoo in the central city of Daejeon on Wednesday, officials said. 5 hrs ago 11 hrs ago [grey-place]Close-up of musician Sefu Shabani in a black bandana with a white design posing with his hands near his face. He is wearing a chunky gold chain necklace and bracelet. Popular Tanzanian musician Matonya charged with rape in Kenya The 43-year-old denies the charge and has been released on bail and had to surrender his passport. 11 hrs ago 15 hrs ago [grey-place]A man wearing sunglasses on his head with his arm around a woman. They are standing on the left and each holding a mini American flag. To their right, is an older woman. Behind her is a man. The background appears to be a black curtain. US has let in 4,499 refugees since October - all but three were South African Trump has given priority to Afrikaners, a white minority group he says is being persecuted. South Africa has objected to his characterisation. 15 hrs ago 24 hrs ago [grey-place]Voters at a polling station in Benin on 11 January to cast ballots in the parliamentary election Fears over West Africa's Islamist insurgency dominate Benin's election campaign Cross-border raids from militant Islamists are increasingly threatening the West African state's stability. 24 hrs ago 1 day ago [grey-place]A profile image of a Nigerian soldier in combat uniform standing on tarmac. He is holding a rifle and behind him, out of focus, a row of parked military vehicles can be seen. US warns citizens to reconsider Nigeria travel on safety grounds The state department has also authorised non-emergency embassy staff to leave on security grounds. 1 day ago --------------------------------------------------------------------- * Home * News * Sport * Business * Technology * Health * Culture * Arts * Travel * Earth * Audio * Video * Live * Documentaries * Weather * BBC Shop * BritBox BBC in other languages The BBC is in multiple languages Read the BBC In your own language Oduu Afaan Oromootiin Amharic zeenaa ba'amaarenyaa Arabic `rby Azeri AZ@RBAYCAN Bangla baaNlaa Burmese m[?]n[?]maa Chinese Zhong Wen Wang Dari dry French AFRIQUE Hausa HAUSA Hindi hindii Gaelic NAIDHEACHDAN Gujarati gujraatiimaaN smaacaar Igbo AKUKO N'IGBO Indonesian INDONESIA Japanese Ri Ben Yu Kinyarwanda GAHUZA Kirundi KIRUNDI Korean hangugeo Kyrgyz Kyrgyz Marathi mraatthii Nepali nepaalii Noticias para hispanoparlantes Pashto pStw Persian frsy Pidgin Polish PO POLSKU Portuguese BRASIL Punjabi pNjaabii khhbraaN Russian NA RUSSKOM Serbian NA SRPSKOM Sinhala siNhl Somali SOMALI Swahili HABARI KWA KISWAHILI Tamil tmilllil ceytikll Telugu telugu vaartlu Thai khaawphaasaaaithy Tigrinya zeenaa betegerenyaa Turkish TURKCE Ukrainian UKRAYiNS'KA Urdu rdw Uzbek O'ZBEK Vietnamese TIENG VIET Welsh NEWYDDION Yoruba IROYIN NI YORUBA Follow BBC on: * Terms of Use * Subscription Terms * About the BBC * Privacy Policy * Cookies * Accessibility Help * Contact the BBC * Advertise with us * Do not share or sell my info * BBC.com Help & FAQs * Content Index * Set Preferred Source Copyright 2026 BBC. All rights reserved. The BBC is not responsible for the content of external sites. Read about our approach to external linking.