A group of chimpanzees in Uganda’s Kibale National Park has split off from each other in an onslaught of deadly violence.
While chimpanzees are known to kill strangers, researchers are troubled by the case because the Ngogo chimpanzees are directing violence at former friends and lifelong companions, according to news outlets.
The violence has occurred between adult males that grew up together and had cooperated their entire lives. Infants were also targeted.
Researchers say they think tensions may have begun in 2015 when the alpha male of the group was killed by another male, which triggered social clusters to avoid one another.
Then an illness in 2017 is said to have further destabilized the group when 25 chimpanzees, mostly infants, died.
After that, two distinct factions formed: the Western Group and the Central Group. The smaller Western group reportedly started attacking the Central group, but the latter never retaliated.
The chimps are known to attack each other by beating, biting, kicking and dragging.
The current attacks are just as brutal, with the confirmed death toll reaching 28 — seven adult males, one adolescent male and multiple infants — but the true number may be higher.
Researchers think the current violence may have been caused by the groups becoming larger, increasing the competition for food and mates.
A study published in the journal Science suggests that shifting social networks within chimp groups can cause conflict and violence. The researchers say that finding also may explain how division and collective violence emerge in human societies.
