Scientists observe chimpanzees using human-like warfare tactic

Researchers have documented the tactical use of elevated terrain in warfare situations while observing on a daily basis two neighbouring communities of wild western chimpanzees in Tai National Park for three years.

On the boundary of dangerous territory, a troop of about 30 individuals engaging in a border patrol climbs a rocky hill to conduct reconnaissance. Detecting the sounds of adversaries a bit too close for comfort, the squad retreats. There is no reason to risk a fight with the odds against you.

It is a scenario that has unfolded innumerable times in the history of human warfare. But in this case, it involved not people but chimpanzees in Tai National Park in southwestern Ivory Coast, West Africa's largest protected area of rainforest.

Researchers said on Thursday they have documented the tactical use of elevated terrain in warfare situations while observing on a daily basis two neighbouring communities of wild western chimpanzees in Tai National Park for three years.

Information obtained during hilltop reconnaissance shaped whether the chimpanzees made forays into enemy territory, the study found, with these apes appearing more apt to do so when the risk of confrontation was lower. The study, the researchers said, records for the first time the use of this age-old human military strategy by our species' closest living relatives.

"It shows sophisticated cognitive and cooperative skills to anticipate where and when to go, and to act upon gathered information in a safe way," said University of Cambridge biological anthropologist Sylvain Lemoine, lead author of the study published in the journal PLOS Biology.

Inter-group violence is ubiquitous in chimpanzees, Lemoine said. Skirmishes occasionally occur in overlapping border areas.

"Chimpanzees compete for space, which encompasses food resources. Large territories are beneficial as it reduces within-group competition, and female reproductive rates are increased in larger territories," Lemoine said.