The war tactics of monkeys. Behaviors previously attributed solely to humans

Chimpanzees have demonstrated the use of intriguing war tactics that were previously thought to be exclusive to humans; they employ methods of surveillance on their enemies.

In the wilds of Western Africa, scientists have observed chimpanzees that utilize a unique method for monitoring enemy groups. These intelligent creatures climb to hilltops to follow the movement of potential adversaries, a tactic previously assumed to be unique to human strategy. This finding has been reported in the highly esteemed scientific journal, "PLOS Biology."

Within the dense forests of Western Africa, chimpanzees use the natural high ground to watch other groups of their species. Atop these hills, these primates can monitor the movements of different groups, a behavior unheard of and exceptional in the natural world. Until now, it has been widely believed that this tactic is unique to humans.

Scientists hypothesize that chimpanzees use this technique to avoid unnecessary, dangerous confrontations with rival groups. If their surveillance from the hilltops assures that no foreign groups are within a territory, they decide to explore that area.

A three-year scientific study on this topic focused on two neighboring chimpanzee groups in Côte d'Ivoire. The scientists observed these monkeys as they migrated across their territories, including those border areas where confrontations occasionally occurred.

The researchers found that the chimpanzees were more than twice as likely to climb hills when venturing towards these disputed territories than when moving deep within their areas. While situated on these border hills, they often refrained from making noise or exhibiting boisterous behavior, favoring quiet and calm. This tranquility allowed them to hear better distant sounds made by foreign groups.

Although other mammals like meerkats also use elevated terrain to spot predators or communicate with their groups, the researchers stress that this is the first recorded instance of a non-human animal using such a strategic approach for assessing intergroup conflict risk.

"The use of landscape for territorial control is deeply ingrained in our evolutionary history. Perhaps we can see a foreshadowing of the small-scale wars likely waged among prehistoric populations of hunter-gatherers in the tactical behaviors of these chimpanzees," explains Sylvain Lemoine, the lead author of the publication and a scholar from the University of Cambridge in the United Kingdom.