Apes in a Human World

Kimberley Hockings, a postdoctoral researcher in Hill’s lab, has spent more than a decade studying the chimpanzee community that lives in the hills surrounding Bossou, a small town in southeastern Guinea. The chimps there regularly raid farms and orchards, absconding with oranges, bananas, corn, cassava, and other delicacies. But stealing human food is a risky proposition, and farmers who discover the interlopers may harass, chase, or attack them. The Bossou chimps have learned to keep quiet while out on their heists; they vocalize significantly less when pilfering crops than when foraging for wild food, Hockings found. They also form more cohesive groups, staying in closer physical proximity to their comrades when ransacking fields. The chimps are also adept at judging the risks presented by roads, waiting longer to cross a large, busy road than a smaller, less trafficked one. Some of the animals have even learned how to deactivate hunters’ wire snares: a team of Japanese researchers once watched as an alpha male clambered down a tree and shook a snare until it broke.
 Further study of the Bossou chimps—and other apes that live in human-influenced habitats—may reveal more about how they detect and respond to risks, as well as their behavioral and cognitive flexibility in rapidly changing environments. continue