Wild capuchins carefully choose the most effective stones for cracking nuts, suggesting primates used stone tools earlier than thought
Wild capuchin monkeys don’t thoughtlessly grab any handy piece of stone to crack open hard-shelled nuts at snack time. These slender, agile primates select the best tool for the job, a new study finds.
Much like people, capuchins translate past experiences into action, say primatologist Elisabetta Visalberghi of the Institute of Cognitive Sciences and Technologies in Rome and her colleagues. These monkeys draw on a reservoir of knowledge about a variety of stones and nuts to select suitable nut-cracking implements, the scientists assert in a study published online January 15 in Current Biology.
Capuchins make mental plans for fracturing a particular nut before selecting an appropriate stone for the task, Visalberghi’s team proposes.