Chimpanzees Display Varying Nut-Cracking Skills, Study Shows

• Ene 8, 2025 - 15:36

A team of anthropologists from the University of Oxford's School of Anthropology and Museum Ethnography, along with a collaborator from Chubu Gakuin University in Japan, has found that not all chimpanzees in the same group are equally skilled at cracking nuts. Their study, published in Nature Human Behavior, delves into the varying abilities of chimpanzees to crack open nuts, based on thousands of video-recorded attempts.

Previous research has demonstrated that some chimpanzees use rocks as tools to crack nuts, allowing them to access the edible insides. This new study aimed to explore whether there were differences in nut-cracking ability within a single chimpanzee community. The team analyzed 3,882 attempts by 21 wild chimpanzees to crack nuts, with videos recorded by researchers studying the chimpanzees in Bossou, Guinea, from 1992 to 2017.

Successfully cracking a nut involves several steps: selecting a nut that can be cracked, positioning it properly on a flat rock, choosing an appropriate rock to use as a hammer, and striking the nut with the right force to break it open. The ability to crack nuts is an example of chimpanzees using tools.

To assess the chimps' nut-cracking skills, the researchers focused on five factors: time taken to crack the nut, number of strikes needed, success rate, frequency of a strike moving the nut, and instances when a chimpanzee abandoned a rock to find another. Upon reviewing the footage, the team found significant variation in the chimps' abilities. Some were highly skilled, while others were notably inefficient, taking twice as long as the average chimpanzee. The study also revealed that the chimps’ skills tended to improve with age, and both male and female chimps demonstrated equal proficiency.

The researchers propose that these differences in nut-cracking abilities may reflect measurable variations in cognitive abilities among chimpanzees within a single community.

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