Some Chimpanzees Crack Nuts Better than Others, New Study Shows

A team of researchers has observed notable differences in the nut-cracking abilities of chimpanzees within the same group, shedding light on their tool-using behaviours. This discovery emerged after analysing extensive video footage of wild chimpanzees from Bossou, Guinea. The footage captured 3,882 instances of chimps attempting to crack open nuts using stones as tools. The study highlighted distinct levels of efficiency among individuals, suggesting varying degrees of cognitive and motor skills within the community.

According to the study published in Nature Human Behavior, the research team, which included experts from the University of Oxford and Chubu Gakuin University, evaluated five key factors to measure the chimps’ abilities. These included the time taken to crack a nut, the number of strikes needed, success rates, instances where a nut was displaced during striking, and occasions when a chimpanzee abandoned one rock in favour of another.

The process of nut cracking involves several steps, including selecting appropriate nuts, positioning them on a flat rock, choosing a suitable stone as a hammer, and striking with sufficient precision and force. Despite the apparent simplicity, the task demands a combination of cognitive and physical skills.
Findings on Skill Variation

As per the study, marked differences were noted in the chimps’ success rates. While some individuals excelled, others struggled, taking twice as long or failing altogether. The analysis revealed that proficiency generally improved with age, and no significant difference was observed between male and female chimps in their skill levels.

The researchers believe these findings point to measurable cognitive variations within chimpanzee communities. This research underscores the complexity of chimpanzee behaviour and provides a window into their problem-solving capabilities, which may mirror early human technological advancements.