Capuchin monkeys remember tools' past uses, study finds

Bearded capuchin monkeys in Brazil exhibit a remarkable level of cognitive skill when it comes to tool use, particularly in cracking cashew nuts. A study published in 'Proceedings of the Royal Society B: Biological Sciences' reveals that these primates do not merely select tools based on material but also recall their previous effectiveness.

The process of cracking cashew nuts is a serious undertaking for these monkeys, requiring careful selection of stones to serve as an anvil and a hammer. They must then precisely position the nut on the anvil and strike it with the hammer stone in the correct location and with appropriate force. Mastering this complex technique is an art that takes the monkeys years to perfect.

Scientists from the Max Planck Institute and the University of São Paulo investigated this behavior by presenting different nut-cracking stations to semi-wild capuchin populations. The findings suggest that the monkeys' choice of tools is influenced by their past experiences, indicating a form of tool memory. This implies a deeper understanding of the physical properties of the stones and how they have been used successfully before.

This research highlights the sophisticated cognitive abilities of capuchin monkeys, demonstrating their capacity for learning, memory, and problem-solving in a practical, tool-based context. Their ability to remember and apply past tool usage underscores the complexity of animal intelligence and tool behavior in the natural world.