Humans were thought to be the only species capable of making or using tools. The foresight, imagination, and dexterity required for tool use and construction were thought to be absent from the non-human primates. That all changed in 1960 when Jane Goodall observed wild chimpanzees modifying sticks in order to extract termites from mounds. Now, not only are chimps and humans the only apes known to use tools, but gorillas and orangutans as well. Even monkey species such as the bearded capuchin and the long-tailed macaque have been reported to habitually use stones as tools in the wild. The monkeys used tools for digging and for cracking seeds.

University of Georgia psychologist Dorothy Fragaszy and co-researchers, have just published the first direct scientific report of tool use among a population of wild capuchin monkeys. Using heavy stones transported to an "anvil" site in northeastern Brazil, the cat-sized monkeys routinely crack palm nuts, which grow in clusters close to the ground. This is the first scientific report to confirm a behavior previously studied only in wild populations of chimpanzees.

The study, appearing in the American Journal of Primatology adds important new information to the increasing body of knowledge that human beings are not the only primates who use tools. At one time, the use of tools was considered an important difference between humans and other primates.

"we see the behavior in an entire population and not in isolated individuals," said Fragaszy. "Also, it is the first time this behavior has been observed in wild capuchins. What we found is that these capuchins are extremely skilled weightlifters. The video we took  shows just how remarkable their ability to lift these stones has become."