Using remarkably heavy stones probably transported to an "anvil" site in northeastern Brazil, these cat-sized monkeys routinely crack palm nuts, which grow in clusters close to the ground. Though this nut-cracking behavior has been common knowledge among local residents for years, this is the first scientific report to confirm a behavior previously studied only in wild populations of chimpanzees.
The study was just published online as the cover story in the American Journal of Primatology and will be published in the hard-copy version of that journal later this month. Co-authors of the journal are Patricia Izar and Eduardo Ottoni of the University of So Paulo, Elizabetta Visalberghi of the Consiglio Nazionale delle Ricerche in Rome, and Marino Gomes de Oliveira of the Fundaco BioBrasil in Bahia, Brazil.
"One of the most significant things about this research is that we see the behavior in an entire population and not in isolated individuals," said Fragaszy, who is considered one of the world's top experts on capuchin monkeys. "Also, it is the first time this behavior has been observed in wild capuchins."
Another study, just published in the journal Science, also reports more generalized tool use among capuchins in a different area of Brazil.
Fragaszy has studied the small, agile primates for years, and she is co-author, with Visalberghi and Linda Fedigan of The Complete Capuchin, just published by Cambridge University Press. She was also president of the International Primatological Society from 2001 to 2004.