This site contains information about Tufted capuchin monkey.
The tufted capuchin has been observed manufacturing tools both in captivity and in the wild. In captivity, it has been reported as making probing sticks to reach normally inaccessible containers with syrup. It is also capable of understanding the concept of "sponging" and using paper towels, monkey biscuits, sticks, leaves and straw to sop up juice and then suck on the sponge to consume the juice. Research in the wild has shown that capuchin tool use is every bit as extensive as in captivity with capuchins being observed using stones to dig holes to get at tubers, an activity previously only seen in humans. The practice of using stones to crack nuts has arisen spontaneously in many locations such as in the Caatinga Dry Forest and Serra da Capivara National Park, all in Brazil and hundreds of miles apart. It has been observed cracking various nuts and fruits such as palm nuts (Attalea and Astrocaryum spp. ) and jatobá fruits. (Hymenaea courbaril) The tufted capuchin has even been observed using stones to dislodge other stones that would later be used as hammers or shovels, an example of a more complex tool using behavior known as second-order tool use previously only found in chimpanzees. Curiously, not all tufted capuchins engage in tool use. Moura and Lee (2004) suggest lack of other food sources as the key factor. Ottoni and Mannu (2001), Fragaszy et al. (2004) and Visalberghi et al. (2005) have proposed this is likely more a factor of a monkey's terrestrial habit: the more time a monkey spends on the ground, the more likely it is to profit from (and thus engage in) tool use.