Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Brazil.
Am J Primatol. 2010 Mar;72(3):270-5. doi: 10.1002/ajp.20771.
Capuchins (Cebus libidinosus) occupy areas of Caatinga in northeast Brazil. They consume the nuts of several species of difficult-to-open fruits (two species of Palmae and one species of Euphorbiacea) and are reported to use stones as hammers to crack open the nuts. This article describes the weight of hammers found on anvils and presumably used for nut-cracking by individuals in two groups of wild unprovisioned capuchin monkeys. Hammer weights ranged from less than 200 to over 3 kg. Based on a correlation between the type of broken nuts found at a site and the stones present on anvils, there was evidence that hammer weight differed according to nut size. These findings are consistent with experimental data recently published by Visalberghi et al. [Current Biology 19, 2009, DOI: 10.1016/j.cub.2008.11.064] and indicate that capuchins are capable of choosing stones of appropriate weight to effectively use pounding tools in natural environments without interference from humans.
卷尾猴（Cebus libidinosus）栖息于巴西东北部的塞拉多地区。它们食用几种难以打开的果实的坚果（两种 Palmae 和一种大戟科植物），并被报道会使用石头作为锤子来砸开坚果。本文描述了在两个无供应野生卷尾猴群体中，个体用于砸开坚果的锤子在砧石上的重量。锤子的重量范围从不到 200 克到超过 3 公斤。根据在一个地点发现的破碎坚果的类型与砧石上存在的石头之间的相关性，有证据表明锤子的重量根据坚果的大小而有所不同。这些发现与 Visalberghi 等人最近发表的实验数据一致[Current Biology 19, 2009, DOI: 10.1016/j.cub.2008.11.064]，表明卷尾猴能够在没有人类干扰的自然环境中选择合适重量的石头，有效地使用敲击工具。
