Biro Dora, Inoue-Nakamura Noriko, Tonooka Rikako, Yamakoshi Gen, Sousa Claudia, Matsuzawa Tetsuro
Primate Research Institute, Kyoto University, Japan.
Anim Cogn. 2003 Dec;6(4):213-23. doi: 10.1007/s10071-003-0183-x. Epub 2003 Jul 29.
Chimpanzees (Pan troglodytes) are the most proficient and versatile users of tools in the wild. How such skills become integrated into the behavioural repertoire of wild chimpanzee communities is investigated here by drawing together evidence from three complementary approaches in a group of oil-palm nut- ( Elaeis guineensis) cracking chimpanzees at Bossou, Guinea. First, extensive surveys of communities adjacent to Bossou have shown that population-specific details of tool use, such as the selection of species of nuts as targets for cracking, cannot be explained purely on the basis of ecological differences. Second, a 16-year longitudinal record tracing the development of nut-cracking in individual chimpanzees has highlighted the importance of a critical period for learning (3-5 years of age), while the similar learning contexts experienced by siblings have been found to result in near-perfect (13 out of 14 dyads) inter-sibling correspondence in laterality. Third, novel data from field experiments involving the introduction of unfamiliar species of nuts to the Bossou group illuminates key aspects of both cultural innovation and transmission. We show that responses of individuals toward the novel items differ markedly with age, with juveniles being the most likely to explore. Furthermore, subjects are highly specific in their selection of conspecifics as models for observation, attending to the nut-cracking activities of individuals in the same age group or older, but not younger than themselves. Together with the phenomenon of inter-community migration, these results demonstrate a mechanism for the emergence of culture in wild chimpanzees.
黑猩猩（Pan troglodytes）是野生环境中最熟练、最多才多艺的工具使用者。本文通过整合来自几内亚博苏一群以油棕榈坚果（Elaeis guineensis）为食的黑猩猩的三种互补方法的证据，研究了这些技能如何融入野生黑猩猩群体的行为模式。首先，对博苏周边群体的广泛调查表明，工具使用的特定群体细节，如选择坚果种类作为砸开的目标，不能单纯基于生态差异来解释。其次，一项长达16年追踪个体黑猩猩砸坚果行为发展的纵向记录突出了学习关键期（3至5岁）的重要性，同时发现兄弟姐妹经历的相似学习环境导致了后期在偏侧性上近乎完美的（14对中有13对）兄弟姐妹对应关系。第三，来自野外实验的新数据，涉及向博苏群体引入不熟悉的坚果种类，揭示了文化创新和传播的关键方面。我们表明，个体对新物品的反应随年龄显著不同，幼崽最有可能进行探索。此外，受试者在选择同种个体作为观察对象时非常有针对性，关注同年龄组或比自己年龄大但不比自己小的个体的砸坚果活动。连同群体间迁移现象，这些结果证明了野生黑猩猩文化出现的一种机制。
