Ontogeny and cultural propagation of tool use by wild chimpanzees at Bossou, Guinea: Case studies in nut cracking and leaf folding

Abstract

The discovery more than four decades ago that wild chimpanzees habitually made and used tools (Goodall 1964) helped to put a fairly abrupt end to the notion that tool use was a defining characteristic unique to humans.Since then, reports of the skilful use of tools from a wide variety of primate and non-primate species have been accumulating steadily.As somewhat of a parallel, initial observations on the establishment and spread of sweet-potato washing behaviour by Japanese monkeys on Koshima island (Kawai 1965) as well as McGrew and Tutin's (1978) original report on regional differences in wild chimpanzee behaviour have been elaborated to such an extent since then (McGrew 1992;Whiten et al. 1999, 2001) that the issue of "culture" in nonhuman primates has become one of the hottest topics in current primatology. The debate centres on behaviours spanning the tool-using, self-maintenance, and social domains, and which are shared by individuals within specific communities but are known to be absent from or assume different forms in other communities. Such regional variation,when it cannot be explained by ecological or genetic factors, gives rise to questions about processes underlying the emergence,maintenance,and propagation of community-specific behaviours as well as the terminology used to describe them.