Author(s):
Biro, Dora 
; Inoue-Nakamura, Noriko ; Tonooka, Rikako ; Yamakoshi, Ren ; Sousa, Cláudia ; Matsuzawa, Tetsuro
Date: 2003
Persistent ID: http://hdl.handle.net/10362/2608
Origin: Repositório Institucional da UNL
Subject(s): Chimpanzees (Pan troglodytes verus); Tool use; Social transmission; Culture
Description
Animal Cognition, V.6, pp. 213-223 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 nutcracking
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 intercommunity migration, these results demonstrate a mechanism
for the emergence of culture in wild chimpanzees.
