Since a first systematical study on postconflict behaviour in chimpanzees of Arnhem colony (de Waal & van Roosmalen 1979), many researchers have examined conflict management strategy following aggression in this species, both in captive (Detroit Zoo & Yerkes Field Station) and in wild (Budongo Forest in Uganda & Tai Forest in Cote d'Ivore). Although reconciliation (a post-conflict affiliation between former opponents soon after the conclusion of a conflict) was consistently seen in all of previous studies, other kinds of post-conflict behaviour were not always confirmed. For example, 'consolation' (a post-conflict affiliation towards a victim of aggression initiated by a third party) was regularly performed in Yerkes, but was absent in Budongo Forest. Comparing macaque species whose postconflict behaviour repertoire did not differ dratistically according to the living condition, intraspecific variation in post-conflict bahavior may evidence a great behavioral plasticity in chimpanzees.
In my talk, I will present my study of post-conflict behaviour in wild chimpanzees at Mahale Mountains, Tanzania. Based on comparison of more than 200 postconflict behaviour (PC) data to matched-control (MC) data, I found that Mahale chimpanzees engaged in various postconflict behaviour, some of which were not reported in previous studies. Most cases of reconciliation occurred in the first two minutes, and chimpanzees reconciled roughly one in seven conflicts. 'Consolation' was common in this group, suggesting that absence of 'consolation' is not a characteristic of wild population. Based on this result, I will discuss intraspecific variation and factors producing this variation.

Kutsukake, N. 2000. Matrilineal rank inheritance varies with absolute rank in Japanese macaques. Primates. 41: 321-335
Kutsukake, N. & Castles, L. D. 2001. Reconciliation and variation in postconflict stress in Japanese macaques. Animal Cognition. 4: 259-268

KUTSUKAKE, Nobuyuki
JSPS Research Fellow
Department of Cognitive and Behavioral Science, Graduate School of Arts and Sciences, The University of Tokyo
Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902, Japan
kutsu@darwin.c.u-tokyo.ac.jp