After-Effects of Allogrooming On Proximity and Locomotion in Pairs of Stumptailed Macaques (Macaca Arctoides)

Abstract

AbstractLaboratory experiments in pairs of stumptailed macaques were aimed at testing the hypothesis that allogrooming behaviour causes a subject to remain close to the partner for a certain period of time. In that case, allogrooming could indeed be regarded as a cohesive force among members of a socially living, natural group. In the experiments, six females were used as subjects; six males were used as partners. Recording concerned various behaviour items (allogrooming, proximity, locomotion, among others) of a subject during her stay in the observation cage. The partner could be present in a compartment adjacent to the observation cage but separated from it by a plexiglass partition sheet. Three experimental situations, each lasting 15 minutes, were used: t) tactile partner situation in which allogrooming could occur through a slit in the plexiglass sheet between subject and partner; v) visual partner situation, with the partner present behind a sheet without slit; and n) no partner situation when the compartment is empty. These situations occurred during two immediately following observations. The order being so as to enable study of 1) effect of differences in immediate situation; 2) changes with time; 3) effects from differences in previous experience. Results confirmed earlier findings that the visual presence of a partner induces in the subject a tendency to be close to the partner and that, if allogrooming is permitted, proximity is enhanced as a consequence of allogrooming. However, there was no evidence in support of the hypothesis that, after allogrooming the partner for some time, the subject would be more in proximity to the male than after it had had no such allogrooming experience. The results showed rather an opposite trend to less proximity and more walking after having groomed a partner for some time, suggesting that the subjects sought contact with the animals in the normal housing quarters which had been left just prior to the beginning of the observations. In view of this, it seems that, if allogrooming acts as a cohesive force between members of a natural group, it docs not act directly upon a tendency to remain close to the (former) allogrooming partner.