Behaviour, biology and the social condition of Cercopithecus Aethiops, the Vervet Monkey.

Abstract

Biotelemetry has been coupled with an ethological approach to investigate a postulate that the physiological, behavioural, and social functioning of individuals coact in order to maintain homeostasis in an everchanging environment. Attention was focussed upon body temperature, behaviour, and the social situation, as they occurred together in each of five 'undisturbed' adult vervet monkeys. One male and one female were housed alone in single cages, and the other three, all females, were part of a natural troop that live together in captivity in a 6.5 metre radius geodesic dome. Intensive studies, including in-depth and multiple repeated measures at each level of functioning permitted comparisons between and within subjects, so that the connections between body temperature, and individual and social behaviour, could be scrutinised. Techniques for observation, data processing, and factor analysis have been considered, and procedures to facilitate the organisation and interpretation of information are suggested. The results pointed to individual variations superimposed upon a rhythmic underpinning of all the functions monitored. A synthesis of the data of body temperature with individual and social behaviour supports the contention that the individual responds to the vagaries of the environment as an integrated system within which the different levels of functioning are linked. It was found that the oscillation in body temperature was greater in the vervets that lived alone than in the vervets that lived in a troop. These results were supported behaviourally since the isolated subjects could only complement autonomic thermoregulatory responses with individually based behavioural strategies, whereas their troop-living conspecifics could utilise both individual and socially directed behavioural mechanisms. Within the troop an inverse relationship between body temperature variation and social status was revealed that is, the lower the status of the subject, the more the body temperature fluctuated around the mean. Behaviourally, it was found that the lower the status of the subject, the more difficult it became to gain access to resources, and to manipulate interpersonal space. In addition, harassment by troop conspecifics increased and, consequently, the efficiency with which behavioural patterns could be executed, was decreased. An analysis of the data also led to the proposal that social grooming has evolved as a thermoregulatory mechanism; to the identification of three different facets of individual behaviour and of social behaviour; and to the idea that the rhythmic changes in the troop's spatial conformation reflected cyclical patterns in behavioural and social activity.