Clasping Behaviour in Macaca Tonkeana

Abstract

AbstractClasping behaviour was studied in two groups of Macaca tonkeana, one being confined in a cage, the other living in a half-hectare park. Five patterns have been distinguished: grasping the hindquarters, grasping, reaching around, embracing and hugging. Clasping may occur in three contexts: greeting, aggression and sexual harassment. There seems to be no direct relationship between context and pattern of clasping. However, there is substantial variation in form and context according to age- and sex-class. Females are the individuals mostly involved in clasps, being initiators as well as receivers; adult males also initiate numerous clasps but receive few. Adult and subadult males especially use grasping the hindquarters while other age- and sex-classes more often use reaching around. Clasping in aggression is more characteristic of females than males. Several behaviours may be associated with clasping. The accompanying behaviours are more frequent in initiator than in receiver. Clasp is often followed by social grooming, mount, wrestle or another clasp. The results of this study in Macaca tonkeana may be compared with information from other studies of non-human primate species. This allows one to draw several conclusions: 1. Frequency, form and distribution of clasping vary from one species to another. There is great variation in certain species, for instance, Macaca tonkeana. 2. Several behaviours usually accompany clasping and may modulate its meaning. 3. Clasping behaviour shows many similarities to mounting behaviour. Although these two behaviours have different origins, they have acquired similar social functions. 4. Clasping plays a prominent role in control of aggression. In Macaca tonkeana, this behaviour is especially used in appeasement (an individual receiving aggression clasps its aggressor during the aggression), reconciliation (an aggressor clasps its antagonist after the aggression) and non-agonistic protection (a third individual intervenes in an agonistic interaction by clasping the aggressor). Non-agonistic protection is an interaction which was until now described only in chimpanzees.