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On a compare chez le macaque rhesus et le macaque de Tonkean (Macaca mulatta, M. tonkeana) les contacts positifs qui surviennent apres conflit entre de precedents adversaires. Le premier contact survient generalement dans la premiere minute qui suit le conflit. La tendance conciliatoire entre femelles non apparentees se revele cinq fois plus elevee chez le macaque de Tonkean par rapport au macaque rhesus. Ceci reste vrai dans les autres categories d'âge et de sexe. La tendance conciliatoire est semblable pour les partenaires apparentes ou non apparentes chez le macaque de Tonkean. Elle est plus importante entre partenaires apparentes chez le macaque rhesus. Ces resultats indiquent que les comportements de reconciliation covarient avec les differences interspecifiques mises en evidence dans les comportements d'agression et de dominance des macaques.

The exchange of information regarding the environment is continuous within social groups of non-human primates. As an outcome, knowledge and decisions are socially distributed. However, we lack evidence regarding the processes through which collective achievements are produced. The study aimed to analyze group performance in Tonkean macaques (Macaca tonkeana) in an experimental foraging task. Eight young individuals were used as subjects. They were released in a 1-acre wooded area during 5-min tests either singly or in subgroups of two, three or four individuals. They had to discover a fruit, whole or in scattered portions. The fruit was to be found either alone or in company of a snake. Results showed that subgroups located baited spots generally sooner than single individuals. The number of spots visited until finding the incentives was weaker as the number of subjects increased. Snake presence could increase finding latency and induce more cohesion among individuals. The balance between competition and snake effects appeared to differ between sexes. Performances improved through conspecifics' visual monitoring, stating the role of information transmission in the foraging task. While subjects behaved selfishly and did not actively communicate, subgroups proved to be effective information units and everyone of their members obtained benefits from them. Cognitive performances occurred in situation, they should be assessed simultaneously at the individual and group levels.

Patterns of aggression and reconciliation were studied in three captive groups of monkeys belonging to different species: Japanese macaques (Macaca fuscata), crested macaques (M. nigra) and Guinea baboons (Papio papio). Consistent differences were found comparing same dyads of individuals in the three groups. Aggression was often followed by retaliation and reconciliation in the group of crested macaques, such responses occurred less frequently in the group of Japanese macaques, more variable results were found in the group of Guinea baboons. Aggressive manual contacts occurred more frequently in crested macaques than in the other two groups. Rates of biting did not differ consistently among groups but bites could induce bleeding in the group of Japanese macaques. The use of peaceful interventions in conflicts was common in crested macaques, rare in Guinea baboons and unobserved in Japanese macaques. Data from other studies indicate that the contrasts found between groups could be due to interspecific variation. The present results suggest that the covariation between conciliation rates, degree of symmetry in conflicts and level of intensity in aggression may stem from phylogenetic constraints.

Possession of objects was studied in a captive group of kin-related brown capuchin monkeys (Cebus apella). Following introduction of an object by the experimenter, social interactions around the object were recorded during 15 min, focussing on takeovers, taking at distance and forced relinquishments. Results showed that individuals behaved according to tactical factors such as value and portability of objects. However, possession by subordinates could remain unchallenged by higher-ranking individuals and the latter tolerated some takeovers by subordinates. To account for such patterns, it is assumed that the dominants' behaviour is sometimes limited by the risk of altering the current state of their social relationships.

Clasping 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.