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To evaluate how constant the form of agonistic interactions in the event of environmental changes is, a group of 11 stumptailed macaques, formed shortly before the start of the study, was observed under the following spatial conditions: in 10 and 18 m[sup2] cages, and in a 50,000 m[sup2] woodland. Results showed that the frequency of agonistic interactions was little affected by spatial density; however, the number of participants involved in aggressive interactions increased in the cage. Formal biting, which presumably acts as a regulator of social tension, was less frequent in the park. Patterning of agonistic interactions was little affected by spatial density. Such "robustness" makes the form of aggression liable to be used as a potentially useful parameter in interspecific comparisons. [ABSTRACT FROM AUTHOR]

Patterns of aggression and response to aggression were studies in three groups of macaques living in semiliberty, each group representing a different species: Macaca mulatta, M fascicularis, and M tonkeana. In Macaca mulatta, intensity of aggression is high (biting is frequent) and symmetry in aggression is low: the aggressee most often flees or submits. In Macaca tonkeana, in contrast, biting is exceptional, aggression is very often bidirectional, and appeasement behaviors are frequently observed. Intermediate patterns are found in Macaca fascicularis with, in addition, especially frequent mild forms of submission. It is argued that relationships exist between intensity of aggression, symmetry in aggression, and development of behaviors controlling aggression. Whether balances between these variables are species-specific is discussed. [ABSTRACT FROM AUTHOR]

The clumped distribution of food resources promotes food defensibility and can lead to the monopolizing of resources by high-ranking individuals. However, the balance of power is set at different levels according to societies, meaning that resource partitioning should vary between them. This study investigates whether dominance asymmetry and resource partitioning are related in non-human primates by comparing two species with contrasting social styles, namely rhesus macaques (Macaca mulatta) which display strong social intolerance and a steep gradient of dominance, and Tonkean macaques (Macaca tonkeana), which exhibit higher levels of tolerance and more balanced dominance relationships. Study groups were kept in semi-free ranging conditions. Animals were provided with fruit in three different clumped conditions during 30-min trials. We found that higher-ranking rhesus macaques had priority for the access to fruit: these individuals spent longer in the feeding area in the first 10-min period of trials, while lower-ranking individuals had diminished access to fruit under the most clumped condition; this was associated with sustained agonistic interactions. Dominance effects were weaker in Tonkean macaques. They exhibited co-feeding between high- and low-ranking individuals in the first period; there was no significant effect of dominance even in the most clumped condition; and frequencies of agonistic interactions remained moderate relative to the number of individuals present in the feeding area. These results show that food resources were more equitably distributed among group members in tolerant macaques than in their intolerant counterparts. Dominance gradient and social tolerance may be considered as two aspects of the same phenomenon., (© 2017 Wiley Periodicals, Inc.)