Social styles in semi-free-ranging Macaca tonkeana and Macaca fascicularis

The species of the Macaca genus are classified into four social styles based on aggression and affiliative patterns, as well as their phylogenetic relationships. However, some studies suggest that social parameters can change under different local conditions, particularly in semi-free-ranging environments. The aim of our study was to examine whether the social parameters (aggression, affiliative behaviors and spatial distribution) of two groups of macaques in semi-free-ranging conditions aligned with their expected social styles. We studied a group of Macaca tonkeana (nine individuals), which the social style expected is high tolerant, and a group of Macaca fascicularis (nine individuals), which the social style expected is low tolerant. Our results indicated that some social parameters in these groups did not conform to the expected parameters. M. tonkeana exhibited lower tolerance than expected, while, conversely, the aggression patterns of M. fascicularis resembled more tolerant behaviors. These findings suggest that group characteristics, such as semi-free-ranging conditions, should be considered when analyzing social parameters like aggression, affiliative behavior, and spatial distribution.