HIERARCHY INFLUENCE IN THE SOCIAL INTERACTION DYNAMICS OF Callithrix jacchus MALES IN NATURAL ENVIRONMENT.
Social networks; Dominance hierarchy; Callithrix jacchus.
Cooperation is an affiliative social interaction that brings a gain to all involved. In a social group, investment in this interaction provides a cooperative response as a direct result. In primates, affiliative social interactions reinforce the bonds between individuals in the group. There are also agonistic interactions, which refer to behaviors used in aggressive and submissive contexts, but these are less frequent in primates. Callithrix jacchus males play an important role in the relationship cooperation x competition in this species. In order to understand the interactions dynamics of more complex societies, many researchers use networks approach to find a refined design of social groups structural aspects. In this study, male subjects (adults and subadult) of a marmosets group were observed twice a month, as well their affiliative and agonistic behaviors were recorded. Affiliative behaviors (grooming and contact) were documented by the focal animal method, recording the duration and frequency of interactions, while agonistic behaviors (avoidance, escape, submission, intimidation and fight) and sexual behavior (mount) were documented by behavioral sampling. The collected data were used in the social network elaboration and other analyzes. The results showed that grooming and contact duration, and the aggressions frequency did not differ statistically. However, the affiliative behaviors frequency, grooming and contact, differs between males, with the dominant showing such behaviors more frequently. Sociograms show that affiliative dynamics and agonistic interactions between males differ. We have verified that the breeder and the second male in the hierarchy succession perform more agonistic displays for other individuals. The breeder also holds the largest number of affiliative interactions while the others are similar in these interactions. We found that there is a social interaction asymmetry involving C. jacchus males in the Caatinga environment, and this asymmetry is related to the dominance position occupied by the animal in the social group.