Dispersal and social structure in black capuchin monkeys (Sapajus nigritus) of Carlos Botelho State Park, São Paulo

Author(s)

Marcos Tokuda

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Psicologia (IP/SBD)
• Defense date: 2013-02-20

Examining board members

Patricia Izar Mauro; Cibele Biondo; Cristina Yumi Miyaki; Briseida Dogo de Resende; Noemi Spagnoletti

• Advisor: Patricia Izar Mauro; Milene Moura Martins

Abstract

Sex-biased dispersal patterns and kinship are related factors extremely important to understand the social structure of primates. In spite of their importance, little is known about how these factors affect individual behavior and the social structure of neotropical primates. Therefore, the aims of this research were: to determine the dispersal pattern of a wild population of black capuchin monkeys (Sapajus nigritus) through genetic analyses, and to verify the effect of kinship on the social structure of groups of S. nigritus. This research was conducted at Carlos Botelho State Park, in the municipality of São Miguel Arcanjo/SP. We used DNA from fecal samples of adult and subadult members from three wild social groups. DNA was amplified by Polymerase Chain Reaction and microsatellite molecular markers were used. Behavioral data were collected systematically for two groups, and we used scan sampling and ad libitum methods to record the behavior of adults. Genetic data indicated that both sexes disperse from their natal groups, since: 1) relatedness between males was not statistically different from relatedness between females, 2) there was no difference between males and females in population genetic differentiation, and 3) there was no difference between males and females in the probability of being born in the group from which they were sampled. The results of the spatial association and social interactions analysis indicate that females are little affiliative and do not form strong relationships among themselves. Adult males established weak relationships, being classified as tolerant, and characterized by no grooming interactions and by low frequency of agonism. The strongest social relationships observed within each group were between males and females. They associated and groomed more than female dyads and male dyads. Moreover, there were fewer agonistic interactions between males and females as compared to same sex dyads. Related and unrelated dyads showed similar rates of association and affiliative behavior. The low level of relatedness/familiarity might be an important factor contributing to the weak social relationship among females in the PECB. However, at the individual level, kinship had low influence on male and female social relationships. The results presented here extended our knowledge about social relationships of neotropical primates and about the factors that influence the relationships. The dispersal pattern and the social structure are flexible elements of social systems, and can vary among populations of the same species or among groups of the same population. In addition, male-biased dispersal is not a general characteristic for all populations of Sapajus, and dispersal by both sexes might be more commom than previously thought (AU)