Many ecological costs and benefits thought to result from group living are a direct result of cooperative interactions among individual group members. Underlying these cooperative interactions are the concepts of kin selection and reciprocity, analysis of which is dependent upon understanding the genetic relatedness of the involved (and non-involved) individuals. Yet traditional difficulties in determining the relatedness of specific individuals in a group have hampered our understanding of if and how postulated ecological benefits are gained by all group members. This study proposes to examine ecological and genetic factors influencing the social system of the coati (Nasua narica), a Neotropical procyonid whose social structure of female-bonded groups and solitary males is unique within the Carnivora. Combining field observations of an extensively known population with genetic fingerprinting techniques will allow examination of three potential ecological explanations (predation, foraging, and parasite pressures) for the evolution and maintenance of the coati sociality-asociality dichotomy. Quantifying the importance of genetic relatedness to variation in cooperative interactions among individuals will provide a better understanding of underlying relationships and constraints and how ecological costs or benefits vary with the relatedness of individuals. The study can provide important clues to the stability and instability of mammalian societies.
