The Behavioral Ecology of Wedge-Capped Capuchin Monkeys (Cebus olivaceus)

Abstract

The relationship between ecology and social structure has been an important area of primatological research since the 1960s (e.g., Crook and Gartlan 1966, Gartlan 1968, Rummer 1971, Eisenberg et al. 1972, Clutton-Brock 1974, Ctutton-Brock and Harvey 1977a). Early work focused on group-level responses to the environment, employing the comparative approach to establish broad correlations between ecology and sociality (Crook and Gartlan 1966, Clutton-Brock and Harvey 1977b). Later, the sociobiological paradigm (Wilson 1975) stimulated investigation of how selection acts on individuals to maximize reproductive success and inclusive fitness within populations. In light of the sociobioiogical model, socioecological research on primates has investigated, among other things, the costs and benefits to individuals of living in groups of different sizes (e.g., van Schaik 1983, Terborgh and Janson 1986). Additional research has examined the extent to which changes in the physical environment, such as resource dispersion, influence foraging and social behaviors of individuals within groups (e.g., South-wick 1967, Whitten 1983, Janson 1985). This chapter explores behavioral responses to elements of both the social and physical environments. The analysis is structured around the hypothesis that (a) individuals experience costs associated with membership in either a large group or a small group (i.e., the social environment), (b) these costs are influenced by facets of the physical environment, in particular fluctuations in resource abundance, and (c) individuals are selected to employ behavioral strategies which mitigate these costs. Specific predictions are tested against data from a two-year study of wedge-capped capuchin monkeys (Cebus olivaceus) at Hato Pinero, Venezuela.