Lisa Rose: Behavioral Ecology of Capuchin Monkeys

"Mr. B," a mid-ranking male who was killed by invading males during a group takeover in 1997.

I came into the graduate program at Washington University in 1993, and am now in the final stage of writing my dissertation. I spent most of 1995 through 1997 in the field in Costa Rica, where I study the behavioral ecology of white-faced capuchin monkeys, Cebus capucinus.

The major questions that I am interested in are the relative benefits and costs of living in groups, particularly for females, and patterns of social interaction within and between the sexes. Male capuchins emigrate prior to maturity, but most females remain and breed in the group where they are born, resulting in a female bonded social system. This led me to ask the question 'why have resident males' in groups. Males are dominant over females and one might assume impose a cost in terms of resources, so what benefits do they provide in return? Also, capuchin groups vary considerably in the number of males in each group, and the ratio of adult ales to females. How does this affect group time budgets and social relationships?

One finding of my research is that adult males often contribute to infant care. Here Nancite group's alpha male, Mel, sits with Split's infant while she drinks at the waterhole.