RAPID Twinning in Monogamous Owl Monkeys of the Argentinean Chaco: Developmental and Behavioral Consequences

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

Few aspects of primate behavior are so intriguing, yet so poorly understood, as the intense care of infants by males. And nowhere among primates is paternal care more extensive than among owl monkeys. Owl monkeys are small, arboreal primates of Central and South America who live in groups with only one reproducing male and one reproducing female. In these monogamous groups, the father is the main provider of infant care, transporting, playing, sharing food and grooming the infant more than the mother. Since 1996, the Owl Monkey Project of Argentina has evaluated hypotheses on the evolution of social monogamy, infant care, and pair bonding in humans and non-human primates. Why do male owl monkeys mate in a monogamous relationship presumably foregoing other reproductive opportunities? Why do they provide so much infant care? The birth of two sets of twins for the first time in 15 years, offers the possibility of further evaluating the hypothesis that males' contribution to infant care reduces the mother's energetic costs. During a 6-month period, this study will characterize the development of the two set of twins and will describe the behavioral interactions between twins and parents, twins and siblings, and parents and older young. Results from this study will be used for comparison with similar data collected over the years in groups with singletons. The study will expand the broad impacts of the Owl Monkey Project. Being the only long-term program on any mammal species in the Argentinean Gran Chaco, the project has multiplying effects on the conservation of this ecosystem and its fauna. It also promotes the development of biological anthropology through the participation over the years of more than 200 students (52% females, 48% males) from the US (100 students), Argentina (120 students) and 14 other countries (30 students).