Doctoral Dissertation Improvement: Cooperation and Conflict in Two Socially Monogamous Primates: Red Titi Monkeys and Equatorial Saki Monkeys

University Of California-Davis, Davis CA

Investigators

Abstract

Social monogamy has long been of interest to anthropologists, primarily because it is a rare social system in mammals, but appears to be more prevalent among primates, and is especially common in humans. Although pair-bonds are considered an important component of human mating and parenting strategies, we understand relatively little about the dynamics of male-female relationships. Reviews of social monogamy across a wide range of taxa, including human societies, have demonstrated significant variation in male-female relationships, which has contributed to a longstanding debate regarding the functional significance of pair-bonds. This project by doctoral student Amy Porter (University of California, Davis), supervised by Dr. Lynne Isbell, investigates comparative aspects of pair-bonding and territorial behavior in two socially monogamous primates, red titi monkeys (Callicebus discolor) and equatorial saki monkeys (Pithecia aequatorialis), in which males and females differ in their degrees of parental care and contributions to territorial behavior. This research will test the hypotheses that 1) differences in direct paternal care and the potential costs of cuckoldry and/or abandonment are related to differences in pair-mate relationships and male-female mate guarding strategies; and 2) vocal communication in titis and sakis is a component of their mate guarding strategies. The hypotheses are tested using systematically collected behavioral data and vocal playback experiments. The fine-scale analysis of social interactions between pair-mates will contribute substantially to broader theoretical issues in evolutionary biology, especially those that relate to mating and parenting strategies. These data are particularly relevant to understanding our own species, where there is substantial variation in male-female relationships and the patterning of gender roles, both within and between populations. This research also will contribute to the field of ornithology by providing comparative data on how two socially monogamous mammals use vocal communication in mate-guarding and territoriality, two common behaviors in birds.