Non-Monogamous Copulations and Potential Within-Group Mating Competition in White-Faced Saki Monkeys (Pithecia pithecia)
Publication Type: |
Journal Article |
Year of Publication: |
2013 |
Authors: |
Cynthia L. Thompson |
Publication/Journal: |
American Journal of Primatology |
Keywords: |
mating harassment, mating system, pair-living, sexual coercion, social organization |
ISBN: |
1098-2345 |
Abstract:
Many primates display within-species variation in social organization and mating system. Individuals of these species may be confronted with both the challenges of between-group competition to exclude same-sex competitors as well as within-group competition for mating opportunities. Free-ranging white-faced saki monkeys (Pithecia pithecia) live in both male–female pairs and small multi-male, multi-female groups. Despite commonly held views that this species is monogamous, there are currently no published accounts of mating patterns in the genus Pithecia. I recorded copulations and sexual behavior from three free-ranging groups of white-faced sakis at Brownsberg Naturepark, Suriname over a period of 17 months. Groups displayed both monogamous and polygynandrous mating. Individuals in polygynandrous groups were not observed to mate more frequently with certain partners. Copulation harassment occurred in 8.6% of copulations (total N = 81) and was performed by both sexes. This harassment successfully prevented ejaculation in six out of seven instances and harassment by males resulted in male–male aggression on four occasions. Two cases of female-directed sexual aggression by males were also observed, which may indicate that males use sexual coercion to influence female mating behavior. Although based on a small number of groups, these data show that white-faced sakis display variability in mating system and that this variability is not directly dictated by social organization. Furthermore, groups with promiscuous copulations exhibit behaviors indicative of within-group mating competition. Am. J. Primatol. 75:817–824, 2013. © 2013 Wiley Periodicals, Inc.