Genetic evidence for dispersal by both sexes in the Central American Squirrel Monkey, Saimiri oerstedii citrinellus

Sex-biased dispersal (SBD) is common in many vertebrates, including primates. However, dispersal patterns in New World primates may vary among closely related taxa or populations in different local environments. Here, we test for SBD in an endangered New World primate, the Central American Squirrel Monkey (Saimiri oerstedii citrinellus). Previous studies of behavioral ecology suggest predominantly female dispersal in S.o. oerstedii in the Southern Pacific region of Costa Rica. However, our genetic data do not support strongly female-biased dispersal in S.o. citrinellus in the Central Pacific region. Our tests for SBD using microsatellite data including comparisons of isolation-by-distance, AIc, and FST values between males and females were not significant. Also, we found greater population genetic structure in mitochondrial markers than in microsatellite markers, indicative of predominantly male dispersal. We conclude that both sexes disperse in S.o. citrinellus, and that males probably disperse over longer distances. We discuss how spatial and temporal variation among local populations should be taken into account when studying dispersal patterns and especially sex bias. Am. J. Primatol. 74:3747, 2012. (C) 2011 Wiley Periodicals, Inc.