Demography and Behavior in Macaca fascicularis in the Anthropogenic Landscapes of Singapore

For most old world cercopithecine species, both the ultimate and proximate reasons for dispersal are debated. To explore primate dispersal dynamics, and investigate whether aggression and peripherilization are important predictors of dispersal, I conducted a behavioral and demographic study of two long-tailed macaque (M. fascicularis) groups was in Singapore for two groups, one located at the MacRitchie Reservoir which experiences much more pedestrian traffic than the other group located in an area of the Upper Seletar Nature Reserve predominantly visited by motorists. Demographic data, especially group size, sex ratios, and age-sex class counts were determined through scan and ad libitum sampling. Four subadult males, two in each group, were followed for focal animal sampling. Results showed that the subadult males experience varied degrees of peripheralization, with individual relationships appearing to be a critical component while aggression did not. This study does not find any conclusive evidence for either male competition or inbreeding avoidance. Interestingly, my results may be due to the significant anthropogenic influence on Singapore's primate population. The costs of high density, intense resource competition and stress, may be outweighed by anthropogenic benefits of increased food sources to supplement forest resources. Results of this study contribute to an understanding of how demography, behavior, and environment predict dispersal, providing a framework for future studies and implications for management and conservation.