Status of urban populations of the long-tailed macaque (Macaca fascicularis) in West Sumatra, Indonesia

We studied long-tailed macaque (Macaca fascicularis) populations in Padang, West Sumatra, Indonesia, focusing on the effect of human provisioning on their demography and dietary composition. We conducted a field survey at three sites in the city: Gunung Meru, Gunung Padang, and Gunung Panggilun. Mean troop size (range 28-68) and infant ratio (range 0.38-1.00) were greater in Gunung Meru, where the macaques have been highly provisioned, than at the other two study sites (troop size 10-15; infant ratio 0.00-0.33). The macaques at all sites consumed both natural and human foods, but dependence on the latter differed among sites: three-quarters of the diet of macaques in Gunung Meru consisted of human foods, while human foods comprised less than 5% of the macaque diet at the other sites. The ability of macaques to modify the proportion of human food is a behavioral flexibility that facilitates the survival of the long-tailed macaque in urban habitats. Without restrictions on provisioning, the degree of dependence of macaques on human foods and population size could increase, especially in Gunung Meru, and human-macaque conflict could escalate. In order to create an effective management policy for urbanized monkeys, long-term quantitative data on macaque behavior and monitoring of population parameters are required.