The human-macaque interface: the impact of anthropogenic factors on the behavioural ecology of Macaca fascicularis in Bangkok (Thailand) and Bali (Indonesia)

The human-macaque interface is increasingly the focus of many researches in East and South-east Asia. The efforts target the understanding of human impacts on macaques and the risks of pathogen transmission, the mitigation of conflicts as well as the establishment of suitable management programs. Commensal relationships between humans and several species of macaques exist for centuries in some Asian locations, like in Bali (Indonesia), Japan or India. However, the frequency and the intensity of these interactions are strongly increasing over the recent decades, due to the extensive urbanization and recruitment of forestlands for cropping. We conducted a comparative study on two commensal long-tailed macaque (Macaca fascicularis) populations, one in Bangkok (Thailand) and the other in Bali (Indonesia), in order to assess the impact of anthropogenic factors (human presence and food provisioning frequency) on some eco-behavioural aspects of this macaque species living in urban landscapes. We found a consistent impact on the activity budget and the diet composition in both populations, suggesting an important role played by these anthropogenic factors for this species. Additionally, we did not find any impact of food provisioning on agonistic interactions in the two populations, contrary to previous studies in other macaque species. We suggest this surprising result could be explained by the high abundance and constant availability of human food in both sites, decreasing foraging pressures and the associated social competition. Further field studies are in progress in other populations of Macaca fascicularis in Bali in order to confirm this consistency of human impact on the behavioural ecology