Responses of the long-tailed macaque (Macaca fascicularis) to variations in anthropic factors in a rural environment, Bali (Indonesia)

The human-macaque interface in Asia is increasingly the focus of numerous studies raising the issue of conflict over space and resources and searching for efficient management strategies. Documenting impacts of interactions with humans and the variations in macaques’ responses to anthropogenic habitats is essential for undertanding adaptation strategies and possibilities of a sustainable coexistence. The long-tailed macaque (Macaca fascicularis) is a very successful commensal species that adapts remarkably well to rural and urban landscapes. In some locations of Bali (Indonesia), this species, which has coexisted with humans for centuries, is used today to promote wildlife-based tourism, often characterized by an intense food provisioning. Here, we present data of a commensal M. fascicularis population in Bali (Uluwatu Temple), particularly well-habituated to human presence and provisioned daily. We analyze the impacts of the daily variations of three anthropogenic factors (microhabitat – human presence degree – food provisioning quantity) on the daily activity, ranging and dietary patterns. We used a focal and scan sampling methodology during a four-month study period between June and October 2010. Four groups constituted this population and their home ranges were particularly small, ranging from 2.4 to 5.6 ha. The eco-behavioural patterns were strongly and consistently influenced by variations in the anthropic factors. Typically, with a high anthropic level (defined as increasing degrees of each anthropogenic factor), macaques spent less time foraging and moving and more time feeding, resting and socializing. Contrary to previous studies on other primate species, we did not find any impact of provisioning on agonistic interactions. 55% of this population’s diet consisted of human foods, while the remainder (45%) of natural foods. Natural food items were preferentially consumed when anthropic level was low, emphasizing the opportunistic style of the diet. In summary, the eco-behavioural modifications induced by variations in anthropic levels did not increase the daily costs of living, confirming the flexibility and the efficiency of the macaques’ responses. However, we also illustrate in another study site (Ubud – Bali) the risk of overpopulation caused by the provisioning, which may potentially increase the human-macaque conflict.