Does Anthropogenic Influence on Habitats Alter the Activity Budget and Home Range Size of Toque Macaques (Macaca sinica)? Insight into the Human-Macaque Conflict

Abstract

While classified as endemic and endangered, the Toque Macaque (Macaca sinica) is also considered a nuisance species in certain habitats in Sri Lanka due to its increased interactions with humans and crop raiding. This study analyzed the activity budget and home range utilization of two M. sinica troops inhabiting two contrasting landscapes to shed light on the species' rather poorly understood behavioral responses under environments of differing levels of anthropogenic pressure. We observed two macaque troops; first in a landscape with lower anthropogenic pressure (LAP) in Yagirala, and second in an area of moderate anthropogenic pressure (MAP) in Korathota, Sri Lanka. We followed the troops for ten months and observed their behaviors using focal animal sampling. Both troops spent most of their time on foraging and locomotion. However, the Korathota (MAP) troop spent more time on vigilance behaviors than the Yagirala (LAP) troop, which spent more time on amicable behaviors. This suggests that time allocation to amicable behaviors by Toque Macaques is higher in areas with lower anthropogenic pressure. The home range size was significantly larger in Yagirala (LAP) troop. We further found a significant difference in average home range size across seasons in both troops (p=0.001) with larger home ranges in the dry season: 2.81ha in the wet season vs 3.98 ha in the dry season for MAP troop and 5.1ha in the wet season vs 8.66ha in the dry season for LAP troop. Findings suggest that the resource availability and the level of anthropogenic pressure influence the activity budget and home range size of Toque Macaques. The outcomes of this study may be instrumental in developing future management strategies for Toques Macaques in anthropogenic settings and reducing human-macaque conflict. Practical management and conservation efforts should reduce the availability of anthropogenic food sources to macaques while increasing the size of natural forest patches.