Effect of temperature on activity budgets of free ranging Dusky Toque Macaques (Macaca sinica aurifrons): A case study from Peradeniya University premises, Sri Lanka

Macaca sinica is the smallest of all 22 extant macaque species in the world. There are three geographically isolated endemic sub-species of M. sinica: M. s. sinica, M. s. aurifrons and M. s. opisthomelas in Sri Lanka. Macaques adjust their activities to deal with changeable environments like weather changes and food availability fluctuations, proving their plasticity nature. Current study focused on assessing the temporal variation of activity budgets and effects of temperature on their activity pattern. Behavioral data were collected using scan sampling method. Overall activity budget analysis found that they allocate more time on resting (32.60 ± 4.97%), whereas less time spent for moving (26.30 ± 3.15%) and feeding (19.60 ± 2.97%). Moving was negatively correlated with monthly average temperature (r= -0.489 p= 0.029). The study found that time allocation for moving was reduced to compensate their thermoregulatory cost in terms of energy. This suggests that changes in movements of M. s. aurifrons are a useful indicator in assessing environmental changes such as temperature alterations.