Lion-tailed macaques live in small groups of between 4 – 30 (average 10 and 20) members, which are usually composed of a single male, several females and their young, but occasionally up to three adult males are seen (2) (5). These macaques spend the majority of their time in the trees, huddling together to sleep at night high up in the forest canopy (4). There is no specific breeding season; females that are ready to mate have small swellings in the region under their tail at oestrous, which the male examines (2) (4). Females give birth to a single offspring after a gestation period of around 6 months (162 – 186 days) (2) (5). Males tend to leave their natal group once they reach maturity and live in bachelor groups (5), whereas females remain, fitting into the hierarchy that exists (6). Groups are territorial and males of this species are the only macaques that use calls to denote territorial boundaries (5).
The mainstay of the lion-tailed macaque diet is fruit, although they will also forage for seeds, young leaves, flowers, buds and even fungi (4). Their distensible cheek pouches are used to quickly gather large amounts of food and when fully extended have the same capacity as their stomach (5).