Editing Trachypithecus (section)

== Behaviour ==

They spend the largest part of the day in the trees, where they crawl along the branches on all fours, although they can also jump well from tree to tree. They are [[diurnal animal|diurnal]], although more active in the early mornings and the afternoon.

They live in groups of five to 20 animals, mostly in [[Harem (zoology)|harem]]s, i.e. a single male with several females. Young males must leave their birth group when fully mature, often forming bachelor groups. If a new male takes over a harem, defeating and scaring off the harem leader, he often kills the children of the group. Lutungs are territorial, with loud shouting to defend their territories from other lutung interlopers, resorting to force if the outsiders are not scared off. They have a common repertoire of sounds with which they warn group members. Also, mutual grooming plays an important role.

Lutungs are [[herbivore]]s, primarily eating leaves, fruits, and buds. To digest the tough leaves, they developed a multichambered stomach.

=== Reproduction ===

Rarely twins, a typical single birth comes after a seven-month gestation period. Newborns usually have a golden-yellow fur. The mother shares responsibilities of rearing the young with the other females ("aunties") of the harem. They hand the young around, play with it, carry it, and cuddle it, while the mother searches for food. If the mother dies, another female adopts the young animal. Lutungs are weaned in the latter half of their first year, and reach full maturity at 4 to 5 years. The life expectancy is estimated at 20 years.