Delacour's langur  (Trachypithecus delacouri)

Delacour's langur has a unimale social system, in which the small group consists of one male, multiple females and their offspring, numbering a total of only three to six individuals (6) (7). The remaining males form all-male bands, from which individuals will eventually invade unimale groups to replace the leader. Males reach reproductive maturity at five years, females at four. A reproductive peak exists between January and June and, after a gestation period of 170 to 200 days, females usually give birth to a single offspring (2).

This diurnal species has a predominantly folivorous diet (7) but will also feed on shoots, fruit, flowers and bark (2). Like other members of the Colobinae subfamily, Delacour's langur has evolved a complex stomach and enlarged salivary glands to aid the digestion of tough leaf material (7).