Langur is the general name given to numerous species of Asian monkeys belonging to the subfamily Colobinae. The term is often restricted to nearly two dozen species of leaf monkeys but is also applied to various other members of the subfamily.
The Purple-faced Langur (Trachypithecus vetulus), also known as the Purple-faced leaf monkey, is a long-tailed arboreal monkey endemic to Sri Lanka. This folivorous species normally has a social system consisting of one resident adult male (Harem), 1-7 adult females and a varying amount of juveniles and infants. All male groups (bachelor) also exist, numbering from 2-14 individuals.