The purple-faced langur (Semnopithecus vetulus), also known as the purple-faced leaf monkey, is a species of Old World monkey that is endemic to Sri Lanka. The animal is a long-tailed arboreal species, identified by a mostly brown appearance, dark face (with paler lower face) and a very shy nature. The species was once highly prevalent, found in suburban Colombo and the "wet zone" villages (areas with high temperatures and high humidity throughout the year, whilst rain deluges occur during the monsoon seasons), but rapid urbanization has led to a significant decrease in the population level of the monkeys. It had traditionally been classified within the lutung genus Trachypithecus but was moved to the genus Semnopithecus based on DNA evidence indicating that is it more closely related to the gray langurs. In Sinhala it is known as ශ්‍රී ලංකා කළු වඳුරා [kʌlu vʌⁿðura] (Sri Lanka black monkey). Description In the purple-faced langur, males are usually larger than females. Males measure in head-body length with a tail of . Females possess a head-body length and tail length of . The pelage may generally vary from blackish to grayish. The species tends to have whitish to gray short 'trousers' rounded off by purplish-black faces with white sideburns. Part of the back is covered with whitish fur, and tail is also furred with black and white mixed colors. The feet and hands are also purplish-black in color. Size varies among the subspecies. Typically adults will weigh somewhere between , averaging about . The smallest subspecies (S. v. nestor) commonly weighs between . Average weight from other subspecies has been recorded up to in females and in males with some exceptionally big langurs weighing up to perhaps . Among the primates that live in Sri Lanka, it is somewhat smaller than the tufted gray langur despite leading males of the group of purple-faced langurs often being larger than the tufted gray langur that lived together in the habitats. In the subspecies known as the "bear monkey" (S. v. monitcola) usually has a darker coat and usually sports a heavy mustache. In this species, the hair of crown directed backwards throughout, not radiating. it lacks the crest of tufted gray langurs and has hair on the crown no longer than on temples and nape. Purple-faced langurs have a rump that is pure white or whitish gray. Subspecies According to the Mammals of Sri Lanka, the 4