Presbytis

Presbytis is a genus of Old World monkeys, known as surilis, leaf monkeys or langurs, whose members live in the Thai-Malay Peninsula and on Sumatra, Borneo, Java and smaller nearby islands. Surilis are small, slimly built primates with fur that is brown, grey, black or orange above and whitish, greyish or sometimes orange below, and several species carry distinctive patterns on the head or hips. A tuft of hair on the crown gives the genus its German name, capped langurs. They differ from other langurs in head shape, with weak or absent brow ridges and prominent nasal bones, in their teeth and in their small thumbs. Adults measure 40 to 60 centimetres with a tail of 50 to 85 centimetres and weigh 5 to 8 kilograms. They are diurnal forest dwellers that spend nearly their whole lives in the trees, living in groups of up to 21 animals that usually hold one male, several females and their young, and their diet is leaves, fruits and seeds. Many species are restricted to regions of heavy habitat loss and are hunted, so 16 of the 19 species are rated vulnerable or worse by the IUCN. Trachypithecus and Semnopithecus were once treated as subgenera of Presbytis, and the species-level taxonomy of the genus is complex and still changing.