The western tarsier (Cephalopachus bancanus) is a small nocturnal primate that inhabits the tropical rainforests of Southeast Asia, including Borneo and Sumatra. It has a body length of about 12 cm and a long tail, and is an excellent leaper. It is entirely carnivorous, preying on insects, frogs, lizards and similar animals; its eyes are very large and it rotates its head to secure its field of view. It is basically solitary and maintains a territory, marking it with urine and scent glands. Gestation lasts about six months and usually results in a single offspring; weaning and sexual maturity require several months to several years, respectively. Population numbers have declined due to deforestation, conversion to agricultural land, and capture, and the species is classified as Vulnerable (IUCN Red List category II).