Census of Eastern Hoolock Gibbons (Hoolock leuconedys) in Mahamyaing Wildlife Sanctuary, Sagaing Division, Myanmar

Abstract

The hoolock gibbons are now ranked one of four genera of the family Hylobatidae (Roos and Geissmann 2001; Brandon-Jones et al. 2004). They occur in closed canopy forest areas between the Salween River in the east and the Brahmaputra River in the west (Groves 1967; Marshall and Sugardjito 1986), including eastern India and Bangladesh, most of Myanmar, and a small part of Yunnan, China, that occurs west of the Salween River. Groves (1967) considered the hoolock to have two subspecies, Hylobates hoolock hoolock, the western Hoolock gibbon, and H. h. leuconedys, the eastern hoolock gibbon, separated by the Chindwin River system. This separation was supported by pelage differences in specimens in the American Museum of Natural History and the British Museum. More recently, Mootnick and Groves (2005) replaced the previous generic name proposed for the genus, Bunopithecus (Prouty et al. 1983), with Hoolock, and proposed elevating the two subspecies to species level. This convention has been accepted in the present volume.