Hose's Langur (Presbytis hosei)
Monkeys in Borneo are represented by two distinct groups: the langurs or leaf monkeys and the Proboscis Monkeys (subfamily Colobinae), and the macaques (subfamily Cercopithecinae). The colobines are mainly arboreal, have a long tail, lack cheek pouches and have a large, sacculated stomach which permits breakdown of leafy material into digestible substances and helps detoxify poisonous leaves. The macaques are partly terrestrial, with a short or long tail, cheek pouches for temporary storage of food and a simple stomach capable of breaking down only a limited amount of leafy material.
Measurements: HB 480-557, T 646-840, HF 172-185 (7 Sabah specimens of P. h. sabana). Wt 6-7 kg.
Identification: Upperparts grey; underparts white, with blackish hands and feet. Face pinkish with a distinct black band across each cheek. Infants white with black lines down the back and across the shoulders. Groups (probably the adult male) sometimes give a unique gargling call. P.h. hosei: adult male with forehead, sides of head and neck white, prominent black crest on top of head; adult female with more black. P.h. sabana: both sexes pale grey head and dark grey crest. P.h. canicrus: brownish crest and back of neck.
Similar species: Adult Silver Langurs, P. cristata, are entirely grey, infants orange.
Ecology and Habitat: Diurnal. Active throughout the tree canopy, occasionally descending to the ground and visiting natural mineral sources. In Sabah and Brunei, most often encountered in groups of 6-8 individuals (but 12 or more reported from Temburong) containing one adult male and two or more adult females. Diet seeds and leaves. Occurs in tall and, less abundantly, secondary forests. Occasionally enters plantations. Ecologically very similar to the Maroon Langur, P. rubicunda, but in some areas (for example, Tabin in Sabah) Hose's Langur is common while the Maroon is rare; in other areas the reverse is true.
Distribution: Confined to Borneo in the lowlands and hill ranges of the north and east. P.h. hosei: known from western Sabah as far north as G. Kinabalu; Brunei; Niah, G. Dulit, Usun Apau and other parts of northern Sarawak. P.h. sabana: occurs from T. Marudu in northern Sabah down the eastern side of Sabah to at least as far south as Kalabakan. P.h. canicrus: recorded definitely only from G. Talisayan and S. Karangan in East Kalimantan but probably also present in Kutai.