Maroon Langur (Presbytis rubicunda)
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 440-580, T673-800, HF 175-185 (5 Sabah specimens of two subspecies). Wt 5.5-7.0 kg.
Identification: General coloration reddish to golden brown. Face with a bluish tinge. Infants whitish with black markings down the back and across the shoulders. P.r. rubicunda: reddish with blackish extremities to the limbs. P.r. rubida and P.r. ignita: entire body reddish - these two subspecies differ only slightly in skull dimensions. P.r.chrysea: pale golden brown.
Similar species: the Orang-utan, Pongo pygmaeus, is similarly coloured but is larger, has no tail, and generally moves more slowly.
Ecology and Habitat: Very similar to Hose's Langur, P.hosei. Group size usually about 8 with only one adult male. In some areas (for example, Sepilok in Sabah) the Maroon Langur is much commoner than the Hose's. At Sepilok, one group investigated occupied about 60 ha of tall lowland dipterocarp forest and fed mainly on young leaves and seeds of trees and lianas, apparently preferring legume species. The Maroon Langur can live in certain tree plantations and may come out of forest into gardens to eat young leaves and seeds.
Distribution: Confined to P. Karimata and Borneo, where it is the most widespread langur species, apparently occurring throughout most of the lowlands, hills and mountains, including the Kelabit uplands. There are no records, however, from extreme western Borneo between Kuching and Pontianak, or Central Kalimantan. P.r. rubicunda: recorded throughout eastern Borneo. P.r. rubida and P.r. ignita: recorded in western Borneo.