Nasalis larvatus (Wurmb, 1787), Indonesia. This is now the only species in the genus Nasalis, and no subspecies are recognized. The species Simias concolor has sometimes been included in the genus Nasalis, but it is sufficiently distinctive to deserve its own genus.
OTHER COMMON NAMES
French: Nasique; German: Nasenaffe; Spanish: Mono narigudo. PHYSICAL CHARACTERISTICS
This is the largest species in the subfamily Colobinae. Fur reddish orange on the crown and back and grayish white ven-trally. The fur on the shoulders, neck and cheeks is pale orange. The legs and the tail are grayish white. In males, the penis is bright red in color, contrasting with the black scrotum. Both sexes have a prominent nose, but there is marked sexual dimorphism in that the nose is particularly long and drooping in males, whereas it is shorter and forward-pointing in females. Sexual dimorphism in body size is also very pronounced, with adult males weighing more than twice as much as adult females. Head and body length: 30 in (74.5 cm) for males and 25 in (62.0 cm) for females; tail length: 26.5 in (66.5 cm) for males and 23 in (57.5 cm) for females. Body mass: 45 lb (20.4 kg) for males and 21 lb 10 oz (9.8 kg) for females.
Occurs throughout Borneo, wherever suitable forest habitat is available.
Occurs in a variety of habits, including lowland rainforest, gallery forest, peat swamp forest and mangrove forest.
Diurnal and essentially arboreal. Individuals and groups have been observed swimming across rivers and even in the sea near the coast. Typically form one-male social groups, with surplus males living in bachelor groups. Individual one-male groups sometimes combine with other groups temporarily. Groups do not show clear-cut territorial behavior.
FEEDING ECOLOGY AND DIET
Feeds predominantly on leaves, but also eats flowers, fruits (mostly unripe), seeds and a small amount of animal prey.
Polygynous. Typically gives birth to a single infant. The species has rarely been kept in captivity and reproductive features such as the gestation period are hence unknown.
Listed as Endangered.
SIGNIFICANCE TO HUMANS Quite often hunted for bushmeat. ♦
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