Asia Two-Horned (Sumatran) Rhinoceros (Dicerorhinus sumatrensis)
Rhinoceroses are characterised by a large, stocky body; short, stout legs with three toes on each foot; and either one or two horns made of compacted hairs on top of the muzzle. The rhinoceros family has a long fossil history and of the five living species (two in Africa and three in Asia), the species found in Borneo most closely resembles the primitive forms found in Europe about 30 million years ago. There appears to have been a relatively recent decrease in body size of Bornean rhinos. Bones from Niah caves in Sarawak, which are less than 30,000 years old, are significantly larger than those of living rhinos. All rhinos have been persecuted for their horns and other parts of the body which are believed to have medicinal properties.
Only one species of rhinoceros now occurs in Borneo, but fossil remains of the Lesser One-horned (Javan) Rhinoceros, Rhinoceros sondaicus, have been found in Madai cave in South-eastern Sabah, dating from about 10,000 years ago.
Measurements: Height at shoulder about 1.2-1.3 m. HB about 2.5 m.
Identification: General coloration usually dark brown, but appearance may vary after bathing in water or mud. Hairy, especially when young, but hairs often not apparent in the field. Front horn rarely exceeds 30 cm in length, smaller in females than in males. Rear horn normally very short, sometimes hardly projecting above the level of the skin; often not visible in the field. Presence usually detected by tracks: footprints of adults on firm soil 18.5-23.5 cm across at widest point, showing 3 clear toe marks. Mud wallows can be distinguished from those of Bearded Pigs, Sus barbatus, by the clear, deep horn marks in the sides of the wallow. Dung consists of balls of coarsely chopped woody material about 9 cm in diameter, usually found in small piles, sometimes in mounds frequently used over long periods. When disturbed unexpectedly, this Rhinoceros usually flees rapidly, sometimes giving a series of short, hoarse barks.
Similar species: Bearded Pigs, Sus barbatus, have slender legs, a large head relative to the body and two-hoofed footprints; adult Malay Tapir, Tapirus indicus, and Lesser One-horned Rhinoceros, Rhinoceros sondaicus (not presently known to occur in Borneo) have footprints which are respectively smaller and larger.
Ecology and Habitat: Mainly active from late afternoon to mid morning. Usually rests during the hot hours of the day in a mud wallow, shaded spot or ridge top. Feeds on mature leaves and twigs from a wide range of woody plants including saplings, lianas and small trees, which may be pushed over to obtain the leaves. Occasionally eats fallen fruits. Natural mineral sources are visited and all accurate records of rhinos in Sabah are within 14 km of a mineral source. Occurs in tall and secondary forests, including very steep areas. Rarely comes out into open areas.
Distribution: Borneo - D.s. harrissoni. There may still be scattered individuals in the remote interior parts of Borneo. Old records cover scattered parts of Sarawak. Rhinoceroses appear to have disappeared from most parts of Borneo as a result of hunting over thousands of years and particularly over the past one hundred years.