Rhinoceroses

Rhinoceroses are large, herbivorous mammals native to Africa and southern Asia. Five living species are recognized: the white rhinoceros and the black rhinoceros in Africa; and the Indian rhinoceros, Javan rhinoceros, and Sumatran rhinoceros in Asia. They are characterized by thick skin with elastic folds, and by one or two horns on the snout composed of keratin.

An important distinction among species is horn number: Indian and Javan rhinos typically have a single horn; Sumatran rhinos have two; black and white rhinos usually have two horns. Size varies by species; white rhinos are the largest.

Rhinos occupy a range of habitats, from savannas and grasslands in Africa to tropical forests and floodplain regions in Asia. Diet is herbivorous: white rhinos graze on grasses; black rhinos browse leaves, shoots, and fruit; other species feed on a mix of grasses and foliage.

Reproduction is slow; after a gestation period of about 15 to 16 months, a single calf is born and remains with the mother for up to two years.

Threats include poaching for horns and habitat loss; all rhinoceros species face conservation challenges. Protected areas, anti-poaching patrols, community conservation, and breeding and translocation programs have helped some populations, particularly in Africa. The two Asian species are among the most critically endangered, with very small remaining populations.

Conservation status varies by species: Javan rhinoceros and Sumatran rhinoceros are listed as critically endangered; black rhinoceros is endangered; Indian rhinoceros is vulnerable; white rhinoceros is near threatened.