Rhinocerotids

Rhinocerotids, commonly called rhinoceroses, are a family within the order Perissodactyla. They are large, herbivorous mammals characterized by thick skin and one or more horns on the snout, composed of keratin. The family contains four living genera and many extinct relatives, and today its members are native to Africa and parts of Asia. Rhinocerotids occupy a range of habitats, from savannas and grasslands to tropical forests, and their ranges have contracted due to human activity.

There are four living genera: Diceros (black rhinoceros), Ceratotherium (white rhinoceros), Rhinoceros (which includes the Indian rhinoceros and the Javan rhinoceros), and Dicerorhinus (Sumatran rhinoceros). Species differ in size, horn number, and lip form related to their feeding strategy: some graze on grasses, others browse foliage. In general, white and black rhinos are African; Indian, Javan, and Sumatran rhinos occur in Asia. Most rhinocerotids are solitary or live in small family groups; horn use and territorial behavior vary by species.

Reproduction is slow, reflecting their large size. Gestation lasts about 15 to 16 months, and calves usually remain with the mother for several years before becoming independent. Lifespans in the wild can exceed 40 years.

Conservation status varies by species, but all extant rhinocerotids face significant threats from poaching and habitat loss. Several populations have declined severely, though some have stabilized in protected areas or through intensive conservation programs. The rhinocerotid lineage has a long fossil record, with many extinct relatives illustrating substantial historical diversity in size and horn development.