Mammals · Rhinocerotids

Rhinoceros

Rhinocerotidae (five living species)

Three of five species Critically Endangered

Rhinoceroses are massive, thick-skinned herbivores best known for the horn — made of keratin, not bone — that gives the family its name. Five living species survive across Africa and Asia, from the armor-plated Indian rhino to the two-horned white and black rhinos of the African savanna, and all but one are threatened chiefly by poaching for that horn.

Classification

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Perissodactyla

Family: Rhinocerotidae

Genera: Ceratotherium, Diceros, Rhinoceros, Dicerorhinus

Living species: 5 — white, black, Indian, Javan, Sumatran

Nearest relatives: Horses, tapirs and other odd-toed ungulates

Size

White rhino largest at up to 13 ft and 5,000 lbs; Sumatran rhino smallest at around 8 ft and 1,300–2,100 lbs.

Habitat

African savanna and grassland (white, black rhino); Asian tropical grassland, floodplain and rainforest (Indian, Javan, Sumatran rhino).

Description

Massive, thick, grey or brown hide with little hair, and one or two horns made of compressed keratin — the same protein as hair and fingernails, not bone or ivory.

Diet

Herbivore. White rhino grazes grass with a wide, flat lip; black, Sumatran and Javan rhinos browse leaves and shoots with a pointed, prehensile upper lip.

Speed

Can run at 30–34 mph despite weighing up to two and a half tons.

Senses

Poor eyesight but an outstanding sense of smell and hearing, aided by oxpecker birds that ride along and call an alarm at danger.

Gestation

15–16 months, among the longest of any land mammal.

Birth & Litter Size

A single calf, weighing 90–140 lbs, able to stand within hours and staying with its mother for 2–3 years.

Sexually Mature

5–7 years for females, 7–10 years for males.

Life Span

35–50 years in the wild.

Social Structure

Adult males are largely solitary and territorial; females and calves may form small loose groups, especially in white rhino.

Conservation status

Javan and black rhino Critically Endangered; Sumatran rhino Critically Endangered with fewer than 50 remaining; Indian rhino Vulnerable; white rhino Near Threatened.

Did You Know?

A rhino’s horn is made entirely of keratin — the same protein found in human hair and fingernails — not bone or ivory, and it continues growing throughout the animal’s life.

Did You Know?

The name "white rhino" has nothing to do with color; it likely comes from a mistranslation of the Afrikaans "wyd," meaning wide, describing its broad, square lip.

Did You Know?

Oxpecker birds ride on rhinos to feed on ticks, and their sharp alarm call warns a rhino of approaching danger long before its poor eyesight would.