Rhinoceros

A rhinoceros, often called a rhino, is one of the largest remaining animals on Earth. There are five types of rhinos alive today, living in Africa and parts of South and Southeast Asia. These big animals can weigh more than half a tonne and have thick, tough skin made of special proteins called collagen.

Rhinos eat plants and have one or two horns on their noses. Unlike many other four-legged animals, they don’t have front teeth and use their lips to grab food. Their bodies can process tough plant material thanks to special stomach areas called hindgut.

Sadly, rhinos face danger because some people want their horns for use in traditional Chinese medicine or as decorative handles. Even though rhino horn is made from the same material as hair and fingernails, it is often sold for very high prices. This has made many rhino species endangered, meaning there are fewer of them than before.

Taxonomy and naming

The word rhinoceros comes from Ancient Greek. It means "nose-horned" because these animals have a horn on their noses. People have used this name since the 1300s. In 1758, scientists gave names to two types of rhinoceros: the Indian rhinoceros and the black rhinoceros.

Later, a scientist named John Edward Gray created a group called Rhinocerotidae in 1821 to organize all rhinoceros species together.

Description

Rhinoceroses are some of the biggest land animals alive today. The smallest living species, the Sumatran rhinoceros, weighs about 775 kilograms. The largest, the white rhinoceros, can weigh up to 2,300 kilograms. Some ancient rhinoceroses were even smaller or larger.

Rhinoceroses have thick skin and usually one or two horns on their heads. These horns are made from special skin cells and grow like human nails. Their bodies are strong, and they walk on three toes on each foot. Most rhinoceroses have very little hair as adults, except for their eyelashes, ears, and tail area. The Sumatran rhinoceros often has more hair.

Behaviour and ecology

Rhinoceroses act in different ways depending on their type. Male rhinos usually live alone, while female Asian rhinos also prefer to be alone. But female African rhinos, like white rhinos, sometimes stay in groups. Their food also changes: some only eat grass, some eat leaves and bushes, and others eat a mix of both. They spend most of their time eating.

When it’s time to have babies, male and female rhinos look for a partner. Males may stay near females and check if they are ready to mate. Sometimes males may argue over females, but these can be gentle or more serious. After mating, the pregnancy lasts over a year. The mother gives birth in a quiet place and protects her baby. Baby rhinos can stand soon after birth and start nursing quickly. They stay close to their mothers for a few years and are safer when they grow older. Mothers may leave older babies when a new one is born. Rhinos grow up in about five to eight years.

Extant species

Rhinos are large animals with thick skin and horns made of a special material called keratin. There are five kinds of rhinos alive today. Two live in Africa, and three live in South and Southeast Asia.

White

Main article: White rhinoceros

The white rhinoceros is actually grey. There are two types of white rhinos: the southern and the northern. The southern type is more common, with many living in the wild. The northern type is in big danger, with only two females left in captivity. White rhinos are big animals with large heads, two horns on their snouts, and strong bodies. They usually eat grass.

Black

Main article: Black rhinoceros

The black rhinoceros is not always black in color. There are four types of black rhinos, but one type in West Africa no longer exists. Black rhinos are smaller than white rhinos and have pointed mouths for eating leaves and twigs. Their numbers dropped a lot during the 20th century but are starting to grow again.

Indian

Main article: Indian rhinoceros

The Indian rhinoceros has one horn and thick, folded skin that looks armored. Most live in India and Nepal, mainly in protected areas like Kaziranga National Park. They are nearly as big as white rhinos and like to live in tall grasslands and forests near the Himalayas.

Javan

Main article: Javan rhinoceros

The Javan rhinoceros is one of the most endangered large animals in the world, with only about 60 left in Indonesia. Like the Indian rhino, it has one horn and folded skin. These rhinos live in dense rainforests and tall grasslands with mud wallows.

Sumatran

Main article: Sumatran rhinoceros

The Sumatran rhinoceros is the smallest rhino and has the most hair. It lives in high altitudes in Borneo and Sumatra. There are only about 275 left, and they face big threats from losing their homes and hunting. They have two horns, with the front one being larger.

Evolution

Rhinoceroses, or rhinos, have been on Earth for a very long time. The first rhino-like animals appeared in Asia about 54 million years ago during the early Eocene epoch. The modern rhino family, Rhinocerotidae, began around 39–40 million years ago in Asia and North America. Over time, rhinos spread to Europe and Africa.

During the Miocene epoch, about 20 million years ago, many different kinds of rhinos lived together. Some looked very different from rhinos today. Climate changes later reduced their numbers, and some groups disappeared. Today, there are five main species of rhinos. Two live in Africa, and three live in South and Southeast Asia.

Subfamilies and genera

• Family Rhinocerotidae
  • †Teletaceras
  • †Uintaceras
  • †Epiaceratherium
  • †Trigonias
  • †Ronzotherium
  • †Diceratherium
  • †Menoceras
  • †Subhyracodon
  • †Molassitherium
  • †Guixia
  • Subfamily Aceratheriinae (sometimes placed in Rhinocerotinae as Aceratheriina)
    • †Alicornops
    • †Aprotodon
    • †Acerorhinus
    • †Aphelops
    • †Hoploaceratherium
    • †Persiatherium
    • †Brachydiceratherium
    • †Diaceratherium
    • †Dromoceratherium
    • †Floridaceras
    • †Galushaceras
    • †Chilotheridium
    • †Mesaceratherium
    • †Plesiaceratherium
    • †Proaceratherium
    • Tribe Aceratheriini
      • †Acerorhinus?
      • †Aphelops?
      • †Hoploaceratherium?
      • †Persiatherium?
      • †Aceratherium
      • †Subchilotherium
      • †Peraceras
      • †Chilotherium
      • †Shansirhinus
    • Tribe Teleoceratini? (sometimes placed as a separate group)
      • †Alicornops?
      • †Teleoceras
      • †Brachypotherium
      • †Prosantorhinus
  • Subfamily Rhinocerotinae
    • Subtribe Rhinocerotina (also used to encompass all modern rhinoceroses)
      • †Nesorhinus
      • Rhinoceros – Indian & Javan rhinoceros
    • Tribe Dicerorhinini or Subtribe Dicerorhinina (also known as the "DCS clade")
      • †Pliorhinus
      • †Coelodonta – Woolly rhinoceros
      • Dicerorhinus – Sumatran rhinoceros
      • †Dihoplus
      • †Stephanorhinus – Merck's rhinoceros & Narrow-nosed rhinoceros
    • Tribe Dicerotini/Diceroti or Subtribe Dicerotina
      • Ceratotherium – White rhinoceros
      • Diceros – Black rhinoceros
      • †Paradiceros
      • †Miodiceros?
    • Rhinocerotinae incertae sedis
      • †Protaceratherium
      • †Lartetotherium
      • †Gaindatherium
      • †Rusingaceros
  • Subfamily Elasmotheriinae
    • †Gulfoceras?
    • †Penetrigonias?
    • †Subhyracodon?
    • †Menoceras?
    • †Diceratherium?
    • Tribe Elasmotheriini / Subtribe Elasmotheriina
      • †Bugtirhinus
      • †Caementodon
      • †Elasmotherium
      • †Eoazara
      • †Hispanotherium
      • †Iranotherium
      • †Victoriaceros?
      • †Kenyatherium
      • †Meninatherium
      • †Samburuceros
      • †Ningxiatherium
      • †Ougandatherium
      • †Parelasmotherium
      • †Procoelodonta
      • †Sinotherium

Predators, poaching and hunting

See also: Rhino poaching in Southern Africa

Adult rhinoceroses have no real predators in the wild, except humans. Young rhinos can sometimes be attacked by big cats, crocodiles, African wild dogs, and hyenas.

Rhinos are large but they are sometimes targeted by people who want their horns. Because rhinos often visit water holes, they can be found and harmed there. Many rhinos are harmed each year trying to protect them. Some governments allow controlled hunting to raise money for conservation, but this is debated by many people.

Horn use

Rhinoceros horns grow from tissues under the skin and are made of a special material called keratin.

In some cultures, these horns have been used to make handles for daggers and in traditional medicines.

There is a misunderstanding that rhino horn can cure diseases, but this is not true. Some people have used it for treating fevers, though scientists say this does not work. Countries like China and Vietnam have taken steps to protect rhinos by stopping the use of their horns in medicines.

Horn trade

The trade of rhinoceros horn is not allowed under special rules since 1977. In 2016, a request to allow this trade again was refused. In South Africa, selling rhino horn stopped in 2009 but was later allowed by a court in 2017. The government there is thinking about making new rules for selling rhino horn, possibly allowing it to be sent to other countries.

Some scientists in 2013 thought that letting people buy rhino horn in a controlled way might help protect the animals. However, groups like the World Wildlife Fund do not agree, fearing it could lead to more people wanting the horn. Another group, IFAW, says more research is needed before making decisions.

Conservation

According to the World Wide Fund for Nature, protecting African rhinoceroses is important because they eat many plants. This helps keep the African landscape healthy and supports local communities.

Ways to prevent poaching

Horn removal

To help stop people from taking rhino horns, some rhinos are given medicine to sleep, and their horns are removed. Rangers work hard to protect rhinos. Removing horns can greatly reduce the chance of rhinos being taken.

Horn poisoning

In 2011, a project began to add a special pink dye mixed with a safe but unpleasant medicine into rhino horns. This makes the horn unsafe for people to use. The dye stays inside the horn and can be seen in scans, even if the horn is made into powder.

The Save the Rhino group has raised concerns about this method, wondering if it will really work and if it can be done for all rhinos.

Historical representations

Long ago, people painted pictures of woolly rhinoceroses on cave walls in Chauvet Cave in France. These paintings are very old, from about 30,000 to 40,000 years ago.

A writer named Agatharchides wrote about rhinoceroses a long time ago.

In Khmer art, a god named Agni is shown riding a rhinoceros. In old stories from Thailand, this god is sometimes called Phra Phloeng and also rides a rhinoceros.

An artist named Albrecht Dürer drew a famous picture of a rhinoceros in 1515. He never saw a real rhinoceros, so his picture is not completely right.

There are old stories from Burma, India, and Malaysia about rhinoceroses helping to stop fires. In Malay language, these special rhinoceroses are called badak api. A movie from 1980 called The Gods Must Be Crazy shows this idea.