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 an old language called Ancient Greek. It means "nose-horned" because these animals have a horn on their noses. People have used this name since the 1300s. Scientists first gave names to two types of rhinoceros in 1758. These were the Indian rhinoceros and the black rhinoceros.

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

Description

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

Rhinoceroses have strong, 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 sturdy, 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 is an exception, as it often has more hair.

Behaviour and ecology

Rhinoceroses behave differently depending on the species. Male rhinos usually live alone, while female Asian rhinos also prefer to be alone. However, female African rhinos, especially white rhinos, sometimes form groups. Their diets also vary: some eat only 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, both male and female rhinos look for partners from the opposite sex. Males may guard females until they are ready, and they taste the females’ urine to check if they are ready to mate. Sometimes males fight over females, but these fights can range from gentle posturing to more serious clashes. After mating, which can last several hours, the pregnancy lasts over a year. The mother gives birth in a quiet place and protects her calf fiercely. Baby rhinos can stand soon after birth and start nursing within a few hours. They stay close to their mothers for a few years and are vulnerable to predators until they are older. Mothers often reject their older calves when a new one is born. Rhinos reach maturity around five to eight years old.

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 over 20,000 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 a long history on Earth. The earliest rhino-like animals appeared in Asia about 54 million years ago during the early Eocene epoch. The modern rhino family, Rhinocerotidae, developed around 39–40 million years ago in both Asia and North America. Over millions of years, rhinos spread to Europe and later to Africa.

During the Miocene epoch, about 20 million years ago, rhinos were very diverse, with many different species living together. Some of these rhinos looked very different from today's species. By the late Miocene, climate changes reduced their numbers, and some groups disappeared. Today, there are five main species of rhinos, with two living in Africa and three 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 sometimes fall prey to big cats, crocodiles, African wild dogs, and hyenas.

Rhinos are large and aggressive, but they are often targeted by people who want to take their horns. Because rhinos visit water holes daily, they can be found and harmed while they drink. Efforts to protect rhinos have become harder, with many rhinos being harmed each year. In some places, more than a thousand rhinos were harmed in a single year. In some cases, rhinos are made sleepy and their horns taken, which causes them terrible harm.

Some governments support controlled hunting to raise money for conservation, but this practice is debated by many people.

Horn use

Rhinoceros horns grow from tissues under the skin and are made of a special material called keratin. These horns have been used in some cultures for making handles for daggers and in traditional medicines.

There is a misunderstanding that rhino horn can cure diseases or act as a medicine, 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 international trade of rhinoceros horn has been made illegal by special rules since 1977. In 2016, a request to allow this trade again was turned down. In South Africa, where most rhinos live, selling rhino horn was stopped in 2009 but later allowed by a court decision in 2017. The government there is thinking about making rules for selling rhino horn, maybe even letting it be sent to other countries for reasons that are not for selling.

Some scientists in 2013 thought that letting people buy rhino horn in a controlled way might help stop animals from being hurt. However, groups like the World Wildlife Fund do not agree, fearing it could lead to more people wanting the horn. Another group, IFAW, says we need to learn more about money matters before deciding.

Conservation

According to the World Wide Fund for Nature, protecting African rhinoceroses is important because they eat a lot of plants, which 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, and studies show that 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. They also note that some rhinos did not survive the medicine used to help them sleep.

Artificial substitute for rhinoceros horn

A suggestion has been made to create an artificial version of rhino horn. This could help reduce the demand for real rhino horn. While many were unsure at first, some believe it might be a future option for protecting 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 from a long time ago wrote about rhinoceroses in his book.

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 made a famous picture of a rhinoceros in 1515. He never saw a real rhinoceros, so his picture is not completely accurate.

There are old stories from Burma, India, and Malaysia about rhinoceroses stamping out fires. In Malay language, these special rhinoceroses are called badak api. They would come when there was a fire in the forest and help put it out. There is a movie called The Gods Must Be Crazy from 1980 that shows this idea.