White rhinoceros

The white rhinoceros, also known as the white rhino or square-lipped rhinoceros (Ceratotherium simum), is the largest living species of rhinoceros and the most social of all rhino species. It has a wide mouth made for grazing on grass.

There are two types of white rhinoceros: the southern white rhinoceros and the northern white rhinoceros.

The northern white rhinoceros is critically endangered and very close to disappearing forever. The last known male, named Sudan, passed away, leaving only a few females in captivity.

Both types of white rhinoceros face serious dangers, mainly from poaching for their horns and habitat loss. These threats have put the species as a whole into a conservation status.

White rhinoceroses are also very fast. They can run up to 40 mph (64 km/h) for very short bursts and can keep up speeds of around 30–31 mph (48–50 km/h) for longer periods. They have good stamina and can keep going for a while.

Naming

The name "white rhinoceros" may have come from a mistake. Long ago, Dutch speakers called the rhino "wijd", meaning "wide" — referring to its broad mouth. English speakers may have thought "wijd" meant "white", which gave us the name we use today. Later, Dutch speakers started using "white rhino" from English.

Another name for this animal is the square-lipped rhinoceros, though it is used less often.

The scientific name, Ceratotherium, was given by a scientist named John Edward Gray in 1868. It comes from Greek words for "horn" and "beast". The name simum also comes from Greek and means "flat-nosed", describing the rhino's wide snout.

Taxonomy and evolution

Scientists used to think the modern white rhinoceros came from an ancient species called Ceratotherium praecox. Newer studies suggest this might not be right. Some believe the white rhino evolved from a different ancient species over millions of years.

There are different ideas about how white rhinos developed. Some scientists think they came from an ancient species in Africa that later spread and changed over time.

Southern white rhinoceros

Main article: Southern white rhinoceros

As of the end of 2023, there were about 17,464 southern white rhinos living in the wild. They are the most common rhinoceros subspecies. Most of them live in South Africa. Smaller groups have been placed in countries like Namibia, Botswana, Zimbabwe, Uganda, and Eswatini. They have also been introduced to Kenya and Zambia.

Northern white rhinoceros

Main article: Northern white rhinoceros

The northern white rhinoceros is in big trouble. There are very few left, and they might not exist in the wild anymore. This type of rhino used to live in several African countries south of the Sahara.

In 2009, four northern white rhinos were moved to Ol Pejeta Conservancy in Kenya to try to help them reproduce. But the group kept getting smaller. The last male rhino, Sudan, passed away in 2018 due to old age. Now, only two females, Najin and Fatu, remain at Ol Pejeta. Scientists are working hard to see if they can use stored samples to help these rhinos have babies, but it is very difficult.

Description

The white rhinoceros is the largest of all living rhino species and one of the biggest megafauna around. Only the three types of elephant are usually heavier. White rhinos have big, strong bodies and large heads with short necks.

Males are bigger than females. Males measure about 3.7 to 4 meters long and weigh between 2,000 and 2,300 kilograms. Females are smaller, about 3.35 to 3.65 meters long and weigh around 1,600 to 1,700 kilograms. They have two large horn-like structures on their noses made of a tough material called keratin, which is also in human hair and fingernails. The front horn can be up to 166 centimeters long.

White rhinos have broad, square mouths perfect for eating grass. They don't see very well but have excellent hearing and smell, with big ears that move and very large nostrils. Their thick skin often gets muddy, giving it various colors, and they have very little hair besides some on their ears and tail. Their strong legs end in wide feet with three toes to help them walk on different lands.

Genome

The white rhinoceros has a special set of instructions inside its cells called a genome. For the southern white rhinoceros, this genome is very long. Each of their cells has small pieces called chromosomes. These come in pairs, and one pair tells if the animal is male or female.

Behavior and ecology

White rhinos are special grazers that mainly eat grass and live in grasslands and savannas. They love to eat and spend much of their day feeding, resting, and doing other activities. They like to play in mud to keep their skin healthy and cool. Because they are so big, white rhinos help shape the land where they live, which is important for many other animals.

White rhinos talk to each other using different sounds like calls, grunts, and bellows. They can run very fast, up to 64 kilometers per hour. They usually live in groups of females and their babies, while males often live alone and mark their areas with dung and urine. Females become ready to have babies around six to seven years old, and males around ten to twelve years old. After about 16 months, a female gives birth to one baby, who stays close to her for protection. Baby rhinos can stand soon after birth but are wobbly at first. Adult rhinos live about 40 to 50 years and are safe from most predators because of their size.

Distribution

The southern white rhinoceros lives mostly in Southern Africa. This group of rhinos almost disappeared in the early 1900s but has grown strongly since then. Most live in South Africa, with others in Namibia, Botswana, Zimbabwe, and Kenya.

The northern white rhinoceros is in big trouble. It used to live in several countries in East and Central Africa but is now close to disappearing. Both types of white rhinos face dangers from losing their homes and from people taking them for their horn.

Poaching

White rhinos are in danger because some people hunt them for their horns. Some people think rhino horn can help with health problems, but this is not true. Rhino horn is made of the same material as human hair and nails.

Because rhino horn is very valuable, some groups work together to hunt rhinos. They use special tools to find and hunt them. This makes it hard to protect rhinos.

In recent years, the number of rhinos being hunted has gone up. This has caused the rhino population to drop quickly. Even in zoos, rhinos have been hurt by hunters looking for their horns.

The high value of rhino horn keeps encouraging people to hunt them. The horn can be worth as much as gold, and hunters continue to find new ways to track rhinos.

Modern conservation tactics

The northern white rhinoceros is in big trouble, with only two females left in the world, both living in captivity. Scientists are working hard to save this animal. In 2009, they moved these two females from a zoo in the Czech Republic to a wildlife area in Kenya, hoping a better place might help them have babies.

Unfortunately, this didn’t work. In 2014, they tried putting a male from the southern white rhinoceros with the females to see if they might breed, but this didn’t succeed. Recently, scientists have used special lab methods to help. In 2019, they made embryos from the eggs of the two females using stored sperm from males who have passed away. These embryos are frozen and will be placed into female southern white rhinoceroses in the future, hoping they will grow into new northern white rhinoceros calves.

In captivity

Most white rhinos in zoos and wildlife parks are southern white rhinos. In 2021, there were over 1,000 of them in captivity. These rhinos can have babies if they have space, good food, and other rhinos.

For the northern white rhinos, the San Diego Zoo Safari Park in California, United States, helped protect them. Two northern white rhinos, Angalifu and Nola, lived there but passed away. Only two northern white rhinos, Najin and Fatu, are left. They live at the Ol Pejeta Conservancy in Kenya and are watched closely to keep them safe.