Rhinos are one of the Big Five animals popular in African safaris, but they also live in Asia and even lived in Europe in the past. There are currently five different species of rhino—two in Africa and three in Asia. All rhinos are famed for their horns. Some species have one horn, while others have two.
Rhinoceros horn is made of keratin, the same material as human fingernails, and they grow continuously throughout a rhino’s life. Like fingernails, rhinoceros horns can be trimmed without discomfort or pain.
Despite two rhino species mentioning colours (black rhino and white rhino), all rhinos are grey. They range in size from 600-kilogram Sumatran rhinos to 3,500-kilogram white rhinos.
Despite their large size, rhinos are herbivores—they only eat plant matter. They make up five of only nine remaining megaherbivore species left on Earth. Their exact diet depends on their habitat. For example, white rhinos have evolved square lips to graze on abundant grass, while black rhinos have developed pointed lips to pick leaves and plants.
Rhinos mainly feed during the night and cooler hours of the day. When the sun is at its hottest, they display a behaviour called wallowing—lounging and rolling around in large pits of wet mud. By doing so, they protect their skin from sun and insects and keep themselves cool.
Rhinos had an ancient ancestor that lived in Siberia during the Ice Age, the woolly rhino. Though it lived at the same time as the woolly mammoth, it’s less well known, and far fewer of its fossils and remains have been found.
Of the African rhinos, black rhinos are solitary and white rhinos are more social, often living in herds. As large mammals, all rhinos have slow reproduction rates. They give birth to just one calf at a time every two to four years, and their gestation period can last up to 16 months.
While adult rhinos have no natural predators, big cats, crocodiles, and wild dogs often target their calves. They are essential to their habitats as they help regulate and maintain plant life and grasslands on which many other species depend.
What is a rhino’s scientific name?
The scientific name of the family all five species belong to is Rhinocerotidae. The two African species of rhinoceros are:
● Diceros bicornis: Black rhinoceros
● Ceratotherium simum: White rhinoceros
The three Asian rhino species are:
● Dicerorhinus sumatrensis: Sumatran rhinoceros
● Rhinoceros sondaicus: Javan rhinoceros
● Rhinoceros unicornis: Greater one-horned rhinoceros
Are rhinos endangered?
According to the IUCN, Javan, Sumatran, and black rhinos are critically endangered, greater one-horned rhinos are vulnerable, and white rhinos are near threatened.
The primary threat faced by all five species of rhinoceros is poaching and illegal trade of their horns. However, habit loss and fragmentation are also threats.
Where do rhinos live?
Black rhinos live in Angola, Kenya, Mozambique, Namibia, South Africa, Tanzania, and Zimbabwe. In the past, their range covered the bottom two thirds of Africa, but they have since become extinct in many places.
White rhinos live in South Africa. Reintroductions and assisted colonisation projects are currently happening in Botswana, Eswatini, Namibia, Uganda, Zimbabwe, Mozambique, Kenya, and Zambia.
The greater one-horned rhinoceros live in India and Nepal. These rhinos have benefitted from successful conservation efforts, which have raised their numbers from around 200 at the beginning of the 20th century to approximately 3,700 today.
The threats facing some rhino species are very severe and require urgent attention. For example, the IUCN lists just 18 mature individuals left in the Javan species. Poaching, illegal trade, and habitat loss all affect rhinos, and their slow reproduction rates make recovery slow and difficult.
Rhino poaching has risen recently—around 7,100 African rhinos have been killed in the last 10 years. Poaching gangs search for rhinos from helicopters, shoot at them with guns or tranquiliser darts, and then remove their horns with chainsaws. They can complete this process in as little as 10 minutes.
Rhino horns are primarily used for traditional medicines and as high-value gifts in Asia, mostly in China and Vietnam. There are even some reports of rhinoceros horn being used as a party drug, a health supplement, and a hangover cure in these countries. In the past, people in Yemen used rhino horns to craft handles for ceremonial daggers.
The demand for rhino horns in Asia enables poaching gangs to make money, so conservationists must find ways to decrease this demand.
Habitat loss and fragmentation
The rhino's habitat and its quality decrease as human populations and infrastructure grow. This can affect food sources, which in turn affects the health and reproduction habits of rhinos.
Fragmentation can also have severe consequences. For example, the Sumatran rhino now exists in seven subpopulations totalling just 80 individuals. Each subpopulation is too separated from the others to allow breeding between them, putting the entire species at risk of inbreeding and potential extinction.
What do rhinos eat?
All rhinos are herbivores, but each rhinoceros species has its own specific diet based on the plants available in its habitat. White rhinos eat grass, black rhinos eat leaves and plants, Javan rhinos eat moist lowland plants, greater one-horned rhinos eat grass and waterside plants, and Sumatran rhinos eat a mix of everything available.
What are rhino horns made of?
Rhino horns are made of keratin, a type of protein, which also makes up human fingernails and parts of other animals. Rhinos can have their horns trimmed or sanded down without experiencing any pain. Horns that have been trimmed will eventually grow back.
Can rhinoceros swim?
All rhinos enjoy wallowing in mud to keep cool during hot days, but only Asian rhinos can swim. They use this skill to cross rivers, while their African counterparts avoid rivers due to the danger of drowning.
Do rhinoceros lay eggs?
Rhinoceros are mammals, so they don’t lay eggs. They give birth to live young and nurse them with milk until they can eat solid food. Rhinos have slow reproductive habits and only produce one calf every two to four years.
How long does a rhinoceros live?
White rhinos live in the wild for around 40-50 years, while black rhinos have a slightly shorter lifespan of 35-50 years. The Asian rhinoceros species have a lower maximum age, usually living for 30-40 years.
How many rhinos are left in the world?
At the turn of the 20th century, there were an estimated 500,000 rhinoceros worldwide. By 1970, this decreased to 70,000, and today there are just 27,000 rhinos left. According to the IUCN, there remain 10,080 mature white rhinoceros, 3,142 mature black rhinos, and an estimated 2,100-2,200 greater one-horned rhinos.
The two most endangered rhinos are the Sumatran and Javan rhinos, whose mature individuals total 30 and 18, respectively.
IFAW and the Wildlife Trust of India (WTI) work together to rescue and rehabilitate rhino calves near Kaziranga National Park. The team relocates and re-releases the rhinos into Manas National Park, which was unfortunately damaged due to ethnic conflicts three decades ago, resulting in the poaching of more than 100 greater one-horned rhinos.
Through our partnership with WTI, we worked to restore the landscape and keystone species and expand the amount of protected land. We also contributed to conservation efforts that brought back greater one-horned rhinoceros numbers from just 200 to 3,500.
In addition to our work in India, we have a dedicated team of rangers working to protect rhinos in Africa, on the border between Zambia and Malawi. In Kenya, IFAW’s Team Lioness also works to combat poaching and promote coexistence between rhinos and humans. Team Lioness is made up of Maasai women who are the first women in their families to secure employment.
At a policy and advocacy level, our teams worldwide always work to reduce demand for rhino horn products and ensure markets remain closed.