Today's rhinos are the descendants of an animal that roamed our planet over 40 million years ago. During the second epoch of the paleogene period, an animal evolved from Asian hyracodonts. Paraceratherium was the largest land mammal ever to walk the Earth's surface. The titan stood over five metres tall at the shoulders, had a 26-foot-long body, and weighed a colossal 20 tonnes.
It is thought that more than 30 genera and 60 different species of rhino once roamed Europe, Asia, and Africa. Even at the turn of the century, there were 500,000 rhinos in the wild, but today an estimated 25,000 individuals represent more than 40 million years of evolution.
Our modern-day rhinos' ancestors have survived searing heat, ice ages, and prehistoric predators such as hyenas and giant crocodiles. They are now up against the most dangerous predator of modern times. Humans.
Order: Perissodactyla (odd-toed ungulate)
• The word rhinoceros comes from two Greek words. 'Rhino' meaning 'nose' & 'keras' meaning 'horn'
• There are 5 species of rhino
• There are 11 sub-species of rhino (a sub-species is a division within a species)
• A group of rhinos is called a crash
• Male rhinos are called bulls
• Female rhinos are called cows
• Infant rhinos are called calves
• Rhinos are ungulates (hoofed feet animals)
• Rhinos are odd-toed with 3 toes on each foot
• Their middle toes support most of their weight
• Their feet have a diameter between 20-35cm
• Horses, tapirs & zebras are related to rhinos
• They lack good binocular vision. A 2008 study suggests their vision is comparable to a rabbit
• All rhinos have 3 molars & 3 premolars on each side of their upper & lower jaws
• Indian & Sumatran rhinos also have incisors
• Sumatran rhinos are the only rhino species with hairy bodies
• Their brains weigh around 500-550g
• Their hearts weight around 10kg
• All five rhino species are herbivores
• Rhinos are either browsers or grazers
• Browsers have pointy lips for plucking foliage
• Browsers eat branches, twigs, bushes & fruit
• Grazers have flat mouths for shearing grass
• Grazers mainly eat grass
• In total, rhinos eat more than 200 varieties of vegetation
• Rhinos can consume the equivalent of 500 chocolate bars each day
• They can poop up to 50lbs of dung each day
• Unlike tusks, which are teeth, and antlers, which are bone, rhino horn is made of keratin
• Indian & Javan rhinos have one horn
• Black, white & Sumatran rhinos have two horns
• Horns grow around 7cm each year
• Horns are used for digging for water, foraging, guiding their young, defence & displays of dominance
• While African rhinos use their horns to fight and protect themselves from predators, Asian rhinos tend to use their teeth
• The longest white rhino horn was recorded in South Africa & reportedly measured 59 inches
• The longest black rhino horn was recorded in Kenya reportedly measuring 51 inches long
• The largest Indian rhino horn weighed approximately 3kg with a base base circumference of 60cm
• Over the past century, rhinos have evolved smaller horns, according to a 2022 study published in People and Nature.
Researchers analyzed 80 profile images of rhinos taken between 1886 and 2018. The study found the horns of all five rhino species had significantly decreased likely due to external factors such as intensive hunting and poaching.
• Rhinos reproduce every 2 to 5 years
• They have an average gestation of around 15 months
• They only give birth to a single calf
• Calves are fully weaned at around 2-2.5 years
• Calves usually stay with mum for 2-3 years
• Most wild calves will never meet their father
• To grow healthy gut bacteria, rhino calves consume their mother's dung (coprophagia).
• Wild rhinos can only be found in Africa & Asia
• White & black rhinos are found in Africa
• Javan, Sumatran & Indian rhinos live in Asia
• African rhinos are found on savannahs, bushveld, tropical & sub-tropical grasslands
• Asian rhinos are found in tropical & sub-tropical forests, wetlands & swamps
• Rhinos are a keystone species and have a major impact on the structure of the habitat and health of the ecosystem. Research in February 2014 by the Journal of Ecology revealed rhino-inhabited areas contained 20 times more grazing lawns. The study also revealed that areas inhabited by fewer rhinos have 60-80% less short grass cover.
• Rhinos are an "umbrella species". This means their conservation results in the preservation of other species within the ecosystem.
• Rhinos are also considered to be "flagship species". These are species considered iconic and synonymous with the particular region they inhabit. Examples of flagship species are rhinos and elephants in Africa and pandas in China. Flagship species promote tourism and generate vital funding for conservation.
• Rhinos use dung and urine to scent mark and define territories. The male Indian rhino uses urine to show dominance, and can spray a diatance of almost 5 meters!
• Rhino dung spreads nutrients, enriches soil, and disperses seeds, and communal piles of dung known as middens foster complex food chains that support birds, mammals, and reptiles. Additionally, they provide visual and olfactory communication. Age, sex, territorial status, reproductive viability, and other personal information are displayed in middens like a notice board or social network.
• A prehistoric rhinoceros known scientifically as Elasmotherium (colloquially referred to as the giant unicorn) holds the record as the largest mammal with a single central horn on its head. Based on fossil evidence, the horn was over two meters long
• The earliest rhinoceros to have borne horns was Menoceras, which was no bigger than today's wild boar
• A female rhino called Bina is the oldest captive Sumatran rhino on record. She celebrated her 41st birthday in 2022 at the Sumatran Rhino Sanctuary, Way Kambas National Park, Indonesia, where she's lived since the early 1990s
• Before she died in 2019 at the age of 57, Fausta, a female eastern black rhino, was considered the oldest wild rhino in the world. She was first sighted at the Ngorongoro crater, Tanzania in 1965