White rhinoceros
The white rhinoceros, a grey giant with a mouth as wide as a lawnmower, lives in two very different worlds. At the end of 2023, an estimated 17,464 southern white rhinos were living in the wild, more than every other rhino subspecies combined. Their northern cousins number just two animals, both female, both living under constant armed guard.
This is the largest of the five living rhinoceros species, and only the three elephant species outweigh it on average. It is also the most social rhino, and yet its name seems to describe a colour it does not have. How did one animal become both a success story and a near-extinction? Why does anyone argue about where it came from? And what are scientists attempting in a laboratory to rescue the last of the northern line?
The rhino called white is grey, often tinted yellowish-brown or dark slate by whatever mud it has last rolled in. So where did the word come from? The honest answer is that nobody knows.
A popular theory blames the Dutch word wijd, meaning wide. Early English-speaking settlers in South Africa, the story goes, heard a description of the animal's broad mouth and wrote down white instead. The theory is tidy, and it has been discredited.
A review of Dutch and Afrikaans writing by Rookmaaker, published in 2003, found no written case of wijd ever being applied to this rhino. The evidence even points the other way. Afrikaans speakers say witrenoster, a direct copy of the English phrase, which suggests the English name came first.
The scientific name is easier to trace. In 1868 the zoologist John Edward Gray coined the genus Ceratotherium from Greek words for horn and beast. The species name simum comes from the Greek for flat-nosed. A less common English alternative, square-lipped rhinoceros, simply describes that same broad snout.
A bull white rhino typically weighs between 2000 and 2300 kg, while a cow averages about 1600 to 1700 kg. Specimens of up to 3600 kg are considered reliably recorded. Claims of 4500 kg have never been verified, so the true maximum remains unknown.
The feature that sets the animal apart is its mouth. Straight and square, it lets the rhino crop wide swaths of short grass with each pass. A muscular hump on the back of the neck holds up the heavy head through long hours of feeding.
The two horns on its snout are not horns in the cattle sense, and they are not bony antlers. Each is a solid mass of tightly packed keratin fibres, the protein in human hair and fingernails. The front horn averages 60 cm, although some cows have grown one as long as 166 cm. A single horn can weigh around 4.0 kg.
Sight is this animal's weakness. Its large tubular ears swivel independently across a wide arc to pinpoint faint sounds. Its smell is even more remarkable: the nasal passages are larger than the brain, and the nostrils are the widest set of any land animal.
Inside each cell lies a genome of roughly 2.58 gigabase pairs, packaged into 82 chromosomes. That genetic blueprint now matters far beyond the laboratory, because it underpins the effort to save the northern subspecies.
A skull found at Langebaanweg, near Cape Town, once seemed to settle the white rhino's ancestry. The remains belonged to a species called Ceratotherium praecox, about seven million years old, and researchers treated it as the direct forerunner of the modern animal.
In 2005 the palaeontologist Denis Geraads challenged that view. He argued that the original specimen of C. praecox looked closer to a black rhino and belonged in the genus Diceros. A separate study by Turner in 2004 had suggested the modern skull grew longer for grazing short grass as Africa dried out. If the old species was really a browser, that explanation weakens.
Teeth from Makapansgat in South Africa add another complication. Carbon isotope analysis showed those Ceratotherium animals took in over 30% browse, unlike today's exclusive grass eaters. Geraads therefore proposed a different line running from Ceratotherium neumayri through Ceratotherium mauritanicum to the living species.
In 2011 Hernesniemi and colleagues offered a rival picture. They started with Ceratotherium efficax, found in Late Pliocene Ethiopia and Early Pleistocene Tanzania, and saw it branching into several lineages, including the northern African C. mauritanicum and the East African C. germanoafricanum. That East African form looks so like the living rhino that it was often counted as an ancestral subspecies. The study also doubted that the southern European C. neumayri gave rise to any African species.
One point has wide support. The common ancestor of black and white rhinos probably ate both leaves and grass, and the two lineages later specialised as browser and grazer. The oldest firm fossil of the living species is about 1.8 million years old and comes from Olduvai Gorge in Tanzania.
Half of a white rhino's day goes to eating. About a third goes to resting, and the rest covers everything else. With water nearby, it drinks twice daily, but in dry country it can last four or five days without a drink.
Such appetites shape the landscape. Scientists regard these animals as ecological engineers whose grazing patterns influence grassland and savanna structure. Losing megaherbivores like them can trigger cascading harm to many other species.
The social lives are more varied than the heavy build suggests. Females and calves gather in groups called crashes, usually up to 14 animals. Most adult bulls live alone. A dominant bull builds 20-30 dung middens to announce his territory, scuffs the ground before spraying urine, and may patrol and mark up to ten times an hour. Subordinate bulls hold no territory, and the fiercest fights erupt over females in breeding condition.
Communication runs from a panting contact call to squeals of alarm and bellows when threatened. A threatening bull wipes his horn on the ground and lowers his head with ears flat. Calls differ between the northern and southern subspecies, and even between individuals. Despite the bulk, a white rhino can sprint at up to 64 km/h.
Females mature at six to seven years old, while males wait until ten to twelve. Courtship can be long and rough, with a persistent bull blocking a cow's path if she tries to leave his territory. Pairs may stay together for 5-20 days. After about 16 months of gestation, a single calf is born and wobbles for its first two or three days. Mothers chase off the previous calf before a new birth, and births come two to three years apart. Lifespan is estimated at 40-50 years.
Adults have no real predators except humans. One rare exception was recorded at Mala Mala Game Reserve in South Africa, where a lion pride killed an ailing bull weighing 1540 kg.
In 2013, poaching in South Africa nearly doubled compared with the year before, according to official statistics. The surge was one chapter in a long story. Colonial-era hunting had already cut white rhino numbers, but organised poaching became the more urgent danger.
The animal's size, calm temperament, poor eyesight and life in groups all make it an easier target. The motive is money. Ground into powder or pressed into tablets, horn is used in some traditional Asian medicines for ailments from fever to cancer, though it has no demonstrated medical value. It is the same keratin as a fingernail. Carved ornaments and status symbols add to demand.
Prices on the black market can reach tens of thousands of US dollars per kilogram, sometimes more than gold by weight. That profit funds transnational criminal syndicates equipped with night vision gear, silenced weapons, veterinary tranquilizers and sometimes helicopters. Armed groups such as the Janjaweed have been linked to the killing in some regions. Poachers even search social media for geotagged tourist photographs to learn where rhinos are standing.
The damage shows in the numbers. Kruger National Park lost roughly 60% of its white rhinos between 2013 and 2021, leaving an estimated 3,529. Mozambique has been identified as a transit route for smuggled horn, and as of 2014 its laws reportedly treated rhino poaching as a misdemeanour.
The reach of the trade extends to Europe. In March 2017, poachers broke into Thoiry Zoo in France and killed a southern white rhino named Vince for his horn, in what is believed to be the first such fatal attack at a European zoo.
By the early 20th century the southern white rhino was close to extinction. It then staged a remarkable recovery. South Africa now holds the great majority, about 12,968 animals in 2021. Namibia, Botswana, Zimbabwe, Uganda and Eswatini host populations reintroduced to the subspecies' historical range, a few survive in Mozambique, and others have been introduced to Kenya and Zambia, outside the old range.
The northern white rhino followed a grimmer path. Its range once stretched across northwestern Uganda, southern Chad, southwestern Sudan, the eastern Central African Republic and northeastern Democratic Republic of the Congo. Its last wild stronghold was Garamba National Park in the Congo.
In August 2005, surveys there found only four animals. By June 2008, reports said the subspecies might be extinct in the wild. Continuing conflict in the region and armed poachers crossing borders undermined every effort to protect them.
Scientists also disagree over what the northern animal even is. Groves and colleagues proposed in 2010 that it should be its own species, Ceratotherium cottoni, because the two lineages may have been separated for at least one million years. The proposal was not universally accepted, and the IUCN still treated it as a subspecies as of 2020. The whole species is rated Near Threatened.
Six northern white rhinos once lived at Dvůr Králové Zoo in the Czech Republic. On the 20th of December 2009, four of them, the only ones able to reproduce, were flown to Ol Pejeta Conservancy in Kenya. Keepers hoped a natural setting, tight security and a managed diet would finally spark breeding.
It did not work. One rhino left in the Czech Republic died in May 2011. Suni died in Kenya on the 18th of October 2014, and Angalifu died at San Diego Zoo Safari Park in December of that year. Those two were the last bulls able to mate naturally. At San Diego, the female Nola, born in 1974, was euthanized on the 22nd of November 2015 as her health declined.
The last male, Sudan, lived under 24-hour armed guard at Ol Pejeta until he was euthanized on the 19th of March 2018 because of age-related illness. That left two females, Najin and Fatu, still guarded around the clock.
In February 2014, a fertile southern white bull from Lewa Wildlife Conservancy had been placed with the females. No pregnancies or matings were reported.
The next attempt moved into the laboratory. On the 22nd of August 2019, scientists announced that eggs harvested from Najin and Fatu had been fertilised by injecting sperm frozen from dead bulls, among them Saut and Suni. Two embryos were announced on the 11th of September 2019, and a third, all from Fatu's eggs, on the 15th of January 2020. They remain frozen, awaiting transfer into southern white surrogates.
Sudan's stored semen offers another hope, though the quality of sperm from an old bull and the difficulty of the procedures remain obstacles. Worldwide, over 1,000 southern white rhinos lived in zoos and parks in 2021, but captive-born females there reproduce at a worryingly low rate that researchers cannot yet explain.
Updated
Common questions
Why is the white rhinoceros called white?
The origin of the name is unknown. A popular theory blames a mistranslation of the Dutch word wijd, meaning wide, but a review of Dutch and Afrikaans writing found no written evidence for it, and the theory is discredited.
How many white rhinos are left?
An estimated 17,464 southern white rhinos lived in the wild at the end of 2023. The northern subspecies is reduced to two females, Najin and Fatu, at Ol Pejeta Conservancy in Kenya.
Are rhino horns made of bone?
No. They are solid masses of densely compacted keratin fibres, the same protein found in human hair and fingernails.
What are scientists doing to save the northern white rhino?
Scientists have created three embryos by fertilising eggs from Najin and Fatu with frozen sperm from dead bulls. The embryos are stored frozen, with plans to transfer them into southern white surrogate females.
How fast can a white rhino run?
A white rhino can run at speeds of up to 64 km/h, despite its great bulk.
All sources
70 references cited across the entry
- 1Ceratotherium simumEmslie, R. — 2020
- 3NewsWorld's last male northern white rhino dies20 March 2018
- 4JournalWhy the name of the white rhinoceros is not appropriateRookmaaker, Kees — 2003
- 5JournalCeratotherium simumColin P. Groves — 1972
- 6BookThe Mammals of the Southern African Sub-regionSkinner, J. D. et al. — Cambridge University Press — 2005
- 8BookEvolving Eden: An Illustrated Guide to the Evolution of the African Large-mammal FaunaTurner, Alan — Columbia University Press — 2004
- 9JournalIsotopic palaeoecology of Makapansgat Limeworks PerissodactylaSponheimer, M. et al. — 2001
- 10BookPalaeontology and Geology of Laetoli: Human Evolution in Context. Volume 2: Fossil Hominins and the Associated FaunaE. Hernesniemi et al. — Springer Science+Business Media B.V. — 2011
- 11JournalPerissodactyla (Rhinocerotidae and Equidae) from KanapoiD. Geraads — 2020
- 12BookCenozoic mammals of AfricaD. Geraads — University of California Press — 2010
- 14BookAfrican Rhino. Status Survey and Conservation Action PlanEmslie, R. et al. — IUCN/SSC African Rhino Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK — 1999
- 16NewsWhite rhino dies in Czech zoo, seven left worldwideRaymond Johnston — 2 June 2011
- 18NewsDeath of rare northern white rhino leaves species on brink of extinctionDrazen Jorgic — 19 October 2014
- 19NewsLast male northern white rhino is put downHannah Ellis-Petersen — 20 March 2018
- 20JournalThe Sixth Rhino: A Taxonomic Re-Assessment of the Critically Endangered Northern White RhinocerosC. P. Groves et al. — 2010
- 21Ceratotherium simum ssp. cottoniEmslie, R. — 2020
- 22JournalThe microbial community in the feces of the white rhinoceros (Ceratotherium simum) as determined by barcoded pyrosequencing analysisG. Bian et al. — 2013
- 23Cumming, D. H. M., Du Toit, R. F., & Stuart, S. N. (1990). African Elephants and Rhinos: Status Survey and Conservation Action Plan: Action Plan for the Conservation of Biological Diversity 10. IUCN/S
- 24JournalAn experimental cropping scheme of Hippopotami in the Letaba river of the Kruger National ParkU. de V. Pienaar et al. — 1966
- 25BookThe New Encyclopedia of MammalsD. Macdonald — Oxford University Press — 2001
- 26BookMegaherbivores: The Influence of Very Large Body Size on EcologyR. Norman Owen-Smith — Cambridge University Press — 1992
- 27BookNamibia (Other Places Travel Guide)Jeremiah Allen — Other Places Publishing — 2010
- 28BookHidden Animals: A Field Guide to Batsquatch, Chupacabra, and Other Elusive CreaturesMichael Newton — Greenwood Press — 2009
- 29JournalThe size of the largest marsupial and why it mattersWroe, S. et al. — 2004
- 30Buyers of Rhino HornPoaching Facts
- 31JournalThe white rhinocerosE. Heller — 1913
- 33Stephen J. O'Brien, Joan C. Menninger and William G. Nash: Atlas of Mammalian Chromosomes John Wiley & Sons, Inc., Hoboken 2005, , S. 678
- 34JournalComparative dental microwear of ruminant and perissodactyl molars: Implications for paleodietary analysis of rare and extinct ungulate cladesMatthew C. Mihlbachler et al. — February 2016
- 35JournalRestoration of a megaherbivore: Landscape-level impacts of white rhinoceros in Kruger National Park, South AfricaJ. P. G. M. Cromsigt et al. — 2014
- 36JournalContact Calls of the Northern and Southern White Rhinoceros Allow for Individual and Species IdentificationIvana Cinková et al. — 2014-06-05
- 37BookThe Behavior Guide to African Mammals: Including Hoofed Mammals, Carnivores, PrimatesRichard Estes — University of California Press — 1991
- 40Wildlife: RhinocerosAfrican Wildlife Foundation
- 41JournalLarge predators and their prey in a southern African savanna: a predator's size determines its prey size rangeRadloff, F. G. — 2004
- 42JournalThe past and present distribution of some African ungulatesJ. Sydney — 1965
- 45WWF | Northern White RhinoWorldwildlife.org
- 46NewsPoachers kill last four wild northern white rhinosLewis Smith — 17 June 2008
- 47Rhino poaching in Africa reaches all-time highChristopher Szabo — 9 September 2013
- 48Rhino Horn Use: Fact vs. FictionPBS — 20 August 2008
- 49African rhino poaching crisisWorld Wide Fund For Nature
- 50NewsStropery: Koerier praat uitVicus Bürger — 28 March 2015
- 52Rhino Poaching UpdateSiyabonga Africa
- 53NewsPoachers Kill Rhino in Brazen Attack at French Zoo7 March 2017
- 54NewsPoachers kill rhino for his horn at French zooBBC News — 7 March 2017
- 55NewsPoachers Break into French Zoo, Kill White Rhino And Steal His HornNPR — 7 March 2017
- 56Rhino WarsPeter Gwin — National Geographic — March 2012
- 57NewsStick to Foodstagramming: Poachers May Be Following Your Safari PicturesLaura Stampler — 7 May 2014
- 58NewsScientists seek to create new rhinos with stem cell technologyDeborah Sullivan — 20 December 2014
- 59NewsMale Southern White Rhino Introduced in Endangered Species BomaOl Pejeta Conservancy — 12 February 2014
- 60NewsScientists Fertilize Eggs From the Last Two Northern White RhinosJacey Fortin — 28 August 2019
- 61Scientists have successfully created embryos of the near-extinct northern white rhinoAbdi Latif Dahir — 11 September 2019
- 63News'Amazing': New embryo made of nearly extinct rhino speciesAnna Cara — 15 January 2020
- 64NewsScientific Detective Work in Practice: Trying to Solve the Mystery of Poor Captive-born White Rhinoceros ReproductionRon Swaisgood — Zoological Society of San Diego — Summer 2006
- 66NewsA northern white rhino has died. There are now five left in the entire worldAbby Ohlheiser — 15 December 2014
- 67NewsNorthern white rhino put down at San Diego zoo leaving just three worldwide23 November 2015
- 70VideoThe Last Two Northern White Rhinos in the WorldAnneka Svenska — 16 August 2019