Northern white rhinoceros

The northern white rhinoceros or northern white rhino (Ceratotherium simum cottoni) is one of two subspecies of the white rhinoceros. The other is the southern white rhinoceros. This subspecies is a grazer that lives in grasslands and savanna woodlands.

It was once found in several countries in East and Central Africa, south of the Sahara. Since 19 March 2018, only two known rhinos of this subspecies have been left, named Najin and Fatu. Both are female. Unless unknown or misclassified males of the northern white rhino exist elsewhere in Africa, this means the subspecies is functionally extinct.

The two female rhinos belong to the Dvůr Králové Zoo in the Czech Republic, but they live in the Ol Pejeta Conservancy in Kenya, where armed guards protect them. The latest assessment by the International Union for Conservation of Nature (IUCN), from 2020, lists the subspecies as "Critically Endangered (Possibly Extinct in the Wild)."

Taxonomy

In 2010, a study using the phylogenetic species concept suggested that the northern white rhinoceros might be a completely different species, rather than a subspecies of white rhinoceros. If so, its correct scientific name would be Ceratotherium cottoni. The study said that clear differences in body shape and genes suggested the northern and southern white rhinoceros had been separated for at least a million years. However, other scientists did not all accept these results.

A study in 2016 found that the two populations split apart between 0.46 and 0.97 million years ago. Their mitochondrial genomes differed by 1.8%. Based on these findings, the study concluded that being a subspecies was the right classification.

Living rhinos

Only two northern white rhinos are left in the world. Both are female. Najin was born in captivity in 1989. Her mother was Nasima and her father was Sudan. Her daughter, Fatu, was born in captivity in 2000 and her father was Saut. Both belong to the Dvůr Králové Zoo in the Czech Republic, but they live at Ol Pejeta Conservancy in Kenya, Africa. They arrived there on 20 December 2009, with two male northern white rhinos, Suni and Sudan. Suni died of natural causes at the conservancy in 2014, and Sudan died on 19 March 2018. The rhinos are watched closely by experts and staff. They live in special enclosures called bomas with a large paddock. Their horns were sawn off so they would not hurt each other, and so they would be less at risk from poaching, since poachers want the horn. Radio transmitters were placed where their horns had been, so their location can be tracked. Armed guards protect them day and night. In 2012, Suni and Najin mated, but no pregnancy followed. In 2014, a male southern white rhino from Lewa Wildlife Conservancy was placed with the females to try to produce offspring. In 2015, tests showed that neither female could reproduce naturally. The BBC programme Last Chance to See, presented by Stephen Fry and zoologist Mark Carwardine, featured the rhinos' move.

Scientists are also trying to help the species reproduce in other ways. At the end of 2015, experts from the Leibniz Institute for Zoo and Wildlife Research, San Diego Zoo Global, Tiergarten Schönbrunn, and Dvůr Králové Zoo made a plan using natural gametes from the living rhinos and induced pluripotent stem cells. Scientists have also grown mouse eggs from simple skin cells, as Katsuhiko Hayashi did. In August 2019, ten egg cells were collected from Najin and Fatu to be artificially inseminated with frozen sperm. In September 2019, scientists reported that they had fertilised eggs in vitro with sperm from dead males, and two of the resulting embryos were viable. Embryos are kept frozen until they can be placed into a surrogate mother, probably a southern white rhino. In 2023, a southern white rhino embryo was placed in a southern white rhino surrogate named Curra, but Curra died in November from a rare bacterial infection. Efforts to carry a northern white rhino pregnancy are still ongoing.

Recently deceased rhinos

The northern white rhino once lived in parts of northwestern Uganda, southern South Sudan, the eastern part of Central African Republic, and northeastern Democratic Republic of the Congo. It may have also reached as far west as Lake Chad, into Chad and Cameroon. Poachers reduced its numbers from 500 to 15 in the 1970s and 1980s, and the population grew back to more than 32 animals by mid-2003. After that, poaching increased again. The last known wild rhinos lived in Garamba National Park in the Democratic Republic of the Congo. In 2005, surveys led by the African Parks Foundation found only four animals, which the World Wide Fund for Nature described as the last known wild northern white rhinos. By 2008, the species was reported to have possibly gone extinct in the wild, and its last possible group in southern Sudan is now considered to have probably gone extinct.

In 2015, only two captive northern white rhinos were left, at the San Diego Zoo Safari Park in the United States and the Dvůr Králové Zoo in the Czech Republic. Both died that year, so no zoo in the world has northern white rhinos now. The Dvůr Králové Zoo, in Dvůr Králové nad Labem, was the only zoo where these rhinos had offspring, with the last calf born in 2000. In 2009, the zoo sent Suni, Sudan and two females to Ol Pejeta Conservancy in Kenya, in a joint effort with Fauna and Flora International, Back to Africa, Lewa, and Kenya Wildlife Service, hoping they would breed in their natural habitat. After Nabire died in 2015, her ovary with its oocytes was sent to a laboratory in Cremona, Italy, where two egg cells were fertilised. The San Diego Zoo Safari Park in California once had eight wild-caught northern white rhinos, including Angalifu, who was on loan from Khartoum Zoo in Khartoum, and Nola.

Population chart