Northern white rhinoceros

Northern white rhinoceros (also called the 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, which means it eats grass. It lives in grasslands and savanna woodlands.

It once lived in several countries in East and Central Africa, south of the Sahara. Since March 2018, only two of these rhinos have been known to be alive. They are named Najin and Fatu, and both are female. Unless there are other northern white rhinos somewhere else in Africa that no one has found, this means the subspecies is functionally extinct. This means that so few are left that they can no longer survive as a group in the wild.

The two female rhinos belong to the Dvůr Králové Zoo in the Czech Republic. They live at the Ol Pejeta Conservancy in Kenya, where armed guards help keep them safe. 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 from the southern white rhinoceros. If so, its correct scientific name would be Ceratotherium cottoni. The study said that the two kinds looked different in body shape and had different genes. It suggested they had been separated for at least a million years. However, not all other scientists agreed with these results.

A study in 2016 found that the two groups separated 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 way to classify them.

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. 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. Sudan died on 19 March 2018.

Experts and staff watch the rhinos closely. They live in special enclosures called bomas with a large paddock. Their horns were sawn off so they would not hurt each other. This also helps keep them safer from poaching, because 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 young. In 2015, tests showed that neither female could have babies 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 have young 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. It used 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. They were to be artificially inseminated with frozen sperm. In September 2019, scientists reported that they had fertilised eggs in vitro with sperm from dead males. 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. 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 also have lived as far west as Lake Chad, in Chad and Cameroon. Hunting greatly reduced its numbers. The population grew back for a while, but then hunting 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. The World Wide Fund for Nature described them as the last known wild northern white rhinos. By 2008, the species was thought to be extinct in the wild. Its last possible group in southern Sudan is now considered to be gone too.

In 2015, only two captive northern white rhinos were left. They lived 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 babies. The last calf was born in 2000. In 2009, the zoo sent Suni, Sudan and two females to Ol Pejeta Conservancy in Kenya. This was a joint effort with Fauna and Flora International, Back to Africa, Lewa, and Kenya Wildlife Service. The hope was that they would breed in their natural habitat. After Nabire died in 2015, scientists sent her ovary and its oocytes to a laboratory in Cremona, Italy. There, two egg cells were fertilised. The San Diego Zoo Safari Park in California once had eight wild-caught northern white rhinos. They included Angalifu, who was on loan from Khartoum Zoo in Khartoum, and Nola.

Population chart