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 being the southern white rhinoceros). This subspecies is a grazer in grasslands and savanna woodlands. Formerly found in several countries in East and Central Africa south of the Sahara, since 19 March 2018, there are only two known rhinos of this subspecies left, named Najin and Fatu, both of which are female; barring the existence of unknown or misclassified male northern white rhinos elsewhere in Africa, this makes the subspecies functionally extinct. The two female rhinos belong to the Dvůr Králové Zoo in the Czech Republic but live in the Ol ...

Kenya

At the end of 2015, scientists from the Leibniz Institute for Zoo and Wildlife Research, San Diego Zoo Global, Tiergarten Schönbrunn, and Dvůr Králové Zoo developed a plan to reproduce northern white rhinos using natural gametes of the living rhinos and induced pluripotent stem cells. Subsequently, in the future, it might be possible to specifically mature the cells into specific cells such as neurons and muscle cells, in a similar way in which Katsuhiko Hayashi has grown mouse oocytes out of simple skin cells. The DNA of a dozen northern white rhinos has been preserved in genetic banks in Berlin and San Diego. In August 2019, ten egg cells (five from Najin and five from Fatu) were harvested to be artificially inseminated with the frozen sperm of a northern white rhino as part of a project by the Leibniz Institute for Zoo and Wildlife Research, Dvůr Králové Zoo, Kenya Wildlife Service, and Avantea. In September 2019, scientists announced that they fertilized in vitro the eggs with frozen sperm taken from dead males; two of the resulting embryos were viable. In January 2020, it was announced that another embryo was created using the same techniques; all three embryos are from Fatu. These embryos are being stored in liquid nitrogen until they can be placed into a surrogate mother, probably a southern white rhino. In December 2020, 14 egg cells were retrieved from Fatu; eight of them were fertilised by the sperm of the dead northern white rhino Suni, resulting in two viable embryos. No egg cells were retrieved from Najin. As of 2025, there are 38 northern white rhino embryos that have been created by BioRescue. The embryos are cryopreserved in labs in Berlin, Germany and Cremona, Italy. The BioRescue team successfully implanted a southern white rhino embryo in a southern white rhino surrogate named Curra in 2023 in a complicated procedure, but Curra died in November due to a rare bacterial infection. Efforts to reproduce the pregnancy with a northern white rhino embryo are ongoing.

Following the phylogenetic species concept, a study in 2010 suggested the northern white rhinoceros may be an altogether different species, rather than a subspecies of white rhinoceros, in which case its correct scientific name would be Ceratotherium cottoni. According to the study, distinct morphological and genetic differences suggest the northern white rhinoceros and southern white rhinoceros have been separated for at least a million years. However, the results of this research were not universally accepted by other scientists. A study in 2016 concluded that the two populations diverged between 0.46 and 0.97 million years ago and found their mitochondrial genomes to be 1.8% divergent. Based on these findings, the study concluded that classification as a subspecies was appropriate.

The northern white rhino formerly ranged over parts of northwestern Uganda, southern South Sudan, the eastern part of Central African Republic, and northeastern Democratic Republic of the Congo. Their range possibly extended as far west as Lake Chad, into Chad and Cameroon. Poachers reduced their population from 500 to 15 in the 1970s and 1980s. From the early 1990s through mid-2003, the population recovered to more than 32 animals. Since mid-2003, poaching has intensified and further reduced the wild population. ==== Garamba National Park ==== The last known surviving population of wild northern white rhinos was in Garamba National Park, Democratic Republic of the Congo (DRC). In January 2005, the government of the DRC approved a two-part plan for five northern white rhinos to be moved from Garamba National Park to a wildlife sanctuary in Kenya. The second part commits the government and its international partners to increase conservation efforts in Garamba, so the northern white rhinos can be returned when it is safe again. However, the translocation did not occur. In August 2005, ground and aerial surveys conducted under the direction of African Parks Foundation and the African Rhino Specialist Group (ARSG) had only found four animals, a solitary adult male and a group of one adult male and two adult females. They were the last known wild northern white rhinos, according to the World Wide Fund for Nature. In June 2008, it was reported that the species may have gone extinct in the wild, since there has been no sighting of these four known remaining individuals since 2006, or of their signs since 2007, despite intensive systematic ground and aerial searches in 2008. One carcass has been found. On 28 November 2009, two Russian helicopter pilots reported seeing rhinoceroses in southern Sudan. It was assumed that the three rhinos that were spotted belonged to the northern white rhinoceros subspecies, as black rhinos had not lived in the area for a long time and southern white rhinos never lived in southern Sudan. However, as of August 2011, no other sightings have been reported, and this population is now considered to have probably gone extinct.

Following the phylogenetic species concept, a study in 2010 suggested the northern white rhinoceros may be an altogether different species, rather than a subspecies of white rhinoceros, in which case its correct scientific name would be Ceratotherium cottoni. According to the study, distinct morphological and genetic differences suggest the northern white rhinoceros and southern white rhinoceros have been separated for at least a million years. However, the results of this research were not universally accepted by other scientists. A study in 2016 concluded that the two populations diverged between 0.46 and 0.97 million years ago and found their mitochondrial genomes to be 1.8% divergent. Based on these findings, the study concluded that classification as a subspecies was appropriate.