Northern white rhinoceros

Northern white rhinoceros
Angalifu, a male northern white rhinoceros at the San Diego Zoo Safari Park. Angalifu died 14 December 2014[1]
Conservation status
Critically Endangered  (IUCN 3.1)[2]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Perissodactyla
Family:	Rhinocerotidae
Genus:	Ceratotherium
Species:	C. simum
Subspecies:	C. s. cottoni
Trinomial name
Ceratotherium simum cottoni (Lydekker, 1908)
Orange = Northern white rhino range, Green = Southern white rhino range

The northern white rhinoceros, or northern square-lipped rhinoceros (Ceratotherium simum cottoni), is one of the two subspecies of the white rhinoceros. Formerly found in several countries in East and Central Africa south of the Sahara, it is listed as Critically Endangered. This subspecies is a grazer in grasslands and savanna woodlands. As of November 2015, there are only three rhinos of this subspecies left. They all belong to the Dvůr Králové Zoo in the Czech Republic but live in the Ol Pejeta Conservancy in Kenya and are protected round-the-clock by armed guards. According to the latest IUCN's assessment from 2011, the subspecies is considered "Critically Endangered (Possibly Extinct in the Wild)".^[2]

Living rhinos

Ol Pejeta Conservancy

A northern white rhinoceros near the equator during translocation to Ol Pejeta Conservancy Photo:Michael Dalton-Smith

One of the northern white rhinos translocated to Ol Pejeta is now living in a semiwild state. Photo:Michael Dalton-Smith

The zoo population is declining, and northern whites have rarely reproduced in captivity. There are now only three northern white rhinos left. They all belong to the Dvůr Králové Zoo in the Czech Republic, but were transported to Ol Pejeta Conservancy in Kenya, Africa.^[3] They arrived at the conservancy after an air and road trip on 20 December 2009.^[4]

The three rhinos (1 male and 2 female), under constant watch by specialists and staff, lived in specially constructed bomas with access to a 400×400-metre paddock area, allowing them to acclimatize to their new surroundings. These three were:

• Sudan, a 43-year-old male (as of 2016), who was caught from the wild in Sudan at 3 years old.
• Najin, a female, was born in captivity in 1989. She is Suni's half-sister and mother of Fatu.^[5]
• Fatu, a female, was born in captivity in 2000. She is the daughter of Najin.^[5]

To prevent any unnecessary injuries they might inflict on each other while interacting in their fenced area, and give their horns an opportunity to regrow to a natural shape (as their front horns had grown bent by much rubbing against enclosure bars in captivity), all three rhinos were sedated and their horns were sawn off. This also made them less vulnerable to the poaching that drove their species to near extinction, as the horn is what the poachers are after. In place of their horns, radio transmitters have been installed to allow closer monitoring of their whereabouts.^[6] They are protected round-the-clock by armed guards.^[7]

Since May 2010, the northern white rhino male Sudan was moved from the initial holding pens to a much larger 700-acre (2.8 km²) semiwild enclosure. There he roams among many African animals, including several southern white rhino females and many plains animals. On 26 October 2011, the females were coaxed into the larger enclosure. Because Najin was overly protective of her daughter Fatu's chance at mating, one of the two moved back into the smaller enclosure two weeks later.

Until 2011, the progress of this attempt at saving the northern white rhinoceros was documented on the initiative's website;^[8] and their life in Ol Pejeta Conservancy is commented on on the Conservancy's website. Several documentaries are in the works, including an episode of Ol Pejeta Diaries entitled "Return of the African Titans" for Oasis HD Canada fall 2010, and a follow-up half-hour episode to follow. This translocation is also the subject of a BBC Last Chance to See special entitled "Return of the Rhino,"^[9] presented by Stephen Fry and the zoologist Mark Carwardine; the TV program reported at the end that the two pairs of rhinos were "flirting."

On 25 April 2012 and on 27 May 2012 Suni and Najin mated.^[10] Pregnancy of the female rhinos was monitored weekly.^[11] Rhinoceros gestation period takes 16 to 18 months,^[12] so in January 2014 the Conservancy considered Najin not pregnant, and a male southern white rhino from Lewa Wildlife Conservancy was put to Najin and Fatu enclosure in Ol Pejeta to at least intercross the subspecies. To achieve this, both female northern white rhinos were separated from their male counterparts, which prevents them, for the time being, from producing a pure northern white rhino offspring.^[13][14] In 2015, however, test conducted by Czech specialists revealed that neither of the females are "capable of natural reproduction".^[15][16]

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 mice out of simple skin cells. The DNA of a dozen northern white rhinos has been preserved in genetic banks in Berlin and San Diego.^[17]

Recently deceased rhinos

Wild population

The northern white rhino (Ceratotherium simum cottoni) formerly ranged over parts of northwestern Uganda, southern South Sudan, the eastern part of Central African Republic, and northeastern Democratic Republic of the Congo.^[18] 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.^[19][20] Since mid-2003, poaching had intensified and reduced the wild population.^[19]

Garamba National Park

The last 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.^[21] 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.^[22] They were the last known wild northern white rhinos, according to the World Wide Fund for Nature.^[23]

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.^[2][24] One carcass has been found.^[2][25][26] On 28 November 2009, two Russian helicopter pilots reported seeing Northern White Rhinos in southern Sudan.^[27] It was assumed that the three rhinoceroses that were spotted belong to this subspecies, as other rhinoceroses have not been living in the area for a long time.^[28] However, as of August 2011, no other sightings have been reported,^[2] and this population is now considered to have probably gone extinct.^[2]

Captive population

At the beginning of 2015, the fully captive northern white rhino population consisted of only two animals maintained in two zoological institutions: in the United States (San Diego Zoo Safari Park) and the Czech Republic (Dvůr Králové Zoo). However, both of them died later the same year, and no zoo in the world has any northern white rhinos any longer.

Dvůr Králové Zoo

A northern white rhinoceros with an Einiosaurus-like horn at the Dvůr Králové Zoo

In 1970, the Dvůr Králové Zoo, located in Dvůr Králové nad Labem, Czech Republic, got six northern white rhinos from Sudan. The zoo is the only one in the world where northern white rhinos produced offspring; the current population are descendants of these six rhinos.^[29][30]

Former residents include:

• Nabire, born at Dvůr Králové Zoo on 15 November 1983. Her mother, Nasima, and father, Sudan, were both northern white rhino (C. s. cottoni).^[31] She died on 27 July 2015.^[32]
• Suni, a male born at Dvůr Králové Zoo in 1980. He had mated while in zoos. Was transferred to Ol Pejeta Conservancy in 2009. Some of his sperm has been collected and frozen. On 17 October 2014, he died from natural causes, probably old age.^[33][34]
• Nesari, a female wild born at Shambe, Sudan, on 19 September 1972, died in 2011.^[35]
• Nasi, a female born at Dvůr Králové Zoo on 11 November 1977, died in 2008.
• Saut, a male wild born at Shambe in Sudan on 19 September 1972, died in August 2006,^[36] age 33.

Dvůr Králové Zoo sent Suni and three other northern white rhinoceros which are still alive, one male and two females, to the Ol Pejeta Conservancy in Kenya on 19 December 2009^[37] in a joint effort by the zoo, Fauna and Flora International, Back to Africa, Lewa, and Kenya Wildlife Service. Hoping to stimulate the rhinos' sexual appetite, the zoo decided to send them back into their natural habitat in Kenya. The agreement with the Kenyan government expects the rhinos never to be returned to the Czech Republic.

Dvůr Králové was the only zoo in which northern white rhinos produced offspring; the last calf was born in 2000.^[38]

The female named Nabire stayed in Dvůr Králové Zoo, because, as Jan Stejskal, a projects coordinator at the zoo, stated, "she is no longer capable of breeding naturally. But it seems she has one healthy ovary and this could provide us with material from which to create an embryo in artificial conditions."^[38] Efforts to do so began in autumn 2014.^[39] Immediately after the death of Nabire in 2015, her ovary with four oocytes was removed and transferred to a laboratory in Cremona, Italy. The laboratory was able to extract two egg cells and fertilise them. However, without consulting the Dvůr Králové Zoo the semen of a southern white rhino was used instead of a northern white rhino, which the zoo considers a wasted opportunity.^[40]

San Diego Zoo Safari Park

The San Diego Zoo Safari Park in San Diego, California, had three wild-caught northern white rhinos:^[19][41] a female named Nadi, who was on loan from the Dvůr Králové Zoo, died on 30 May 2007;^[41] a male named Angalifu (b. 1974, on loan from 1990 from Khartoum Zoo in Khartoum) died on 14 December 2014;^[1][42] and a female named Nola (b. 1974, on loan since 1989 from Zoo Dvůr Králové)^[43][44][45] died on 22 November 2015.^[46]

The San Diego Wild Animal Park provided Angalifu's semen to female rhinos at the Dvůr Králové Zoo but the insemination attempts were unsuccessful. The only reproductive animals of this subspecies were transported to Ol Pejeta Conservancy in Kenya.

In 2016 it was reported that scientists were exploring alternatives (such as artificial insemination, in vitro fertilization and embryo transfer) to develop northern white rhino embryos and implant them in female Southern white rhinos at the San Diego Zoo.^[47]

Population chart

*estimate

Taxonomy

Following the phylogenetic species concept, recent research has suggested the northern white rhinoceros may be an altogether different species, rather than a subspecies of white rhinoceros, in which case the correct scientific name for the former is Ceratotherium cottoni. Distinct morphological and genetic differences suggest the two proposed species have been separated for at least a million years.^[49] However, the results of the research were not universally accepted by other scientists.^[2]

References

External links

• Ol Pejeta Conservancy
• A detailed IUCN Red List entry
• An older list of northern white rhinos in captivity (In Czech)

Wikispecies has information related to: Ceratotherium simum cottoni

Wikimedia Commons has media related to Northern white rhinoceros.