Northern white rhinoceros

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Northern white rhinoceros
Northern White Rhinoceros Angalifu.jpg
Angalifu, a male northern white rhinoceros at the San Diego Zoo Safari Park. Angalifu died 14 December 2014.[1]

Critically endangered, possibly extinct in the wild (IUCN 3.1)[2]
Scientific classification e
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)
Mapa distribuicao original white rhino.png
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 two subspecies of the white rhinoceros (the other being the southern white rhinoceros). Formerly found in several countries in East and Central Africa south of the Sahara, this subspecies is a grazer in grasslands and savanna woodlands. As of 19 March 2018, there were only two known rhinos of this subspecies left, 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 Pejeta Conservancy in Kenya and are protected round-the-clock by armed guards.

According to the latest International Union for Conservation of Nature (IUCN) assessment from 2011, the subspecies is considered "Critically Endangered (Possibly Extinct in the Wild)."[2]

Living rhinos[edit]

Ol Pejeta Conservancy[edit]

A northern white rhinoceros near the equator during translocation to Ol Pejeta Conservancy.
One of the northern white rhinos translocated to Ol Pejeta was living in a semiwild state.

The zoo population is declining, and northern whites have rarely reproduced in captivity. There are now only two northern white rhinos left:

  • Najin, a female, was born in captivity in 1989. She is the mother of Fatu.[3] Her mother was Nasima and her father was Sudan.[4]
  • Fatu, also a female, was born in captivity in 2000.[3] Her mother is Najin and her father was Saut.[5]

They both belong to the Dvůr Králové Zoo in the Czech Republic, but live in Ol Pejeta Conservancy in Kenya, Africa.[6] They arrived at the conservancy after an air and road trip on 20 December 2009,[7] along with two male northern white rhinos from the Dvůr Králové Zoo, Suni and Sudan. However, Suni, a male born at Dvůr Králové Zoo in 1980, died from natural causes in Ol Pejeta Conservancy in 2014.[8][9] Sudan, caught from the wild in 1975, died on 19 March 2018.[4][10][11]

After the transport, the four rhinos were under constant watch by specialists and staff, and lived in specially constructed bomas with access to a 400×400-metre paddock area, allowing them to acclimatize to their new surroundings.[citation needed] 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 the 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.[12] They are protected round-the-clock by armed guards.[13] Poachers have been selling their horns for $50,000 per kilo.[14]

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 roamed 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.[citation needed]

Until 2011, the progress of this attempt at saving the northern white rhinoceros was documented on the initiative's website;[15] 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 was also the subject of a BBC Last Chance to See special entitled "Return of the Rhino",[16] 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.[17] Pregnancy of the female rhinos was monitored weekly.[18] Rhinoceros gestation period takes 16 to 18 months,[19] 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 prevented them from producing a pure northern white rhino offspring.[20][21] In 2015, however, tests conducted by Czech specialists revealed that neither of the females are "capable of natural reproduction".[22][23] According to the director of the Dvůr Králové Zoo, it was possible Najin became pregnant but miscarried shortly after, which resulted in pathological changes in its uterus, preventing another impregnation.[24]

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.[25]

Recently deceased rhinos[edit]

Wild population[edit]

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.[26] Their range possibly extended as far west as Lake Chad, into Chad and Cameroon.[citation needed]

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.[27][28] Since mid-2003, poaching has intensified and further reduced the wild population.[27]

Garamba National Park[edit]

The last known surviving population of wild northern white rhinos was in Garamba National Park, Democratic Republic of the Congo (DRC).[29]

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.[30] 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.[31] They were the last known wild northern white rhinos, according to the World Wide Fund for Nature.[32]

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][33] One carcass has been found.[2][34][35] On 28 November 2009, two Russian helicopter pilots reported seeing rhinoceroses in southern Sudan.[36] 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.[37] 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[edit]

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[edit]

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

In 1975, the Dvůr Králové Zoo, located in Dvůr Králové nad Labem, Czech Republic, got six northern white rhinos from Sudan and, in later years, two more from English zoos. One rhino from an English zoo arrived pregnant. The Dvůr Králové Zoo is the only one in the world where northern white rhinos birthed offspring, with the last calf being born in 2000;[38] the current world population consists of their shared descendants.[39][4][5]

Former residents include:

  • Ben, a male wild born in Africa in about 1951. He was transferred to Dvůr Králové Zoo from a faculty in England and died 25 June 1990.[4]
  • Nasima, a female wild born in Uganda in about 1965. She was transferred pregnant to Dvůr Králové Zoo from a faculty in England. She was the mother of Nasi, Suni, Nabire, and Najin. She birthed four out of five Northern White Rhino calves born in captivity, making her the most fruitful Northern White in captivity to date.[4][40] She died in 1992 at about age 27.[5]
  • Saut, a male caught from the wild in Sudan in 1975 at about 3 years of age.[4] He was the father of Suni and Fatu. He was loaned to San Diego Zoo Safari Park by Dvůr Králové Zoo from 1989 until 1998 when he was returned to Dvůr Králové Zoo. He mated with females at both faculties.[5][41] He died in August 2006 around age 33.[42]
  • Nuri, a female caught from the wild in Sudan in 1975 at about 3 years of age. She died 4 January 1982 at about age 10.[4]
  • Nesari, a female caught from the wild in Sudan in 1975 at about 3 years of age. She died in 2011 at age 39.[43][4]
  • Nasi, a female born at Dvůr Králové Zoo on 11 November 1977 and died in 2007. Her mother was Nasima and her father was a southern white rhino, which made her a northern and southern white rhino hybrid.[4][44]
  • Suni, a male born at Dvůr Králové Zoo on 8 June 1980. He was the half-brother of Najin and Fatu, but through different parents. His mother was Nasima and his father was Saut.[5][4] 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.[8][9]
  • Nabire, born at Dvůr Králové Zoo on 15 November 1983. Her mother was Nasima and her father was Sudan. She died on 27 July 2015.[4][45]
  • Sudan, caught from the wild in Sudan in 1975 at about 3 years of age. He was the father of Najin and the late Nabire.[4][40] In March 2018, his state seriously deteriorated despite intensive care due to a recurrent infection in his right hind leg,[46] and he was euthanized on 19 March 2018.[10][11] He was the last known male of the subspecies.

Dvůr Králové Zoo sent Suni, Sudan and two females, which are still alive, to the Ol Pejeta Conservancy in Kenya on 19 December 2009[47] 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.

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.[48] 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.[49]

San Diego Zoo Safari Park[edit]

The San Diego Zoo Safari Park in San Diego, California, had eight wild-caught northern white rhinos.[50][5]

Former residents include:

  • Dinka, a male caught from the wild in Sudan in 1957 at about 5 years of age, which arrived from another U.S. zoo in 1972. He died in 1974.[5]
  • Bill, a male caught from the wild in Sudan in 1956 at about 4 years of age, which arrived from another U.S. zoo in 1972. He died in 1975.[5]
  • Lucy, a male caught from the wild in Sudan in 1956 at about 4 years of age, which arrived from another U.S. zoo in 1972. He died in 1979.[5]
  • Joyce, a female caught from the wild in Sudan in 1957 at about 5 years of age, which arrived from another U.S. zoo in 1972. She died in 1996.[5]
  • Saut, a male caught from the wild in Sudan in 1975 at about 3 years of age, which was on loan from Dvůr Králové Zoo from 1989–1998. He died in August 2006 at about age 33.[5][42]
  • Nadi, a female caught from the wild in Sudan in 1975 at about 3 years of age, which was on loan since 1989 from Dvůr Králové Zoo. She died on 30 May 2007 at about age 35.[50][5]
  • Angalifu, a male caught from the wild in Sudan in 1973 at about 1 year of age, which was on loan since 1990 from Khartoum Zoo in Khartoum. He died on 14 December 2014 at about age 42.[1][5]
  • Nola, a female caught from the wild in Sudan in 1975 at about 1 year of age, which was on loan since 1989 from Dvůr Králové Zoo.[51][52][53] She died on 22 November 2015 at about age 41.[54]

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.[55]

List[edit]

Timeline of known northern white rhinoceros in captivity
List of known northern white rhinoceros in captivity (updated 2011)[56][57]
Stud # Sex Name Date of birth Place of birth Date of death Place of death
15 M Paul 1948-08-07 Sudan 1968-04-13 Antwerp Zoo
16 F Chloe 1948-06-07 Sudan 1985-08-07 Antwerp Zoo
19 M Ben 1950-07-25 Uganda 1990-06-25 Dvůr Králové Zoo
27 M Bill 1954-03-04 Sudan 1975-05-02 San Diego Zoo Safari Park
28 F Lucy 1954-03-04 Sudan 1979-03-15 San Diego Zoo Safari Park
54 M [n/a] 1963-04-01 Sudan 1985-12-31 Riyadh National Zoo
55 F [n/a] 1963-04-01 Sudan 1985-12-31 Riyadh National Zoo
74 M Dinka 1952-07-28 South Sudan 1991-01-28 San Diego Zoo Safari Park
75 F Joyce 1953-01-28 South Sudan 1974-08-15 San Diego Zoo Safari Park
290 F Bebe 1950-07-01 Uganda 1964-05-29 Zoological Society of London
345 F Tofacha 1970-01-01 Sudan 1978-09-12 Al Ain Zoo
347 M [n/a] 1968-04-01 Sudan 1978-01-18 Khartoum Zoo
348 M Angalifu 1972-04-01 Sudan 2014-12-14 San Diego Zoo Safari Park
351 F Nasima 1965-07-01 Uganda 1992-08-28 Dvůr Králové Zoo
372 M Sudan 1973-09-19 Sudan 2018-03-19 Ol Pejeta Conservancy
373 M Saut 1972-09-19 Sudan 2006-08-14 Dvůr Králové Zoo
374 F Nola 1974-09-19 Sudan 2015-11-22 San Diego Zoo Safari Park
375 F Nuri 1973-09-19 Sudan 1982-01-04 Dvůr Králové Zoo
376 F Nadi 1972-09-19 Sudan 2007-05-30 San Diego Zoo Safari Park
377 F Nesari 1972-09-19 Sudan 2011-05-26 Dvůr Králové Zoo
476 F Nasi 1977-11-11 Dvůr Králové Zoo 2007-07-20 Dvůr Králové Zoo
630 M Suni 1980-06-08 Dvůr Králové Zoo 2014-10-18 Ol Pejeta Conservancy
789 F Nabire 1983-11-15 Dvůr Králové Zoo 2015-07-27 Dvůr Králové Zoo
943 F Najin 1989-07-11 Dvůr Králové Zoo
1122 F [n/a] 1991-07-18 Dvůr Králové Zoo 1991-07-18 Dvůr Králové Zoo
1123 F [n/a] 1963-04-01 Sudan 1967-08-02 Khartoum Zoo
1252 ? [n/a] 1948-11-17 Sudan 1949-01-29 Khartoum Zoo
1305 F Fatu 2000-06-29 Dvůr Králové Zoo

Population chart[edit]

Northern White Rhino Population by Location and Year, 1909–2018
Location 1909[58] 1960* 1975* 1984 1995 1996 1998 2000 2003 2006 2007 2008 2009 2011 2014 2015 2017 2018
Wild 2,000–3,000* 2,000*[18] 500*[27] 15[40] 35[40] 29[28] 26-31[28] 30-36[28] 30[34] 4[34] n/a 0[34][40] 0 0 0 0 0 0
Central African Republic n/a n/a n/a 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Dem. Republic of Congo n/a n/a n/a 15 35 29 26-31 30-36 30 4 n/a 0 0 0 0 0 0 0
South Sudan n/a n/a n/a 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Uganda n/a n/a n/a 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Captivity n/a 7[5] 15[5] 16[4][5] 11[4][5] 10[4][5] 10[4][5] 11[4][5] 11[4][5] 10[4][5][42] 8[5][44][50] 8[59] 8[59] 7[60] 5[1] 3[54] 3[61] 2[62]
Dvůr Králové Zoo,

Czech Republic

n/a 0 6 9 6 6 7 8 8 7 6 6 2 1 1 0 0 0
Khartoum Zoo, Sudan n/a 0 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Ol Pejeta

Conservancy, Kenya

n/a 0 0 0 0 0 0 0 0 0 0 0 4 4 3 3 3 2
San Diego Zoo, USA n/a 0 2 1 5 4 3 3 3 3 2 2 2 2 1 0 0 0
Other zoo faculties n/a 7 5 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Total 2,000-

3,000*

2,000* 500* 31 46 39 36-41 41-47 41 14 8 8 8 7 5 3 3 2

*estimate

Taxonomy[edit]

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.[63] However, the results of the research were not universally accepted by other scientists.[2]

References[edit]

  1. ^ a b c "A northern white rhino has died. There are now five left in the entire world". The Washington Post. 15 December 2014. 
  2. ^ a b c d e f g Emslie, R. (2011). "Ceratotherium simum ssp. cottoni". IUCN Red List of Threatened Species. IUCN. 2011: e.T4183A10575517. Retrieved 12 March 2018. 
  3. ^ a b "Last Chance to Survive – Northern White Rhino Conservation Project". Archived from the original on October 24, 2014. Retrieved December 7, 2014. 
  4. ^ a b c d e f g h i j k l m n o p q r s Breeding Experience With Northern White Rhinos At Zoo Dvur Kralove. Zoo Dvur Kralove (1990) Retrieved 31 August 2017.
  5. ^ a b c d e f g h i j k l m n o p q r s t u v w Holečková, Dana & Tomášová, Kristina. "Narodí se ve Dvoře Králové nejvzácnější mládě roku 2000?" [Expecting the Rarest Offspring of the Year 2000] (PDF): 184.  Retrieved 31 August 2017.
  6. ^ Northern White Rhinos. Olpejetaconservancy.org (20 December 2009). Retrieved 16 April 2015.
  7. ^ Northern White Rhinos Arrive on Ol Pejeta Archived 29 March 2010 at the Wayback Machine., Ol Pejeta Conservancy website, Saturday, 23 December 2009
  8. ^ a b Gap, Frontier. (27 October 2014) The Death Of Suni, A Rhino Conservation Icon. Thedodo.com. Retrieved 16 April 2015.
  9. ^ a b Vzácný nosorožec Suni sešel stářím –. Novinky.cz. Retrieved 16 April 2015.
  10. ^ a b "Last male northern white rhino dead." reuters.com retrieved on 20 March 2018.
  11. ^ a b Ellis-Petersen, Hannah (20 March 2018). "Last male northern white rhino is put down". The Guardian. Retrieved 20 March 2018. 
  12. ^ Northern White Rhinos Progress Archived 27 March 2010 at the Wayback Machine., Ol Pejeta Conservancy (15 January 2010).
  13. ^ At home with the world's last male northern white rhinoceros | Environment. The Guardian. Retrieved on 2015-11-27.
  14. ^ Houreld, By Katharine. "Horny male seeks mate: Kenya's last northern white rhino joins Tinder". af.reuters.com. Retrieved 2017-04-26. 
  15. ^ "Last Chance to Save the Northern White Rhino" (2014) Lewa Wildlife Conservancy. Web.archive.org. Retrieved 16 April 2015.
  16. ^ "Return of the Rhino". BBC, 2010, first aired on 31 October 2010, on BBC 2 (UK).
  17. ^ Hope for the northern white rhinos Suni and Najin mate; Twice! Archived 6 November 2012 at the Wayback Machine.. olpejetaconservancy.org (11 June 2012).
  18. ^ a b Meeting the Northern white rhinos – Al Jazeera Blogs. Al Jazeera.com (4 January 2013). Retrieved 7 April 2013.
  19. ^ "A Day in the Life of a Northern White Rhino" Archived 6 August 2013 at the Wayback Machine.. Ol Pejeta Conservancy. 11 June 2013
  20. ^ "Ol Pejeta’s Northern White Rhinos to Embark on Plan B" (7 January 2014) Archived 14 January 2014 at the Wayback Machine.. Ol Pejeta Conservancy (7 January 2014). Retrieved 16 April 2015.
  21. ^ "Male Southern White Rhino Introduced in Endangered Species Boma" Archived 9 October 2014 at the Wayback Machine.. Ol Pejeta Conservancy. 12 February 2014
  22. ^ And then there were three.... Ol Pejeta Conservancy. Retrieved on 2015-11-27.
  23. ^ Northern white rhinos. Ol Pejeta Conservancy (2009-12-20). Retrieved on 2015-11-27.
  24. ^ https://zpravy.aktualne.cz/domaci/je-velmi-pravdepodobne-ze-se-sudanovi-narodi-potomek-uchovam/r~973fbf662c2e11e8b8310cc47ab5f122/
  25. ^ "Reproduction, stem cell researchers set up a rescue plan for Northern White Rhino". Science Daily. 22 December 2015. 
  26. ^ Sydney, J. (1965). "The past and present distribution of some African ungulates". Transactions of the Zoological Society of London. 3: 1–397. doi:10.1017/S0030605300006815. 
  27. ^ a b c International Rhino Foundation. 2002. Rhino Information – Northern White Rhino. 19 September 2006
  28. ^ a b c d Smith, Kes Hillman (July–December 2001). "Status of northern white rhinos and elephants in Garamba National Park, Democratic Republic of the Congo, during the wars" (PDF). Pachyderm journal of the African Elephant, African Rhino and Asian Rhino Specialist Groups. 31: 79–81. 
  29. ^ https://archive.is/20141207163226/http://mammals-of-papua.webs.com/whiterhino.htm
  30. ^ IUCN. (25 January 2005). Reprieve planned for Garamba's rhinos: extra efforts promised to safeguard their homeland. Gland, Switzerland.
  31. ^ IUCN. (6 July 2006). West African black rhino feared extinct. Gland, Switzerland.
  32. ^ "Northern White Rhino". Worldwildlife.org. Archived from the original on 5 June 2011. Retrieved 7 April 2009. 
  33. ^ Smith, Lewis (17 June 2008). "News | Poachers kill last four wild northern white rhinos". The Times. London. Archived from the original on 29 June 2011. Retrieved 7 April 2009. 
  34. ^ a b c d Smith, Lewis (17 June 2008) Poachers kill last four wild northern white rhinos. The Times.
  35. ^ Skinner, J.D. and Smithers, R.H.N. (1990). The Mammals of the Southern African Subregion, Cambridge University Press, p. 567, ISBN 0521844185.
  36. ^ An alternative approach to species conservation. Back to Africa (20 December 2009). Retrieved 7 April 2013.
  37. ^ V Súdánu objevili téměř vyhynulé bílé nosorožce. Novinky.cz (3 January 2010). Retrieved 7 April 2013.
  38. ^ a b Lazarová, Daniela (25 September 2014). "Dvůr Králové Zoo spearheading international efforts to save northern white rhino from extinction". Radio Prague. Archived from the original on 26 September 2014. 
  39. ^ Královédvorská zoo spouští unikátní projekt na záchranu vzácných nosorožců –. Novinky.cz. Retrieved 16 April 2015.
  40. ^ a b c d e Northern white rhinos. Public Broadcasting Service (28 July 2016) Retrieved 31 August 2017.
  41. ^ Breeding rhinos: Not an easy chore. CNN(2 March 1996) Retrieved 31 August 2017.
  42. ^ a b c The Rhino Resource Center – Rhino Images. Rhinoresourcecenter.com. Retrieved 7 April 2013.
  43. ^ Johnston, Raymond (2 June 2011). "White rhino dies in Czech zoo, seven left worldwide". Czech Position. Archived from the original on 13 April 2014. 
  44. ^ a b The Sixth Rhino: A Taxonomic Re-Assessment of the Critically Endangered Northern White Rhinoceros. journals.plos.org. Retrieved 31 August 2017.
  45. ^ Rare rhino dies at Czech zoo, leaving just four northern white rhino on Earth. The Guardian (28 July 2015) Retrieved 31 August 2017.
  46. ^ Torchia, Christopher (March 1, 2018). "Health of world's last male northern white rhino in decline". ABC News. 
  47. ^ Four of the World's Last Known Eight Northern White Rhinos Come Home to Africa Archived 30 March 2010 at the Wayback Machine., Ol Pejeta website, Saturday, 19 December 2009
  48. ^ "Zoo se snaží rozmnožit nosorožce, samici Nabiré zavěsili na jeřáb". Mladá fronta DNES (in Czech). 8 October 2014. Retrieved 19 October 2014. 
  49. ^ Tůmová, Štěpánka (4 August 2015) V Itálii oplodnili vajíčka uhynulé nosorožčí samice, ale špatným semenem – iDNES.cz. Hradec.idnes.cz. Retrieved on 24 November 2015.
  50. ^ a b c Eastman, Q. (2007) Northern white rhinos in danger. North County Times (11 June 2007) via Web Archive.
  51. ^ Last Chance to Survive: Northern White Rhino Conservation Project. Frequently Asked Questions. Northern white rhino. olpejetaconservancy.org
  52. ^ Severní bílí nosorožci v zajetí. .rozhlas.cz. Retrieved on 24 November 2015.
  53. ^ Kohoutová, Kateřina (13 May 2015) Samice nosorožce bílého Nola je nemocná. Patří k posledním zvířatům svého druhu | Příroda. Rozhlas.cz. Retrieved on 24 November 2015.
  54. ^ a b "Nola, a northern white rhino at San Diego Zoo's Safari Park, has died". latimes.com. Retrieved 22 November 2015. 
  55. ^ Morrow, Chris (5 February 2016). "Bringing Northern White Rhinos Back From Brink of Extinction". Huffington Post. Retrieved 24 February 2016. 
  56. ^ Dr Andreas Ochs. "International studbook for the African white rhinoceros, Ceratotherium simum (Burchell, 1817), 01.01.2001 Ninth edition". Rhino Resource Center. Retrieved 2018-03-31. 
  57. ^ Joe Christman. "International studbook for the white rhinoceros Ceratotherium simum (Burchell 1817), vol. 12 (status 31.12.2011)". Rhino Resource Center. p. 289-291. Retrieved 2018-03-31. 
  58. ^ "The White Rhinoceros". diglib1.amnh.org. Retrieved 2 September 2015. 
  59. ^ a b Final hope: four white rhinos shipped to Kenya. theguardian.org. (20 December 2009) Retrieved 11 September 2017.
  60. ^ Johnston, Raymond. "White rhino dies in Czech zoo, seven left worldwide". Czech Position. Archived from the original on 13 April 2014. Retrieved 11 September 2017. 
  61. ^ "With 1 male left worldwide, northern white rhinos under guard 24 hours". cnn.com. Retrieved 11 September 2017. 
  62. ^ "Sudan, the last male northern white rhino has passed". reuters.com. Retrieved 20 March 2018. 
  63. ^ Groves, C.P.; Fernando, P; Robovský, J (2010). "The Sixth Rhino: A Taxonomic Re-Assessment of the Critically Endangered Northern White Rhinoceros". PLoS ONE. 5 (4): e9703. Bibcode:2010PLoSO...5.9703G. doi:10.1371/journal.pone.0009703. PMC 2850923Freely accessible. PMID 20383328. 

Further reading[edit]

External links[edit]