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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. , 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)".〔 After 2000, six northern white rhinoceroses had lived in the Dvůr Králové Zoo in the Czech Republic but four of them (which were also the only reproductive animals of this subspecies) were transported to Ol Pejeta Conservancy in Kenya, Africa, in 2009,〔(Northern White Rhinos ). Olpejetaconservancy.org (20 December 2009). Retrieved 16 April 2015.〕 where scientists hoped they would successfully breed and save this subspecies from extinction; one of the four died in October 2014. One of the two remaining in the Dvůr Králové Zoo died in late May 2011. The last rhino there, Nabiré, died in July 2015.〔(Vzácná samice Nabiré, jeden z posledních pěti severních bílých nosorožců, uhynula ). zoodvurkralove.cz(28 July 2015)〕 Two rhinos lived at the San Diego Zoo's Safari Park in California: Angalifu, a male rhino, died in December 2014; Nola, a female, died on 22 November 2015.〔(【引用サイトリンク】url = http://www.latimes.com/local/lanow/la-me-ln-nola-death-20151122-story.html )〕 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. However, the results of the research were not universally accepted by other scientists.〔 ==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. 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.〔International Rhino Foundation. 2002. (Rhino Information – Northern White Rhino ). 19 September 2006〕 Surveys in 2000 indicated the population had started recovering, with 30 animals confirmed in 2000, and possibly six others. Since mid-2003, poaching had intensified and reduced the wild population to only 5 to 10 animals living in Garamba National Park.〔 In 2006, four rhinos living in Garamba National Park were the last known wild northern white rhinos, according to the World Wide Fund for Nature. However, in June 2008 it was reported that the subspecies may be extinct in the wild as there has been no sighting of these four known remaining individuals since 2006 and of their signs since 2007, despite an intensive systematic ground search and aerial searches in 2008.〔 One carcass has been found. As of 2011, this population is now considered as probably extinct.〔 If confirmed, this would make the northern white rhino extinct in the wild apart from the last-chance efforts by the Ol Pejeta Conservancy to reintroduce it in a wild state. On 28 November 2009, two Russian helicopter pilots reported seeing Northern White Rhinos in southern Sudan.〔(An alternative approach to species conservation ). Back to Africa (20 December 2009). Retrieved 7 April 2013.〕 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.〔(V Súdánu objevili téměř vyhynulé bílé nosorožce ). Novinky.cz (3 January 2010). Retrieved 7 April 2013.〕 However, as of August 2011, no other sightings have been reported.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Northern white rhinoceros」の詳細全文を読む スポンサード リンク
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