| White Rhinoceros[1] | |
|---|---|
| White rhinoceros in Kruger Park | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Perissodactyla |
| Family: | Rhinocerotidae |
| Genus: | Ceratotherium |
| Species: | C. simum |
| Binomial name | |
| Ceratotherium simum (Burchell, 1817) |
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| Subspecies | |
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Ceratotherium simum cottoni (Northern) |
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| White Rhinoceros original range [orange: Northern (C. s. cottoni), green: Southern (C. s. simum)]. | |
| White Rhinoceros range (brown - native, pink - reintroduced, red - introduced) |
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The White Rhinoceros or Square-lipped rhinoceros (Ceratotherium simum) is one of the five species of rhinoceros that still exist. It has a wide mouth used for grazing and is the most social of all rhino species. The White Rhino consists of two subspecies: the Southern White Rhino, with an estimated 17,460 wild-living animals at the end of 2007 (IUCN 2008), and the much rarer Northern White Rhino. The northern species has very few remaining, all in captivity.[3]
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A popular theory of the origins of the name "White Rhinoceros" is a mistranslation from Dutch to English. The English word "white" is said to have been derived by mistranslation of the Dutch word "wijd", which means "wide" in English. The word "wide" refers to the width of the rhinoceros' mouth. So early English-speaking settlers in South Africa misinterpreted the "wijd" for "white" and the rhino with the wide mouth ended up being called the White Rhino and the other one, with the narrow pointed mouth, was called the Black Rhinoceros. Ironically, Dutch (and Afrikaans) later used a calque of the English word, and now also call it a white rhino. This suggests the origin of the word was before codification by Dutch writers. A review of Dutch and Afrikaans literature about the rhinoceros has failed to produce any evidence that the word wijd was ever used to describe the rhino outside of oral use.[4] Other popular theories suggest the name comes from its wide appearance throughout Africa, its color due to wallowing in calcareous soil or bird droppings or because of the lighter colour of its horn. An alternative common name for the White Rhinoceros, more accurate but rarely used, is the square-lipped rhinoceros. The White Rhinoceros' generic name, Ceratotherium, given by the zoologist John Edward Gray in 1868,[5] is derived from the Greek terms keras (κερας) "horn" and therion (θηριον) "beast". Simum, is derived from the Greek term simus (σιμος), meaning "flat nosed".
The White Rhinoceros of today was said to be likely descended from Ceratotherium praecox which lived around 7 million years ago. Remains of this White Rhino have been found at Langebaanweg near Cape Town.[6] A review of fossil rhinos in Africa by Denis Geraads has however suggested that the species from Langebaanweg is of the genus Ceratotherium, but not Ceratotherium praecox as the type specimen of Ceratotherium praecox should, in fact, be Diceros praecox, as it shows closer affinities with the black rhinoceros Diceros bicornis.[7] It has been suggested that the modern White Rhino has a longer skull than Ceratotherium praecox to facilitate consumption of shorter grasses which resulted from the long term trend to drier conditions in Africa.[8] However, if Ceratotherium praecox is in fact Diceros praecox, then the shorter skull could indicate a browsing species. Teeth of fossils assigned to Ceratotherium found at Makapansgat in South Africa were analysed for carbon isotopes and the researchers concluded that these animals consumed more than 30% browse in their diet, suggesting that these are not the fossils of the extant Ceratotherium simum which only eats grass.[9] It is suggested that the real lineage of the White Rhino should be; Ceratotherium neumayri -> Ceratotherium mauritanicum -> C. simum with the Langebaanweg rhinos being Ceratotherium sp. (as yet unnamed), with black rhinos being descended from C. neumayri via Diceros praecox.[7] It is likely then that the ancestor of both the Black and the White rhinos was a mixed feeder, with the two lineages then specialising in browse and graze, respectively.
There are two subspecies of White Rhinos; the Southern White Rhinoceros (Ceratotherium simum simum) and the Northern White Rhinoceros. As of 31 December 2007, there were an estimated 17,480 Southern White Rhino in the wild (IUCN 2008), making them the most abundant subspecies of rhino in the world. South Africa is the stronghold for this subspecies (93.0%), conserving 16,255 individuals in the wild in 2007 (IUCN 2008). There are smaller reintroduced populations within the historical range of the species in Namibia, Botswana, Zimbabwe and Swaziland, while a small population survives in Mozambique. Populations have also been introduced outside of the former range of the species to Kenya, Uganda and Zambia.[10]
Wild-caught southern whites will readily breed in captivity given appropriate amounts of space and food, as well as the presence of other female rhinos of breeding age. For instance, 91 calves have been born at the San Diego Zoo Safari Park since 1972. However, for reasons that are not currently understood, the rate of reproduction is extremely low among captive-born southern white females.[11]
The Northern White Rhinoceros (Ceratotherium simum cottoni), formerly found in several countries in East and Central Africa south of the Sahara, is considered Critically Endangered or Extinct in the Wild. Recent research has suggested that the Northern White Rhinoceros might be a distinct species, and should therefore be renamed Ceratotherium cottoni. Distinct morphological and genetic differences suggest that the two proposed species have been separated for at least a million years.[12]
As of 2006, there were only four Northern White Rhinos left in the wild according to the World Wide Fund for Nature.[13] However, in June 2008 it was reported that the subspecies could be extinct in the wild since none of these four known remaining individuals has been seen since 2006.[3]
On November 20 a herd of 4 Northern White Rhinos from Dvůr Králové Zoo was transported to Kenya. The Czech Dvůr Králové Zoo was the world's only zoo where Northern White Rhinos reproduced offspring. But as the last offspring were born in 2000, the zoo management decided to stimulate the Rhino's sexual appetite by putting them back into their natural habitat. The agreement with Kenya government expects the Rhinos never to be returned to the Czech Republic. Reportedly they are supposed to be heavily guarded to ensure safety from poachers.[14] The Northern White Rhino formerly ranged over parts of north-western Uganda, southern Chad, south-western Sudan, the eastern part of Central African Republic, and north-eastern Democratic Republic of the Congo.[2] 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. Surveys in 2000 indicated that the population had started recovering, with 30 animals confirmed in 2000, and possibly six others.[3] Since mid-2003, poaching had intensified and reduced the wild population to only 5 to 10 animals (7 actual count worldwide).[4]
The last surviving population of wild Northern white rhinos was located in Garamba National Park, Democratic Republic of the Congo (DRC). In January 2005, the government of the Democratic Republic of Congo (DRC) approved a two-part plan for the translocation of five northern white rhino 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 that the northern white rhinos can be returned when it is safe again.[5] The translocation did not occur, due to the death of the remaining animals. 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.[5] In June 2008, it was reported that the subspecies might be extinct, since none of these four known remaining individuals had been seen since 2006.[6]
While not in a totally wild state because of the surveillance they are currently under, four of the six rhinos that used to live in the Dvůr Králové Zoo in Czech Republic were transferred to the Ol Pejeta Conservancy in Kenya in a last bid to save their species. They arrived at the conservancy after an air and road trip on December 20, 2009[7] and seem to be integrating very well in their new home. The four rhinos, under constant watch by specialists and staff, are currently living in a 400 by 400 meters breeding area where they will be acclimatizing to their new life in the wild until they are deemed ready to be released into the conservancy. In order 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, all four rhinos were sedated and had their horns removed. This will also make them less vulnerable to the poaching that drove their species to near extinction when they are released, as only the horn, which is believed to have aphrodisiac properties, is of interest to poachers. In place of their horns, radio transmitters have been installed to allow closer monitoring of their whereabouts.[8] The Progress of this attempt at saving the Northern White Rhinoceros is documented both on the initiative's own website and on the Conservancy's website as well.
The captive northern white rhino population consists of only four animals and is maintained in two zoological institutions in the U.S.A. and the Czech Republic. The zoo population is declining, and is possibly not viable. Northern whites have rarely reproduced in captivity. Therefore, those four capable of breeding have been returned to their former range in Kenya where they are held in partial captivity.
The European Association of Zoos and Aquaria (EAZA) has some internationally coordinated breeding programmes of wild animals such as the European Endangered Species Programme (EEP). There is also a White Rhino EEP. This EEP includes only three individuals, of which two pure, of the Northern White Rhinoceros subspecies. These individuals were located in the Dvůr Králové Zoo in Dvůr Králové nad Labem, Czech Republic.[9] Nesari, female wild born at Shambe, Sudan, on 19 September 1972. Nesari died of old age on May 26, 2011, leaving only Nabire at the Czech zoo.[15] Nasi, female born at Dvůr Králové Zoo, Czech Republic, on 11 November 1977. Nabire, female born at Dvůr Králové Zoo, Czech Republic, on 15 November 1983. The male named Saut, wild born at Shambe in Sudan on 19 September 1972, died in August 2006.[10] The zoo holds one hybrid female. The mother of this female was a Northern White Rhino (C. s. cottoni), but the father was a Southern White Rhino (C. s. simum) named Arthur. This zoo was also home to four other Northern White Rhinoceros, two males and two females, but they were transferred to the Ol Pejeta Conservancy in Kenya on December 19, 2009[11] in a joint effort by the zoo, Fauna and Flora International, Back to Africa, Lewa and Kenya Wildlife Service. The Czech Dvůr Králové Zoo was the world's only zoo, where Northern White Rhinos produced offspring. But as the last offspring came to the world in 2000, the zoo management decided to stimulate the Rhino's sexual appetite by returning them into their natural habitat.
The San Diego Zoo Safari Park in Escondido, California, U.S.A., has two Northern White Rhinos,[4] both of which were wild-caught. They are a female named Nola (over the age of 40 and past breeding age) and a male named Angalifu. One other female, named Nadi, which was not behaviorally receptive, died on May 30, 2007.
The White Rhinoceros is the world's largest land mammal after the three species of elephant.[16] It has a massive body and large head, a short neck and broad chest. The head and body length is 3.4 to 4.2 m (11 to 14 ft), with the tail adding another 37 to 71 cm (15 to 28 in). Shoulder height is 1.5 to 2 m (4 ft 10 in to 6 ft 7 in). Weight in this animal typically ranges from 1,360 to 3,630 kg (3,000 to 8,000 lb). The male, averaging 2,300 kg (5,100 lb) is slightly heavier than the female, at an average of 1,700 kg (3,700 lb).[17][18][19] The largest recorded White Rhinoceros was about 4,500 kg (9,900 lb).[20] On its snout it has two horn-like growths, one behind the other. These are made of solid keratin, in which they differ from the horns of bovids (cattle and their relatives), which are keratin with a bony core, and deer antlers, which are solid bone. The front horn is larger and averages 90 cm (35 in) in length, reaching as much as 150 cm (59 in). The White Rhinoceros also has a noticeable hump on the back of its neck. Each of the four stumpy feet has three toes. The color of the body ranges from yellowish brown to slate grey. Its only hair is the ear fringes and tail bristles. White Rhinos have a distinctive broad, straight mouth which is used for grazing. Its ears can move independently to pick up sounds but it depends most of all on smell. The olfactory passages which are responsible for smell are larger than their entire brain. The white rhinoceros has the widest set nostrils of any land based animal.
White Rhinoceroses are found in grassland and savannah habitat. Herbivore grazers that eat grass, preferring the shortest grains, the White Rhinoceros is one of the largest pure grazers. It drinks twice a day if water is available, but if conditions are dry it can live four or five days without water. It spends about half of the day eating, one third resting, and the rest of the day doing various other things. White Rhinoceroses, like all species of rhinoceros, love wallowing in mudholes to cool down.
White Rhinoceroses produce sounds which include a panting contact call, grunts and snorts during courtship, squeals of distress, and deep bellows or growls when threatened. Threat displays (in males mostly) include wiping its horn on the ground and a head-low posture with ears back, combined with snarl threats and shrieking if attacked. The White Rhinoceros is quick and agile and can run 50 km/h (31 mph).
White Rhinoceroses live in crashes or herds of up to 14 animals (usually mostly female). Sub-adult males will congregate, often in association with an adult female. Most adult bulls are solitary. Dominant bulls mark their territory with excrement and urine. The dung is laid in well defined piles. It may have 20 to 30 of these piles to alert passing rhinoceroses that it is his territory. Another way of marking their territory is wiping their horns on bushes or the ground and scrapes with its feet before urine spraying. They do this around 10 times an hour while patrolling territory. The same ritual as urine marking except without spraying is also commonly used. The territorial male will scrape-mark every 30 m (98 ft) or so around its territory boundary. Subordinate males do not mark territory. The most serious fights break out over mating rights to do with a female. Female territory is overlapped extensively and they do not defend it.
Females reach sexual maturity at 6–7 years of age while males reach sexual maturity between 10–12 years of age. Courtship is often a difficult affair. The male stays beyond the point where the female acts aggressively and will give out a call when approaching her. The male chases and or blocks the way of the female while squealing or wailing loudly if the female tries to leave his territory. When ready to mate the female curls its tail and gets into a stiff stance during the half hour copulation. Breeding pairs stay together between 5–20 days before they part their separate ways. Gestation occurs around 16–18 months. A single calf is born and usually weighs between 40 and 65 kg (88 and 140 lb). Calves are unsteady for their first 2 to 3 days of life. When threatened the baby will run in front of the mother, who is very protective of her calf and will fight for it vigorously. Weaning starts at 2 months, but the calf may continue suckling for over 12 months. The birth interval for the white rhino is between 2 and 3 years. Before giving birth the mother will chase off her current calf. White rhinos can live to be up to 40–50 years old. Adult white rhinos have no natural predators due to their size,[21] and even young rhinos are rarely attacked due to the mother's presence or preyed on due to their tough skin.
The northern subspecies is now found only in the Republic of Congo while the southern subspecies or majority of White rhino live in southern Africa. 98.5% of White Rhino occur in just five countries (South Africa, Namibia, Zimbabwe, Kenya and Uganda). Almost at the edge of extinction in the early 20th century, the southern subspecies has made a tremendous comeback. In 2001 it was estimated that there were 11,670 White Rhinos in the wild with a further 777 in captivity worldwide, making it the most common Rhino in the world. By the end of 2007 wild-living Southern White Rhino had increased to an estimated 17,480 animals (IUCN 2008).
Like the black rhino, the White Rhino is under threat from habitat loss and poaching, most recently by Janjaweed. The horn is mostly used for traditional medicine although there are no health benefits from the horn; the horn is also used for traditional necklaces.
The Northern White Rhino (Ceratotherium simum cottoni) formerly ranged over parts of north-western Uganda, southern Chad, south-western Sudan, the eastern part of Central African Republic, and north-eastern Democratic Republic of the Congo (DRC).[22] The only confirmed population today occurs in north-eastern DRC.
Poachers reduced their population from 500 to 15 in the 1970s and 1980s. By the early 1990s through mid 2003 the population recovered to more than 32 animals. Surveys in 2000 indicated that the population had started recovering with 30 animals confirmed in 2000 with up to a possible six others.[23] Between 2003 and 2006 poaching intensified and reduced the wild population to only 5 to 10 animals.[24] According to the WWF, there are now only four Northern White Rhinos left in the wild,[25] however in June 2008 it was reported that the species may have gone extinct in the wild.[3] As of 2011, the total number of Northern White Rhinos on the planet is reported to be five males and two females.[26]
The last surviving population of wild Northern White Rhinos are all located in Garamba National Park, Democratic Republic of the Congo (DRC). Recent civil wars and disruptions have been cause for much concern about the status of this last surviving population.[24]
In August 2005, ground and aerial surveys conducted under the direction of African Parks Foundation and the African Rhino Specialist Group (ARSG) have only found four animals. A solitary adult male and a group of one adult male and two adult females. Efforts to locate further animals continue.[2] According to Newsweek ("Extinction Trade," March 10, 2008) there were only two Northern White Rhinos alive in Garamba—"a death sentence for that population."
Most White Rhinos in zoos are Southern White Rhinos; in 2001 it was estimated that there were 777 White Rhinos in captivity worldwide. The San Diego Wild Animal Park in San Diego, California, U.S.A. previously had three Northern White Rhinos,[24] all of which were wild-caught. Only a female named Nola, and a male named Angalifu remain after the second female, Nadi, died in late May 2007 from what was believed to be old age. Nola is not fertile, and Nadi was not behaviorally receptive, so this captive population is not breeding.
Angalifu is one of the last known male Northern White Rhino in existence. A collaboration was underway between the San Diego Wild Animal Park and the Dvůr Králové Zoo in Dvůr Králové nad Labem, Czech Republic to provide Angalifu's semen to female Rhinos in captivity in the Czech Republic in a final effort to save this subspecies. So far the insemination attempts in Northern White Rhinos have failed and other methods are being considered.
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