Instruct: Given a question, retrieve documents that answer the question.
Query: Where can black wildebeest be found?
The natural populations of black wildebeest, endemic to the southern part of Africa, were almost completely exterminated in the 19th century, due to their reputation as pests and the value of their hides and meat. However, the species has been reintroduced widely from captive specimens, both in private areas and nature reserves throughout most of Lesotho, Swaziland, and South Africa. It has also been introduced outside its natural range in Namibia and Kenya.
All species of African wildebeest and hartbeest can be infected or at least carry this virus. There is no direct evidence that other African wild variants like addax can be hosts, but research is ongoing. The alcelaphine antelope affecting form is primarily found in Africa, in the natural habitat of wildebeest, hartebeest, and topi. It has also occurred in zoos and wild animal parks that also kept wildebeest. The increasing popularity in North America of wild animal parks may spread its range further.
Today, many wildebeest populations are experiencing rapid declines. Overland migration as a biological process requires large, connected landscapes, which are increasingly difficult to maintain, particularly over the long term, when human demands on the landscape compete. The most acute threat comes from migration barriers, such as fences and roads. In one of the more striking examples of the consequences of fence-building on terrestrial migrations, Botswanan authorities placed thousands of kilometres of fences across the Kalahari that prevented wildebeests from reaching watering holes and grazing grounds, resulting in the deaths of tens of thousands of individuals, reducing the wildebeest population to less than 10% of its previous size.[54] Illegal hunting is a major conservation concern in many areas, along with natural threats posed by main predators (which include lions, leopards, African hunting dogs, cheetahs and hyenas). Where the black and blue wildebeest share a common range, the two can hybridise, and this is regarded as a potential threat to the black wildebeest.[22]
The black wildebeest is currently included in the same genus as the blue wildebeest (Connochaetes taurinus). This has not always been the case, and at one time the latter was placed under a separate genus of its own, Gorgon.[7] The black wildebeest lineage seems to have diverged from the blue wildebeest in the mid- to late Pleistocene, and became a distinct species around a million years ago.[8] This evolution is quite recent on a geologic time scale.[9]
Before the arrival of Europeans in the area, wildebeest roamed widely, probably in relation to the arrival of the rains and the availability of good forage. They never made such extensive migrations as the blue wildebeest, but at one time, they crossed the Drakensberg Range, moving eastwards in autumn, searching for good pastures. Then they returned to the highvelds in the spring and moved towards the west, where sweet potato and Karoo vegetation were abundant. They also moved from north to south as the sourgrass found north of the Vaal River matured and became unpalatable, the wildebeest only consuming young shoots of sourgrass.[2] Now, almost all black wildebeest are in reserves or on farms, and the extent of their movements is limited.[1]
Blue wildebeest fossils dating back some 2.5 million years ago are common and widespread. They have been found in the fossil-bearing caves at the Cradle of Humankind north of Johannesburg. Elsewhere in South Africa, they are plentiful at such sites as Elandsfontein, Cornelia, and Florisbad.[17] The earliest fossils of the black wildebeest were found in sedimentary rock in Cornelia in the Orange Free State and dated back about 800,000 years.[16] Today, five subspecies of the blue wildebeest are recognized, while the black wildebeest has no named subspecies.[18][19]
Black wildebeest are mainly active during the early morning and late afternoon, preferring to rest during the hottest part of the day.[26] The animals can run at speeds of 80km/h (50mph).[26] When a person approaches a herd to within a few hundred metres, the wildebeest snort and run a short distance before stopping and looking back, repeating this behaviour if further approached. They communicate with each other using pheromones detected by flehmen and several forms of vocal communication. One of these is a metallic snort or an echoing "hick", that can be heard up to 1.5 km (1 mi) away.[27] They are preyed on by the lion, spotted hyena, Cape hunting dog, leopard, cheetah, and crocodile. Of these, the calves are targeted mainly by the hyenas, while lions attack the adults.[2]
However, black wildebeest can also affect human beings negatively. Wild individuals can be competitors of commercial livestock, and can transmit fatal diseases such as rinderpest, and cause epidemics among animals, particularly domestic cattle. They can also spread ticks, lungworms, tapeworms, flies, and paramphistome flukes.[6]
The black wildebeest is known to hybridise with its taxonomically close relative, the blue wildebeest. Male black wildebeest have been reported to mate with female blue wildebeest and vice versa.[11] The differences in social behaviour and habitats have historically prevented interspecific hybridisation between the species, but hybridisation may occur when they are both confined within the same area. The resulting offspring is usually fertile. A study of these hybrid animals at Spioenkop Dam Nature Reserve in South Africa revealed that many had disadvantageous abnormalities relating to their teeth, horns, and the wormian bones in the skull.[12] Another study reported an increase in the size of the hybrid as compared to either of its parents. In some animals, the auditory bullae are highly deformed, and in others, the radius and ulna are fused.[13]
The black wildebeest is particularly susceptible to anthrax, and rare and widely scattered outbreaks have been recorded and have proved deadly.[21] Ataxia related to myelopathy and low copper concentrations in the liver have also been seen in the black wildebeest.[22] Heartwater (Ehrlichia ruminantium) is a tick-borne rickettsial disease that affects the black wildebeest, and as the blue wildebeest is fatally affected by rinderpest and foot-and-mouth disease, it is also likely to be susceptible to these. Malignant catarrhal fever is a fatal disease of domestic cattle caused by a gammaherpesvirus. Like the blue wildebeest, the black wildebeest seems to act as a reservoir for the virus and all animals are carriers, being persistently infected, but showing no symptoms. The virus is transmitted from mother to calf during the gestation period or soon after birth.[23]
The blue wildebeest is a herbivore, feeding primarily on the short grasses which commonly grow on light, and alkaline soils that are found in savanna grasslands and on plains. The animal's broad mouth is adapted for eating large quantities of short grass and it feeds both during the day and night. When grass is scarce, it will also eat the foliage of shrubs and trees. Wildebeest commonly associate with plains zebras as the latter eat the upper, less nutritious grass canopy, exposing the lower, greener material which the wildebeest prefer. Whenever possible, the wildebeest likes to drink twice daily and due to its regular requirement for water, it usually inhabits moist grasslands and areas with available water sources. The blue wildebeest drinks 9 to 12 litres of water every one to two days. Despite this, it can also survive in the arid Kalahari desert, where it obtains sufficient water from melons and water-storing roots and tubers.
Both species of wildebeest are even-toed, horned, greyish-brown ungulates resembling cattle. Males are larger than females and both have heavy forequarters compared to their hindquarters. They have broad muzzles, Roman noses, and shaggy manes and tails.[25] The most striking morphological differences between the black and blue wildebeest are the orientation and curvature of their horns and the color of their coats. The blue wildebeest is the bigger of the two species. In males, blue wildebeest stand 150cm tall at the shoulder and weigh around 250kg, while the black wildebeest stands 111 to 120cm tall[26] and weighs about 180kg. In females, blue wildebeest have a shoulder height of 135cm and weigh 180kg while black wildebeest females stand 108cm at the shoulder and weigh 155kg. The horns of blue wildebeest protrude to the side, then curve downwards before curving up back towards the skull, while the horns of the black wildebeest curve forward then downward before curving upwards at the tips. Blue wildebeest tend to be a dark grey color with stripes, but may have a bluish sheen. The black wildebeest has brown-coloured hair, with a mane that ranges in color from cream to black, and a cream-coloured tail. The blue wildebeest lives in a wide variety of habitats, including woodlands and grasslands, while the black wildebeest tends to reside exclusively in open grassland areas.[18] In some areas, the blue wildebeest migrates over long distances in the winter, whereas the black wildebeest does not.[27] The milk of the female black wildebeest contains a higher protein, lower fat, and lower lactose content than the milk of the blue wildebeest.[28] Wildebeest can live more than 40 years, though their average lifespan is around 20 years.[29]
The blue wildebeest is native to eastern and southern Africa. Its range includes Kenya, Tanzania, Botswana, Zambia, Zimbabwe, Mozambique, South Africa, Swaziland and Angola.[34] It is no longer found in Malawi but has been successfully reintroduced into Namibia. Blue wildebeest are mainly found in short grass plains bordering bush-covered acacia savannas, thriving in areas that are neither too wet nor too dry. They can be found in habitats that vary from overgrazed areas with dense bush to open woodland floodplains.[32] In East Africa, the blue wildebeest is the most abundant big game species, both in population and biomass.[25] It is a notable feature of the Serengeti National Park in Tanzania, the Maasai Mara National Reserve in Kenya and the Liuwa Plain National Park in Zambia.[29]
The black wildebeest is a herbivore, and almost the whole diet consists of grasses. Water is an essential requirement. The three distinct social groups are the female herds, the bachelor herds, and the territorial bulls. They are fast runners, and communicate using a variety of visual and vocal communications. The primary breeding season for the black wildebeest is from February to April. A single calf is usually born after a gestational period of about 8.5 months. The calf remains with its mother until her next calf is born a year later. The black wildebeest inhabits open plains, grasslands, and Karoo shrublands.
In the early 20th century, one species of the wildebeest, C. albojubatus, was identified in eastern Africa. In 1914, two separate races of the wildebeest were introduced, namely Gorgon a. albojubatus ("Athi white-bearded wildebeest") and G. a. mearnsi ("Loita white-bearded wildebeest"). However, in 1939, the two were once again merged into a single race, Connochaetes taurinus albojubatus. In the mid-20th century, two separate forms were recognised, Gorgon taurinus hecki and G. t. albojubatus.[12] Finally, two distinct types of wildebeest – the blue and black wildebeest – were identified. The blue wildebeest was at first placed under a separate genus, Gorgon,[13][14] while the black wildebeest belonged to the genus Connochaetes. Today, they are united in the single genus Connochaetes, with the black wildebeest being named (C. gnou) and the blue wildebeest (C. taurinus).[10]
Black wildebeest act as hosts to a number of external and internal parasites. A study of the animal in Karroid Mountainveld (Eastern Cape Province, South Africa) revealed the presence of all the larval stages of the nasal bot flies Oestrus variolosus and Gedoelstia hässleri. The first instar larvae of G. hässleri were found in large numbers on the dura mater of wildebeest calves, specially between June and August, and these later migrated to the nasal passages.[24] Repeated outbreaks of mange (scab) have led to large-scale extinctions.[2] The first study of the protozoa in blue and black wildebeest showed the presence of 23 protozoan species in the rumen, with Diplodinium bubalidis and Ostracodinium damaliscus common in all the animals.[25]
The black wildebeest is depicted on the coat of arms of the Province of Natal in South Africa. Over the years, the South African authorities have issued stamps displaying the animal and the South African Mint has struck a 5-rand coin with a prancing black wildebeest.[2][34]
The black wildebeest is depicted on the coat of arms of the Province of Natal in South Africa. Over the years, the South African authorities have issued several stamps displaying the animal and the South African Mint has struck a two cent piece with a prancing black wildebeest.[57]
The black wildebeest or white-tailed gnu (Connochaetes gnou) is one of the two closely related wildebeest species. It is a member of the genus Connochaetes and family Bovidae. It was first described in 1780 by Eberhard August Wilhelm von Zimmermann. The black wildebeest is typically 170–220cm (67–87in) in head-and-body length, and the typical weight is 110–180kg (240–400lb). Males stand about 111–121cm (44–48in) at the shoulder, while the height of the females is 106–116cm (42–46in). The black wildebeest is characterised by its white, long, horse-like tail. It also has a dark brown to black coat and long, dark-coloured hair between its forelegs and under its belly.
Features necessary for defending a territory, such as the horns and broad-based skull of the modern black wildebeest, have been found in their fossil ancestors.[8] The earliest known fossil remains are in sedimentary rock in Cornelia in the Orange Free State and date back about 800,000 years.[10] Fossils have also been reported from the Vaal River deposits, though whether or not they are as ancient as those found in Cornelia is unclear. Horns of the black wildebeest have been found in sand dunes near Hermanus in South Africa. This is far beyond the recorded range of the species and it has been suggested that these animals may have migrated to that region from the Karoo.[2]
Aerial photography has revealed that a level of organisation occurs in the movement of the herd that cannot be apparent to each individual animal; for example, the migratory herd exhibits a wavy front, and this suggests that some degree of local decision-making is taking place.[41] Numerous documentaries feature wildebeest crossing rivers, with many being eaten by crocodiles or drowning in the attempt. While having the appearance of a frenzy, recent research has shown a herd of wildebeest possesses what is known as a "swarm intelligence", whereby the animals systematically explore and overcome the obstacle as one.[42] Major predators that feed on wildebeest include the lion, hyena, cheetah, leopard, and crocodile, which seem to favour the wildebeest over other prey.[29] Wildebeest, however, are very strong, and can inflict considerable injury even to a lion. Wildebeest have a maximum running speed of around 80km/h (50mph).[43][44] The primary defensive tactic is herding, where the young animals are protected by the older, larger ones, while the herd runs as a group. Typically, the predators attempt to cut out a young or ill animal and attack without having to worry about the herd. Wildebeest have developed additional sophisticated cooperative behaviours, such as animals taking turns sleeping while others stand guard against a night attack by invading predators. Wildebeest migrations are closely followed by vultures, as wildebeest carcasses are an important source of food for these scavengers. The vultures consume about 70% of the wildebeest carcasses available. Decreases in the number of migrating wildebeest have also had a negative effect on the vultures.[45] In the Serengeti ecosystem, Tanzania, wildebeest may help facilitate the migration of other, smaller-bodied grazers, such as Thomson's gazelles (Eudorcas thomsonii), which eat the new-growth grasses stimulated by wildebeest foraging.[46]
More than 18,000 individuals are now believed to remain, 7,000 of which are in Namibia, outside their natural range, and where they are farmed. Around 80% of the wildebeest occurs in private areas, while the other 20% is confined in protected areas. The population is now trending upward (particularly on private land) and for this reason the International Union for Conservation of Nature (IUCN), in its Red List of Threatened Species, rates the black wildebeest as being of "Least Concern". Its introduction into Namibia has been a success and numbers have increased substantially there from 150 in 1982 to 7,000 in 1992.[1][14]
Where it lives alongside the blue wildebeest, the two species can hybridise, and this is regarded as a potential threat to the maintenance of the species.[1][11] The black wildebeest was once very numerous and was present in Southern Africa in vast herds, but by the end of the 19th century, it had nearly been hunted to extinction and fewer than 600 animals remained.[15] A small number of individuals was still present in game reserves and at zoos, and from these, the population was rescued.[1]
The blue wildebeest is a herbivore, feeding primarily on short grasses. It forms herds which move about in loose aggregations, the animals being fast runners and extremely wary. The mating season begins at the end of the rainy season and a single calf is usually born after a gestational period of about 8.5 months. The calf remains with its mother for 8 months, after which it joins a juvenile herd. Blue wildebeest are found in short-grass plains bordering bush-covered acacia savannas in southern and eastern Africa, thriving in areas that are neither too wet nor too arid. Three African populations of blue wildebeest take part in a long-distance migration, timed to coincide with the annual pattern of rainfall and grass growth on the volcanic soil short-grass plains where they can find the nutrient-rich forage necessary for lactation and calf growth.
The black wildebeest is native to southern Africa. Its historical range included South Africa, Swaziland, and Lesotho, but in the latter two countries, it was hunted to extinction in the 19th century. It has now been reintroduced to them and also introduced to Namibia, where it has become well established.[1]