The black wildebeest or white-tailed gnu (Connochaetes gnou) is one of two wildebeest species. These are members of the cattle family and form herds on grassy plains. The natural populations of black wildebeest, endemic to the southern part of Africa, were almost completely exterminated, 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, South Africa, Namibia, and Kenya. It has also been introduced outside its natural range.
The black wildebeest is placed in the genus Connochaetes and family Bovidae. It was first described by German zoologist Eberhard August Wilhelm von Zimmermann in 1780. The black wildebeest seems to have diverged from the blue wildebeest (Connochaetes taurinus) in the middle to late Pleistocene. The earliest evidence for this is fossil remains found in sedimentary rock in Cornelia in the Orange Free State dating back about 800 thousand years ago.
The black wildebeest has a dark brown or black coat which is slightly paler in summer and coarser and shaggier in the winter. It has a bushy mane that sticks up from the back of its neck. The hairs which compose this are white or cream-coloured with dark tips. On its muzzle and under its jaw it has black bristly hair. It also has long, dark-coloured hair between its forelegs and under its belly. Its long tail is greyish-white with a black base and reaches nearly to the ground. It has a pair of stout horns which are broad and close together at the base, sweep forward in a curve and rise to sharp tips. It has scent glands in front of its eyes, under its hair tufts and on its forefeet. Males are larger than females. The adult weight is about 110 to 157 kilograms (240 to 346 lb) and its height about 2 metres (6 ft 7 in).
Distribution and habitat
The black wildebeest is native to southern Africa with its range including South Africa, Swaziland and Lesotho. It is no longer present in much of this range but private herds are maintained on game reserves and private land. Its typical habitat is open grassy plains, karoo shrublands, flat rolling hills and mountainous areas with altitudes ranging between 1,350 and 2,150 metres (4,430 and 7,050 ft).
Black wildebeest form herds, although solitary males may also be found. Larger herds have a single dominant male, a number of females and their offspring. Other males, including yearlings ousted from their herds by the dominant male, are often found in "bachelor" groups. The diet consists largely of grass but shrubs and herbs are also eaten. Coarse grass is avoided and short green growth selected where possible. In the past the black wildebeest was a migratory animal undertaking long distance treks to make use of the different patterns of grass growth across its range. Nowadays it is largely confined to game reserves and private land and remains sedentary.
A dominant male black wildebeest will have a harem of females and will not allow other males to mate with them. The breeding season occurs at the end of the rainy season and lasts a few weeks between February and April. His repeated calls of "ge-nu" at this time gives the wildebeest its common name of "gnu". When one of his females comes into oestrus the male concentrates on her and mates with her repeatedly. During the breeding season, the male loses condition as he spends little time grazing. The gestation period lasts for about eight and a half months and nearly all the young in the herd are born within a short time frame in November and December. The calf (occasionally there are two) has a tawny, shaggy coat and weighs about 11 kilograms (24 lb). It is able to stand and run shortly after birth, a period of great danger for animals in the wild. It is fed by its lactating mother for six to eight months and remains with her until her next calf is born a year later. Females reach maturity at 1.5 to 2.5 years but males are not mature until they are 3 years old. A black wildebeest may live for about twenty years.
The main natural threats to the black wildebeest are carnivorous mammals such as lions, leopards, hunting dogs and hyenas. Disease outbreaks sometimes occur and farmers have shot the animals, believing they pass on disease to their cattle and compete with their animals for pasture. The black wildebeest was once very numerous and was present in southern Africa in vast herds but by the end of the nineteenth century, it had nearly been hunted to extinction. A small number of individuals was still present in game reserves and zoos and it is from these that the population was rescued. There are now believed to be about eighteen thousand individuals, seven thousand of which are in Namibia, outside its natural range, and where it is farmed. Where it lives alongside the blue wildebeest, the black wildebeest can hybridise, and this is regarded as a potential threat to the maintenance of the species. The population is now stable or trending upward and for this reason the IUCN in its Red List of Threatened Species, rates the black wildebeest as being of "Least Concern".
- IUCN SSC Antelope Specialist Group (2008). "Connochaetes gnou". IUCN Red List of Threatened Species. Version 2010.2. International Union for Conservation of Nature. Retrieved 28 August 2010. Database entry includes a brief justification of why this species is of least concern.
- von Richter, W. (1974). "Connochaetes gnou". Mammalian Species (The American Society of Mammalogists) (50): 1–6.
- Wilson, D. E.; Reeder, D. M., eds. (2005). Mammal Species of the World (3rd ed.). Johns Hopkins University Press. p. 676. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Codron, Daryl; Brink, James S. (2007). "Trophic ecology of two savanna grazers, blue wildebeest Connochaetes taurinus and black wildebeest Connochaetes gnou". European Journal of Wildlife Research 53 (2): 90–99. doi:10.1007/s10344-006-0070-2.
- Lundrigan, Barbara; Bidlingmeyer, Jennifer (2000). "Connochaetes gnou: black wildebeest". Animal Diversity Web. University of Michigan. Retrieved 2013-08-21.
- "Black wildebeest (Connochaetes gnou)". ARKive. Wildscreen. Retrieved 2013-08-21.
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