Blue wildebeest (brindled gnu) lack the dirty-
wbite tail and mane of the black wildebeest
tailed, Unlike the latter, they also
don't have the forward-facing borns, the black
tuft of bair along the ridge of the nose or the
beard of black hair on the chest between the
forelegs. This baby is only a few days old - note
the umbilical cord.
Scientific classificatione
Kingdom ~ Animalia
Phylum ~ Chordata
Class ~ Mammalia
Order ~ Artiodactyla
Family ~ Bovidae
Subfamily ~Alcelaphinae
Genus ~ Connochaetes
Type species
Antilope gnu
Species
Connochaetes gnou – black wildebeest
Connochaetes taurinus – blue wildebeest
Fossil records suggest these two species diverged about one million years ago, resulting in a northern and a southern species. The blue wildebeest remained in its original range and changed very little from the ancestral species, while the black wildebeest changed more as adaptation to its open grassland habitat in the south. The most obvious way of telling the two species apart are the differences in their colouring and in the way their horns are oriented.
In East Africa, the blue wildebeest is the most abundant big-game species; some populations perform an annual migration to new grazing grounds, but the black wildebeest is merely nomadic. Breeding in both takes place over a short period of time at the end of the rainy season and the calves are soon active and are able to move with the herd, a fact necessary for their survival. Nevertheless, some fall prey to large carnivores, especially the spotted hyena.
Wildebeest often graze in mixed herds with zebra, which gives heightened awareness of potential predators. They are also alert to the warning signals emitted by other animals such as baboons. Wildebeest are a tourist attraction but compete with domesticated livestock for pasture and are sometimes blamed by farmers for transferring diseases and parasites to their cattle. Illegal hunting does take place but the population trend is fairly stable and, with some in national parks or on private land. The International Union for Conservation of Nature lists both kinds of Wildebeest as least-concern species weWildebeest inhabit the plains and open woodlands of parts of Africa south of the Sahara. The black wildebeest is native to the southernmost parts of the continent. Its historical range included South Africa, Eswatini, 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. It inhabits open plains, grasslands, and Karoo shrublands in both steep mountainous regions and lower undulating hills at altitudes varying between 1,350 and 2,150 m (4,430 and 7,050 ft). In the past, it inhabited the highveld temperate grasslands during the dry winter season and the arid Karoo region during the rains. However, as a result of widespread hunting, the black wildebeest no longer occupies its historical range or makes migrations, and is now largely limited to game farms and protected reserves.
The blue wildebeest is native to eastern and southern Africa. Its range includes Kenya, Tanzania, Botswana, Zambia, Zimbabwe, Mozambique, South Africa, Eswatini and Angola. 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. In East Africa, the blue wildebeest is the most abundant big game species, both in population and biomass. 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
Migration
Not all wildebeest are migratory. Black wildebeest herds are often nomadic or may have a regular home range of 1 km2 (0.39 sq mi). Bulls may occupy territories, usually about 100 to 400 m (300 to 1,300 ft) apart, but this spacing varies according to the quality of the habitat. In favourable conditions, they may be as close as 9 m (30 ft), or they may be as far apart as 1,600 m (5,200 ft) in poor habitat. Female herds have home ranges of about 250 acres (100 ha; 0.39 sq mi) in size. Herds of nonterritorial bachelor males roam at will and do not seem to have any restrictions on where they wander.
Blue wildebeest have both migratory and sedentary populations. In the Ngorongoro, most animals are sedentary and males maintain a network of territories throughout the year, though breeding is seasonal in nature. Females and young form groups of about 10 individuals or join together in larger aggregations, and nonterritorial males form bachelor groups. In the Serengeti and Tarangire ecosystems, populations are mostly migratory, with herds consisting of both sexes frequently moving, but resident subpopulations also exist. During the rutting season, the males may form temporary territories for a few hours or a day or so, and attempt to gather together a few females with which to mate, but soon they have to move on, often moving ahead to set up another temporary territory.
In the Maasai Mara game reserve, a non-migratory population of blue wildebeest had dwindled from about 119,000 animals in 1977 to about 22,000 in 1997. The reason for the decline is thought to be the increasing competition between cattle and wildebeest for a diminishing area of grazing land as a result of changes in agricultural practices, and possibly fluctuations in rainfall.
Each year, some East African populations of blue wildebeest have a long-distance migration, seemingly timed to coincide with the annual pattern of rainfall and grass growth. The timing of their migrations in both the rainy and dry seasons can vary considerably (by months) from year to year. At the end of the wet season (May or June in East Africa), wildebeest migrate to dry-season areas in response to a lack of surface (drinking) water. When the rainy season begins again (months later), animals quickly move back to their wet-season ranges. Factors suspected to affect migration include food abundance, surface water availability, predators, and phosphorus content in grasses. Phosphorus is a crucial element for all life forms, particularly for lactating female bovids. As a result, during the rainy season, wildebeest select grazing areas that contain particularly high phosphorus levels. One study found, in addition to phosphorus, wildebeest select ranges containing grass with relatively high nitrogen content. largest migration of the animal is being found in serengeti national park only in the whiole world.
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