Blue wildebeest rivers of herds still cross East Africa
Connochaetes antelopes—wildebeest or gnu—belong to Bovidae's Alcelaphinae and live in eastern and southern Africa. Fossils suggest blue and black wildebeest split about a million years ago. In East Africa the blue form is the most abundant big-game antelope; some populations migrate annually while black wildebeest stay more local.
Dutch settlers heading into the South African interior around 1700 named the animals wildebeest, "wild beast" or "wild cattle," for their ox-like look; the alternative name gnu may come from a Khoekhoe word or from the San name for the black species. The genus name Connochaetes, coined by Hinrich Lichtenstein in 1812, joins Greek words for "beard" and "flowing mane." Their closest relatives are hartebeest, the hirola, topi and blesbok, and taxonomists shuffled the blue form between genera and races through 1914 and 1939 before settling on two species.
Fossils and mitochondrial DNA put the split at about a million years ago. The blue wildebeest, C. taurinus, stayed in the ancestral northern range and changed little; its fossils, some 2.5 million years old, are common in the caves of the Cradle of Humankind. The black wildebeest, C. gnou, adapted to southern open grassland, with the oldest fossils about 800,000 years old. A blue bull stands about 150 cm and weighs around 250 kg, against 111–120 cm and 180 kg for a black bull, and the horns curve differently. Where fenced together the two interbreed, producing fertile young that often have faulty teeth, horns and skull bones.
Blue wildebeest are the most plentiful big game in East Africa by both numbers and biomass, famous in the Serengeti, Maasai Mara and Zambia's Liuwa Plain. Some herds migrate while others, as in Ngorongoro, stay put, with males holding territories all year. Calving is squeezed into a short window at the end of the rains, and calves must keep pace with the herd almost at once, though spotted hyenas still take many. Grazing alongside zebras, and heeding baboon alarms, sharpens predator warning. Lifespans average about 20 years.
Black wildebeest were hunted out of Eswatini and Lesotho in the 19th century and no longer migrate, surviving mostly on game farms and reserves, though reintroductions have followed. Competition with cattle cut a resident Maasai Mara population from about 119,000 in 1977 to roughly 22,000 by 1997. Both species are nonetheless rated least concern.
Source: Wildebeest
