Black wildebeest
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. 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. A small number of individuals was still present in game reserves and at zoos, and from these, the population was rescued.
Black wildebeest
The black wildebeest can maintain its body temperature within a small range in spite of large fluctuations in external temperatures. It shows well-developed orientation behaviour towards solar radiation, which helps it thrive in hot, and often shadeless, habitats. The erythrocyte count is high at birth and increases till the age of 2-3 months, while in contrast, the leucocyte count is low at birth and falls throughout the animal's life. The neutrophil count is high at all ages. The haematocrit and haemoglobin content decreases till 20-30 days after birth. A peak in the content of all these haemological parameters occurs at the age of 2-3 months, after which the readings gradually decline, reaching their lowest values in the oldest individuals. The presence of fast-twitch fibres and the ability of the muscles to use large amounts of oxygen help explain the rapid running speed of the black wildebeest and its high resistance to fatigue. Individuals may live for about 20 years.