Black wildebeest
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. Repeated outbreaks of mange (scab) have led to large-scale extinctions. 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.
Blue wildebeest
The blue wildebeest is native to Angola, Botswana, Kenya, Mozambique, South Africa, Swaziland, Tanzania, Zambia, and Zimbabwe. Today, it is extinct in Malawi, but has been successfully reintroduced in Namibia. The southern limit of the blue wildebeest range is the Orange River, while the western limit is bounded by Lake Victoria and Mount Kenya. The blue wildebeest is widespread and is being introduced into private game farms, reserves and conservancies. So, the International Union for Conservation of Nature and Natural Resources rates the blue wildebeest as being of least concern. The population has been estimated to be around 1.5 million, and the population trend is stable.