Black wildebeest the hybrid as compared to either of its parents. In some animals, the auditory bullae are highly deformed, and in others, the radius and ulna are fused. Black wildebeest are sexually dimorphic, with females being smaller in size and more slender than males. The head-and-body length is typically between . Males reach about at the shoulder, while females reach . Males typically weigh and females . A distinguishing feature in both sexes is the tail, which is long and similar to that of a horse. Its bright-white colour gives this animal the vernacular name of "white-tailed gnu", and also distinguishes
Blue wildebeest bovine appearance. The blue wildebeest is susceptible to foot-and-mouth disease, anthrax, sarcoptic mange, and hoof gangrene. The herpesvirus was first isolated from the blue wildebeest in 1960 by veterinary scientist Walter Plowright. Although the causes of death vary from year to year, in one drought in Botswana, young calves and aged females were the most likely to die. On another occasion, an estimated 47% of deaths were caused by disease, 37% were due to predation, and the remainder were the result of accidents. The animal can be host to a number of different parasites. In one study, blue wildebeest were