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 found to be hosts to 13 species of nematodes, one trematode, larvae of five oestrid flies, three species of lice, seven ixodid tick species, one mite, and the larvae of a tongue worm. Of these, most were more prevalent at some times of the year than others. Generally, the larvae of "Gedoelstica" and "Oestrus" occur in the nasal passages and respiratory cavities of the blue wildebeest, and sometimes migrate to the brain. Compared to some other bovids, blue wildebeest are resistant to infestations by several species of ticks. The blue wildebeest is mostly active during the morning and the late