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
Wildebeest predators are more easily seen in open areas. The seasonal presence of thousands of migratory wildebeests reduces local lion predation on giraffe calves, resulting in greater survival of giraffes. Wildebeest can also listen in on the alarm calls of other species, and by doing so, can reduce their risk of predation. One study showed, along with other ungulates, wildebeests responded more strongly to the baboon alarm calls compared to the baboon contest calls, though both types of calls had similar patterns, amplitudes, and durations. The alarm calls were a response of the baboons to lions, and the contest calls were