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
Black wildebeest of wildebeest feeding at night also increased. During cool weather, they lay down to rest, but in hotter conditions they rested while standing up. Male black wildebeest reach sexual maturity at the age of 3 years, but may mature at a younger age in captivity. Females first come into estrus and breed as yearlings or as 2-year-olds. They breed only once in a year. A dominant male black wildebeest has a harem of females and will not allow other males to mate with them. The breeding season occurs at the end of the rainy season and lasts a few weeks