Gnu , also wildebeest, large African antelope with an oxlike head, horns, and shoulders; bristly facial hair and mane; and a horselike tail. Two species exist: the black wildebeest, which was once abundant in South Africa but has now been hunted back to about 10,000 individuals; and the blue wildebeest, herds of which are common on grassy plains from Kenya south to northern South Africa. Both sexes of both species have broad, smooth horns that curve downward, outward, and then upward. Blue wildebeests, which vary from bluish-gray to brown, form resident nursery herds of females and young. Single males defend territories and court estrous females crossing their land. Males without territories form loose bachelor herds. In dry seasons some herds migrate in huge congregations. Although the bristly faces and massive shoulders make gnus appear menacing, they go into antics when approached, dashing off and wheeling about to gaze at the intruders. Females bear single calves, which can run a few minutes after birth. The young are frequently taken by hyenas, and the adults are a favorite prey of lions .