Activity patterns of wildebeest Connochaetes taurinus were determined over a period of one year (May 1977-May 1978), using marked individuals as focal animals, and by scanning herds at Etosha National Park, South West Africa/Namibia. Activity was categorised as resting, grazing, movement, drinking water, suckling and social encounters. Diurnal and nocturnal activity of bull herds and mixed herds was compared on a seasonal basis.