In the early 1970s the huge lechwe herds gave the Kafue Flats in Zambia one of the highest carrying capacities in the world – an estimated 11,000kg per sq km. But these highly specialised antelopes depend on the annual floods of the Kafue river, to which particularly they have adapted their breeding behaviour and the leks in which they mate. Since the completion of two huge dams on the Kafue these floods are now controlled in the interests of making electricity, and not of the lechwe. The author, who studied the lechwe's social organisation and behaviour in the Lochinvar National Park, first describes the lechwe's remarkable lek system, how they are adapted to the floods to the point of being able to graze in water up to their shoulders, and the remarkable way in which they maximise the resources of the Flats. In the second part (page 481) he shows how the new flood control can disrupt their breeding behaviour and social organisation, which might lead to the extinction of the Kafue lechwe.