(1) To estimate the efficiency of the foraging strategy described in Pellew (1984), the rates of food intake of adult giraffe in the Serengeti National Park are assessed. Daily energy intakes derived from the diet are compared with estimates of the energy requirements for year-round reproduction. The reproductive performance of giraffe in the Serengeti is discussed in the light of such energy budgets. (2) Giraffe are exerting a major impact upon the development of the Acacia regeneration, removing up to