Is it always necessary to cull large populations of wild animals such as elephants and hippos, when they appear to be destroying their habitat? In ORYX May 1969, C. A. R. Savory argued the case for doing so in Rhodesia, and the question of whether to crop elephants in parks such as the Tsavo and the Kruger has caused heated controversy. In this article the authors, drawing on their experience of the Luangwa Valley in Zambia, where a cropping scheme was started in 1966, suggest that what appears to be destruction there may not necessarily be so, and that the real vegetation killer is fire in the dry season. R. M. Lawton is an ecologist with the Land Resources Division of the British Directorate of Overseas Surveys, and Mrs Gough is a skilled observer of animal behaviour with considerable experience in Zambia.