Stratégie de pâturage d'une population d'éléphants en saison sèche : le cas du parc de Zakouma au Tchad

During the dry season, Acacia seyal stands in the savannah areas of south-eastern Chad are one of the main food sources for the elephant population of Zakouma National Park. Forming a more or less dense mosaic, this tree savannah is an essential additional source of nutri- tion for these huge herbivores. This note does not set out to estimate the aerial grazing potential of the savannah for the elephants in the park, but to identify, through remote sensing, the areas that are either essential or marginal in terms of their food needs. Satellite imagery was used to establish quantitative and spatial values for these vegetation resources, whose use does not appear to be related to food quality or palatability, but to result from several concomitant physical and edaphic factors, i.e. a permanent water network and the fact that tree densities of more than 400 trees per hectare limit access for the elephants to these dry-season food resources.