Group sizes of oribis in different habitats

Abstract

Data collected on group sizes of the oribi Ourebia ourebi at midland elevations in Natal, South Africa, were compared with available data from montane (Drakensberg) and tropical (East Africa) grasslands. Mean group sizes were lowest in montane grassland and highest in tropical grassland. In the montane areas adults occurred mainly in pairs or as single animals, whereas small harem herds predominated in tropical grassland, while the organization at midland areas was intermediate. It is suggested that the social organization of the oribi is influenced by habitat suitability, and availability and quality of food during winter. This hypothesis is discussed in relation to the three areas considered.