Group sizes of oribis in different habitats

ENGLISH 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. *********** AFRIKAANSE OPSOMMING: Data wat versamel is van die groepgroottes van die oorbietjie Ourebia ourebi in die middellandgebiede van Natal is met die van berggebiede (die Drakensberge) vergelyk, sowel as met data van tropiese grasvelde (Cos-Afrika). Gemiddelde groepgroottes was die laagste in die Drakensberge en die hoogste in tropiese grasveld. In die berggebiede het volwasse oorbietjies hoofsaaklik as pare of enkellopendes voorgekom. In tropiese grasveld kom hulle hoofsaaklik in klein troppies (0 en > 1 <2 )voor, en in die Natalse middellande is die sosiale organisasie tussen die van die berge en die van tropiese grasveld. Daar word voorgestel dat die sosiale organisasie van die oorbietjie deur die geskiktheid van die habitat be"invloed word, sowel as die beskikbaarheid en kwaliteit van voedsel gedurende die winter. Hierdie teorie word bespreek met betrekking tot die drie gebiede.