The Uganda defassa waterbuck is a large African antelope which in western Uganda breeds throughout the year. The adult male averaged 520 lb and the adult female 410 lb in weight. After weaning, at six to eight months, males joined a bachelor herd whilst some females possibly formed spinster groups. The bachelor herd inhabited a home range covering several male territories. At age five to six years a bachelor male attempted to establish his own territory, normally becoming territorial by age seven. A year-round territory was then maintained throughout life, but at age nine to ten owners were often driven into small, unfavourable areas by younger males. Boundaries were defended by fighting and by typical bovid intimidatory displays. Territories were not actively marked by their owners but owners were apparently identified by odour. Females adopted home ranges covering several male territories, restricting their ranging with increasing age. These home ranges seemed owned by groups of females who moved within them as individuals, associations between particular females being fluid.