The spatial organization of one clan of spotted hyenas Crocuta crocuta in the centre of the Etosha National Park, Namibia, is described during the dry and the wet seasons. The clan comprised 11 adults and sub-adults and occupied a territory of 160 km2 in the dry season and 320 km2 in the wet season. The dry season territory contained a low density (one animal/km2) of resident herbivores, such as gemsbok Oryx gazella, kudu Tragelaphus strepsiceros, giraffe Giraffa camelopardis, steenbok Raphicerus campestris and ostrich Struthio camelus, and a higher density of migratory species (12 animals/km2), principally springbok Antidorcas marsupialis, zebra Equus burchelli and wildebeest Connochaetes taurinus. These migratory species were the main prey of clan members. At the start of the wet season, the migratory herbivores migrated to the north-west, resulting in a considerable decline in the density of prey in the area used by clan members during the dry season. In response to this decline in prey, clan members followed the migratory herds and shifted the focus of their activities to an area grazed by migratory herbivores during the wet season. There existed a strong spatial relationship between the hyena density and the migratory prey density in both the dry and wet season. We postulate that the considerable enlargement of the clan territory in the wet season is a response to both the migratory movements of prey and an increase in the dispersion of prey during the wet season.