GPS collars linked to the GSM (cellular phone) network open new opportunities for documenting the responses of animals to changing environmental conditions. These collars supply sequential location records according to a pre-set schedule, without any interference by an observer with animal movements. We report findings from a preliminary analysis of data from collars placed on two adjoining herds of sable antelope (Hippotragus niger) in the central region of the Kruger National Park. These collars functioned for 11.5 months and 15 months, respectively, routinely supplying GPS positions of both herds at 12 h (or shorter) intervals. From these data we derived diel displacement distances between locations 24 h apart, as well as diurnal and nocturnal (12 h) displacements. Annual home ranges of these herds covered 118 km² and 65 km², respectively. Diel displacements did not show any consistent distinction between short movements within foraging areas and long movements between foraging areas. Diel displacements increased over the course of the dry season, largely as a result of journeys to water every 3–4 days. Animals moved relatively more nocturnally during the hot months of the dry season than at other times of the year. Longer movements suggested higher energy expenditures and greater risks of predation in the late dry season.