The nutritional status of springbok, Antidorcas marsupialis, in the Kalahari was assessed in four habitats and three seasons by means of faecal profiling. Habitat only had a significant effect on the faecal nitrogen concentration in the cold-dry season, whereas faecal phosphorus concentrations showed no significant differences across habitats within a season. Seasonal differences in faecal nitrogen and phosphorus concentrations were more pronounced than habitat differences. Both faecal nitrogen and phosphorus concentrations differed significantly seasonally in the Nossob riverbed and in the dunes. Faecal concentrations of phosphorus and nitrogen were similar to that of springbok in other areas, but faecal nitrogen and phosphorus were below the critical range during the cold-dry season in the dune habitat and at a critically low level in the Nossob riverbed. Springbok in the southwestern Kalahari may experience nutritional stress during the dry winter period, especially in the interior dune fields.

Seasonal changes in crude protein, phosphorus and calcium contents of five common plant species in the south-western Kalahari were investigated. Three species that are browsed by springbok (Acacia erioloba, Grewia flava and Rhigozum trichotomum) and two grass species (Schmidtia kalahariensis and Stipagrostis obtusa), were included in the study. Browse species had higher crude protein, phosphorus and calcium contents than the grass species, but the fluctuation range was similar to that of the grass species. In general, the crude protein content of the food plant species sampled in the present study was above the level required by African ungulates for maintenance. However, the diet of springbok in the south-western Kalahari appeared to be phosphorus deficient. Crude protein and phosphorus levels in plant food were especially low during the cold-dry season, when the crude protein content of the grass species was at or below that which is required by springbok for sustenance. The phosphorus content was below ruminant requirements in all plant species in all habitats during the cold-dry season. Faecal crude protein and phosphorus percentages higher than that of the selected plant species investigated imply that springbok have the ability to select the most nutrient-rich plant species and plant parts available. The Ca:P ratio of the plant species that were sampled in the present study fell outside the range that is considered to be healthy for ruminants in all instances, with calcium in excess.