It seems that, at best, slightly more than 500km2 of suitable habitats for reedbuck, waterbuck, lechwe and puku are conserved in State Protected Areas. The remainder (2,500km2) is subject to cattle grazing pressure and must be regarded as less than optimum. If the densities given below (intermediate values taken from ASG 1998) are assumed to be carrying capacity for the four species, then the expected populations in State Protected Areas would be as follows:

It is apparent from the survey data and general observations that the actual populations are far lower than these estimates.

However, the carrying capacity for all four species is likely to fluctuate in synchrony with the long term rainfall regime.

This has been stressed for roan, sable and tsessebe. In particular, the cumulative surpluses and deficits above and below the mean rainfall were seen as having a long term effect on population performance. This effect is likely to be even more pronounced in the case of wetland grazers. The floodplain vegetation types (Mendlesohn & Roberts 1997) will vary in their potential to support populations of wetland grazers depending on the moisture in the soil and the extent of surface water. Lechwe are likely to suffer the most from this factor.