Differences in mammal and bird assemblages between commercial and communal rangelands in the Succulent Karoo, South Africa

Small mammal and bird assemblages were compared across fence-lines between one communal and three adjacent commercial range-lands in Namaqualand, South Africa. The communal area has twice the recommended stocking rate of sheep and goats, and has less perennial plant cover and more annual plants than neighbouring commercial rangelands. Commercial rangelands supported a larger and more diverse assemblage of small mammals and birds. Small mammal species composition on communal lands was a subset of that on adjacent commercial rangelands, with only one species equally abundant in both treatments. Diurnal mammals were scarce in communal rangelands, apparently due to the lack of cover for predator avoidance and herbivory. Management to maintain a diversity of small mammals requires a minimum level of effective cover. Bird richness and diversity was also reduced on communal rangelands, with many species, especially insectivores, less abundant. A few bird species, notably granivores, were more abundant on communal rangelands, probably because of the increase in annual plant cover. The absence of some large bird species regularly found in Namaqualand, but absent from both treatments (e.g., bustards), suggests that neither management practice is optimal.