A comparison of the community dynamics of bioturbating small mammals between livestock and wildlife farming areas in the Kalahari, Namibia

Abstract

The study compared abundance and diversity of small mammals between a commercial livestock and neighbouring game farm in the Kalahari Thornveld of Namibia's Omaheke region. Sherman traps baited with standard small-mammal attractants were set out in grids in similar habitats on each land use for four trap-nights during the growing season and the non-growing season of 2015. In total, 174 individuals of five species of small mammals were trapped, 118 on the livestock farm, and 56 on the game farm. Species richness totalled five species of the order Rodentia of which the bioturbating species Gerbillurus paeba represented 79.9% (n=139). All five species were trapped on the livestock farm, and only three on the game farm. With similar stocking rates but different grazing management strategies, it is expected that rangeland condition and perennial grass cover differences influenced the densities and species richness of small mammals. This suggests that ecosystem services associated with these mammal species would be more effective on the livestock farm, leading to better soil moisture infiltration and retention, as well as more effective soil nutrient cycling and seed dispersal.