Does the ice rat Otomys sloggetti robertsi contribute to habitat change in Lesotho?

Rodents can contribute to habitat change through their activities. In the Lesotho Drakensberg, soil erosion has increased markedly recently, supposedly as a result of the combined activities of the ice rat Otomys sloggetti robertsi and domestic livestock. Ice rats are diurnal, herbivorous, burrow-dwelling rodents, endemic to the alpine regions of southern Africa. We erected exclosure plots to investigate the single or combined effects of ice rats and domesticated livestock oil the vegetation and soil characteristics in their habitat and whether their activities potentially influence soil erosion. Contrary to our prediction, vegetation changes and soil movement were greatest in plots accessed only by ice rats. Therefore, ice rats are likely to be a major contributor to habitat change in the Lesotho Drakensberg because of their foraging and burrowing activities, and soil erosion is likely to be exacerbated by their increasing population numbers recently. Nonetheless, soil erosion is a complex problem involving several abiotic and biotic contributing factors, and long-term Studies are required to fully understand the determinants underlying the Causes of erosion in the Lesotho Drakensberg. (C) 2009 Elsevier Masson SAS. All rights reserved.