Biogeography of Montane Small Mammals in Malawi, Central Africa

Small mammals were surveyed in montane forests and grasslands on Zomba Plateau, Nyika Plateau and Mulanje Mountain in Malawi. Nine species were recorded, all confined in Malawi to montane habitats. Community densities varied from 20/ha on Nyika Plateau to 29/ha on Zomba Plateau. Five or six species were livetrapped in each region, but only four species (Lophuromys flavopunctatus Thomas, Mus triton (Thomas), Thamnomys sp. and Praomys delectorum (Thomas)) occurred in all regions. Each species has a different habitat preference. Tests of similarity between these small mammal faunas showed that each region was different but with considerable similarity between them. There was little difference between similar habitats within a region. Each species has had a different evoluti9nary history and pattern of dispersal, and the present mixture of species is a result of these differences and the past changes in climate and vegetation. The present species composition may be explained by the continuous presence of a forest-grassland mosaic which must have shown altitudinal change in response to changing climates in the past.