An ecological study of small rodents in the woodland savanna of Liwonde National Park, Malawi



A community of small rodents was studied in the woodland savanna of Liwonde National Park, Malawi from September 1984 to June 1985. Seven species were recorded on two 11 ha grids, using a capture-mark-release technique. Three species (Aelhomys chrysophilus, Acomys spinosissimus and Tatera leucogasler) comprised 78% of all trapped individuals. Average population numbers fluctuated from 3 to 17 individuals/ha. The grid with the densest vegetation supported the greatest number of individuals. Highest population numbers occurred in the mid-dry season (when the grids appeared to act as refugia) and in the early wet season (due to recruitment of young animals). Areas which had been burned during the dry season did not support as many individuals as unburnt areas. Population survival rates were low, with only about 50% of individuals surviving to the following month. The number of individuals/ha in Liwonde NP was lower than in similar habitats in other parts of eastern Africa, probably because of the shorter rainfall season and the consequent strong seasonal fluctuations in food resources, reduced opportunity for reproduction, and overall low productivity of the ecosystem.