Altitudinal distribution of rodents (Muridae and Gliridae) on Mt Elgon, Uganda

Abstract

Small mammals were surveyed along a transect in Mt Elgon National Park, Uganda, at altitudes from 2900 to 4300 m a.s.l., with the main focus in the Afroalpine grasslands above 3500 m a.s.l. In this study, 13 species belonging to the Muridae were recorded, but only one species Lophuromys flavopunctatus Thomas 1888, occurred in all habitats. The highest species and individual numbers were found in richly structured vegetation in the Afro-alpine zone. Twenty-four species of Muridae and one Gliridae have been recorded from the Mt Elgon NP, Uganda (> 2000 m a.s.l.) so far, two more have been found on the Kenyan side and are likely to occur in Uganda. A total of 34 species of Muridae have been recorded on the whole range of Mt Elgon, two being endemic to the Afro-alpine zone, one listed as vulnerable and one as rare by the IUCN (LIDICKER 1985).

The present distribution patterns and composition of the montane rodent communities are a result of different evolutionary histories mainly brought about by past changes in climate and vegetation. A number of montane rodents in Africa are relict forms, which declined due to habitat changes and competition from invading “modern” species.

KEY WORDS:

• rodents
• Mt Elgon
• ecology
• elevation gradient
• conservation
• biogeography