Taxonomic and genetic diversity of rodents from the Arsi Mountains (Ethiopia)

The Arsi Mountains (Southeastern Ethiopian mountain block) are a unique region comprising a range of habitats, including natural montane forest, extensive ericaceous scrub and small, restricted patches of Afroalpine ecosystem. During 3 years of sampling small mammals, 13 rodent species were recorded, including the extremely rare Mus imberbis and Dendromus nikolausi. Genetic analysis was used to shed light on the taxonomic diversity of rodents in the Arsi Mountains and their evolutionary associations with populations from other Ethiopian montane massifs (including the neighbouring Bale Mountains). All species recorded are endemic to the Ethiopian highlands. The results of this study provide the first genetically confirmed data on the occurrence of such endemic species as Lophuromys melanonyx, L. chrysopus and a yet undescribed Dendromus species in the Arsi Mountains. The genetic affinities of some Arsi rodents with their conspecifics in the neighbouring Bale Mountains were also explored. The results suggest the Arsi Mountains as one of the most important hotspots of unique Ethiopian mammal diversity.