SYSTEMATICS AND GEOGRAPHIC-VARIATION OF ETHIOPIAN ARVICANTHIS (RODENTIA, MURIDAE)

Arvicanthis, the unstriped grass-rat, is a widespread genus occurring in many regions of Africa and is a major pest in agricultural farmland . Despite its economic importance for developing countries, the taxono my of the genus is still in a chaotic state. We used univariate and mu ltivariate morphometrics to investigate two species, A. abyssinicus an d A. dembeensis, occurring in Ethiopia. Results show that these taxa a re well separated, this contradicting authors who lump all Arvicanthis as A. niloticus. There is a longitudinal cline in the morphology of A . dembeensis from eastern regions along the Rift Valley. Differences b etween the species in morphology seem to reflect adaptation to differe nt ecological niches at high (A. abyssinicus) and low (A. dembeensis) altitudes.