Range shifts of mouse lemurs in south-eastern madagascar: Evidence from mitochondrial genetic data

Abstract

The gray mouse lemur, Microcebus murinus , occurs mainly in dry forests in western Madagascar, but its distribution extends into humid littoral forests in the south-eastern Anosy Region. We sequenced the mitochondrial hypervariable region 1 for 282 M. murinus individuals from 13 south-eastern study sites. The spatial distribution of mitochondrial haplotypes and the varying genetic distances within two haplotype clades indicated a trend of decreasing genetic diversity towards the south-eastern margin of the range. Rufous mouse lemurs, Microcebus cf. rufus , have a complementary distribution in south-eastern Madagascar which does not overlap with that of M. murinus . Taken together, the spatial distribution of genetic diversity within M. murinus and the distinct ranges of the two species could indicate a recent expansion of gray mouse lemurs into littoral forests in south-eastern Madagascar.