Phylogeography of Père David’s red-backed vole, <i>Eothenomys melanogaster</i> (Rodentia: Cricetidae), in Taiwan

Abstract Sympatrically distributed mammal species do not always show congruent phylogeographical traits. In Taiwan, montane mammals show two different phylogeographical patterns: some species have no clear genetic diversification, whereas others show clear north–south genetic divergence. The ecological characteristics of each species might be important factors determining each pattern. The former species group is adapted to rich forest habitats, whereas the latter species group requires more complicated habitats consisting of both forested and non-forested areas. If the latter group has experienced similar historical processes, we might find a congruent zoogeographical pattern that separates its northern and southern populations. To test this hypothesis, we examined the phylogeographical characteristics of Eothenomys melanogaster found in the habitat of the latter species group, based on mitochondrial and nuclear DNA sequences and chromosomes. All genetic markers demonstrated clear north–south divergence. The boundary between the two populations was in the mountainous areas, including Mount Houhuan. Our results suggested that the southern population was the first to immigrate from the Asian continent to the south of the boundary, followed by the immigration of the northern population to the north of the boundary. Both populations could have been isolated from each other by a boundary in Taiwan during the Pleistocene.