Multiple levels of allopatric divergence in the endemic Philippine fruit bat Haplonycteris fischeri (Pteropodidae)

As part of a larger comparative phylogeographical study of Philippine fruit bats, I used fragments of the mitochondrial genes cytochrome b and ND2 to investigate phylogeography and diversification in Haplonycteris fischeri, a pteropodid bat endemic to the Philippines but widespread within the archipelago. Genetic diversity in H. fischeri was extremely high in these commonly studied genes, with 101 unique haplotypes in 123 sequenced individuals, although small, continuously isolated islands had less diversity than had large island complexes. Seven monophyletic groups and one paraphyletic group were restricted to individual islands, groups of islands, or parts of islands. Each Pleistocene island complex had a single resident monophyletic lineage; these five groups were separated by approximately 6-8% sequence divergence and apparently have been diverging for 4-6 Myr. Within island groups, monophyletic lineages on some individual islands suggest that current ocean channels have also been barriers to gene flow; in some cases, multiple allopatric clades were present on single islands. Basal divergence dates were estimated to be in the early Pliocene, and most diversification was apparently connected to the ongoing geological evolution of the Philippines. Geological history and current geography interact with ecology to cause substantial genetic differentiation within this primary forest-specialist species.