Implications of cytochrome b sequence variation for biogeography and conservation of the northern flying squirrels (Glaucomys sabrinus) of the Alexander Archipelago, Alaska

The Alexander Archipelago of southeast Alaska is a highly fragmented landscape that is suspected to support a relatively large number of endemic mammals. At least two subspecies of northern flying squirrels (Glaucomys sabrinus) have been recognized from the region, the endemic Prince of Wales Island flying squirrel, Glaucomys sabrinus griseifrons, and the Alaska Coast flying squirrel, G. s. zaphaeus. We examined 56 northern flying squirrels from Alaska, Washington State, and Yukon Territory, using the DNA sequence from the mitochondrial cytochrome b gene to assess geographic variation. Flying squirrels from Washington were highly divergent (7.3%) from those of Alaska and Yukon Territory. Variation among Alaska and Yukon Territory populations was minimal, but five haplotypes were found. One predominantly "mainland" haplotype was widespread throughout Alaska, one island haplotype was confined to nine islands in southeast Alaska ("Prince of Wales complex"), and three haplotypes were unique. Flying squirrels of the Prince of Wales complex appear to be neoendemics and descended from a single founder population. Mitochondrial variation, although minimal, is consistent with the continued recognition of G. s. griseifrons. Our results, in light of increased habitat fragmentation in southeast Alaska, suggest that molecular data can provide important base-line information for effective management of insular populations.