Distribution and genetic structure of the Japanese wood pigeon (Columba janthina) endemic to the islands of East Asia

The Japanese wood pigeon (Columba janthina) is endemic to the islands of East Asia and it is included in the Japanese and Asian Red Lists because of its narrow habitat range that is restricted to mature forests on small islands and because of the destruction of these habitats. We examined the genetic structure of Columba janthina by studying 463 base pairs of the mitochondrial control region sequences. We analyzed 154 samples from eight populations and identified 27 haplotypes. Three population groups were identified based on the pairwise Phi(ST) values. A substantial gene flow, as reflected by the low and non-significant Phi(ST) values, is maintained among the northern group that includes six populations found on the Okinawa, Tokara, Goto, Setouchi, Oki, and Izu islands. In contrast, the southeastern group found on the Ogasawara Islands had large Phi(ST) values with every population from other regions (0.910 < Phi(ST) < 0.962). The southwestern group found on the Sakishima Islands also had significant but small Phi(ST) values with every population from the northern group (0.081 < Phi(ST) < 0.205). The Mantel test showed a highly significant correlation between the Phi(ST) values and the route length of the habitat network, as well as the linear distance with correction of the habitat gap effect, indicating the importance of the closely connected structure of the habitats. The three groups mentioned above could be considered as independent management units, and the southeastern group has the highest conservation priority due to its narrow distribution range and small population size.