Bubo owls (1 Viewer)

Omote, Nishida, Dick & Masuda (in press). Limited phylogenetic distribution of a long tandem-repeat cluster in the mitochondrial control region in Bubo (Aves, Strigidae) and cluster variation in Blakiston’s fish owl (Bubo blakistoni). Mol Phylogenet Evol. [abstract]

Bubo blakistoni

Omote, Surmach, Kohyama, Takenaka, Nishida, Masuda. 2018. Phylogeography of continental and island populations Of Blakiston's Fish-owl (Bubo blakistoni) In northeastern Asia. J. Raptor Res. 52(1):31-41.
https://doi.org/10.3356/JRR-16-65.1

Abstract
The endangered Blakiston's Fish-Owl (Bubo blakistoni) has a fragmented distribution in the northeastern Eurasian continent, as well as on Hokkaido, southern Kuril, and Sakhalin islands. To examine the phylogeography of this species, we analyzed mitochondrial sequences. The whole mitochondrial genome, which included duplicated genes, was the largest (>21 kbp) in vertebrates to date. A Bayesian phylogenetic analysis of mitochondrial gene sequences revealed a clear separation between two clades. The insular clade comprised the mitochondrial haplotypes from Hokkaido, southern Kuril, and Sakhalin islands, whereas the continental clade consisted of those from the Eurasian continent, including the Primorye, Amur, and Magadan areas. Analyses based on whole mitochondrial sequences suggested that the level of genetic differentiation between the two subspecies, B. b. blakistoni on the islands and B. b. doerriesi on the continent, was enough to recognize them as separate species. The estimated divergence time between the clades was at least 500,000 yr before present. In contrast, the divergence times within the clades were less than 10,000 yr before present, indicating that the haplotypes within the clades diverged after the last glacial maximum (LGM). Information on the distribution of vegetation suggests that the main areas currently inhabited by B. blakistoni were unsuitable as habitats during the LGM. Lower diversities, higher growth rate, and the pattern of haplotype distribution in the continental population suggest a severe bottleneck and rapid dispersion through the last glacial period. In contrast, the insular population retains a higher haplotype variation. Because southern Hokkaido Island was covered with forests in the LGM, the area could have acted as a refugia for this species.

Keywords: Blakiston's Fish-Owl, Bubo blakistoni, genetic diversity, glacial periods, molecular phylogeny, population bottleneck, whole mitochondrial genome

Using bioacoustic tools to clarify species delimitation within the Blakiston’s Fish Owl (Bubo blakistoni) complex​

Author links open overlay panelNyanasengeranMovinaTatjanaGamovabSergei G.SurmachbJonathan C.SlaghtcA.A.KisleikodJames A.EatoneFrank E.Rheindta
Although Blakiston’s Fish Owl (Bubo blakistoni) is widely treated as a single species, marked differences in the structure of pair duets between continental and insular populations have been documented. However, no study has quantitatively assessed these vocal differences. We obtained 192 duets from 22 pairs of Blakiston’s Fish Owl: 15 pairs of B. b. blakistoni from the Japanese island of Hokkaido and the Russian Kuril island of Kunashir, and seven pairs of B. b. doerriesi from Primorye on the Russian mainland. This is a sizeable dataset for such a large, retiring, and rare owl. We conducted bioacoustic examinations of 14 vocal parameters using principal component analysis and the Isler criterion to quantitatively test species boundaries within the B. blakistoni complex. We found that the insular populations on Hokkaido and Kunashir emerged as vocally similar to each other but markedly different from the continental populations of B. blakistoni, corresponding closely with presently accepted subspecies limits. Bioacoustic differences in the duets of the insular and continental groups are greater than the pairwise comparisons of territorial vocalisations between other sympatric owl species. Based on the reproductive importance of vocal duets in owl biology, we propose the taxonomic elevation of the continental subspecies to species level as Northern Fish Owl B. doerriesi. Our study corroborates the importance of bioacoustics in ascertaining species boundaries in owls and has important implications for the management of the two newly delimited species, each likely to be assessed as Endangered. Both species should be managed independently to optimise conservation outcomes.