title: Recent fragmentation of the endangered Blakiston's fish owl (Bubo blakistoni) population on Hokkaido Island, Northern Japan, Revealed by Mitochondrial DNA and Microsatellite Analyses.
abstract: BACKGROUND
  Blakiston's fish owl (Bubo blakistoni) was previously widespread on Hokkaido Island, Japan, but is now distributed only in limited forest areas. The population size on Hokkaido decreased during the 20th century due to reduction and fragmentation of the owl's habitat. To elucidate temporal and spatial changes in population structure and genetic diversity, we analyzed 439 individuals collected over the last 100 years.
  
  
  RESULTS
  We detected a population bottleneck and fragmentation event indicated by mitochondrial DNA (mtDNA) haplotype and microsatellite analyses. The lowest value for effective population size, which was estimated by moment and temporal methods from microsatellite data, occurred in the 1980s. Five haplotypes were found in the mtDNA control region; most haplotypes were previously widespread across Hokkaido, but have become fixed in separate areas after the bottleneck period. Genetic differentiation among local populations, as indicated by both mtDNA and microsatellite data, likely arose through population fragmentation.
  
  
  CONCLUSIONS
  The owl population may have been divided into limited areas due to loss of habitats via human activities, and have lost genetic variability within the local populations through inbreeding. Our mtDNA and microsatellite data show that genetic diversity decreased in local populations, indicating the importance of individuals moving between areas for conservation of this species on Hokkaido.
authors.affiliation: Department of Natural History Sciences, Graduate School of Science, Hokkaido University, Sapporo, 060-0810 Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Omote
authors.affiliation: Department of Natural History Sciences, Graduate School of Science, Hokkaido University, Sapporo, 060-0810 Japan.
authors.forename: Chizuko
authors.initials: C
authors.lastname: Nishida
authors.affiliation: FILIN, Sapporo, 063-0842 Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Takenaka
authors.affiliation: Institute for Raptor Biomedicine, Kushiro, 084-0922 Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Saito
authors.affiliation: Kushiro City Zoo, Kushiro, 085-0201 Japan.
authors.forename: Ryohji
authors.initials: R
authors.lastname: Shimura
authors.affiliation: Kushiro City Zoo, Kushiro, 085-0201 Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujimoto
authors.affiliation: Faculty of Letters, Keio University, Tokyo, 108-8345 Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Sato
authors.affiliation: Department of Natural History Sciences, Graduate School of Science, Hokkaido University, Sapporo, 060-0810 Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Masuda
keywords: Bubo blakistoni; Genetic diversity; Microsatellite; Mitochondrial DNA haplotype; Population bottleneck; Population fragmentation