The mitochondrial control region of the Hazel Grouse Bonasa bonasia was analyzed using 126 samples collected from Hokkaido, 11 samples from Magadan in Far East Russia and two samples from Bohemia in Europe. A total of 32 polymorphic sites were detected in the sequence data from 428 by in the left domain of the control region, defining 47 haplotypes. A phylogenetic tree using the 47 haplotypes and B. sewezowi as an outgroup showed that haplotypes of B. bonasia was not separated with a significant bootstrap value; and all the haplotypes belonged to a single continuous cluster.Network analysis with the 47 haplotypes indicated that most of these haplotypes were connected with l-substitution difference radiating from hypothetical node consisting of same haplotypes. It might suggest a large genetic expansion from these haplotypes in Hokkaido, or circum area in northern Asia, in a recent period, possibly during the last glaciation.
The geographical distribution of the haplotypes in Hokkaido populations are genetically overlapped except the southern population.However, the haplotype coexistence between Ishikari area and east Tokachi area, south Abashiri area and Nemuro area were remarkably low, suggesting that movements of the hazel grouse might be restricted by mountains higher than 1000 m. Haplotype diversities (h) larger than 0.8, suggested that a reasonable population size has been maintained through the history, though the population of the Hazel Grouse in Hokkaido had a rapid decline over the last 50 years.