Distribution of Hazel Grouse Tetrastes bonasia in Hokkaido, Japan

摘要

A distribution map of the Hazel Grouse Tetrastes bonasia in Hokkaido,Japan,is presented based on the data obtained by transect and spot censuses,records in the literature and unpublished personal records.Hazel Grouse were recorded mainly in mountainous areas,where they were present in 758 out of 1,291 censused quadrats(58.7%).This density was significantly greater than that in the quadrats in plains and basins,where Hazel Grouse were recorded in 109 out of 750 censused quadrats(14.5%).This difference is clearly evident in the distribution map provided in this study.Numerical data of occurrence rates were obtained from presence and absent data.Some vacant quadrats in distribution maps published previously were occupied,and this map might be the most detailed and accurate record of the distribution of Hazel Grouse in Hokkaido.