Abstract
The nesting, roosting, and feeding trees of Black Woodpeckers (Dryocopus martius) were investigated in natural mature beech forests for clarifying the current geographical distribution of Black Woodpeckers at Aomori, Akita, and Iwate Prefectures in the northern Tohoku District, Japan. Home range sizes of the Black Woodpecker investigated were determined based on the distribution of field signs (new and old nesting, roosting, and feeding trees) in beech forests on Mt. Moriyoshi, and Mt. Oppu of the Shirakami area, especially during the breeding seasons. The area of natural beech forests in the study areas of the above mentioned three prefectures occupied about 370, 600ha. A home range size (HRS) was about 1, 000ha. Distribution range (DR) was about 64, 000ha in size, and the available range (AR) for the woodpecker was about 23, 000ha. By dividing the areas of DR and AR by HRS, the population size of Black Woodpecker was estimated to be 174 birds in the northern Tohoku District.
