NAITOH Toshiko Botanical Garden, Tohoku Univ. Asist., 理学部・附属植物園, 助手 (20004393)
ARISAWA Hiroshi Tokyo Univ. Exp. Forest of Hokkaido headquarters, 農学部・附属北海道演習林, 助手 (00012089)
CHIBA Shinji the Institute for Nature Study, Natural Science Museum, Tokyo, Chief Investigato, 附属自然教育園, 研究員 (90000140)
由井 正敏 森林総合研究所, 東北支所, 研究員
NARA Noriaki College of General Education, Hirosaki Univ. Prof., 教養部, 教授 (40003454)
YUI Masatoshi Forestry and Forest Products Research Institute, Tohoku Rest Center of Forestry,
We have researched the fundamental ecology(especially its distribution, environment, foods and and the estimation of its numbers of individuals) of the Black Woodpeckers that is the national natural monument during the May 1988 and the Dec. 1989 in the northern Tohoku districts( Aomori Pref., Akita Pref. and Iwate Pref.).
(1) The distribution of the Black Woodpeckers; we investigated the distribution of the Black Wood peckers in the above mentioned three Prefs. by the observation records, the nesting trees, the sleeping trees and the feeding marks of this woodpeckers. At the results, we recognized that the Black Woodpeckers would live at the Mt. Shiragami area,Towada-Hakkoda area,Mt. Hachimantai area, Mt. Mahiru area, Dokuga-Mori area and Mt. Kurikoma area. Fortunately, we found the breeding of this bird at June 1989 in Mt.Shiragami area(Aomori Prof.), and could record the detailed breeding ecology of this bird.
(2) From the results analyzed the contents of drops of the Black Woodpeckers gathered at this time, we could be clear the food items of this bird.
(3) We estimated the total areas(the present investigated areas) of the natural beech forest where the Black Woodpeckers have lived, that is estimated about 200,000 ha.
(4) From the above mentioned result, we estimated that the black Woodpeckers would live about 100 to 200 individuals of this bird in the present investigated areas. Furthermore, we estimated that the carrying capacity would be 250 individuals in the upper limit.