鳥類の種組成に基づく都市の鳥類生息環境評価指数の提案

Abstract

Though many papers have been published on avian distribution in urban areas and on the factors that influenced species richness and / or composition of bird communities in urban habitats, no convenient measure of environmental evaluation of avian habitats along urbanization gradient has been developed. In the present study an environmental evaluation index using avian species composition is proposed based on the previous studies on avian distribution along urbanization gradient. Bird species were classified into two categories, i.e., urban avoider and urban adapter considering the distribution range of each species along urbanization gradient. Species that were recorded widely along the gradient were categorized as urban adapters while species that mainly occurred on the rural part of the gradient were categorized as urban avoiders. Based on the classification a new index of avian habitat evaluation was proposed as the sum of the number of urban adaptor species and two times of the number of urban avoider species. The appropriateness of the bird species classification and the effectiveness of the index were discussed.