Structure of the Japanese avian community from city centers to natural habitats exhibits a globally observed pattern

Abstract

The number of avian species in urban areas throughout the world, particularly in Europe and the USA is low; however, their total density is higher than that observed in surrounding habitats. Nevertheless, it has not been confirmed whether this is true in Japan. Japanese cities have fewer green areas than European and American cities, and Japanese suburbs are likely to face forests on mountain slopes, whereas cities in most other countries face open grasslands, rural areas, or flatlands. These differences could influence the structure of avian diversity from city to native habitat. We compared the number of species and individuals of all species among city centers, suburbs, and forested areas in Japan. Similar to other countries, the structure of avian communities in Japanese cities was dominated by a handful of species, and total abundance was highest among the other environments. This suggests that the underlying mechanism determining the structure of the avian community is the same between Japan and other previously studied countries. However, species richness was not the highest in the intermediate areas, which is typical in Europe and the USA. This is because suburbs face forested areas and moderately urbanized areas are scarce in the study area. The lack of intermediate area is moderately typical in Japan. This difference is important not only for managing avian diversity but also total diversity from the city to native habitats in Japan.