Comparison of avian community assembly and its disease transmission risk between urban and surrounding rural area in Shanghai, China

Urbanization has expanded rapidly worldwide in recent decades, and has led to a series of environmental changes. With the improvement of the urban habitat, the density of wildlife is on the rise, especially for the birds. However, birds are host to a variety of viruses, pathogenic microorganisms and parasites, and the increase of their density may amplify the risk of disease transmission in cities. Thus, understanding the characteristics of regional bird community aids the integration of knowledge about the risk of disease transmission by birds. Here, we conducted a field survey in summer, 2021, to compare the differences in vegetation, species richness and individual numbers of bird in Shanghai urban and surrounding areas covering 28 zones along an urbanization gradient and to assess the possibility of bird transmission risk in Shanghai. We recorded 122 plant species and 3416 bird individuals of 23 species. Our results found that urbanization has led to a decline in bird species and densities than relatively pristine habitats (rural, agroforestry habitat, urban park), and based on our literature collection, most species carrying avian influenza virus were migratory waterbirds (anatidae and shorebird) that relatively away from urban area. Our study suggests that urbanization reduces bird diversity, but urban birds may have a low probability of transmitting the avian influenza virus to humans.