Spatio-Temporal Variation in Bird Assemblages in a Subtropical Urban Ecosystem

Simple Summary Given the background of global urbanization and its detrimental effects on avian diversity, it is of great importance for us to gain a spatial-temporal perspective on the gross avian communities residing in different habitat types within a given urban area. Based on field survey and multiple statistics, our results showed that urban environments filter avian species by their feeding types, which result as simplified bird communities in highly urbanized green spaces. Based on the seasonal fluctuations in avian communities' residing habitats of different urbanization levels, we recommend that high-quality habitats (large municipal parks) must be effectively protected to promote the sustainable development of human-environment ecosystems. Our results provide important practical guidance for regional urban landscape planning. Background: Being an excellent indicator of habitat quality, birds are more and more popular in urban studies. Selective impacts of urban environments on avian communities have been repeatedly demonstrated, however, limited information is available under a spatial-temporal perspective, especially for subtropical young cities. Methods: Bird communities were surveyed and environmental data were collected in different types of urban green spaces surrounded by urban matrix during 2018 and 2019. Various statistical analyses were used to describe avian communities residing in different habitats and evaluate bird-environment relationships. Results: Avian community structure differed between major habitat types. At intensely urbanized roadside green spaces sites, omnivores dominated over insectivores, which were regional dominators. Woodland area was key in all urban habitat types, however, the importance decreased with increasing woodland size. Bird species richness in residential parks and individual abundance in roadside green spaces were negatively influenced by environmental noise and visitor density, respectively. Resident bird species and individuals dominated over migrants, and municipal parks presented higher species richness and abundance than other habitat types during winter. Conclusions: Highly simplified habitats in urban areas represent poor wintering habitats, whereas municipal parks served as key refugia. Continued urbanization will place further pressure on habitats which are more natural; thus, municipal parks and other natural habitats must be protected to construct sustainable human-coupled ecosystems.