Evaluation of microhabitats for wild birds in a Shanghai urban area park

Abstract

Shanghai is the most crowded city in China and the conservation of biodiversity is essential for the health of its urban ecosystem. The best methods for quantifying and enhancing the function of urban green spaces as wild bird habitats are major concerns. This type of study may explain how the wildlife community responds to different vegetation compositions and provide important insights into urban re-vegetation with respect to biodiversity conservation in a city experiencing rapid urbanization. Thus, we studied the interactions between bird communities and the microhabitat vegetation composition in Binjiang Forest Park. Birds were surveyed at 40 sampling sites and in interconnecting habitat line transects. The bird species richness, abundance, and behavior were quantified, and these indices were related to plant species richness, density, and a vegetation structure. Among the 60 bird species observed in the three habitat types, significantly more species, i.e., 55 species, were observed in woodland with shrubs, 36 species in woodland without shrubs, but only 29 species we recorded on lawns. Multiple linear regression models confirmed that the vegetation complexity and the structure had significant positive effects on the bird community compositions. Regression tree analysis also demonstrated that the woody plant species richness and diversity were significant microhabitat variables for all of the three bird community indices (i.e., bird species richness, abundance, and diversity). Moreover, we confirmed that the vegetation horizontal coverage, particularly the horizontal shrub coverage, was essential for birds living in heavily human-disturbed areas. In addition, our data suggested that well-designed water systems may be beneficial for bird conservation in urban areas. This study highlights the importance of the microhabitat vegetation composition and structure for bird conservation in heavily urbanized areas. However, we also suggest that studies of the relationships between bird communities and urban green vegetation in Shanghai City should be performed in more urban parks in the near future based on considerations of the urban landscape context.