The Effects of habitat area, vegetation structure and insect richness on breeding bird populations in Beijing urban parks

Abstract

Urban parks are isolated fragmentary areas within the urban environment, providing both recreational spaces for its citizens and habitat for birds. This study focuses on analyzing factors, which affect the richness of breeding bird communities in 26 urban parks within Beijing city. A bird census and a survey of biological factors were carried out from April to November, 2012. Simultaneously, non-biological factors were examined. A path analysis based on a structural equation model was carried out to explore biological and non-biological environmental variables affecting bird communities breeding in wooded habitats. In total, 38 species of wild breeding birds were observed in the 26 parks. Based on the results, we conclude that the size of green space in parks is the most significant variable affecting bird occurrence. Green spaces surrounding a park are positive and significant factors for breeding bird communities. Wild grasses/herbs are also crucial because they maintain a high level of insects. Omnivorous bird species and birds nesting in trees did benefit by an increasing area covered by coniferous trees, by increasing richness of grass/herb species and increasing richness of woody plant species. The richness of insect communities (phytophagous and pollinating insects) has a significant effect on the richness of breeding bird communities. This study confirmed the importance of connectivity that the parks are connected to surrounding green spaces, thus forming an integrated green system avoids impervious surfaces. Proper management of coniferous woody plants, promoting wild grasses/herbs, reducing the area of planted monocultures and minimizing the use of pesticides in urban vegetation management will contribute effectively to improve the quality of breeding bird habitats in urban parks.