Insectivorous birds are more sensitive to urban greenspace changes in Guangzhou city, China

Urban development leads to drastic changes in bird habitat patterns, causing fluctuations in bird species composition and functional groups. However, composition and distribution of avian feeding guilds in response to changing environments are still not well understood in urban ecology. The study evaluates the relationship between bird communities and heterogeneous urban landscapes, and analyzes how landscape factors influence the distribution of different avian feeding guilds. From 2019-2022, a systematic sampling survey of bird species was conducted at 20 sites in Guangzhou city, China. Bird feeding guilds were divided into insectivores, omnivores, carnivores, and frugivores & nectarivores. Landscape parameters for each site were quantified to test the key factors influencing the spatial distribution of different bird feeding guilds. The results of redundancy analysis indicated that bird species with specialized dietary guild (i.e. insectivores) tended to inhabit intact and highly connected patches, whereas omnivorous birds showed better adaptation to the fragmentation caused by urbanization. Furthermore, the size and arrangement of urban green spaces positively correlated with avian richness, while edge density and the presence of roads negatively impacted diverse avian feeding guilds. Therefore, we suggest that urban landscape planning in the future should enhance the quality of core patches, optimize the pattern of ecological corridors, and reconstruct small-scale green spaces.