Noise and tree species richness modulate the bird community inhabiting small public urban green spaces of a Neotropical city

Small public urban green spaces (SPUGS) are important for human life-quality and for maintenance of biodiversity within urban landscapes. However, little is known about how local characteristics and spatial location are related to biodiversity inhabiting SPUGS in tropical cities. In this study, we aimed at assess how noise, vegetation aspects (local characteristics), distance from a major habitat patch and from water (spatial location) are related to the bird community (species composition, species richness, total abundance and feeding guilds) inhabiting SPUGS in a medium-sized Neotropical city (Rio Claro, Brazil). We expected local characteristics to be the most important variables influencing the bird community. Bird observations were conducted in 28 SPUGS (< 1 ha) and we used generalized linear models and a multi-model inference to assess the relationships between SPUGS' attributes and the bird community. Permutational multivariate analysis of variance was used to assess which SPUGS characteristics modulate species composition. We made 1,808 records of 75 bird species distributed in 26 families. Noise was negatively related to bird species richness, total abundance, and abundance of granivorous species. On the other hand, tree species richness presented positive relationships with bird species richness and total abundance. Noise and tree species richness also were responsible for modulating the composition of species inhabiting SPUGS. Therefore, we demonstrated that local characteristics modulate birds inhabiting SPUGS; while noise is a strong limiting factor for birds inhabiting these small green spaces, increasing tree species richness can enhance SPUGS' ability in harboring a diverse bird community.