Vegetation structure drives taxonomic diversity and functional traits of birds in urban private native forest fragments

Many studies in urban landscapes have revealed that vegetation structure influences the taxonomic diversity and traits of birds and drives greater bird richness in greenspaces. However, most of these studies have been carried out mainly in public spaces. Private lands represent large components of cityscapes worldwide, and so understanding the role they play in the maintenance of biodiversity, and how vegetation traits drive the ecological attributes of birds, remain poorly known. Here we identified local factors of vegetation related to the bird fauna of urban private native forest fragments in Sorocaba, state of São Paulo, Brazil, with a focus on their ecological attributes. We predicted that increased vegetation structure would select birds that depend on forest environments and the resources they support. We sampled 13 vegetation traits in 28 private urban native forests to evaluate the relationship between vegetation structure and taxonomic diversity and functional traits of birds. Confirming our prediction, vegetation structure shaped the ecological attributes of birds, with five vegetation traits driving bird taxonomic diversity and functional traits, of which the number of standing dead trees was related to more bird ecological attributes. Vegetation structure in urban private native forest fragments may increase habitats and resources, thus supporting habitat- and feeding-specialist species. Our results provide insights for public policies aimed at management and maintaining vegetation structures that benefit bird fauna (e.g. number of standing dead trees, tree richness, canopy cover), in support of the ecological functions they perform in urban landscapes.