Green cover and human disturbance are important local factors shaping urban bird communities, while climatic and topographic variables can be important when analyzing cities in different biomes. However, the roles of large-scale and local variables influencing bird species composition have been scarcely explored in urban areas. This study aimed to analyze the association of climatic, topographic, landscape, and local variables with bird species composition in streets dominated by buildings and urban parks. I expected park bird composition to be more related to large-scale variables, whereas bird species in streets to be more associated with local-scale variables. Bird surveys were conducted in nine cities along a climatic and topographic gradient. Bird species composition in urban parks and streets were related to climatic and topographic variables, local vegetation greenness, and distance to non-urban areas. However, bird composition in streets was also related to noise and pedestrian traffic. The classification of bird composition in urban parks aligned with the phytogeographic provinces, whereas the streets’ bird composition was unrelated to phytogeographic provinces. The results showed that urban habitats with increased vegetation cover allow the colonization of native bird communities and are more aligned with natural large-scale environmental gradients. In contrast, more urbanized sites are decoupled from climatic and topographic gradients and invaded by exotic and widespread native species.

Bird plumage color has been assessed as a possible trait driving the presence of bird species in urban areas. Although some species can see the ultraviolet (UV) spectrum, the mentioned studies did not take into account UV reflectance when characterizing bird plumage. This study aimed to use a recent database of the colorfulness in passerines that incorporated the UV spectrum to compare bird colorfulness and other traits between urban parks and rural areas in Central-East Argentina. Birds in urban parks were surveyed in 51 parks in 6 cities during breeding and non-breeding seasons. A list of Passeriformes species from parks was created, and a list of urban avoider species was created from the bibliography. Species traits were body mass, clutch size, migratory status, nesting site, diet and habitat breadth, and plumage colorfulness. A total of 85 species were detected in the regional pool, of which 30 species were detected in urban parks. Bird species present in urban parks were more colorful than bird species only present in rural areas. In addition, bird presence in urban parks was positively related to their regional frequency and diet breadth. Moreover, urban presence was related to nesting on trees and buildings, whereas species not present in urban parks nested on the ground. The results obtained showed that bird color is significantly associated with presence of bird species in urban parks.