As landscapes get more urbanized and natural habitats lose ground, it is crucial to assess the role of green spaces in urban areas for birds. I investigated whether local or landscape level variables were better predictors for bird species diversity and richness on urban green spaces in Vienna, Austria. I assessed as well, whether patterns change for different foraging and feeding groups. Here, I focused on three types of urban green spaces that varied in size and structure. Finally, I analysed the connectivity of green spaces and forests in Vienna by comparing two network models. In total 2208 individuals of 48 bird species were observed. Species diversity was lowest in small parks and cemeteries and was accordingly also positively related to size of the green spaces. Species richness was not influenced by size. Abundances of species did not differ significantly among the different patch types. Patches differed mainly in their vegetation layer structure at the local level. When focusing on the variables on the patch and within the landscape, most of the variance was found in the thickness of deciduous tree stems, the height of trees and herbs and the vegetation contact from one to two meters on the patch. Within the landscape a the heterogeneity of landcover and the percentage of urban and agricultural areas were found to account for most of the variance between the patches. Species diversity increased on patches with a higher canopy, less understory and smaller trees. In the landscape a heterogeneous landcover mixture and preferably adjacent and evenly intermixed landcover were favouring diversity. Species richness was influenced only by a heterogeneous landcover. When grouping the species assemblage in different functional groups (foraging and feeding groups), predictors differed strongly among them. Connectivity analyses showed in general a very low level of connection between green and forest patches in both network models.