Comparative analysis of the breeding avifauna of Italian cities

We carried out a large-scale analysis on quantitative and qualitative composition of the bird communities living in Italian urban ecosystems, comparing them with the avifaunas of regional areas. The comparison between these two territorial levels makes it possible to identify the effects of urbanization in different biogeographical and ecological contexts. Particularly, we have analysed the variation of some diversity indexes, biogeographical and chorological categories according to latitudinal gradient. In contrast with the expected biogeographical peninsular effect, the decreasing in species richness for Italian cities is significantly less steep than that observed for their corresponding not urbanized areas. Moreover, Palearctic-Oriental species clearly prevail in cities, regardless of latitude. In the cities small Passerine species are more abundant than in the surrounding areas. The diversity found in the cities, relative to biogeographical categories, may be imputable to the typical ecological diversity of the urban ecosystems. This probable also is the reason of the small size of birds found in the cities and of the differences with surrounding areas