Authors: Ventura, Lior; Strubbe, Diederik;Shwartz, Assaf;

Urbanization is a major driver of biodiversity decline globally, but a growing body of research indicates that cities can retain considerable biodiversity. Therefore, we still lack an understanding of the relationship between urban biodiversity and the regional species pool, which is needed for planning cities that optimize contribution to nature conservation. In this study, we carried out an extensive bird point-count survey across a 300 km2 region in Israel, including a major metropolitan area comprising 12 municipalities, and adjacent agricultural and natural land. Nearly 2,200 points were surveyed, randomly located across the region, in a variety of urban and non-urban habitats. Each point was visited twice during the spring season of 2021. Overall, the species pool of urban and non-urban areas in the region was surprisingly similar, with an 80% overlap. Mean local species richness and diversity were similar in urban and non-urban points as well, but these indices differed between species groups (e.g., migrant, non-native, and rare). Turnover among non-urban points was higher than among urban points, both spatially and temporally. Our results suggest that cities are not necessarily species-poor, with a considerable representation of the regional species pool, but community composition is more homogenized, compared to non-urban areas.