Birds in the City : Bird biodiversity in a boreal northern urban environment

Abstract: Urbanization is a growing threat to biodiversity across the globe. As more and more habitats are being destroyed and species extinction rates are rising, we have started looking at how we might decrease this loss of biodiversity. One answer is changing our urban environments to more biodiversity friendly ones. Since conditions within a city and a natural landscape might differ, it is important to understand how landscape variables affect biodiversity in urban areas. The purpose of this study was to investigate how landscape variables (Coniferous/mixed forest, Open uncultivated land, Fields, Deciduous forest, Water, High and Low urban development, and Industrial area) affect bird diversity, richness, and community assembly in a small city in central Sweden. Surveys were conducted on 33 sites. Results from a multiple regression comparing the environmental variables to richness or diversity showed that Water was positively correlated to both diversity and richness. A redundancy analysis (RDA) showed that bird species assemblage was significantly affected by Coniferous/mixed forest, Water, and Fields when the whole bird community was considered. However, when only passerines were included in the RDA, Urban development and Coniferous/mixed forest had the strongest impact. When conservation efforts are made in urban areas, these variables need to be considered since they are correlated with different species and they might not be the same ones that are associated with richness or diversity of birds.