Distribution and habitat selection of wintering birds in urban environments

Habitat selection of wintering land-birds was studied in 31 human settlements in Finland. A total of 26 wintering bird species representing 5155 individuals were observed. Between-year variation (CV_B%) and short-term fluctuation within one winter (CV_W%) in species richness (CV_B=10% CV_W=15%) were low, as were total numbers of birds (CV_B=22% CV_W=24%) and populations of the most common bird species (CV_B=20–40% CV_W=15–47%). The most abundant bird species (e.g., Passer domesticus, Parus major and Pica pica) occurred in most of the study sites. The total densities of omnivorous birds, sedentary birds and bird species that commonly use feeding tables were higher in a heavily urbanized areas than in moderately or less urbanized areas. According to the Canonical Correspondence Analysis, three corvid species populations, P. domesticus and Columba livia domestica were positively related to human population density. Corvus corone cornix and P. domesticus populations correlated positively with the proportion of the built-up areas in the study plots. The omnivorous diet of these species was a possible reason for their success in urban environments. Dendrocopus major, Parus montanus, Parus cristatus, Parus ater and Certhia familiaris were negatively related to the urbanization axis. These species live mainly in coniferous forest habitats and are probably unable to use deciduous-dominated urban parks in winter time. To attract these species, coniferous trees and shrubs should also be used in park management and planning in northern latitudes. Many species, like Pic. pica, Carduelis chloris and Parus caeruleus, were located at an intermediate place on an urban–forest gradient axis. We suppose that these species are the most probable candidates for colonizing or increasing their abundances in European towns and cities in near the future. All of these species use feeding tables, which help them to adapt to urban environments.