The effects of weather conditions on the numbers of wintering birds and the diversity of their assemblages in villages and crop fields in east-central Poland

Winter in northern and central Europe can be a harsh time, especially for farmland birds. When fields are covered by snow, birds must search for food elsewhere, moving away to areas with more favourable weather or to habitats where food is more readily available. This study examines the changes in the numbers of wintering birds and the diversity of their assemblages in the farmlands and rural settlements of eastern Poland as a response to weather conditions. Deeper snow and low ambient temperatures caused the numbers of birds to increase in settlements but decrease in farmland. The numbers of species in both habitats were independent of the weather conditions, however. Among the species more frequently found in both habitats, only yellowhammer and tree sparrow showed a negative correlation between their numbers in settlements and in the surrounding farmland. This strongly suggests that these two species move back and forth between the two habitats, depending on the weather.