Changes in the distribution of wintering birds in Japan and the effects of climate change

Abstract

Using national wintering bird survey data, we examined changes in the wintering bird fauna in Japan from the 1980s to the 2010s and the factors influencing these changes. We also examined the differences between wintering and breeding seasons by comparing the data with breeding bird survey data. The results showed that wintering birds expanded their distribution area more northward compared to the breeding season from the 1980s to the 2010s. Non-forested ground-feeding birds, shallow-water foragers, and aerial foragers, for which low temperatures and snow cover are thought to be limiting factors in distribution, moved their distribution northward. Arboreal, submerged, and marine foragers moved the northern edge of their distribution northward. Aerial foraging birds moved northward in their distribution as temperatures increased, but other species did not move as far north in their distribution as expected by temperatures. These results suggest that the effects of climate change on wintering birds differ from those during the breeding season and are positive for birds whose distribution was restricted by cold.