Shift in migration phenology of a wintering population of Dippers Cinclus cinclus in northern Sweden

Abstract

Many organisms have been found to respond to global warming by adjusting one or several aspects of their ecology, such as timing of migration events, time at reproduction and size at maturity. We examined changes in arrival and departure times, and age and sex ratios of overwintering White-throated Dippers Cinclus cinclus in northern Sweden, by comparing data collected in 1975–1979 to a similar dataset from 2010–2014. Between these periods, the average winter temperature had increased by about 2°C. During the latter period the Dippers arrived in their winter area two weeks earlier and departed three weeks earlier. We found no change in age and sex ratios during the study period.