Hanöbukten in SE Sweden (including Blekinge archipelago) is an important wintering and staging area for a number of waterbird species. The inshore parts have been covered by counts from the shore during the International Waterbird Counts (IWC) since 1969. In the present study we analyze these counts for the period 1969–2014. When the counts started the total number of wintering waterbirds varied between 20,000 and 40,000 per year. However, from the early 1990s the number doubled, reaching 60,000 to 80,000 birds per year. All species with the exception of the Long-tailed Duck Clangula hyemalis showed similar increase. The area had a high proportion of the Swedish wintering population of Pochard Aythya ferina and Smew Mergellus albellus. Large numbers of Tufted Duck Aythya fuligula also wintered in the area, and some parts of the archipelago had internationally important concentrations of Tufted Duck and Smew. The increase in numbers in the study area showed the same pattern as in all Sweden and was most probably a result of milder winters in recent years.
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