Changes in numbers and distribution of wintering waterbirds around Gotland 1969–2020

The coastal areas of the island Gotland in center Baltic Sea is an important wintering site for waterbirds Sweden. offers extensive shallow feeding grounds and, due to its location, some open waters remain available even during harsh winters. Wintering have been counted annually on since start International Waterbird Census 1967, with full coverage all inshore around main obtained years 1969–1978 and 2013–2020. Between these two periods, mean total number increased from 32,000 111,500. most numerous species were Mallard Anas platyrhynchos, Tufted Duck Aythya fuligula, Common Goldeneye Bucephala clangula. Some such as Eurasian Wigeon Mareca penelope, Teal crecca, Gadwall strepera started winter second period. Marked increases also found Smew Mergellus albellus Greater Scaup marila, likely related progressively milder winters recent years.