Förändringar i antal och utbredning av häckande sjöfåglar i svenska fjällkedjan mellan 1972—1975 och 2009

Abstract

During 1972—1975, the breeding waterfowl populations of the northern parts of Fennoscandia (south to 65° N in Sweden) were surveyed for the first time. In 2009, a new survey was undertaken in the Swedish part of the mountain chain. Censuses were performed from the air in transects of 5×5 km squares and in special areas. The distribution of the different species was largely similar between the two periods but there were a number of differences on the regional level. Most species had more or less the same population sizes but there were some variation in the different parts of the mountains. Three species showed clear increases between the periods. Cygnus cygnus had the same increase in the mountain chain as in the rest of the country. Melanitta nigra was about four times as common in 2009 compared to the 1970s and Mergus merganser also had higher counts in 2009. Melanitta fusca decreased markedly in the mountain chain as along the coasts.