Övervakning av fåglarnas populationsutveckling. Årsrapport för 2020.

We present the results of the Swedish Bird Survey, run by the Department of Biology, Lund University, as a part of the National Monitoring Programme of the Swedish Environmental Protection Agency. The results for 2020 include data from: 564 winter point counts in 2019/2020 (45th winter), of which 274 were carried out during the Christmas/New Year count, 210 summer point count routes (46th year) and 550 Fixed routes (25th year). In the programme for covering night-active birds (11th season), 151 routes were covered on up to three occasions each (March, April and June). In addition, 372 waterbird routes (6th season) and 200 archipelago squares (6th season) were surveyed. New for this year is that we also
include the International Waterbird Census (IWC) from September (47th year, 145 sectors) and January (55th year, 1066 sectors), and nationwide goose counts in September, October, November and January (44th season, 1537 sites). In total 759 persons were involved in the surveys reported here. Population trends were analyzed using TRIM and trends for 228 different bird species are presented, as well as the geographical distributions of the covered routes. Larger mammals are counted on the Night routes and the Fixed routes since 2010 and 2011, respectively, and we present short-term trends for 12 mammal species based on these two systems. We also present trends from the new schemes of water- and archipelago birds, through which we can now follow yet more species with
systematic counts during the breeding period. The long-term trends show both winners and losers among the Swedish birds. In general breeding bird numbers have decreased since the 1970s. Among the winners are swans and geese,
raptors and cranes. Most species of autumn staging and wintering waterbirds have increased in numbers during the same period. When it comes to the wintering birds, the increases are most likely a result of generally milder winters with more open water and snow-free ground. Year 2020 was in general a good bird year in Sweden and based on 204 taxa recorded on the Fixed routes over the last 10 years, there are more species significantly increasing in numbers (26%), than decreasing in numbers (15%). For the remaining species (59%), no statistically significant changes were recorded during the last ten years. Based on the winter point counts, the trends during the last ten winters are strongly positive. In
total 35 % of 114 species have increased significantly, while only 8 % have decreased. For waterbirds specifically, the majority of the surveyed species (67%) have increased in winter during the last ten years and only one species (3%) decreased significantly. The increasing numbers of wintering waterbirds is also in the short perspective a result of mild winters. With the additions of our latest survey programs we can now follow the population development of somewhere between 80 and 90% of the about 250 bird species breeding in Sweden.