- Department of Ecology, Swedish University of Agricultural Sciences
Inventering av sjöfåglar, gäss och tranor i Sverige
Nilsson, Leif; Månsson, Johan
Sweden. Annual report 2009/10. Department of Biology, Lund University. 53 pp. This report presents the results of the International Waterfowl Census (IWC) in January, including the supplementary national September count, the International Goose counts in Sweden, and a national crane count. The main aim of the January and September counts are to produce annual population indices for the more common species. The midwinter counts have been organized every year since the start of the IWC in 1967, whereas September counts started in 1973. The report also give the preliminary results from offshore aerial surveys of Swedish waters in 2010. Since 1987-89, the coverage has been standardized to give representative indices for the southern parts of the country (there is no open water further north). Indices are calculated as chain indices, i.e. comparing counts in two consecutive years, then recalculating primary indices to the master years. In the last comparison data from 159 sites in September and 577 in January were used (see Fig. 1). The indices are shown in Tables 2 and 3 and graphs are presented in the species sections. The winter of 2010 was unusually cold and most indices showed marked decreases since the year before. The forth countrywide survey of wintering Whooper Swans gave only 4000 compared to more than 9000 during the previous survey in 2005 as many swans had left the country during the hard winter. Aerial surveys of the important areas around Gotland and the Midsjö banks and some other areas gave an estimated total of 705 000 Long-tailed Ducks compared to 475 000 in 2009. Compensating for uncovered area the estimate for 2010 will be 750 000. The higher counts were made on Hoburgs Bank, whereas the other sites had normal numbers, th high counts probably due to movements from ice-covered areas along the Baltic coast, especially the Bay of Riga. Regular goose counts started in Sweden in 1977/78 and have been undertaken every year since then. Now they include counts in September (started in 1984 for Greylag Geese), October, November counts and January counts. Annual totals for the more important species are presented in graphs with examples of distribution maps for the last season. Totals counted during the last season are found in Table 5. Since the start of the Greylag Goose in 1984 the numbers counted in Sweden has increased from about 20 000 to more than 225 000. In October the majority of the Taiga Bean Geese are probably staging in Sweden. In October 2009 as in October 2007 and 2008, more than 60000 Bean Geese were counted in the country, i.e. more than in the preceeding years. About 9200 of the Beans were of the tundra form “rossicus” according to special checks of important sites. The Canada Goose is still increasing, with more than 70000 counted in January 2009 and slightly less in January 2010. The Barnacle Geese was still common in the autumn of 2010 with close to 80000 counted but numbers were much higher in October 2007 with 150000 counted. The increase for this species has been very marked and reflect markedly changed staging habits September counts of Cranes started in 2005. In September cranes were found all over the country. During the first years numbers varied between 40000 and 45000 but in September 2009 54700 cranes were reported.
Publisher: Lunds universitet
UKÄ Subject classification
Environmental Sciences related to Agriculture and Land-use
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