Övervakning av fåglarnas populationsutveckling. Årsrapport för 2011.

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 2011 include data from 589 winter point count routes in 2010/2011 (36th winter), of which 273 were carried out during the Christmas/New Year count and 262 summer point count routes (37th year). A third programme is running since 1996 with 716 Fixed routes, systematically (semi-randomly) distributed over Sweden (combined line transect and point counts). In total 462 Fixed routes were completed in the summer of 2011 (fourth best year). Trends were analyzed using TRIM. A programme for covering night-active birds started in 2010 (point counts along roads with one route per 25x25 km square of the country). In 2011, 115 routes were covered at three occasions each (March, April and June). The distribution of the covered routes is presented in Figure 1. In the Christmas/New Year count 2010/2011, about 75,000 individuals of 109 species were counted by 221 observers. The winter was unusually harsh and started already in November. This certainly explains many of the dramatically low winter figures. Moderate to strong increases in winter populations over the last decade are present in seven species. Declines over the same period are prominent in nine species (Fig. 10). On the point count routes in summer 2011, about 94,000 birds of 199 species were counted by 161 observers on 262 routes. From the Fixed routes 129,000 birds of 217 species were reported by 236 persons. Trend graphs for a large number of species are presented in Fig. 11. More graphs and indices can be found on the homepage (address below). Over the last 10–12 years, the most pronounced declines are found in Grey Heron, Wigeon, Merlin, Willow Grouse, Ruff, Herring Gull, Little Gull, Swift, Siberian Tit, Goldcrest, Common Rosefinch, Ortolan, Rustic and Lapland Bunting. The strongest increases are shown by Cormorant, Greylag Goose, Red Kite, Hobby, Hazel Hen, Crane, Whimbrel, Stock Dove, Blue Tit, Great Tit, Mistle Thrush, Blackcap, Chiffchaff (both Swedish ssp.), Goldfinch, crossbills, A second consecutive hard winter, did not seem to affect cold sensitive species like Grey Heron, Wren and Goldcrest as dramatically as the year before. It was a good year for lemming-eating birds such as Rough-legged Buzzard, Long-tailed Skua, Hawk Owl and Short-eared owl. The night routes showed higher owl activity and better breeding results in the north compared to 2010. In the southern part of the country owl numbers and breeding output was lower than in 2010. Very high numbers of Quail were recorded during the night routes in 2011. The numbers of larger mammals counted were relatively similar to the year before. Both bird and mammal data from the night routes will be used for calculating trends as soon as the time series are long enough. Bird indicators were calculated for Sweden based on summer point counts and the species selection and methods of the Pan-European Common Bird Monitoring Scheme (page 14). Farmland birds (“Vanliga jordbruksfåglar”, 11 species) show a more than 50% decline since 1975. Woodland birds (“Vanliga skogsfåglar”, 26 species) have declined with about 30%, whereas a group of other common birds (“Övriga vanliga fåglar”, 21 species) have declined with about 10%. We also present the corresponding indicators based on the new system with Fixed routes (indices since 1998). All but one of six indicators turned downwards during 2010. In the recent 5–10 years, the indicators based on the two schemes have become more and more similar within each habitat. Another set of indicators, official indicators of biodiversity within the national Environmental Objectives set by the Swedish Parliament based on data from the Fixed routes, are presented as well (Fig. 6). Among these, the indicator for mountain birch forest birds is the only one showing a significant trend (negative) for the last ten years. Five indicators (lakes and streams, forest, mountain tundra, mountain birch forest and ‘a rich diversity of plant and animal life’) showed negative changes between 2010 and 2011. The indicators for birds in wetlands (both northern and southern) and farmland showed unchanged or higher values 2011 compared to 2010.