Otis 19(2011), Sonderheft

Summary

The results of the German breeding bird atlas pro­ject(ADEBAR) in the time-frame 2005 to 2009 for the federal states of Brandenburg and Berlin were combined and compared with the results of an atlas project conducted in the period 1978 to 1982. Bree­ding grid maps, grid frequency, populations and population trend for the last 15 years are shown and discussed. During the time-frame of both at­las projects a total of 200 of the 217 breeding bird species ever registered in the region were recorded as nesting species. During the current ADEBAR atlas project 195 species were recorded, compared with 183 species recorded as breeding in the earlier period. Whereas six breeding bird species(Caper­caillie, Hen Harrier, European Roller, Bee-eater, Nutcracker, Redwing) were no longer recorded as breeding species during the current atlas project, 17 new or returning breeding bird species compa­red with the 1978 to 1982 project were registered (Whooper Swan , Canada Goose, Egyptian Goose , Peregrine Falcon , Black-winged Stilt, Pied Avocet , Ringed Plover, Mediterranean Gull, Yellow-legged Gull, Caspian Gull, Lesser Black-backed Gull, Little Tern, Whiskered Tern, White-winged Tern, Tengmalm‘s Owl , Pygmy Owl, Eagle Owl ).

The species density per grid square slightly in­creased between both mapping periods. Areas with the highest species densities and highest numbers

of Red List species were concentrated in the Ucker­ mark region and along the central and lower Havel valley.

In total, there are some 4,400,000 to 6,900,000 bird territories in the federal states of Brandenburg and Berlin . In a nationwide comparison, a high percentage of the total breeding population of the following species breeds in Brandenburg : Osprey , Great Bustard, Little Crake, Black Tern, Hoopoe, Savi‘s Warbler, Great Reed Warbler and Tawny Pi­pit. The last remaining Aquatic Warbler breeding site in Germany is in the Lower Oder Valley natio­ nal park .

Since the first mapping period some 80% of the breeding bird species showed either no or a positive change in grid frequency with only 20% of the spe­cies settling fewer grid cells. Breeding birds of wet meadows and farmland show exceptionally high spatial losses.

More than one third(69) of 186 closely studied bird species showed a significantly negative popu­lation trend over the past 15 years. Disproportio­nately affected are not only long distance migrants and wader species, but also common breeding birds such as Skylark, Starling, White Wagtail and Green­finch. The most serious adverse effects on breeding bird communities were on farmland and in human settlements, a trend that continues today.