Aleksander Winiecki, Sławomir Mielczarek
Ornis Polonica 2018, 59: 17–55
https://doi.org/10.12657/ornis.2018.1.1
Abstract: The paper describes birds breeding in the SPA Middle Warta Valley (Dolina Środkowej Warty PLB300002) in recent years, as well as changes in avifauna across last 40 years. The study area (ok. 570 km2) is unforested, temporarily flooded river valley covered mostly by meadows and pastures, and riparian forests in its western part. During the last 40 years numerous species disappeared from the study area or their numbers significantly declined, including the Ferruginous Duck Aythya nyroca, Pintail Anas acuta, Eurasian Stone Curlew Burhinus oedicnemus, Ruff Calidris pugnax, Great Snipe Gallinago media, Hen Harrier Circus cyaneus, Short-eared Owl Asio flammeus, European Roller Coracias garrulus, Aquatic Warbler Acrocephalus paludicola and many waterbirds, mainly waders, terns and gulls, ducks, harriers. Among few species that appeared in the valley and significantly changed their numbers are the Greylag Goose Anser anser, Goldeneye Bucephala clangula, Common Merganser Mergus merganser, Common Crane Grus grus, White-winged Tern Chlidonias leucopterus and Whiskered Tern Ch. hybrida. At present the area hosts breeding populations of several species, important at a national scale, including Pintail, Shoveler A. clypeata, Garganey A. querquedula, Common Pochard Aythya ferina, Greylag Goose, Common Redshank Tringa totanus, Black Tern Ch. niger, Black-tailed Godwit Limosa limosa, Hoopoe Upupa epops and Middle Spotted Woodpecker Dendrocopos medius. Important habitat changes that have gradually occurred during the last 40 years, negative for the breeding birds, are the result of global trends but also changing local habitat management. They include: regulation works, creation of enbankments and polders, changes in the frequency of floods after building of the dam reservoir „Jeziorsko”. Another problem is related to the cessation of grazing by cows and house geese, and predation of American Minks Neovison vison, Common Foxes Vulpes vulpes and Carrion Crows Corvus cornix. The authors present proposals of methods of future monitoring of the area, as well as methods of protection of birds and their habitats, included in the project of Action Plan for this area.
Keywords: long-term population trends in avifauna, Special Protection Area for Birds NATURA 2000, the Warta River, waterbirs
