The nature and landscape complex Wielikąt is situated in valley of the upper river Odra, near the Moravian Gateway, in the district of Wodzisław Śląski (Upper Silesia). The aggregate area is 636.6 ha including 370.5 ha of water bodies. Systematic research was carried out in the years 2002-2004 with a total of ca. 200 inspections. In 2004 the complex was recorded in the list of bird sanctuaries of international significance and proposed for inclusion into the European Ecological Network Nature 2000. Until now 226 bird species have been recorded there, including 128 breeding or probably breeding ones. 114 species of water-mud birds were recorded. In 1992-1996 the breeding water-mud avifauna of the Wielikąt ponds had 45 species while now it has 43 ones. Breeding of two species failed to be confirmed (Cormorant and Black-tailed Godwit) while one species (White-tailed Eagle) has recently begun nesting in the vicinity of Wielikąt. The numbers recorded for at least 13 species (Bittern, Mute Swan, Teal, Red-crested Pochard, Common Pochard, Tufted Duck, Moorhen, Little Ringed Plover, Green Sandpiper, Bluethroat, Sedge Warbler, Reed Warbler and Great Reed Warbler) were comparable to those recorded in the years 1982-1996. In the years 1982-2004 six species (Little Grebe, Grey Lag Goose, Gadwall, Marsh Harrier, Grasshopper Warbler and Reed Bunting) recorded increases in their numbers while decreasing tendencies were found in the case of eight species (Red-necked Grebe, Shoveler, Ferruginous Duck, Lapwing, Common Redshank, Kingfisher, Marsh Warbler, Penduline Tit).