In the 1995 - 1998 period, 45 species of aquatic and riparious birds were recorded during 112 observation days at Hrase pools, these shallow and highly eutrophieated cesspools along the cowsheds of ...the local agricultural plant. Most of the birds dwell at the pools during their passage, but some also breed here due to the very favourable living conditions in this particular area, Most frequent amongst the passage migrants are Common Teal Anas crecca and Garganey Anas querquedula, while Common Snipe Gallinago gallinago and Wood Sandpiper Tringa glareola are most frequent as far as waders are concerned, Among the species that occur in Slovenia rarely or in small numbers, let us mention the Great Bittern Botaurus stellaris, Common Shelduck Tadoma tadoma, Ferruginous Duek Aythya nyroca, Black-winged Stilt Himantopus himantopus and Bluethroat Luscinia svecica, In 1996, when the water surface reached its highest peak due to the blocked outflow of the pools, a pair of Black-necked Grebes Podiceps nigricollis bred here successfully, which was the first confirmed breeding of this species in Slovenia. The regular breeders at Hrase pools are Uttle Grebe Tachybaptus ruficollis, Mallard Anas platyrhynchos, Common Coot Fulica atra, Moorhen Gallinula chloropus, Northern Lapwing Vanellus vanellus and Marsh Warbler Acrocephalus palustris, while Little Bittern Ixobrychus minutus and Water Rail Rallus aquaticus breed here only periodically.