The reservoir, which has an area of 105.4 hectares (260 acres) is attractive to waterbirds; in particular wintering wildfowl and gulls. Wildfowl present regularly in winter include Mallard , Gadwall ( Anas strepera ), Tufted Duck , Pochard ( Aythya ferina ), Wigeon , goldeneye ( Bucephala clangula ) and Goosander . A