 Other waterfowl include whooper and mute swans, eider duck, Slavonian grebe, goldeneye, long-tailed duck and wigeon.The elusive corncrake and sanderling, ringed plover and curlew sandpiper are amongst the summer visitors.Resident birds include red-billed chough, hen harrier, golden eagle, peregrine falcon, barn owl, raven, oystercatcher and guillemot.