It's an female Ring Neck from the best I can tell. Notice the black tip on the bill and that most of the body is black/dark grey.
http://www.allaboutbirds.org/guide/Ring-necked_Duck/id . Its either that or a eclipse red head. But I am leaning towards the ring neck female.
Last edited by ACutting; 10-19-2010 at 08:28 AM.