I was just reading on a waterfowl site about guys in illinois shooting woodducks the other day.. I would have thought they would have gone south already,, apparently not! It wouldnt hurt too get a half dozen woodduck decoys as well,, put them closer too the vegetation than you do the mallard and goose decoys,, seperate them from any other decoys. Dont bother with woodduck calls,, theyre either committing or they arent.. get ready too hammer them when they are over the dekes,, they usually only give you a good look and they are gone! very humbling duck,, they are tough too hit, very erratic flight.

get a good book on waterfowl identification. here is a good sitet too look at as well for id'ing purposes.
http://www.npwrc.usgs.gov/resource/birds/duckdist/index.htm