Female wood duck

Kent,  Kidding aside, this camera angle works well due to the duck's head being turned so far.  Probably checking to see if you are about to intrude on her 'comfort zone'.  The flat overcast lighting is great for revealing details in this dark coloured creature.  If you start from the premise that it's easier to find fault with a shot than it is to take a good one my observation won't hurt as much.  The head, and thus the all important eye, is not in focus.  Got the back feathers though.  Tough to get great DOF with a 400mm.  A smaller aperture may have done the trick at the expense of higher ISO or slower shutter speed; both with their own limitations.  I do like the composition though & were it mine I'd still keep it.  I see you have a ton of great bird shots so you are obviously not a bird newby.  Always room to improve though, it seems.  Best, LM.