I like the walking pose you got here. I find that on shorebird images unless you are trying to get a full reflection then you want to be as low as possible to take the photo from their level. It makes for a more dynamic shot. The dark spots behind the bird should be cloned out. It is quite difficult to get the exposure correct on this bird. One of the hardest there is because it is black and white. It looks like you were over exposed as the shoulder and neck area are blown out and lack any fine feather details. The rest of the whites on the bird are gray which typically comes from lowering the exposure too much. For this bird it is vitally important that you check your histogram in the field and make sure you have not blown your whites. If you try to recover in post then you get these artificial looking gray whites. Also the black on the back of the wing is blocked and also lacking in fine feather details. Keep at it and hopefully you will get another chance at these beautiful birds. By the way you still are not posting the gear used and your settings.