You have a winner here Jim. I love the bird's pose, and the fact that he is looking back really works well here. I think that one of the reasons that makes this image compelling is the way that the curve of the tail/wing feathers lead the viewer to your subject's eye. In addition, you have great light and details and the dunlin is tack sharp. The shallow DOF is very pleasing but I am not sure about the blades of grass. I might try a little NR on the sharper part of the BG (the part with the grass).
Beautiful setting, pose, low angle, eye contact, sharpness and colors! I would be inclined to take a smidge of the bottom and move the subject a bit to the left in the frame but that is very minor. Congrats on an excellent shot!