Bill, this is lovely as always. I do have a challenge for you, though...
Although I like the soft, high key look, I find the bird is getting a little lost in all the softness. I suggest brightening the yellow of his eye and legs just a bit more so the viewer's eye instantly is drawn to him. It doesn't have to be anything brash - just a little more pop and saturation to those two areas.
Wonderful shot. Love the composition!!! Simple, unified colors. Great position of the hawk--dynamic. I was going to suggest saturation, contrast and curves adjustments to brighten up the image and bring some light to the hawk's head. Jules' suggestion might do the same. There is a Red Tailed Hawk that visits us, sitting on a branch over our meadow. I can see him from my desk.