Hi Ivan
nice guy and image, what a bokeh! (thanks to the 500mm ; -)
I would have cropped it more, or less… (because of the foot and the tail)
I'd first try to get those parts from other pictures taken in the same session. Since the beginning of photography, building the picture in the darkroom, doing whatever is necessary has been a respected part of the craft. Here, if it's possible then it would be a great benefit.
If not, then, of course, Nicolas' instincts for cropping further are on the table. I thought, hmm, do I agree with that? At first I thought, of course he is correct! There's another way perhaps. The picture is so beautiful that it still works. I think here one would choose the matting to be a double or triple matt. The edge to the image would be via several steps in the matt cuts, so it looks like we are viewing the bird though a window. Then I think the cut of tail and toes would not matter but even add to the sense of realism.
Asher