Lovely diffused light!
I would crop a bit from the right and top for a stronger composition and hopefully eliminate the distracting element in top left.
When birds are preening, it's best to wait till the head is parallel to the camera for best results. The eye needs a bit more sharpening exactly because of this.
The foreground is exquisite. Just a few pointers to make this even better. Nice plumes :)
I agree with other's comments. There is a strong green cast on the image but that can be fix without a problem. As far as the composition goes, I would try to have the feathers facing away from the frame and not centered.