I really like the arching lines of the wings and neck - lots of nice curves here! I do wish that said neck was better lit. What this image needs is more room in front of the heron for it to fly into, and a better head angle (HA). Good job on the sharpness and exposure.
As Daniel mentioned, very nice curve of wings and neck. Nice that the bill doesn't merge with the wing.
Agree on moving the bird to the left in the frame.
The bird has a subtle blue case, which shows up in the eye and over the body in general. A little tweak to eliminate that does seem to improve the image for me.