Nice soft light. I would crop some off the bottom as the bird is too high in the frame for me and the extra clouds don't add anything to the image. I would also sharpen a little more. A slight head turn towards us would be nice.
I agree the extra clouds at bottom don't add much...but the blue patches of sky above do. If you have it in your original I would re-crop by removing some at bottom and adding at top. Gulls are among the best in-flight practice subjects...keep at it!!