Hi Stuart, I like the high-ke effect and the detail in the wings. I see good sharpness and your exposure looks good. I only wish that the bird was flying more towards. I am undecided about the rock. There are probably many options for composition. Three that I see are:
1. Leave it as is.
2. Remove the rock (if that is within your ethics).
3. Crop a little off the top and behind the bird.
Personally I prefer number three as the negative space at the top and behind do not add anything in my opinion and eliminating it helps balance the image for me. Just suggestion. Thanks for sharing.