Great shot. You've really caught the 'essense' of gull. And the soft lighting's just right, too, with no harsh shadows. I just put a sheet of paper over the screen, to block off the land at the top: seems to make the bird stand out even more (the eye doesn't 'wander' up and down the pic). Try it...
This is an old packhorse bridge in the English Lake District, made of slate and held together by nothing more than gravity...