I think Sandy covered it beautifully in her comments. There are only two things you might consider doing: One is to clone out the partial beak shadow below the beak, so the beak stands out fully. The other is to mute the contrast of the alternating black-and-white feathers behind the subject gull, as it draws the eyes, and there isn't enough of the second gull visible to save the feather colours. But this is an excellent photo, especially since facing bird shots are usually not very good, and this one definitely IS, due to the head angle.
Gail R.
Good exposure and just the right amount of dof to show off all the feathering details of the subject. Lovely warm lighting warms up an otherwise cool environment and adds lovely light of life to the subject's eye!
Sincerely,
Sandy Stewart :)