Cormorants are tough to capture in flight, mostly because they are so dark that it's tough to get the feather detail you want without totally blowing out the sky. This is about as good a cormorant flight shot as I've gotten.
Canon 50D, 400mm, f/7.1, 1/4000, ISO 640, no flash, hand held
I agree, they are challenging, especially if they have black and white plumage. You've done well on this one with good wing position, feather detail and that lovely green eye
These birds are not easy to get, at all, as James said this shotis as good as it can be o more ;) The pose, the light, exposure, detail, all is terrific! Congratualitons!