Jack,
A nice pose and the background is nice and clean. I think you could improve the composition with a different crop. The bird is too low in the frame for me. Do you have anything below that you could expand into, or alternatively would I stand up to more of a crop from above? i this wasn't originally shot in vertical, I would like to see a horizontally cropped version too. I feel you could also work on bringing a little more feather detail out, perhaps with a touch more sharpening.
Jack- Nice portrait. I like the soft light and the great background. There is too much room at the top, and I'd give a tad more room at the bottom. I would brighten up the face a little just to give a stronger connection to the bird.