Challenging amount of light, as mentioned. I shoot Nikon, but it seems most of the Canon folks aren't happy pushing the 7D to that ISO level. What type of post did you run, noise reduction, etc.?
Good look back pose on your bird. Soft background works well with his coloration.
I would move the bird out of the center of the frame by cropping from the left.
Besides the technical challenges, the perch does tend to distract from the bird. I know they land where they want!
Hope you catch the next one with a bit better light and a more natural looking perch.
You did well handling the noise of the 7D at ISO 1600. The bird is sharp and the profile is decent, but a head turn towards us would have improved things. I find the image to be slightly underexposed as presented. I think a vertical crop would have been a good choice for this type of pose and perch, because the gray on either side of the bird doesn't really add anything to the image. You might consider a bit more room at the top and bottom of the frame. And I agree with Randy about the perch. Of course a gray ghost is a one of the birds where you take what you get; definitely a nemesis bird for me!
Jon, nice post, looks sharp, I agree with the appearance of a bit underexposed (as you stated, the light was low and difficult) but the noise levels look good for that ISO. Good looking bird. Thanks for sharing.