Michael, terrific details and colors. Head parallel is perfect. And what a nice catch the bird got. Liked the perch and the BG as well.
You can post upto 1024 X 800 here. If mine, I wouldnt have gone with a square crop. You definitely need some more room on the right and bottom.... and some on left will be fine as well...as the bird is directly looking that way.
With a camera like 5D markII, you could have increased ISO and stopped down more. When the bird has back towards you, then you need more DOF... reason being....the OOF tail, since its on viewer's side, becomes distracting.