Would suggest posting at the max size to be able to evaluate. Do like the pose, exposure and sharpness. Feel the image is a little tight so more room would be advisable.
For birds with bright red colors might want to reduce saturation in the red channel a few points. All digital cameras seem over saturate the color. One other point of importance is the oof leaf up front. Large oof elements that stand out in the foreground should be avoided since they grab attention. You did really well with the low shutter speed !!!!
hi jim!! bird looks good. i think you could have upped the ISO to get a faster shutterspeed. i think a little more flash would have helped brighten the dark areas of the face. were you using a better beamer? if not, with a 600mm lens your flash probably did not reach the bird.
agree with al too about being a little tight in the frame. you could add some canvas up top and left.