Canon 5D Mark II
300mm 2.8
1..4TC
f6.3
1/640
ISO 400
cropped, removed oof branch lower right, sharpened, selected bird and branch and increased contrast and brightness.
Nicely exposed, with good detail in the whites, blacks and everything in between. Tough to do with chickadees. More DOF might have been nice, but you probably didn't want to reduce the SS and I don't know how the Mark II handles noise with ISO above 400. So all things considered this is nicely done.
Hi - nice exposure, a little tight in the frame for me, good HA and eye contact.
More DOF required - should be good to 1600ISO I would have thought.
:)