Nice shots Eric. I can never get close to Green Heron out in the open. And you have a full-frame shot.
Recently I printed some 11x16 at 300DPI shots using my 10D and 400mm lens. I was suprised at the print outs. These were not full-frame shots, and I had to use bicubic smoother thing in PS but I was veryimpressed at the final print outs. I used mpix.com for printing.