I don't remember the specifics but light seems pretty harsh here. I used the recovery slider to heal some of the bird, also went in and did a few minor burns on the perch highlights. In retrospect I think this may have been better at f/8 . Slight crop from left, right, and top. NR on BG, high-pass sharpening on bird.
Tripod, AV Mode
Camera: Canon EOS 40D
Exposure: 0.001 sec (1/800)
Aperture: f/5.6
Focal Length: 700 mm
Exposure Bias: +2/3 EV
ISO Speed: 400
The light angle was your main enemy here. Comp looks a bit centered - a further crop at left and adding back above and right would likely work well IMO. DOF looks fine to me as is. Great BG!