I like it. I have a couple of Green Jay shots from Choke Canyon but they are not perched (on the ground).
One of the things that I like about the 600 f4 is it's buttery smooth background when shot wide open. Unfortunately, when you are close to the subject, DOF is razor thin. All things considered, I like it...
Agree with the others on the nice light and exposure. The problem is less a DOF issue and more that the image is front focused, with the stick on the left side of the frame sharper than the bird.