Nice comp and bird. Excellent pose, and I like the greenish sheen on the wings. Exposure perfect, and good details on the heron. BG looks great for the most part, but I would just smooth out the lighter spot in LLC. I see a ouple of post-processing artefacts along the contour of the heron (see small triangle above head and a couple others out of the neck, and between legs and tail). Perch is smoothed out from NR?
Looks like the perch has been affected by a blur filter used on the BG:confused: Everything else (apart from the artifacts mentioned) looks fantastic (colours, exposure, sharpness).
Sharpness (on the bird's head and main body), pose, composition and exposure is fantastic. But I agree with the comments re processing artifacts. I'd add to what has been mentioned before that the bird's left leg and the outline of its lower body (butt?) seems to have been excluded from a sharpening layer and/or included in a blurring layer. The subject is worthwhile trying again and reposting. JR