Lovely warm colours and I like the pose. What colour temp did you use in processing this, Sid? Flash looks good - not obvious - I assume you're using a Better Beamer at this distance.
Sid I like the composition a lot, the nice light, the fantastic BG and the wise use of flash fillin but I am tempted to modify the white point because the image seems too much "pink" to my taste. If this image were mine I would keep the BG as it and would modify the white point only in the heron :)
Wonderful BG and the pinkish cast when removed makes a much better Heron. Very nice shot and you'll have fun with the Nikon flash system, so many possibilities with more than one, I often used 3 flashes wirelessly.