Great job with the fill light. Subtle, but effective (especially with the catchlight). Head turn is great and for some reason I really like that I can see the end of the perch. Background leave striations are killer as well.
Nice looking heron, and good showcase pose for the back feathers, which I always like. I also like the water drop off the beak. If you had a little more up top, that might work to balance the frame better (for me), but a nice photo as is too.