Lovely light, like the comp, attentive gaze, colors, slight diagonal in the grass to his left.
Although always a balance, a frame or two with a bit more dof to sharpen up his tail area would have helped, but it is clearly the eye/head that draws our attention.
Nice pose and I love the intense stares that all herons and egrets give when hunting. Bird looks great against that background which I find to be a pleasant change of pace from the typical shot of one on a perch or in the water. I agree with Randy re the dof. Also this may be me just being too picky but my eye is drawn to the bright and curved bit of vegetation immediately to the right of the birds neck. If mine I would clone that bit out and use some of the darker areas as a source.
Really like the HA and eye intensity, Those dorsal feathers are too much - looks like he's been playing in the flour tin. Only wondering about this shot is the level... is this flat level or on an angle?
The bird really pops in this one Jon. The situation you've caught this one in really works well to provide that separation. The intense hunting stare is very nice and the comp looks good to me. I also like the way the shadows in the foreground and background frame this.