The size of the Great Blue Heron makes them easier to spot than a Green Heron, but the tendency of the Green Heron to conceal themselves on the edge of the water behind vegetation makes it hard to spot them. A few days ago I scared a Green Heron out of my pond and the following day another flew out of the cattails along the road. And again today, while I was mowing, I think I chased the same heron away.  Even when I search for them, I never spot the heron until it is airborne and maybe I might get a photo if I see where it lands in a tree, where even there it is hidden by leaves.

Green Heron Hiding