Part of the strategy of a heron while hunting is to find a place where he blends in with his immediate surroundings. As seen in this next shot, they become masters of disguise, the blend so good that very nearly missed seeing him. This stump/tree area is a favored haunt for several of the park's Great Blues and given I've never seen un underfed one, the camouflaging must work pretty well. I think the tree works as a part of his ability to not be as readily seen from a fish looking up. It's a guess, anyway.
