Normally we associate this kind of ferocity with the gathering of food. But these herons are gathering sticks, as they float down the San Antonio River. It seems odd at first, almost a game, gathering sticks; we all used to do it as children. But there is a competition going on here. The tree to which they return has well over a hundred nests; that is a lot of sticks, and no sticks, no nests; no nests, no eggs. You get the idea.