Herons getting territorial

Yesterday, while out swimming around dusk, I saw herons chilling on the shore.  This is nothing new, though lovely, and I will say that I don't remember them there back in the 80s. 

 However, for the first time, I saw one swoop in on another and drive it away from the shore. That was something, swimming along, watching one prehistoric looking thing chasing after another with its great loping flight.

A couple of weeks ago, one of the lifeguards down at the lake said that he has observed the herons taking target practice at the floating docks with their mighty heron poop.  That was news.  I had thought that was all goose guano.