Okay folks, I ask you, can these two birds be the same species?
They are obviously both herons. I took the picture on the left a few days ago; Craig took the one on the right last June. Notice that the colors are so different, even using the same camera and lens. Evening light in the right hand picture may account for some of the difference, but the birds I have been seeing lately are really blue, and I don't know why.
I began to study about herons at Audubon and the Cornell Ornithology sites, as well as a few others. They agreed that there is no color difference between males and females; the males are just bigger. Both males and females have the ruffs of mating feathers. Apparently they are just hard to distinguish from one another.
Herons also look very different full-face and profile: Notice that this bird's feet face forward and his face is turned back, scoping out a treat. (Yuck!)
We irritated it and it did this, revealing his full face and a lot of feathers.
I would be happy to hear any insight you're care to share. Between these herons and the egrets, I am reading a lot about water birds!