Check out that link that RSG provided,.
The first two photos show two Great Blues,., the first one looks pretty much like the ones I have photographed,. and looks like the ones that most of the reference books illustrate,..
....but the second one looks just like your Great Blue,. (Dude,. it's YOUR BIRD! )
...which is what I spent most of my life thinking Great Blues looked like.
These extra long feathers, the white on the neck,. this is all new to me except in photos. All the ones I had seen in person were all blue grey like your pal in "The Bruce Pit"
So there is clearly a large variation in plummage,. which seeing as how our recent photos were taken days apart can not be purely seasonal.
I have seen drastic plummage variation in other species as well,. (Osprey, Red Tailed Hawks,.. etc) but I never know whether it is just an "individuality" type thing or age?
So far none of the reference material I have read gives much mention to it. But RSG's link DOES!!!
With this simple sentence:
* Shaggy neck and back plumes in alternate plumage
I had a problem ID-ing the Adult Green Herons the first time I saw them some months ago ... as they were in the middle of a plummage "moult" (spelling) ... I'll see if I can dig up a photo...
Thanks for that Link RSG!