The Great Egret in Western PA

You can raise a lot of attention, & controversy, in the birder world ( and in probably any other community ) when you float some thoughts that go against current thinking. Fortunately, in the birder world, that’s not going to generally result in hostile treatment on Facebook or the ‘twitterverse’, etc., because these are mostly very nice people. But on to my report.
Over last couple of years I’ve spotted a solitary, large white bird standing in the shallows of some local, Washington Co, lakes a few times. But I was either driving by in my car, or walking our dog, without my field glasses every time. The consensus of birder/naturalist friends was that it might be a Great Egret. Think Great Blue Heron-like bird except it’s all white. Not easy to miss. Since it would be very unusual to have a purely solitary bird in a species that only nests in colonies, I thought there might be a ‘home base’ nearby. Egrets feed in shallow waters & marshy areas and the closest one would be Canonsburg Lake. In my, long ago, youth it was a great place to fish for Crappies, but 60 years of development in it’s watershed have left much of the lake silted into a shallow water, marshy habitat. A great place for wading birds. Turned out to be a good first guess. I saw several of them there.
Then I wondered, if they’re here much of the summer, could they be nesting here? The PA Game Commission Regional Office promptly replied that most Great Egrets nested in large colonies in the SE USA & after nesting season dispersed outward. And while some nesting colonies have been identified in SE PA, none have been seen in SW PA. But, they advised, get into an e-loop with other birders & exchange info. OK.
A week later I met a photographer/birder that I hadn’t seen in several weeks so we exchanged stories on recent sightings. When Great Egrets came up, he advised what I’d already discovered – that there are more on Canonsburg Lake & he said they’re nesting around here. I told him about  my exchange with the PA Game Commission. He said, yes, but “I saw a plainly juvenile ‘sized’ egret with 2 adult sized birds”. Further, in a large Sycamore off the Heidelberg exit on I79 there was a colony of nesting Great Blue Heron (I’d heard about this nesting colony from other birder/photogs). I’ve seen Great Egret in tree there also, he said. Moreove, he said, around old ‘Morganza’ ( Former ‘reform school’ in my youth. ) in Canonsburg/Southpoint area, there are 5 large Sycamores housing another nesting colony of Great Blue Heron. He implied that there were egret among them also, although less definitively. And, it is true, that Great Egret will nest with other colony nesters like the Great Blue Heron.
It was when I shared this with some birder/naturalist friends that the controversy broke out. e.g. ‘Seeing some birds is a long way from proving they’re nesting’. ‘Might be a white morph of a Heron’. ‘If some birds are not successful in their 1st nesting attempt they will leave the nesting ground & disperse early’. My replies, in turn, were : I know. The orange yellow bill & black legs is pretty definitive. Unless Canonsburg Lake is some kind of a half-way house for failed nesters that can’t be the answer.
I got the feeling that for some folks a time/date/GPS stamped photo of the bird holding up an egg (so I could confirm the black legs & the egg) might satisfy them. Well, just means that early next Spring I’m going to be scouting out these nesting Great Blue Heron colonies toting my binocs & telephoto lensed camera. See if I can, at least, satisfy my own curiosity about these birds.
Have fun out there.