@Terry Thomas Nope, confirmed with a keeper that they are Great Egrets- they have a resident pair raising their chicks.
She said the pair were in full breeding flush hence the plumes and blue-green facial skin.
@WhistlingKite24 Thought only little egrets had black bills? Also neck looks quite short, but that could just be the stance when photo was taken. I am often wrong!
@Terry Thomas It was quite a big bird. Much too big to be a Little Egret. I’ve checked a few of my bird books and it certainly matches a Great Egret. It seems Great Egrets have black bills when they are in breeding plumage.
Little Egrets have a black bill and yellow facial skin.