These birds are almost certainly not mates. Most Great egrets are in the process of laying eggs now. So they may be neighbours. The second shot shows those lovely breeding plumes which almost caused the species extinction.
As for scott's surprise of seeing these birds so far north.
The largest Colony In Canada is north on Toronto In Georgian Bay 141 nests last year.
Best place and time to see large numbers of Great Egrets is in Luther Marsh in late August.