They have a nest nearby on a rock face. The female is noticeably larger than the male and this particular female is larger than others I've seen so she's at least 1/3 larger.
Strathroy - A pair bred here last year. A male has returned but there was no female yet. The next closest breeding is possibly Manitoba (rarely) and Saskatchewan but mainly Alberta. It's a great find.
Cornwall - I'm pretty sure this is the remaining bird from the pair that had bred here for several years. The male was injured in the spring and because its wing could not be repaired it was euthanized unfortunately. They had been using an old industrial smokestack platform as a nest site. The dark area behind the bird is inside the smokestack.