Perhaps I can shed a small amount of light on the falcons' activities; I work on the 18th floor of the Investors Group building Portage & Colony, just down the street from the Radisson (I can see the nest ledge from here), and we have received fairly frequent visits in the past two weeks. We have a parapet on both the north and south sides of the building at the 18th floor, which consist of a raised semi-circle ledge surrounding an area covered in large gravel. About a week and a half ago, I spotted an adult peregrine feeding on the ledge on the north side of the building. I got within about 8' (with glass separating us) and could definitely tell it was a peregrine - we regarded one another, I backed away, and the bird took off. Later in the day, I took a closer look at the parapet, which had about two dozen under-feathers scattered about, indicating some extent of visitation. When I mentioned this to another 18th floor employee, she said that she had seen the same thing several times over the previous week.
A few days later, a juvenile was spotted in the exact same place. In this instance, there was a photo shoot going on just a few feet away, and the photographer managed to get one shot of the bird before it took off. This led to a story about the winged visitors on our internal company website, featuring the photo.
Since then, there have been a couple of sightings of falcons flying past the 18th floor windows, but not setting down. We did have a successful falcon nest nearly a decade ago, according to one of my co-workers, but they eventually moved on to another home after measures were put on the roof to discourage pigeons. Building maintenance has already said that if falcons were to nest on our building again, they would do everything they could to make it appropriate for them. Hooray!
I'll let you folks know whenever there is a sighting at Investors Group. See ya!