Usually the chicks leave first in my experience, the adults stay later. Interestingly enough, except for Madame who used to overwinter here, the bird that remained latest was the one that hatched on the building. Now in the Radisson case, that's always been the males, but as I recall Burnsie was a female of ours who came back to nest and she was the last one at a nestsite she had with an unbanded male ...
When do I expect them to leave?
Short answer: as long as the weather remains good, they don't "have" to leave.
Longer answer: The weather is good, the eating is good (it keeps flying by) so we could see them into October if the weather stays like this. They will follow the prey, then leap frog them further south. Peregrines can take a week to fly from Mexico to Wood Buffalo in northern Alberta but that I think is pretty quick. I do know that one of the U of M chicks (one of T-Rex's) was last spotted in Winnipeg a month before it was spotted on a beach in Veracruz Mexico. How reliable is that sighting? The chick was observed by participants at an international peregrine falcon recovery meeting. They sent us a postcard with the bird's location circled on the photo of the beach. Cracked me up actually.
The geese are moving but I don't know if they are staging here as the eating is good or if they are actually making concerted efforts to head south. I found a real-time GIS mapping software on a hunting website, but so far no one has submitted any information on the migration yet - could have something to do with hunting season start dates which I don't know about, or something. Its a new find, but I'm going to keep an eye on it as it looks pretty cool .... from what I read/see, its suppose to update every 15 minutes, so as long as folks submit data, the map should change frequently. You also have a choice of things to look at i.e., all waterfowl, dark geese, light geese (I assume that's feather colour), puddle ducks, divers and teal.
Here's the link if you want to keep an eye on it too:
Waterfowler.com's National Migration Mapping