It seems that the male seen at the nest ledge was probably just passing through. From an update on Donna Daniel's blog on September 21:
As summer winds down we're seeing more of Scout. Before she had been spending most of her time away from the nest ledge (and view of the cameras), however, in the past two weeks she has been seen more days than not. On 9/17 she was in the nestbox. It appears there is the beginnings of a new scrape in the fresh gravel. This is a factor of the amount of daylight during this fall season and not because a possible new male is in the area.
Speaking of such...there has been no sign of that second falcon that was seen last week so it is possible he was "just passing through" and has a territory of his own established somewhere else. With as many peregrines that are on the move right now for fall migration, it's possible we could be in store for a number of these teases! Regardless, the activity last week has surely renewed interest in watching! As always, we appreciate all of the extra eyes out there on the lookout for leg band information when the opportunity presents itself.