The falcon spending time on the roof of the nest box finally raised a leg - showing off its aluminium USGS band. This identifies it as the male of the pair.

Comparing the size of this bird to that of the previous video and photos indicated that the visits over the past few days have all been the male. This most recent video capture shows the male calling repeatedly - perhaps communicating with female nearby(see video below). The breeding season is still a month or more away - but the male spending time at this site is a positive sign.

Peregrine falcon nests are simple affairs. The birds will simply scrape out a shallow bowl in the dirt or gravel of a nesting ledge (or nest box). The male selects potential nest sites and will generally initiate a scrape. The female will ultimately decide which site the pair use.