I've seen all the photo's from today so I have to ask - is this a normal thing for Beauty to check out another male & would there be a battle for her if Archer came back & found another male hanging around. She is a sight to behold for sure - loved seeing her at the nest box.
Generally speaking, during to non-mating season when reproductive hormones are not raging, birds are more likely to just companionably hang out together. We've often seen visitors that hang around for a good part of the winter. My take on today's episode is the tiercel is a migrant bird from further north. He saw prime PeFa real estate and he was more-so checking out Beauty than she checking him out. She didn't seem to me to be defensive at all until he stepped foot in HER nest box. Now we're talking territory even without hormones. She was quick to chase him off then (video soon).
It's most likely he'll go back where he came from when the spring migration starts. If Archer returns before that he'll chase off any intruders. But any floating unmated tiercels will keep an eye out for prime nesting spots in case Archer doesn't return.
Ei