To address this issue, we decided to give the nest box an upgrade this season, and fixed an infrared spy-cam to the ceiling of the box. I routed the 100 feet of audio and video cable through a window in our living room up to the television, and made a custom "Owl Switch" with a red light to indicate when the cam is on or off. This gives us 24 hour access to what's happening inside the box, and for the past month it's been a whole lot of nothing. We've watched the configuration of leaves and sticks in the box shuffle around, adding to the assumption that something had been rustling around in there, but for what has felt like a very long time we've seen nothing. That all changed last night.
Casey flipped on the Owl Switch during a midnight pee run and sure enough, Owlfred had returned. The tips of his primaries and tail obscured half of the box, and he was calling. This meant that Owlfred was perched at the entrance facing out, broadcasting to potential mates that he had found a nice place to raise some chicks. To hear his calls, check out the brief video below.