I Fledge Allegiance

At 8:10pm tonight, the first owlet stepped up to the window, got first one, then two feet out, looked around, and flew off into the trees next to the box. All of this took 40 seconds, although he had earlier spent a good amount of time in the window before dusk set it. He actually hovered for a second or two as he looked for a place to land. Other fledging flights we have seen in the past have been more direct downward glides. This one has been in the box an extra 2 or 3 days beyond the average, and has probably developed his flight muscles and feathers to the degree that he is capable of slightly more sustained flying. He will still spend most of his time walking in the branches for the next part of his life, but he has achieved freedom from the box.
Meanwhile, back in the box, there have been no feedings as of 9:45 pm, so the parents seem to be either starving them as inducement to leave, or focusing their attention on the first fledgling (or both of the above.)
Early dusk is the normal fledging time we have seen in the past, although last year we did have 2 owlets fledge on the same night, with the second one being closer to 10pm. But in that case, he was the last of 4 to leave, so was probably quite ready to be out of the box. This year, due to the bee incident the box material isn't smelly and full of poop and bone fragments. We have always thought that ought to be a strong incentive to leave on time.
We found one of the parents vigilantly watching the whole thing in the bush just behind the nest tree. We also heard a Barred Owl not far from our property shortly after the fledging, so this added a bit of nervous tension to the evening. (Barred Owls are much bigger, and predate on Screech Owls, among other birds, rodents, etc.)
We'll keep an eye on what the other two do.