Just as I was about to take a photo of the changes inside the nesting box in the predawn today, Mrs. Ace the screech owl returned and perched in the opening.
For the next 15 minutes, she made a traditional screech-owl call every 10 to 15 seconds.
Hear a 15-second Real Audio clip here. Morning owl calls.WMA
She then sat quietly in the opening for another 15 minutes before hopping down into the box and settling in for a nap.
While she was in the opening, I scanned the woods for any sign of a companion, for naught.
What I had noticed inside the box was a different arrangement of feathers.
Slowly but surely, the owl is sticking more and more prey feathers into the small gaps between the door and the box itself. (Note, in the upper right-hand corner of this image, all of the feathers crammed into the corner of the box where the opening is.)
So many feathers are plugging the gaps that I've noticed one feather sticking through to the outside of the box.
I am hoping this caulking with feathers is part of the preparation for egg-laying, as it was two years ago. But it's always risky to guess the reasons behind screech owl behaviors, and it's always foolish to get too excited about events that are beyond one's control.
The timetable for the start of nesting in earnest is probably still a week away, and the big question is whether Mrs. Ace will choose this box to lay her eggs or opt for an alternate site.
It is anybody's guess.