Life returned to the box today. Well, actually we have been chasing squirrels out of the box for several weeks, hoping for owls to return. This morning, at 2:50am, an owl visited the box for 7 minutes. Then, from 7:30am to about 8:00pm a (presumably) female owl occupied the box all day. She spent most of the day at the top of the box, observing the window or sleeping in the window.
A couple of times, a starling entered the box, and sat on the floor looking up at her. She didn't seem to take any steps to chase or harm the starling. Perhaps the starling's long pointy beak was too dangerous for her to drive out the intruder. Starlings can be very aggressive and persistent. I have watched them drive out woodpeckers from holes they had spent days making. Hopefully they won't get in the way of Mrs. Owl's nesting. She didn't seem too bothered in any case.
After she left in the evening, I went up to clean off a smear on the plastic that the squirrels had left. I found a colony of Acrobat Ants in the camera compartment. Like many ants, they seem attracted to electricity. I cleaned them out (wearing by puure coincidence a shirt with an ant on it that says "small entrepeneur"). Hopefully a light dusting of diatomaceous earth in the camera compartment (completely isolated from the nesting chamber) will discourage the ants.
We actually had had one previous very short visit on February 21st, but probably nothing else in between, though we were using the camera intermittently to save power on the monitoring computer.
Welcome to the 2012 season. Hopefully this will be their 5th successful season in a row.