Last year the WB Nuthatch used a box, raised the kids, and when they left the box in came the VG Swallows. Same thing this year. The nuthatches are almost done (the kids look like they are ready to fledge in about a week) and the VG Swallows keep circling and landing on the nuthatch box. The swallows are also looking at the Oak Titmouse nest box about 4 ft. away... the titmouse family is at about the same stage, i.e. ready to fledge soon. So the box that empties first, assuming the swallow can fit through the smaller opening of the titmouse box, will become the VG Swallow nest... possibly.
The status of the rest of the boxes around our home:
Tree Swallow - 5 boxes, I think all with eggs
Barn Owl - sitting on eggs or young; I've checked her several times and she doesn't move except once to look up at me only 18" from her... and she has never flown out of the box because of my peeping.
Western Kingbird - until last year they were successful nesting on the utility pole hardware; last year the wind blew down their nest faster than they could build it. Same thing this year and I expect they will give up soon and move to a location with less wind.
Barn Swallow - nothing happening yet... they nested in the barn for several years and I've seen them around but not building a nest yet.
Downy Woodpecker - nesting in cavity of tree but can't get to it to record progress
Western Bluebird - claimed one box (same as swallow box)
Acorn Woodpecker - using a new cavity in the same oak tree as last year
Bullock's Oriole - probably several nests but they are very well camouflaged and I haven't found one yet.
Ash-throated Flycatcher - somewhere close, probably across a small field from our house.
Another observation/theory - there seems to be more WF Ibis in Jackson County this year, possibly because of the poor water conditions in the Klamath Basin. Another similar thing I've noticed is that I have YB Chats in the creek below my house. I've heard them only once each year in previous years and this year I have heard them several times. I figured they were only moving through the area in past years and this year because of the fire along the greenway they have sought new habitats... plausible?