How far away from the flagpole did you put the box? You don’t want any predator being able to reach or jump from the pole to the box. Assuming that is, that the pole the box is on is baffled.
Good luck getting the blues back. How far apart will the two boxes be? I had to go at least 25 feet apart to get to different birds nesting in paired boxes, any closer and the first bird to claim one box would protect both boxes. Some people to have success though having them closer than that.
They’re only ~15 ft apart but it’s the farthest I can go and stay in the mulched circle. Each box is ~ 7 or 8 feet from the flag pole which is a slick metal one that would be darn hard to climb. I didn’t baffle the 1/2″ emt that the boxes are mounted on but did polish the heck out of it and gave it a good coat of slick car wax. It’s enough to keep the squires from climbing the pole up to my sunflower seed feeders so I believe it’s a decent deterrent. The tree swallows checked out the second box super intensely even as I was erecting it. There was a strong breeze and they nearly hovered directly over me as I worked. I’m sure being that close to their home was a large part of the cause for close scrutiny.
Just received permission from another neighbor to put a box or two on the mulched moat in her acre plus yard. After finding a piece of 4″ pvc pipe in our odds and ends that’s just long enough to make a couple of Gilbertson boxes the timing couldn’t be better.
Off to build a couple more boxes.
Cheers,
Hugh