Bluebird Houses in Winter (Shallow Thoughts)

Bluebird Houses in Winter

Last week, a flock of western bluebirds suddenly became fascinated with my two bluebird houses.

First I noticed a bluebird clinging to the outside of the downhill bluebird house. He would poke his head in the hole briefly, a couple of times, flutter to the top of the house, flutter back down to cling outside the hole and stick his head in. He never actually went in, and eventually lost interest and flew away.

Then a few minutes later, there were several bluebirds fluttering around the birdhouse that's outside the upstairs bedroom. I counted at least five individuals; I think they were all males. (The photos here are of a different, mixed-gender flock.) They were taking turns perching on top of the birdhouse, clinging to the outside and poking their heads in the hole. They attracted a junco, a robin and a flicker who apparently came to see what was so interesting; eventually the big flicker was apparently too intimidating, though she wasn't doing anything threatening, and all the bluebirds departed.

Neither of my birdhouses has ever had a bluebird breeding in it; they've had ash-throated flycatchers and a juniper titmouse during breeding season. Neither of them has been cleaned out since the last breeding season; I've been meaning to do that but haven't gotten around to it yet.

Are they looking for a place to shelter in cold weather? Or scouting out sites to have an advantage in next year's breeding season? Should I hurry to clean them out so they'll look more appealing during the winter? I posted to the local birders' list, but nobody seemed to know.

I'd love to have more bluebirds around; they usually only visit briefly to bathe and drink. Alas, they haven't been back, but I put the heated birdback out a few days ago and it should be popular once the days get colder.