Why You Shouldn't Clean Out Bluebird Boxes

I’ll admit that I can be a little bit lazy. I know that you’re supposed to clean out bluebird boxes after the young fledge. The old nests tend to harbor botflies and other parasites, which can certainly be detrimental to the next brood. Bluebirds successfully raised a brood at our Adams County cabin several weeks ago, but I didn’t get around to cleaning out the box until I saw the adults checking out the available lodging for a second brood.

You can see the old nesting material spilling out of the hole. Time to stop being lazy, and get it cleaned out. It only takes a few seconds, after all. It’s not like cleaning out my car. But when I opened the box, I realized that it wasn’t empty. I thought at first a mouse had taken up residence, but it was quite a bit bigger.

This guy scampered out of the box, up the tree, and then glided to another nearby tree. It’s a Southern Flying Squirrel, Glaucomys volans. Although they are supposedly fairly common, it’s only the second time I have ever seen one. My first sighting was many years ago, at a feeder in Hamilton County which they were known to frequent.

Flying Squirrels are strictly nocturnal, as you might guess from its large eyes. This one wouldn’t have been in the open if I hadn’t rousted it from its daytime abode. Since they frequently live in abandoned woodpecker holes, the bluebird box was a logical substitute. They aren’t capable of powered flight, like a bird or a bat. Instead they glide downward from one tree to another, as this one did, using a membrane which stretches between their wrists and ankles to get a little lift.

I’ll leave this box alone for a few weeks before I check it again, and I won’t clean it out until my guest moves on. The bluebirds will just have to find another place for their next nest.