Bluebird Housing

This weekend I did something that I should've done a long time ago. I built and put up two bluebird houses, placing one of them on our property and the other on a neighbor's. Bluebirds are in this area year-round and hopefully they'll soon find these boxes and nest in them this spring. Unlike purple martins which normally produce one clutch, bluebirds can produce as many as 3 clutches each season. For some strange reason, which I'm ecstatic about, is that I rarely see any house sparrows here. I have enough problems with these viscious non-native nest-site competitors at my purple martin colony at home and am happy not having to deal with them here. There are lots of house wrens here which could try and take control of the boxes, so I placed them as prescribed by "The Bluebird Monitor's Guide" away from thickets and brushy areas which wrens love. The piece of pvc you see attached to the pole serves as a predator guard against climbing predators that's not only slippery but also wobbles making it more difficult to climb. An invasion by climbing predators such as raccoons and snakes, and believe you me there's plenty of both of them around here, would lead to nest abandonment by the parent bluebirds. Can't be raising a family in a house that predators have access to. If any activity is observed everyone will definitely hear about it.