The most conspicuous of all birdhouses is obviously the martin house. However, the most common and recently most popular are the bluebird houses.
Bluebirds are popular, whether they are the eastern, western, or mountain species. However, with the ever-increasing human population in the east, large amounts of bluebird habitat have been destroyed. Other birds that have similar requirements, like the house sparrows and starlings, have sadly competed with the bluebird.
The harsh winter of 1957-1958 resulted in thousands of bluebirds freezing to death in the south. Because the diet of the bluebird is berries and insects, they were especially vulnerable. The death count was estimated at one third to half of the entire bluebird population.
Then it got worse. Six terrible winters followed. By 1963 the lowest eastern blue bird population was ever recorded.
At this time the North American Bluebird Society was formed. A campaign to rebuild the bluebird population, it was at this time that a concentrated effort to provide specific bluebird boxes, and educate bird lovers everywhere on building and placing bird boxes.
The bluebird house is designed to attract bluebirds and to discourage others.
The box should be 5 inches long by 5 inches wide. The depth of the cavity should be 8 inches. The height of the entrance above the floor should be six inches and the hole should be 1 1/2 inches.
Placing and mounting a box can be anywhere between five and ten feet above the ground.
Each box should be placed 300 to 400 feet apart. The entrance hole should face south. Do not attach on a perch. Mount on a fence or pole. Put up the box in late winter or early spring.
Make sure the box has ventilation, and clean out the box in between broods. Bluebirds have two broods.
Houses out in the open should be left natural or, if colored, a light color.
Be sure there is some protection for the young birds to fly to when trying out their new wings.
Also see Backyard Wildlife Habitat.Tip: An old wooden drawer can be used as a propagation box. It's excellent for drainage and a good depth.