South Carolina Bluebird Society
What Can You Do?
Birdhouses are readily available, but not everything called a "bluebird house" is really suitable for them. Real bluebird conservation takes a bit of effort, but it is well worth it when you see your first brood of fledglings take flight. Several things to keep in mind when you decide to put up a nest box for bluebirds are:
Bluebirds prefer to nest in an area that includes open space, scattered trees, and low ground cover such as lawns, golf courses, pastureland, parks and school & industrial campuses. They do not nest in heavily forested areas. They also do not like land that is completely open (no trees or shrubs), but one that still provides perches for hunting (such as fences, telephone lines, posts, shepherd's hooks, etc.) and trees nearby for both shade and to offer the baby birds at a safe destination for fledging. Care should be taken not to place the next box so close to trees and fences, however, that predators are afforded easy access to the box from above. Keep boxes at least 200 yards from barnyards and feed lots where House Sparrows are abundant. Avoid areas with heavy pesticide use. Bluebirds are territorial, so multiple boxes should be placed at least 300 feet apart as a rough guide. Vegetation and topography might make closer location possible. There should be no direct line of sight between multiple boxes.
Proper Nest Box
Purchase or build a nest box designed specifically for bluebirds. Preferably, these are made of unpainted cedar, redwood, cyprus or pine. If you must paint your nest box, it should be painted ONLY on the outside, in a very light color, to avoid overheating. The box should have an overhanging slanted roof, NO perch, and a round entrance hole 1-1/2" in diameter. It should have ventilation and drainage holes, be deep enough so predators can't reach in to get to the eggs, and have a door that opens for ease of monitoring and cleaning. In areas of intense heat, additional measures should be taken to avoid overheating, such as the use of 3/4" lumber, and overhanging roof on all sides, and placement in a location that receives shade from the afternoon sun.
Nest boxes may be mounted at any time, but to attract bluebirds for their first nesting of the season, they should be in place by early February to mid-March, depending on your geographic location. You may see nest boxes mounted on trees, wooden fence posts or metal poles. Metal poles may be difficult for predators such as snakes and raccoons to climb. A metal mounting post need not be elaborate or expensive. Smooth, round 1" electrical conduit is inexpensive and works well; although any smooth scrap round pipe will work. The next box should be mounted on the post so that the entrance hole is 5 feet off the ground.
Next Section - Feeding Bluebirds