Bluebirding

Bluebirding is an effective method of providing suitable habitats for bluebirds through the establishment of nesting sites or bluebird trails.  The Eastern bluebird is a small thrush known for its sweet, melodious whistling sounds and distinctive physical features. Like many bird populations, the bluebird population is dependent on several factors, including food and nesting availability, environmental conditions, predation, and commercial development. Over the past few decades, bluebird populations have declined drastically. Declining populations have been hypothesized to be the result of habitat destruction and competition with more aggressive species. In an effort to protect Eastern bluebirds, bluebirding has become a very popular nature-related activity.  There are several important aspects of bluebirding, including nest box construction, location, maintenance, and monitoring.

Nest boxes may be constructed using various materials such as polyvinyl chloride or untreated wood. Treated wood should not be used because it may be toxic to the bluebird. Cedar and redwood are often recommended; however, pine, Douglas fir, cypress, and exterior plywood may be used. Painting of the outside of the nest box is recommended for durability. Only light colors should be used to prevent overheating of the box and to blend in with the natural surroundings. For the general construction of the nest box, the following specifications may be used: inside dimensions of 4x4, an entrance no larger than 1.5 inches, a bottom entrance hole located about 6 inches from the ground, top ventilation holes (approximately one-fourth an inch), and bottom drainage holes (approximately half an inch). Entrance holes should be located in a northerly, easterly or northeasterly direction to prevent direct sunlight from entering the hole during the afternoon. The boxes should be accessible from the top or side. Perches are not necessary for bluebird nest sites because bluebirds do not require perches to enter or exit the box, and perches attract sparrows. Predator guards should be attached to keep snakes, raccoons, cats, and other predators from raiding nests. Nest boxes may be mounted on galvanized pipe or other structures such as fence posts or poles, at least four to five feet above the ground, and they should be established during the late fall or winter. To construct a bluebird trail, nest boxes should be placed 125-150 yards apart to reduce bluebird territory overlap. 

The selection of a suitable location for mounting bluebird nest boxes is very important. Nest boxes should be established in areas that will attract the Eastern bluebird. They prefer open areas with scattered trees and short ground cover. Nest boxes may be mounted in semi-grassland areas, such as farmyards, orchards, woodlands, parks, yards, pastures, meadows, gardens, and roadsides. Locations with fence lines, average size trees, or telephone lines may supply bluebirds with perches for hunting and guarding of their nests. Nest boxes should not be placed near the edge of the woods because they often attract other bird species such as chickadees, wrens, nuthatches, or tree swallows.

Proper monitoring and maintenance is an essential component of successful bluebirding. The failure to properly monitor and maintain nest boxes may actually be counterproductive as the population of some competitive species, such as house sparrows, may increase through the use of nest boxes intended for the bluebirds. Nest boxes should be monitored at least once a week during the nesting season (March-July). The best times to monitor are in the afternoon and during calm, dry weather conditions. A slight tap on the side of the nest box may be used to flush the adult female bluebird from the nest. The box can be checked, and notes on the mating and nesting habits of the bluebirds can be recorded. Careful note taking may be beneficial to avoid monitoring when the nestlings are older. Nest boxes with front and side openings should not be monitored 12-14 days after eggs have hatched to prevent premature fledging. Because bluebirds often raise more than one brood per season, old abandoned nests should be removed from the boxes after each brood fledges. Some boxes may be left at the end of the nesting season to provide shelter for other species or wildlife; however, all of the nesting materials should be removed before the beginning of the bluebird nesting season. With proper maintenance and monitoring of nest boxes, two or three nesting attempts per year may be encouraged at constructed nesting sites. 

To attract bluebirds to the nesting sites, supplemental food and water may be necessary. Food may be supplied during early spring, late fall, or winter to supplement food from insects. During the summer months, bluebirds prey on a number of insects, including mealworms, crickets, caterpillars, and grasshoppers. Eastern bluebirds may also eat snails, sow bugs, earthworms, and spiders. During the fall and winter months, Eastern bluebirds may eat the berries and fruits of a number of plants and trees, including holly, blueberry, hackberry, elderberry, dogwoods, red cedars, sumacs, bayberry, and Virginia creepers. Bluebirds will not eat seeds because their short, slender beaks do not permit them to crack open seeds. Dried fruit, chopped peanut kernels, and mealworms are some food items that may be placed on a tray or platform type feeder to attract bluebirds.