Eastern bluebird information

Eastern bluebirds (also known as Wilson’s bluebird, blue robin, common bluebird, blue redbreast, American bluebird, and blew bird) are not only known for their distinctive sounds but also for their distinguishing physical features. These small birds have short, slim beaks and short legs. The weight of an adult blue bird ranges from 27 to 34 grams. The Eastern bluebird is a member of the thrush family, and it is known as the state bird of both Missouri and New York. Male and female bluebirds are easily identified by their striking colors. A bright blue upper body, an orange-red throat, and white belly and undertail coverts characterize adult male bluebirds. Adult female bluebirds have a gray crown and back, white eye ring, a brownish breast, throat, and sides, blue wings, and a white belly and undertail coverts. The female bluebirds’ coloring is a bit more duller compared with the male bluebird. Dull wings and tail, gray crown and back, white eye ring, and spotted underparts characterize juvenile bluebirds.

Eastern bluebirds are known for their sweet, melodious whistling sounds. Their distinctive sounds are their main form of communication. Different songs are used for various purposes, including mating and territoriality. The bluebird calls sound like chir-wi or chur-lee. Visual signals may also be used for communication. In general, the Eastern bluebird is a very social bir, often gathering to include flocks of 100 or more bluebirds.

Eastern bluebirds can be found in a variety of habitats, including farmyards, orchards, woodlands, suburban parks and yards, hedges, pastures, meadows, gardens, and roadsides. They prefer open areas with scattered trees and short ground cover. These birds usually prefer open land areas to meet their feeding, nesting, and perching needs. Open areas with scattered trees provide bluebirds with an opportunity to build their nests. Bluebirds frequently use old woodpecker holes and cavities (eg. hollow limbs and holes in trunks) to establish their nests. Fence posts and nest boxes also provide refuge for these birds. Eastern bluebirds are located east of the Rocky Mountains from the south of Canada to the Gulf States and into South America.

Mating for Eastern bluebirds typically occurs during the spring and summer months. At least one successful group of young bluebirds may be raised each season by an adult female bluebird. There are generally 2-3 broods raised per season. Female bluebirds will lay an average of 4-5 pale blue eggs in each set, and the eggs incubate for a period of 12-16 days. Incubation periods may be longer during colder months. Newly hatched bluebirds are in a relatively underdeveloped state and require the care of the adult bluebirds for feeding and mobility. After 15-20 days, the young bluebirds are ready to leave the nest. Some juvenile bluebirds may stay with the nest to help raise other groups of bluebirds during the upcoming season.

The diet of Eastern bluebirds may vary depending on the season. Eastern bluebirds have migratory habits. They may have to leave their homes when food, temperature, or environmental conditions change. During the summer months, bluebirds prey on a number of insects, including crickets, caterpillars, grasshoppers, beetles, katydids, and mealworms. Eastern bluebirds may also eat snails, sow bugs, earthworms, and spiders. These birds may hunt from a perch and dive down to catch their prey. Flycatching or gleaning techniques may be used to gather food. Bluebirds have great speed and eyesight with measured speeds of 17 miles per hour and the ability to locate food from more than 100 feet away. 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. The bluebirds do not feed on seeds because their short, slender beaks do not permit them to crack open seeds. Ponds, streams, and birdbaths may serve as a source of water for bluebirds.

The population of Eastern bluebirds is dependent upon a number of factors, including predators, food and nesting availability, and environmental conditions. Predators of Eastern bluebirds vary greatly. Eastern chipmunks and flying squirrels prey upon eggs and newly hatched bluebirds. Adult bluebirds are preyed upon by a number of predators, including house sparrows, European starlings, fire ants, cats, black bears, small falcons, rat snakes, black racers, and raccoons. Male Eastern bluebirds will often give a song-like cry to warn of predators. Females will sing to alert the attention of male bluebirds. Adult males and female bluebirds will exhibit wing jerking and vibratory singing to warn other bluebirds of nearby predators.

Eastern bluebirds largely depend upon others for their nesting needs. Naturally occurring cavities, cavities made by other birds, or nest boxes are commonly used by bluebirds. The beaks of these birds are not strong enough to enable them to hollow out their own nests. At the nest cavity, the male Eastern bluebird does a nest demonstration to attract the attention of the female bluebird, and he provides nest material. The female bluebird primarily builds the nest. The bluebird nest is composed mainly of grass with other components, including rootlets, pine needles, or deer hair. Eastern bluebirds must compete with more aggressive birds (eg. Eastern starlings and house sparrows) for food and nesting sites. The availability of nesting sites is also largely dependent upon land use. Conversion of the Eastern bluebirds’ habitat into farmland and commercial property has reduced a large number of available nesting locations.

In order to promote the conservation of bluebird species, including the Eastern bluebird, the building of nest boxes has been introduced in various habitats that meet the requirements for bluebirds. Suitable habitats include open areas with low predator populations, especially house sparrows. Materials used for the construction of nest boxes include bald cypress, pine, or eastern red cedar. Nest boxes are built 4-5 feet off the ground with predator guards to protect against potential predators. The entrance hole is placed appropriately to prevent overheating from direct sunlight and the force of strong winds. Appropriate cleaning and maintenance of nest boxes during the nesting season can encourage at least 2-3 nesting attempts during each year.