The bluebirds are a group of medium-sized, mostly insectivorous or omnivorous bird in the order of Passerines in the genus Sialia of the thrush family (Turdidae). Bluebirds are one of the few thrush genera in the Americas. They have blue, or blue and rose beige, plumage. Female birds are less brightly colored than males, although color patterns are similar and there is no noticeable difference in size between the two sexes.
Bluebirds species include:Eastern bluebird, Sialia sialis
Western bluebird, Sialia mexicana
Mountain bluebird, Sialia currucoides
Bluebirds are territorial and prefer open grassland with scattered trees. This is similar to the behaviour of many species of woodpecker. Bluebirds can typically produce between two and four broods during the spring and summer (March through August in the Northeastern United States). Males identify potential nest sites and try to attract prospective female mates to those nesting sites with special behaviors that include singing and flapping wings, and then placing some material in a nesting box or cavity. If the female accepts the male and the nesting site, she alone builds the nest and incubates the eggs.
Predators of young bluebirds in the nests can include snakes, cats, and raccoons. Bird species competing with bluebirds for nesting locations include the common starling, American crow, and house sparrow, which take over the nesting sites of bluebirds, killing young, smashing eggs, and probably killing adult bluebirds.
Bluebirds are attracted to platform bird feeders, filled with grubs of the darkling beetle, sold by many online bird product wholesalers as mealworms. Bluebirds will also eat raisins soaked in water. In addition, in winter bluebirds use backyard heated birdbaths.
By the 1970s, bluebird numbers had declined by estimates ranging to 70% due to unsuccessful competition with house sparrows and starlings, both introduced species, for nesting cavities, coupled with a decline in habitat. However, in late 2005, Cornell University's Laboratory of Ornithology reported bluebird sightings across the southern U.S. as part of its yearly Backyard Bird Count, a strong indication of the bluebird's return to the region. This upsurge can be attributed largely to a movement of volunteers establishing and maintaining bluebird trails.
Of all the birds a gardener could choose to attract, the bluebird is the quintessential helpful garden bird. Gardeners go to extreme lengths to attract and keep them in the garden for their advantageous properties. Bluebirds are voracious insect consumers, quickly ridding a garden of insect pests.
Maurice Maeterlinck introduced the concept of a "blue bird of happiness" in his play The Blue Bird (1908). The bird in that play is not actually a bluebird, but merely a bird that is blue (which is, in the play, a symbolically significant color); subsequent use of the phrase, however, tended to blur this distinction. As a result, bluebirds became a widely recognized symbol of happiness and cheer, and have been used as such by numerous songwriters. Examples are Jan Peerce's signature song, "Bluebird of Happiness", Judy Garland's "Hello, Bluebird", "Over the Rainbow" ("Somewhere over the Rainbow/Bluebirds fly"), "I'm Always Chasing Rainbows" ("I'm Always Chasing Rainbows/Waiting to find a little bluebird in vain"), "Zip-A-Dee-Doo-Dah" ("Mr. Bluebird's on my shoulder"), David Bowie's "Lazarus" ("I'll be free / just like that Bluebird"), Vera Lynn's "The White Cliffs of Dover" ("There'll be bluebirds over/The White Cliffs of Dover"; a particularly remarkable instance, as there are no bluebirds in Europe), and Paul McCartney and Wings' "Bluebird".
Songwriters have also portrayed the bluebird as a muse, as in the song "Voices in the Sky" by the British rock group The Moody Blues, from their 1968 album In Search of the Lost Chord.