bluebird, common name for a North American migratory bird of the family Turdidae (thrush family). The eastern bluebird, Sialia sialis, is among the first spring arrivals in the North. It is about 7 in. (17.8 cm) long. The plumage of the male appears vivid blue in bright light and black at a distance; the breast is cinnamon-red, the under parts white. The female's coloring is duller. The bluebird usually nests in orchards or on the edges of woodlands but will also use nesting boxes. As a destroyer of insects it is of great value; it also eats wild fruits. Related birds are the mountain, the western (genus Sialia ) or chestnut-backed, and the Florida bluebirds. Bluebirds have a cheerful call and a sweet, warbling song. They raise several broods during a single mating season. The female is responsible for the incubation duties. Bluebirds are classified in the phylum Chordata, subphylum Vertebrata, class Aves, order Passeriformes, family Turdidae.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.