Encyclopedia Definition

Bluebird, common name for three small songbirds of the thrush family. The eastern bluebird of eastern and midwestern North America, ranging south to Nicaragua, is about 18 cm (7 in) long. The throat and breast of the male are reddish brown, the abdomen is white, and the upperparts are sky blue; the female is less brightly colored. The female builds a grass-lined nest in a tree hole or other cavity, and lays four to six pale blue eggs. The western bluebird has less reddish brown on the underparts and a brown patch on the back; the mountain bluebird is all blue. Both the western and mountain bluebirds are found in western North America.

All bluebirds readily accept artificial nest boxes in place of natural tree holes. Northern populations of the eastern and mountain bluebirds are migratory; southern populations and the western bluebird are mostly sedentary.

Scientific classification: Bluebirds make up the genus Sialia in the family Turdidae. The eastern bluebird is classified as Sialia sialis, the western bluebird is classified as Sialia mexicana, and the mountain bluebird is classified as Sialia currucoides.