One of three species of thrushes (family Turdidae) found in North and Central America: the eastern (Sialia sialis), western (S. mexicana), and mountain (S. currucoides) bluebirds. They are small, about 20 cm in body length, with blue or blue and beige plumage, males being more brightly coloured than females. They occur in open grassland with scattered trees, and in gardens, and feed mainly on insects.