About 6 inches long, bluebirds breed in the United States, southern Canada, Mexico, and Guatemala, wintering in the southern half of the Eastern United States and south to Guatemala.

The bluebird was once a familiar tenant of towns, hailed as the herald of a new vernal season, and decidedly domestic in its habits. About the time that starlings became so very numerous, it declined in numbers. No one is sure why its numbers fell but competition for nest sites by starlings and house sparrows is certainly partly responsible. Recently it has begun to reappear in many places.

Its favorite nesting sites are natural cavities in old trees, boxes made for its use or crannies in buildings. Nesting boxes may be restoring the species, whose occupants pay rent by destroying insects. The bluebird’s diet consists of 68 percent insects and 32 percent vegetable matter. The commonest items of insect food are grasshoppers first and beetles next, while caterpillars stand third. Small flocks sometime invade yards for the red fruits of flowering dogwood trees.