Taking the time to watch birds and butterflies as they fly around is a large part of the enjoyment of a garden. And particularly so for bluebirds because of their distinctive color and tuneful song. This article by Rhiannon Crain which I found on the Houzz website describes the three different species of bluebirds found in North America and then suggests ways you can encourage them to visit your garden.

For many people in the birding world, the joy of a bluebird may be unparalleled. From their magnificent plumage and melodic song to the uplifting thrill of their recovering population, no other bird inspires art, music or citizen-science participation quite like our native bluebirds. With a little help, the bluebird of happiness can be a part of your backyard too.

Photo by Steve Peck
Scientific and common names: There are three species of bluebirds in North America, all in the genus Sialia: eastern bluebird (S. sialis), western bluebird (S. mexicana), shown here on toyon (Heteromeles arbutifolia), and mountain bluebird (S. currucoides).

Philip Dunn

Male eastern bluebird

Distribution: Clues to the distribution of bluebird species across North America can be found in their common names. The eastern bluebird resides east of the Rocky Mountains, from the Canadian border to the Gulf Coast, extending its summer range into Canada and venturing into Mexico during the winter. The western bluebird lives in the West, from high in the mountains down to sea level, wintering in the deserts and lowlands, and finding breeding grounds in more forested uplands, but rarely seen east of the Rocky Mountains.
In the West, from the Rockies to the Pacific Coast, the mountain bluebird, seen in this photo, can be found above 5,000 feet, wintering as far south as central Mexico and breeding in the summer as far north as Alaska.