|Female Mountain Bluebird at Tuolumne Meadows|
Male Mountain Bluebirds are the real lookers: they are as vividly blue as the clear sunny heavens above the alpine firmament they call home. To see one of these gems flutter from above to perch on a branch, you may even believe a little piece of the sky has just fallen before you. They are absolutely breathtaking.
The unfortunate and less poetic truth of the matter is that as of yet, no male Mountain Bluebird has seen fit to pose for a portrait for me! Mountain Bluebirds spend most of the year in open areas from mid to high elevations in the Sierra and across western North America. (Try looking for them at Yosemite's Tuolumne Meadows.) In the winter, they venture to lower elevations and may make appearances in the Sierra Nevada foothills and the Great Central Valley's grasslands and farmlands.
In contrast to Mountain Bluebirds, Western Bluebirds (pictured below, for the sake of comparison) are stockier and a much deeper, richer blue color; males and females both have a rusty red/orange wash on their breast, flanks and back. (I should also mention that in the Central Valley, year-round, you are far more likely to see Western Bluebirds than Mountain Bluebirds.)
|Western Bluebird along the Tuolumne River in Stanislaus County|
Bluebirds of all kinds (including North America's third species, the well-known Eastern Bluebird (Sialia sialis)) are in the thrush family (Turdidae) along with robins, solitaires and, well, thrushes. They are cavity nesters, and Mountain Bluebirds have historically nested in holes excavated by woodpeckers; they readily take to human-made nest boxes as well, which has allowed researchers to study them fairly easily. As with other native birds that nest in cavities (like Tree Swallows), competition is fierce from non-native, introduced European Starlings and House Sparrows.
*Note: Upon further investigation, it looks like a few Northern Cardinals do turn up in southern California now and then, probably naturalized individuals from introduced stock. As a general rule, they are considered rare here.