Mountain Bluebird

The Mountain Bluebird breeds across open, high-elevation habitats of western North America, from grasslands and sagebrush steppe to alpine meadows near the treeline. Unlike the Eastern and Western Bluebirds, males lack any rusty orange on the breast, appearing an almost uniform sky-blue, which makes them one of the most recognizable songbirds of the region's open country.

• Body feathers (male): Overall sky-blue, slightly paler and grayer on the belly, with no rufous breast patch.
• Body feathers (female): Grayish-brown overall, with blue restricted mainly to the wings and tail.
• Wing and tail feathers: Show the brightest, most saturated blue in both sexes, especially visible in flight.
• Shape: Feathers are soft and fine-textured, giving the bird a smooth, rounded silhouette typical of bluebirds.
• Compared to similar species: Lacks the rusty-orange breast of Eastern and Western Bluebirds; the male's essentially all-blue body is diagnostic.

Adult males are almost entirely sky-blue, with a slightly paler blue-gray belly and no orange or rufous tones. Females are mostly gray-brown with blue confined largely to the wings, rump, and tail, and a faint blue wash may appear on the breast in some individuals. Juveniles show spotted, scaly brownish plumage typical of young thrushes, gradually molting into adult-like coloration by their first fall. A single complete molt after breeding replaces the plumage annually.

Mountain Bluebirds breed in open habitats including montane meadows, sagebrush flats, high plains, and areas near the treeline across the western United States and Canada, extending into Alaska. They are cavity nesters, often using old woodpecker holes or nest boxes in open or lightly wooded terrain. Most populations are migratory, wintering in the southwestern United States and Mexico in open grassland and desert scrub.

This bluebird forages by hovering and dropping onto insects on the ground, or by catching flying insects in the air, a technique distinct from the more perch-and-pounce style of other bluebirds. It readily uses nest boxes, laying pale blue eggs in a simple cup of grass. Its call is a soft, low chatter, and the song is a subdued warbling phrase given from a perch or in flight. Wintering flocks often gather in open fields, feeding on berries and invertebrates.