Written by Peter Pearsall/Photo by Peter Pearsall
The Mountain Bluebird (Sialia currucoides) is a stunning and vibrant thrush of mountain meadows, grasslands, and sagebrush plains across the western half of North America.
Adult males display an intense, sky-blue plumage on their upperparts, head, and throat, which contrasts with a paler blue on their underparts. Females, juveniles, and non-breeding males exhibit more muted shades of blue with brownish tones. The blue hue of these birds comes not from pigment but from reflective keratin structures in their feathers.
Mountain bluebirds breed in the ponderosa pine/Western juniper forests surrounding Harney Basin and usually pass through the Refuge during migration.
The diet of these birds primarily consists of insects, including beetles, grasshoppers, and caterpillars. They are also known to consume berries and fruits, especially during the non-breeding season. In winters where food grows scarce at higher elevations, these colorful thrushes may congregate in the Harney Basin to feast on juniper “berries” and other winter fruits.
During the breeding season, females construct cup-shaped nests in tree hollows, bird boxes, or similar structures. The nests are composed of grasses, feathers, and other soft materials. Clutches usually consist of four to six pale blue eggs. Both parents take part in feeding and caring for the chicks, which fledge after about 18 to 21 days.
The mountain bluebird population is generally considered stable, and they are not currently listed as a species of concern. Conservation efforts often focus on providing suitable nesting sites, as these birds readily use artificial nest boxes.
