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Cavity Nester ⌀ 1.5" Standard

Western Bluebird

Sialia mexicana

Floor
5" × 5"
Interior height
10"
Entrance hole
⌀ 1.5"
Mount height
4–6 ft
Breeds
Apr–Jul
Broods / yr
1–2
Cool Facts

Things you didn't know about the Western Bluebird

01

Western Bluebirds form cooperative breeding groups — yearling males often help their parents raise the next brood.

02

They're more colorful than their Eastern cousins: rust-orange wraps around the throat and shoulders, set against indigo wings.

03

Habitat loss in the early 1900s nearly extirpated them from California's coastal ranges; nest-box trails restored most populations.

04

They eat mistletoe berries in winter and are major dispersers of mistletoe across western oak woodlands.

Attract Them

How to bring the Western Bluebird to your yard

Almost the same playbook as Eastern Bluebirds: mealworms, open ground, predator-proof boxes — but they want oak or pine nearby.

Food

Mealworms in a tray or specialized feeder. They'll also take suet shreds and dried fruit in winter.

Box placement

Pole-mount 5–6 ft up at the edge of open ground with oak or pine within 100 ft. Predator baffle is essential.

Cover & landscaping

Plant native oak species, manzanita, toyon, or mistletoe-bearing trees for winter forage.

Water

Shallow bath with sloped sides; running or dripping water is a draw.

Competitors

Mount paired boxes 15–20 ft apart so swallows can claim one and bluebirds the other — they often nest as neighbors.

Avoid

Don't site boxes in dense suburbs without open foraging ground; they need short grass or bare soil to hunt insects.

Range & Habitat

Where you'll find them

The bluebird of western forests and oak woodlands, ranging from southern BC down through the Pacific states, the Rockies, and into the Mexican highlands.

By region
  • Pacific Coast

    Resident from southern BC south through Washington, Oregon, and California. Higher elevations breed only in summer.

  • Interior West

    Breeds throughout the Rockies, Great Basin, and Sierra Nevada. Many migrate to lower elevations in winter.

  • Southwest & Mexico

    Year-round in Arizona, New Mexico, and the highlands of central and southern Mexico.

Habitat preferences

Open pine and oak woodlands, savanna, and burned areas with standing snags. Increasingly common in suburban yards near oak or pine where nest boxes are provided.

open woodlands orchards rangelands
Approximate range centroids — see the regional breakdown above for the specifics
Fledge Kit

The right house for the Western Bluebird

Cavity Series

Medium body + 1½" panel

Body sized to 5"×5" floor. The 1½" panel locks out larger nest competitors while letting the Western Bluebird pass cleanly.

See the full lineup
Seasonal Care

When to install. When to clean.

Install by
By March
Cleaning
Empty between broods; October final clean
Winter use
Yes — overnight roosts
California / Southwest
Year-round resident — box also serves as winter roost.
Northern Rockies / Pacific NW
Migratory; install by April.

Prefers more open habitat than Eastern Bluebird — face entrance toward open ground.