Western Bluebird
767. Sialia mexicana occidentalis. 7 inches.
Range.—British Columbia to Lower California, along the Pacific coast. These familiar birds build in cavities in trees, or in bird houses, and make themselves at home near dwellings, especially if in the vicinity of orchards of any kind. The note of the western bird has the same familiar warble as their eastern relative. They live on small insects and caterpillars, and some of the small berries. Their four eggs are a pale bluish white (.80 ×.60).
Mountain Bluebird
768. Sialia currucoides. 7½ inches.
Range.—Rocky Mountain regions from Canada to Mexico. Their habits are just the same, eggs averaging slightly larger.
Chestnut-Backed Bluebird
767a. Sialia mexicana bairdi. 7 inches.
Range.—Rocky Mountains from Colorado to Texas (not illustrated).