719b. Baird's wren. Thryomanes bewickii leucogaster. Rare summer resident.

721b. Western house wren. Troglodytes aëdon aztecus. Common summer resident; from plains to 10,000 feet; raises two broods, sometimes three.

722. Winter wren. Anorthura hiemalis. Rare resident; no nest found.

725a. Tulé wren. Cistothorus paludicola. Summer resident; not uncommon; breeds from plains to 8,000 feet; some remain all winter in hot-water swamps.

725c. Western marsh wren. Cistothorus palustris plesius. Summer resident; not uncommon locally.

726b. Rocky Mountain creeper. Certhia familiaris montana. Common resident; in breeding season confined to the immediate vicinity of timber-line, where some remain the year round.

727. White-breasted nuthatch. Sitta carolinensis. Resident; not common.

727a. Slender-billed nuthatch. Sitta carolinensis aculeata. Common resident; western form; commonly breeds from 7,500 feet to timber-line.

728. Red-breasted nuthatch. Sitta canadensis. Not uncommon resident; migrant on the plains; resident in the mountains to about 8,000 feet, sometimes 10,000.

730. Pigmy nuthatch. Sitta pygmæa. Abundant resident; mountain bird; makes scarcely any migration; most common from 7,000 to 10,000 feet.