Nesting habitat: Open, deciduous, or mixed coniferous-deciduous forests containing ponderosa pine, aspen, willow, and spruce trees.

Nest site: Cliff crevices, natural tree cavities, woodpecker holes, in old nests of Banks and Cliff Swallow, under the eaves of buildings, and in nest boxes. Built 5-15 feet off the ground.

Nest type: The nest is constructed of stems, twigs, grasses, fur, and horse hair. During egg-laying and incubation, the male brings feathers with which to line the nest. The female is the primary nest builder and can take from six days to three weeks.

Eggs:
Clutch size: 4-6 eggs.
Color: White.
Egg size: 18.7 x 13.1 mm.

Incubation period: 13-15 days.

Nestling period: The female tends the young, with the male assisting. Fledge between 23 to 25 days.

Number of broods per season: 1, rarely 2.