The Pygmy Nuthatch (Sitta pygmaea), is a tiny songbird that ranges from southern British Columbia south through a variety of regions throughout the western United States, and into central Mexico. Its habitat is pines, Douglas-firs, and other coniferous trees. It is very similar to the Brown-headed Nuthatch of the southeastern U.S., however, their ranges do not overlap.
It is 10 inches long and weighs about three tenths of an ounce. They have a warm gray cap, bluish-gray upperparts, and whitish underparts. there is a whitish spot on the nape that mainly occurs in the summer plumage. Its vocalizations are a variety of chirps, peeps, and chattering.
Pygmy Nuthatches nest in cavities in dead stubs of conifers, lining the bottom of the cavity with pine-cone scales, plant down, and other soft plant and animal materials. They may use fur to fill the cracks and crevices around the entrance. The female lays 4 – 9 eggs and are incubated mainly by the female for 16 days. Young leave the nest about 22 days after hatching.
This species is highly gregarious. A nesting pair may have other birds as helpers. Outside the breeding season, this bird wanders in noisy flocks. It also roosts communally with sometimes up to 100 or more birds huddled in a single tree cavity. Pygmy Nuthatches clamber acrobatically in the foliage of these trees, feeding on insects and seeds.