Best identified by its prominent crest, the juniper titmouse is an otherwise nondescript small, gray bird with a short, bulky bill.
It is a resident of juniper woodlands or pinyon-juniper woodlands where juniper is dominant; it requires large trees that provide natural cavities for nesting. In Wyoming, this species preferred mature juniper stands with high juniper cover, senescent trees, dead limbs, and presence of pinyon pines; the old trees provide cavity-nest sites; the pinyon pines may be preferred foraging substrate. In the Red Cliffs Desert Reserve, it is most likely observed in higher elevations areas, such as the Red Mountain Wilderness.
This species nests in tree cavities excavated by woodpeckers or formed by rot or broken branches. It will also use artificial nest boxes. It may partially excavate its own nest cavity if the wood is soft or rotten.
The juniper titmouse is nonmigratory, and pairs defend their territories year-round, although some birds may leave their nesting grounds in winter if food becomes scarce.
This species eats seeds (and is known to be a major consumer of pinyon seeds), terrestrial invertebrates, and fruits. In fall and winter it eats mainly seeds and juniper berries. The insects are gleaned from the foliage and bark of trees and shrubs and from the ground.
Breeding Bird Survey (BBS) data for 1966-2005 do not show statistically significant population trends at the national scale or the scale of the western U.S., but they do show significant declines for the BBS Pinyon-Juniper Woodland Ecoregion (-2.7% per year), Colorado (-4.3% per year), and New Mexico (-2.8% per year).