Adult males are grayish overall with a cinnamon rump and crown patch (both sometimes difficult to see). Female and immatures are duller, with rump and crown often a yellowish brown or reddish yellow.
Forages acrobatically through thorny trees, much like a chickadee, looking for small insects. Males sing tirelessly in spring, in territories often packed close together. Most migrate to less arid habitats to molt, then continue their migration to wintering grounds.
Nests in desert stands of mesquite, tamarisk, acacia, hackberries, and willows, especially along streambeds. May also nest in cottonwood, and at higher elevations in dry, open forests with ash, walnut, sycamore, and oak.