A tiny, thin-billed, wing-flicking insectivore, it has a conspicuously striped head. Polytypic. Length 4".
Adult male: dull grayish olive above, paler whitish below, head boldly marked with white supercilium, blackish lores and eye line. Yellow crown bordered broadly with black. Orange in center of yellow crown visible only during display, or when bird is agitated. Black at base of secondaries, contrasting with white wing bar. Adult female: similar to male, no orange in crown. Immature: somewhat pointier tail feathers than adult; a few males may lack orange in crown.
Western subspecies (apache and olivaceus) slightly smaller, somewhat brighter, with longer white supercilium, longer bill.
Call: when flocking, a very high, sibilant jingling, tsii tsii tsii. Also, a quiet, high single note, tsit, and