Lucy's Warbler Identification Guide

Key Field Marks

• Size & shape: The smallest warbler in North America — small, compact, plain-looking, with a fine, thin bill and a fairly short tail.
• Plumage: Overall pale gray above and whitish below, lacking the bold streaking, wing bars, or yellow tones shown by most warblers, giving it an almost nondescript appearance at first glance.
• Rump: A rufous-chestnut rump patch, often the most visible field mark, especially noticeable in flight or when the bird flicks its tail and wings while foraging.
• Crown: Adult males show a rufous-chestnut crown patch, though it is often subtle or partly concealed and not always easy to see in the field.
• Eyering: Thin white eyering on an otherwise plain gray face.
• Behavior: Active and warbler-typical, gleaning insects from foliage; notably, it nests in cavities (tree holes, crevices, sometimes old woodpecker holes) rather than open cup nests, unusual among wood-warblers.

Separating from Virginia's Warbler

• Underparts color: Virginia's Warbler shows a yellow patch on the breast and yellow undertail coverts; Lucy's Warbler lacks yellow almost entirely, appearing essentially gray-and-white apart from the rufous rump and crown patches.
• Habitat: Lucy's favors low desert washes and mesquite bosques; Virginia's favors higher-elevation brushy slopes and pinyon-juniper or chaparral habitat, though migrants can occur together.
• Overall impression: Lucy's looks plainer and paler; Virginia's shows more contrast from the yellow patches.

Where & When to See It

Breeds in desert riparian habitats of the southwestern United States — mesquite bosques, desert washes, and streamside thickets in the Sonoran Desert region of Arizona, southeastern California, southern Nevada, and New Mexico. It is a summer resident, arriving early in spring, and winters in western Mexico.

Voice

Song is a fast, bubbly series of whistled notes, often ending with a lower flourish. The call note is a sharp, dry chip.