Fairly common but local in tall deciduous trees near water. Another warbler that loves the heights. Song is series of buzzy notes in 2–3 parts, getting higher, somewhere between BTBW and NOPA in tone. ID: Very similar to CEWA with a slightly shorter tail. All have dark ear coverts, 2 bold wing bars, flank streaking and pale underparts. Ad ♂ br: beautiful blue upperparts. Dark breast band and bold flank streaking usually catch the eye. In fall, blue-green upperparts, losing breast band. Ad ♀/1st-yr ♂: green upperparts with blue tinge. Diffuse flank streaking with yellow wash extending across breast. Imm ♀: dullest with wash over most of underparts. BLBW very similar from below but has more distinct ear coverts, brighter throat, and white along outer tail feathers (subterminal spot in CEWA can also be seen in flight).