olive-crowned yellowthroat Geothlypis semiflava

Small yet chunky warbler of wet, grassy, and shrubby areas. Very similar to Common and Masked Yellowthroats: olive above, yellow below, black mask. However, note lack of whitish or gray border to black mask. Female also similar to other yellowthroats but with entirely yellow underparts and olive face. Song is somewhat variable, always including sweet repeated notes but sometimes with a complex chattering ending.