This is one of the most misidentified warblers in North America. A locally abundant migrant in the Fall, immatures such as this sport a pale eye-ring, pinkish bill and faint yellow wing-bars. These birds may be confused with some plumages of Wilson's, Orange-crowned, Nashville, Connecticut, and even Virginia's Warblers. The yellow underside to the tail is a good field mark. Formerly a common breeder in our area, they have succumbed to brood parasitism from invading Brown-headed Cowbirds. Eastern populations thwart the cowbirds by building multiple nests, but our birds have not had time to evolve such strategies as the cowbirds only moved into California in the 20th Century.
