Townsend's Warbler

These birds have a yellow face with a black stripe across their cheeks extending into an ear patch, a thin pointed bill, two white wing bars, olive upperparts with black streaks on their backs and flanks, and a white belly. Adult males have a black cap, black throat and yellow lower breast; females have a dark cap and a yellow throat. Immature birds are similar to females with a dark green cap and cheeks.
Wikipedia