For once, the Ornithological High Priests who name birds were able to come up with a name that is simple, true, and memorable: this is a male Yellow Warbler.
Yellow Warblers have more yellow on their little (about 5-inch) bodies than any other of our warblers. Both sexes resemble dabs of sunshine. The males have rusty breast streaks, as you see above. The females don’t have those streaks or only faintly have:
The males are very musically talented – they reportedly compose and perform up to 3.240 different happy arias a day to attract females, but they also hiss like snakes when protecting their territory.