Widespread, the Yellow Warbler nests in a wide variety of habitats from open broad-leafed forest and arctic willows to desert riparian forests. It gleans insects from leaves at mid to high levels in the trees, but will also eat fruits in late summer. The nest is a small cup-shaped structure made of grass and shredded bark and placed in low bushes to branches in high cottonwoods and willows. The resident population on the coasts of Mexico to Ecuador is considered a separate species by some experts, the Mangrove Yellow Warbler.
The four-digit banding code is YWAR.