Tiny warbler of mesquite woodlands. Constantly flitting about as it searches for insects. Pale gray with whitish belly, rufous rump, and faint rufous crown (difficult to see). Sharp bill. Faint white eyering. Most similar to Virginia's Warbler but lacks yellow; also compare with Verdin, but note bill shape. Departs breeding grounds early in summer and migrates to Mexico for the winter. Sweet song similar to Yellow Warbler but typically includes sharper notes at end.