Blue-winged Warbler

Field marks

1. Bright yellow head and underparts with an olive-green back
2. Thin black eyeline passing through the dark eye; typically grayer and less distinct in females
3. Sharp, pointed black bill that appears relatively substantial for a small warbler
4. Blue-gray wings crossed by two prominent white wing bars
5. Short tail with white outer-feather markings and white undertail coverts
6. Small, well-proportioned body with slender legs