4.75 inches long. The Blue-winged Warbler male is has a yellow body and crown with a greenish back. There is a prominent black eye line. The wings are blue-gray with two white wing bars. The female is duller with a darker crown.
The Blue-winged Warbler is seen only during migration. It is seldom seen in the Forest as its migration route is east of Nebraska.
The Blue-winged Warbler is closely related to the Golden-winged Warbler and often hybridizes in areas where their breeding zones overlap.