One of the smallest warblers; look for short tail and sharply pointed, bicolored bill. Bluish-gray above with distinctive lime-green patch on the back, white wingbars and eye-arcs, yellow on throat, and white belly. Found in forested areas; has a fondness for nesting in Spanish moss in the southeastern U.S. Loud song is buzzy, ascending trill with sharp chip at the end; sounds like a zipper. Winters mainly in Mexico and Caribbean.