A long thin feather called a filoplume can be seen extending from the back of the head. For an analysis of these feathers and their possible function see "Functional interpretation of protruding filoplumes in oscines" [PDF]. These attractive warblers were fairly common in the keys. Two races have been described. The nominate race is migratory, but there is a resident race (S. d. paludicola) found in coastal mangroves on Florida. Paludicola is larger with relatively larger white tail spots. This individual was not in mangroves, but there was an extensive mangrove forest nearby. Spring warbler migration was already underway, so this individual could have been a member of either race.
Nikon P510 Coolpix Point-and-shoot.