Posted by Robin Diaz on December 04, 2016 at 20:09:46
ID tips for this warbler: 1) Look for a pale patch at the bend of the wing, which David mentions (see photos); and 2) The undertail coverts will be the same yellowish color as the bird's belly (see photo). The Stephenson/Whittle _Warbler Guide_ is one of the few books to use the pale patch as a field mark. We probably get the nominate race (celata) wintering here, which can have a gray hooded look. They also have a distinctive chip note and are very vocal. Apologies for the separate post but I couldn't figure out how to add photos to a continuing thread.