This is normally a very shy bird, usually hiding in dense vegetation along watercourses. It is much more often heard than seen. Its loud song includes whistles, cackles and chattering. Although currently classified as a Wood Warbler (Parulidae) it's genetically quite different and its true affinities are uncertain.
Two subspecies are recognized. This is the Western race I. v. auricollis, sometimes called "Long-tailed Chat." According to Ridgway, Western birds are supposed to have the tail longer than the wing but this formula does not seem to work for Arizona specimens. A modern review of geographic variation in this species is needed.
Digiscoped with Panasonic DMC-LZ5 | Nikon FieldScope III | 30XWA | hand-held (no adapter)