The oriantha subspecies, dubbed "Interior West" by Sibley, breeds in the mountain West, and winters in the desert southwest and Mexico. It is distinguished by black lores (visible in this picture), and bill color tending toward dark pink (somewhat obscured here by the insects this bird is carrying to feed its nestlings.) For a wintering bird of this subspecies in Arizona, see http://www.pbase.com/image/139113867 .