Found in the United States and Mexico, specifically their range extends from Oklahoma south through the Edwards Plateau and Big Bend National Park, Texas, to at least the Sierra Madera in central Coahuila in Mexico.
This songbird measures about 12 cm (4.5 inches ) in length.
Adult males have an olive green upper plumage, and the lower parts are white, with faint yellow flanks. The crown and upper half of the head is black. It has white eye-rings and lores (the areas between the beak and the eyes). The eyes are brownish-red and the bill is black.
Females are generally duller; the plumage below is washed with greenish yellow, and their crowns are slaty grey.