High Quality Content by WIKIPEDIA articles! The Red Warbler (Ergaticus ruber) is a small passerine bird endemic to the highlands of Mexico, north of the Isthmus of Tehuantepec. It is closely related to, and forms a superspecies with, the Pink-headed Warbler of southern Mexico and Guatemala. There are three subspecies, which are found in disjunct populations. They differ primarily in the color of their ear patch and in the brightness and tone of their body plumage. The adult is bright red, with a white or gray ear patch, depending on the subspecies; young birds are pinkish-brown, with a whitish ear patch and two pale wingbars.