This map by Borja Milá of Museo Nacional de Ciencias Naturales in Madrid, one of Ellen Ketterson's collaborators, shows the various Dark-eyed and Yellow-eyed Junco color varieties across North America. Based on DNA evidence, Milá's work suggests that Dark-eyed Juncos evolved from Yellow-eyed Juncos that migrated north from Mexico into the United States and Canada in the past ~13,000 years after glaciers receded. It includes a Dark-eyed Junco variety not covered in this article: the recently described Guadalupe Junco (GUJU), which breeds only on the tiny Guadalupe Island off the coast of Baja California. (Key, counter-clockwise from top left: ORJU=Oregon; PSJU=Pink-sided; GUJU=Guadalupe; BAJU=Baird's; YEJU=Yellow-eyed; GTJU=Guatemalan Yellow-eyed; VOJU=Volcano; CHJU=Chiapas; RBJU=Red-backed; GHJU=Gray-headed; WWJU=White-winged; SCJU=Slate-colored)