The Dark-eyed Junco grey-headed (Junco hyemalis) has dark grey underparts and wings, a flesh coloured bill and a dark iris. It breeds in northern Nevada, Utah, and Colorado and winters in southern Utah, Colorado, Arizona, and New Mexico. It sings a typical Dark-eyed Junco trill. The other two taxa, “Red-backed” Dark-eyed Junco and Yellow-eyed Junco, are more similar to each other in plumage, song and breeding/migratory behavior, really differing only in eye color and the amount of rufous in the wing coverts. Both differ from “Gray-headed” Dark-eyed Junco in having a bicolored bill (dark gray upper mandible, silvery lower mandible in Red-backed, yellowish lower mandible in Yellow-eyed), light gray underparts and usually some rufous in the wing coverts (more extensive in Yellow-eyed, sometimes absent or faint in Red-backed). Both of these forms have similar songs that differ from the trill of other juncos.