Song also differs between these subspecies, with "Red-backed" birds in northern Arizona singing more complex songs on average (slower trills, often 2-3 trills per song, often with 1-2 non-trill notes at start or end) than our "Gray-headed" Juncos in Colorado. In general there is a gradual transition through the mountains of northern Arizona and New Mexico from the fast, simple, usually 1-trill songs of northern juncos (essentially identical in the Oregon, Pink-sided, Gray-headed, White-winged, and Slate-colored races) to the slow, complex songs of Yellow-eyed Juncos. As you continue south through Mexico, the changes continue, with Yellow-eyed Juncos in Oaxaca singing shorter songs with more different note types and fewer repetitions than Yellow-eyed Juncos in Arizona.
This information probably isn't helpful in identifying off-track migrants, but if one were to find a potential "Red-backed" Junco on territory somewhere in Colorado, song would be a key field mark. Nathan Pieplow Boulder -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to cobirds+unsubscr...@googlegroups.com. To post to this group, send email to cobirds@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
