John J. Audubon wrote about the junco, “So gentle and tame does it become on the least approach of hard weather, that it forms, as it were, a companion to every child. Indeed, there is not an individual in the Union who does not know the little Snow-bird, which, in America, is cherished as the Robin is in Europe.”
And in America, the snowbird is second in abundance to the American robin. Population estimates range from nearly 3 million to around 6 million. Juncos nest across most of Alaska and Canada to northern California and New England and down the Appalachians to northern Georgia. It overwinters from southern Canada to northern Mexico.
Because there are so many juncos and they are so widely distributed, their taxonomy is and has been somewhat jumbled.
At one time, at least six species of juncos were recognized in North America. Today, I believe the species count is two — dark-eyed junco, Junco hyemalis, and yellow-eyed junco, Junco phaeonotus. The yellow-eyed junco is predominantly a Mexican species that barely reaches southern New Mexico and southern Arizona, and the former “species” of junco like Oregon, white-winged, slate-colored, etc. are considered subspecies and/or races of J. hyemalis.
We have a resident species of junco here in the Southern Appalachians — J. hyemalis carolinensis. Like most of the dark-eyed juncos of the slate-colored variety carolinensis is grey above and white below with conspicuous white outer tail feathers. Bird-banders will tell you it has shorter wings than most dark-eyed juncos, a trait you cannot see in the field. But there is a way to tell whether the juncos at your feeders are local or if they’re like Uncle Bernie and Aunt Esther. Most dark-eyed juncos have pinkish bills, but the Southern Appalachian race has a bone-white or bluish bill.
Juncos band together in flocks during the winter. These flocks generally number between 15 and 25 birds and have a strict hierarchy.
As long as food and cover are adequate a flock will normally spend the winter on a 10-12-acre territory.
The oldest recorded dark-eyed junco was a little over 11 years old. It was first captured in West Virginia in 1991 and was recaptured at the same site in 2001. Some other interesting tidbits about dark-eyed juncos include: mating pairs are thought to be monogamous; to help the snowbird through winter, their winter molt contains 30 percent more feathers than summer; and probably because of the sheer numbers of juncos, they appear to have one of the higher rates of leucism (loss of pigmentation) in the bird world.
I expect many winter birders across Western North Carolina have had a burst of snow bunting adrenaline on initial sighting of a partially leucistic junco.