This morning, a dark-eyed junco visited the bird feeder. Junco is a type of American sparrow, but it’s not quite as common as the house sparrow. It’s a cool bird, and I was happy to capture one on video.
The Dark-eyed Junco (Junco hyemalis) is the best-known species of the juncos, a genus of small grayish American sparrows. This bird is common across much of temperate North America and in summer ranges far into the Arctic. It is a very variable species, much like the related Fox Sparrow (Passerella iliaca), and its systematics is still not completely untangled.
Adults generally have gray heads, necks, and breasts, gray or brown backs and wings, and a white belly, but show a confusing amount of variation in plumage details. The white outer tail feathers flash distinctively in flight and while hopping on the ground. The bill is usually pale pinkish.
Males tend to have darker, more conspicuous markings than the females. Also they are 5–6.5 in (13–17 cm) in length. Juveniles often have pale streaks and may even be mistaken for Vesper Sparrows (Pooecetes gramineus) until they acquire adult plumage at 2 to 3 months. But junco fledglings’ heads are generally quite uniform in color already, and initially their bills still have conspicuous yellowish edges to the gape, remains of the fleshy wattles that guide the parents when they feed the nestlings.
The song is a trill similar to the Chipping Sparrow’s (Spizella passerina), except that the Red-backed Junco’s (see below) song is more complex, similar to that of the Yellow-eyed Junco (Junco phaeonotus). Calls include tick sounds and very high-pitched tinkling chips.
A sample of the song can be heard at the USGS web site here (MP3) or at the Cornell Lab of Ornithology web site here.
The Dark-eyed Junco was first described by Linnaeus in his 1758 Systema naturae as Fringilla hyemalis. The description consisted merely of the laconic remark “F[ringilla] nigra, ventre albo. (“A black ‘finch’ with white belly”), a reference to a source, and a statement that it came from “America”.
Linnaeus’ source was Mark Catesby who described the Slate-colored Junco before binomial nomenclature as his “snow-bird”, moineau de neige or passer nivalis (“snow sparrow”) thus:
“The Bill of this Bird is white: The Breast and Belly white. All the rest of the Body black; but in some places dusky, inclining to Lead-color. In Virginia and Carolina they appear only in Winter : and in Snow they appear most. In Summer none are seen. Whether they retire and breed in the North (which is most probable) or where they go, when they leave these Countries in Spring, is to me unknown.” [italics in original]
Still, at least the Slate-colored Junco is unmistakable enough to make it readily recognizable even from Linnaeus’ minimal description. Its modern scientific name means “winter junco”, from Latin hyemalis “of the winter”.