Original description: Fringilla hyemalis Linnaeus 1758
Taxonomic history in AOU/AOS Check-list
AOU 1 (1886): Slate-colored Junco, Junco hyemalis
AOU 2 (1895): Slate-colored Junco, Junco hyemalis; Carolina Junco, Junco hyemalis carolinensis
AOU 3 (1910): Slate-colored Junco, Junco hyemalis hyemalis; Carolina Junco, Junco hyemalis carolinensis
AOU 4 (1931): Slate-colored Junco, Junco hyemalis hyemalis; Carolina Junco, Junco hyemalis carolinensis
AOU 5 (1957): Slate-colored Junco, Junco hyemalis hyemalis, Junco hyemalis carolinensis
AOU 6 (1983): Dark-eyed Junco, Junco hyemalis [hyemalis group]
AOU 7 (1998): AOU 6 (1983): Dark-eyed Junco, Junco hyemalis [hyemalis group]
IUCN Conservation Status: Of least concern H
Behavior: Slate-colored Juncos are busy, gregarious ground-feeders, readily flocking in winter with other sparrows and finches; when one is seen in the company of Oregon Juncos, its large size is often conspicuous.
Fairly tame at all seasons, Slate-colored Juncos feed quietly in short grass and fallen leaves, scratching and kicking through the duff in search of insects and seeds. They are also very common feeder visitors in winter.
Voice: Flushed or startled, Slate-colored Juncos are noisy, swooping away to the accompaniment of metallic dzz flight calls and flashing the white outer tail feathers on takeoff and on landing.
Males sing from tall bushes or at mid-height in trees. The tail is slightly depressed and the neck slightly stretched, and the bill is usually opened and held just above the horizontal. Females’ short-range songs are given mostly while the birds are feeding on the ground.
Detailed description and measurements drawn from standard reference works
Adult Junco hyemalis hyemalis: Central tail feathers slaty black. Outermost pair, rectrix 6, entirely white on both webs, rarely with some black in females. Rectrix 5 entirely or, more frequently, mostly white on both webs. Rectrix 4 entirely black on outer web in about half of birds, whiter or even pure white in a few; inner web mostly or entirely black. Rectrix 3 black on both webs, a very few males showing a trace of white. Upper tail coverts, rump, back, and scapulars slaty gray, darker in males and browner in many females. Primaries and secondaries blackish with paler gray edges. Outer webs of tertials grayish, more brownish in many females. Greater and median coverts gray, the innermost with paler or brownish edges; occasionally with white tips forming loose wing bars. Nape slaty gray, often with brownish tinge in females, approaching blackish in some males.
Under tail coverts, vent, belly, and lowermost breast white. Flanks gray to grayish brown; in some, especially younger birds, the feathers extensively tipped buffy or dull cinnamon but still with gray bases. Upper breast and throat slaty gray to grayish brown, approaching blackish in some males, sharply set off from lower breast but flowing smoothly into similarly colored breast sides and flanks.
Crown slaty gray, more brownish in some females, approaching blackish in many males. Ear coverts and lores dark slaty gray, approaching blackish in some males.
Tarsus and toes light pinkish brown. Bill pale pinkish white.
Juvenile Junco hyemalis hyemalis: Central tail feathers slaty black; outer two pairs entirely or mostly white. Upper tail coverts and rump gray with black streaks. Back dull grayish brown, sometimes slightly tinged rusty, with fine black streaks. Scapulars dull brown. Primaries and secondaries blackish with paler gray edges. Outer webs of tertials mostly brownish. Greater and median coverts gray with broad brown edges; rarely with white tips forming loose wing bars. Nape grayish brown with blackish streaks.
Under tail coverts, vent, belly, and lowermost breast whitish. Flanks, breast, and throat buffy white with blackish streaking, heaviest on breast.
Crown and sides of head grayish brown with black streaks.
Tarsus and toes dull pinkish brown. Bill dull grayish pink.
First-winter birds of both sexes browner, especially on tertials and flanks. Formative females may show virtually no pure gray in the field.
Length 133-158 mm (5.2-6.2 inches)
Wing chord 71-82 mm (2.8-3.2 inches)
Tail 62-71 mm (2.4-2.8 inches)
Mass 20 g