The Dark-eyed Junco is a medium-sized sparrow with a rounded head, a short, stout bill and a fairly long, prominent tail. They vary across the country, but in general they’re dark gray or brown birds brightened up by a pink bill and white outer tail feathers that periodically flash open, especially in flight.
Dark-eyed Juncos are small birds slightly larger than the Chipping Sparrow, weighing 0.6-1.1 ounces (18-30 grams) and a length of 5.5-6.3 inches (14-16 centimeters). They have a wingspan of 7.1-9.8 inches (18-25 centimeters).
Regional DiffrencesThere is a huge range of geographic variation in the Dark-eyed Junco. Among the 15 described types, six forms are easily recognizable in the field and five used to be considered separate species until the 1980s. In general there are two widespread forms of the Dark-eyed Junco: the “slate-colored” junco of the eastern United States and most of Canada, which is smooth gray above, and the “Oregon” junco, found across much of the western U.S.,Yellow-eyed Juncos.
Dark-eyed Juncos are residents to medium-distant migrants. They breed in coniferous or mixed-coniferous forests across Canada, the western U.S., and in the Appalachians at elevations ranging from sea level to more than 11,000 feet. During winter and migration, they are found in open, grassy areas in most of the U.S.
Dark-eyed Juncos are primarily seed-eaters. During the breeding season, Dark-eyed Juncos also eat insects.
The female chooses the nest site, typically very near or on the ground. Occasionally, juncos nest higher (rarely as high as 45 feet). Females build the nests, using her beak to weave together materials and her body to give the nest its shape. Nests can be quite variable depending on where they are built. The nests usually take 3-7 days to build, and when finished they are 3-5.5 inches across, with an inner diameter of 2.4-2.8 inches and depth of 1.6-2.8 inches. It’s rare for a Dark-eyed Junco to reuse a nest.
Dark-eyed Juncos have one to three broods with three to six eggs in each per year. The eggs are white, gray, pale bluish white, or pale-greenish white speckled with brown, gray and green. They are sometimes unmarked. The eggs are 0.8 inches (1.9-2.1 centimeters) in length and 0.6 inches (1.5-1.6 centimeters) in width. Incubation period is 12-13 days and nesting period is 10-13 days. The hatchlings are naked except for dark gray down on the back, their eyes are closed, and they are clumsy at hatching.
When foraging, Dark-eyed Juncos typically hop (rather than walk) on the ground, pecking or scratching at the leaf litter, or fly very low in underbrush gleaning food from twigs and leaves. They sometimes fly up from the ground to catch insects from tree trunks. In flight, they flap continuously and pump their tails so the white outer tail feathers flash. Their flight is very agile as the bird maneuvers through its tangled surroundings.
Male juncos are very territorial in summer, chasing off intruders in rapid flights accompanied by excited calls. When males court females, they fan or flick open their wings and tail, hop up and down, and pick up pieces of nest material or moss. The females seem to prefer males that show more white in the tail.
During winter, Dark-eyed Juncos form fairly large flocks. Where wintering ranges overlap you may find several subspecies in a single flock. These juncos also forage with other sparrows and bluebirds. Junco flocks typically have a pecking order, where earlier arrivals tend to rank higher in the group than later arrivals.
Male Dark-eyed Juncos sing an even, musical trill of 7-23 notes that lasts up to 2 seconds. This song is loud enough to be heard from several hundred feet away. Both males and females sing a much quieter song as well, a series of whistles, trills, and warbles. This song typically doesn’t carry any farther than about 40 feet.
Juncos calls include a high, short chip note that they often give in rapid succession when they fly and more slowly as they forage. The note may encourage other juncos to follow. A sharp but musical kew usually given by the dominant bird seems to indicate aggression and encourages two birds to move apart. You may also hear juncos give a high, fast twittering call of 6–19 notes during squabbles or as birds flush.
Dark-eyed Juncos are numerous and widespread, though they have had a small decline recently.
- Juncos are the "snowbirds" of the middle latitudes, retreating to higher elevations during warmer months.
- The Dark-eyed Junco is one of the most common birds in North America and can be found across the continent. A recent estimate set the junco’s total population at approximately 630 million individuals.
- The oldest recorded Dark-eyed Junco was at least 11 years and 4 months old when it was recaptured and rereleased during banding operations in West Virginia in 2001. It was banded in the same state in 1991.
- Dark-eyed Juncos are called Junco Pizarroso in Spanish and Junco ardoisé in French.