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 markings than females. The Dark-eyed Junco is 13 to 17.5 cm (5.1 to 6.9 in) long and has a wingspan of 18 to 25 cm (7.1 to 9.8 in). Body mass can vary from 18 to 30 g.


Habitat and Distribution

This bird is common across much of temperate North America and in summer ranges far into the Arctic. In winter, juncos are familiar in and around towns, and in many places are the most common birds at feeders.


Feeding

These birds forage on the ground. In winter, they often forage in flocks that may contain several subspecies. They mainly eat insects and seeds.


Breeding

They usually nest in a cup-shaped depression on the ground, well hidden by vegetation or other material. Sometimes nests are found in the lower branches of a shrub or tree. Normally two clutches of 4 eggs are laid during the breeding season. The slightly glossy eggs are grayish or pale bluish-white and heavily spotted with various shades of brown, purple or gray. The female incubates the eggs for 12 to 13 days.


Calls and Songs

The song is a trill similar to the Chipping Sparrow's. Calls include tick sounds and very high-pitched tinkling chips.