The Robinson Library
Dark-Eyed JuncoDark-Eyed Junco

Junco hyemalis

Description

5 to 6.5 inches long. Average wingspan of 9.25 inches. This species has dark gray plumage on its head, breast and upper parts, with striking white plumage on its outer tail and belly. Females and immatures are somewhat browner than males.

Distribution and Habitat

breeding range in red; winter range in blue; year-round in purpleBreeds from Alaska and central Yukon to Labrador and Newfoundland, south to central coastal California, in the mountains to eastern California, central Arizona, and western Texas, southern Alberta, northern and east-central Minnesota, central Michigan, southern New England, and in the Appalachian Mountains to northern Georgia and northwestern South Carolina. Winters from central and south coastal Alaska, coastal British Columbia, and across southern Canada south to Mexico, the Gulf Coast, and northern Florida.

Found from sea level to timberline in a variety of woodland areas that have openings with dense herbaceous ground cover. Avoids deep forest interiors in favor of woodland edges and openings. In winter it prefers weedy fields, but also inhabits open woodlands, hedgerows, suburbs, and farmyards.

Reproduction

Dark-eyed juncos are monogamous. Males usually arrive on breeding grounds well ahead of the females, and pairs are formed by mid-April. Males claim territories of 2 to 3 acres. When a female enters a male's territory, the male pursues her aggressively. Once a pair is formed, males follow their mates and are seldom more than 50 feet away.

The female builds the nest over a period of 1 to 9 days, but the male usually helps by bringing nest material. Nests are usually built on the ground near the edge of openings in wooded areas or in a slight depression. They are occasionally built up to 8 feet above ground in a shrub or tree. 3 to 6 white or pale green eggs spotted with brown are laid per clutch. Incubation is done by the female alone for 12 to 13 days. Chicks leave the nest 9 to 13 days after hatching, and become independent of their parents at about 3 weeks of age. Both parents defend the nest from predators, keep the nest clean, and feed the chicks. Sexual maturity is reached at about 1 year of age. Most dark-eyed juncos will raise 2 or 3 broods per season.

Diet

This species forages on the ground for a wide variety of seeds and some insects. In the non-breeding season, it feeds primarily on insects, non-insect arthropods, and seeds. During the breeding season, it feeds mostly on insects. Dark-eyed juncos will visit bird feeders during migration and in the winter months, but prefers to feed on the seeds that have fallen to the ground rather than from the feeders themselves.

Other Habits and Behaviors

Dark-eyed juncos usually hop or walk as they move along the ground.

This species is social during autumn and winter months. Winter flocks typically contain 15 to 25 individuals, with the flocks forming in the morning and dispersing in the evening. Flocks tend to winter in the same area year after year. Within winter flocks, males tend to be dominant over females and adults are dominant over the younger birds. Females tend to winter farther south away from the males.

Older males almost always return to their old, established breeding territories.

Dark-eyed juncos have a variety of songs in their repertoire. Only males sing.

Scientific Classification

phylum Chordata
subphylum Vertebrata
class
Aves
order
Passeriformes
family Emberizidae
genus & species Junco hyemalis

Questions or comments about this page?


Aynsley Carroll. "Junco hyemalis (Dark-Eyed Junco." Animal Diversity Web. University of Michigan Museum of Zoology, 2004. animaldiversity.ummz.umich.edu/site/accounts/information/Junco_hyemalis.html
"Dark-Eyed Junco." All About Birds. Cornell Lab of Ornithology, 2003. www.birds.cornell.edu/AllAboutBirds/BirdGuide/Dark-eyed_Junco.html

Alaska
California
Arizona
Texas
Michigan
New England
Georgia
South Carolina
Canada
Mexico
Florida
Insects
Arthropods
The Robinson Library--Science.--Zoology.--Chordates. Vertebrates.--Class Aves.--Order Passeriformes.

This page was last updated on 06/20/2008.