Dark-eyed Junco

Junco hyemalis
STANFORD LOCATIONS:

Uncommon and local summer resident, fairly common and more widespread during migration and in winter. Breeding birds on main campus nest almost exclusively in dense mats of ivy and other vines planted around buildings and court-yards, although the choice of nesting cover may be more diverse in woodland and scrub habitats near the Dish and in the faculty housing area. From fall through spring, flocks (sometimes fairly large in the Arboretum) occur throughout campus.		  
Nest
Location
Nest
Type
Eggs
Mating System
Dev.
Parental Care
Primary &
2ndary Diet
Foraging
Strategy
F
I: 12-13 DAYS
ALTRICIAL
BANK
 (To 20 feet)
CAVITY
 F -M
3-5
(3-6)
MONOG?
F: 9-13 DAYS
MF
INSECTS
HAWKS
BREEDING: Conif and decid forest and edge, open woodland, bogs. 2 broods, occ 3 in s, 1 at higher elevation and latitude.
DISPLAYS: Courting pair hop with wings drooped, tail fanned displaying white outer feathers; from low perch male droops wings, spreads and droops tail, sings softly.
NEST: Usu in shallow depression with overhead protection, often against vertical surface; rarely in shrub, tree, or building; of coarse grass, moss, rootlets, forbs, bark, twigs, lined with fine materials,
EGGS: White to pale bluish-white, marked with reddish-browns, often wreathed. 0.8" (19 mm).
DIET: Includes few spiders; wide variety of seeds. Nestlings fed 100% insects, initially partly regurgitated.
CONSERVATION: Winters s to n Mexico. Uncommon cowbird host.
NOTES: Territorial conflict uncommon. Female broods nestlings. Later clutches smaller. Rapid tarsal development enables nestlings to run from nest if threatened before they can fly. Foraging flocks occ with chickadees, bushtits, nuthatches, kinglets, sparrows, in spring and fall. Roosts in conif trees, old nests, rock crevices, on ground. Winter flocks of 10-30 with definite social ranking and mutually exclusive foraging territories. Males tend to winter farther n than females. Several races, formerly regarded as species, now combined in Dark-eyed Junco: Slate-colored, Oregon, White-winged, Gray-headed, and Guadalupe Junco.
ESSAYS: Eye Color; Walking vs. Hopping; Birds and the Law; Dominance Hierarchies; Taxonomy and Nomenclature.
REFERENCES: Balph, 1979; Ketterson and Nolan, 1982; Smith and Andersen, 1982.

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Except for Stanford Locations, the material in this species treatment is taken, with permission, from The Birder's Handbook (Paul Ehrlich, David Dobkin, & Darryl Wheye, Simon & Schuster, NY. 1988).