Montana Field Guide

Medium-sized songbird. Plumage is characterized by white outer tail-feathers that flash when the bird takes flight and by a gray or blackish "hood" (head, nape, throat) and dark back that contrast with its whitish breast and belly. Exhibits marked geographic variation in plumage coloration and moderate variation in size with intergradations between the five distinctive groups. Identification of most groups is well covered by Howell and Webb (1995), Rising (1996), Dickinson (1999), and Sibley (2014) (Nolan et al. 2002).

For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.

The Bozeman migration for the Dark-eyed Junco (Oregon) is from March 25 to May 10 and September 6 to November 5. For the Dark-eyed Junco (Slate-colored), migration dates are from April 2 to May and October 3 to November 15.

Occurs across the continent from northern Alaska south to northern Mexico. Conspicuous ground-foraging flocks are often found in suburbs (especially at feeders), at edges of parks and similar landscaped areas, around farms, and along rural roadsides and stream edges (Nolan et al. 2002).

Seeds and arthropods; occasionally fruit and waste grain in agricultural fields. Most food obtained from ground and leaf litter (Nolan et al. 2002).

Territory sizes for the Oregon form of 1.7 to 2.6 acres in Douglas-fir and lodgepole pine in western Montana have been recorded.

Nest site highly variable. Most often in small cavity on sloping bank or rock face, under protruding rock, among roots (especially on vertical surface of root ball of large trees topple by wind), and in sloping road cut (especially if overhung by grass or other vegetation). Eggs are elliptical, white, gray, pale bluish white, or pale-greenish white in color. Clutch size most often 4 eggs, 5 and 3 not uncommon (Nolan et al. 2002). Near Fortine, egg dates range from May 1 to August 3. Statewide, nesting is from mid-April to August.