Small, 11.4 to 12.8 cm. Sexually and seasonally dimorphic. Male breeding plumage: lemon yellow; forehead, crown, and lores black; wings jet black, white tips worn; wing coverts yellow with greater coverts white tipped; tail black, white on inner webs; bill orange. Female breeding plumage is a "brighter" version of the basic plumage. Basic plumage: olive brown above, olive yellow below, shading to buff on sides and flanks; males have brighter yellow throats, jet black flight feathers, yellow or olive yellow lesser coverts, black greater coverts, tipped white; females have blackish brown flight feathers, olive lesser coverts, blackish greater coverts tipped white or buff. Both sexes are frequently misidentified in their muted winter plumages (Middleton 1993).
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.
Western Hemisphere Range
In Bozeman area normal migration periods are May 20 to June 5 and September 10 to October 15.
Widely distributed in temperate North America. Common in weedy fields, river flood plains, early second growth forest, and also cultivated lands, roadsides, orchards, and gardens (Middleton 1993).
Daytime feeders and usually feed in the company of others. Seeds of many annual plants are consumed; composites preferred. Small seeds of various trees. Insects only as encountered (Middleton 1993).
Nests are built in shaded locations under canopy of leaves or dense cluster of needles. Clutch size varies from 2 to 7 and is influenced by age, habitat, date, and season. Renesting common in pairs that lose first nest (Middleton 1993). Statewide, nesting begins in July and continues through August; young observed leaving a nest on September 14 in Gallatin County.