This handsome little finch, the state bird of New Jersey, Iowa, and Washington, is welcome and common at feeders, where it takes primarily sunflower and nyjer. Goldfinches often flock with Pine Siskins and Common Redpolls. Spring males are brilliant yellow and shiny black with a bit of white. Females and all winter birds are more dull but identifiable by their conical bill; pointed, notched tail; wingbars; and lack of streaking. During molts they look bizarrely patchy.
Weedy fields, open floodplains, and other overgrown areas, particularly with sunflower, aster, and thistle plants for food and some shrubs and trees for nesting. Goldfinches are also common in suburbs, parks, and backyards.
Goldfinches eat seeds almost exclusively. Main types include seeds from composite plants (in the family Asteraceae: sunflowers, thistle, asters, etc.), grasses, and trees such as alder, birch, western red cedar, and elm. At feeders prefers nyjer and sunflower.
American Goldfinches are active, acrobatic finches that balance on the seedheads of thistles, dandelions, and other plants to pluck seeds. They have a bouncy flight during which they frequently make their po-ta-to-chip calls. Although males sing exuberantly during spring, pairs do not nest until mid-summer, when thistles and other weeds have gone to seed. Goldfinches do not join other songbirds mobbing predators.
The nest is an open cup of rootlets and plant fibers lined with plant down, often woven so tightly that it can hold water. The female lashes the foundation to supporting branches using spider silk, and makes a downy lining often using the fluffy “pappus” material taken from the same types of seedheads that goldfinches so commonly feed on. It takes the female about 6 days to build the nest. The finished nest is about 3 inches across on the outside and 2-4.5 inches high.
Adult males in spring and early summer are bright yellow with black forehead, black wings with white markings, and white patches both above and beneath the tail. Adult females are duller yellow beneath, olive above. Winter birds are drab, unstreaked brown, with blackish wings and two pale wingbars.