Spinus tristis

Breeding adult male is bright yellow, with black wings, a bold white wing-bar, and a black forehead. Breeding adult female has yellow-brown plumage with dark wings and light wing-bars. Nonbreeding male resembles adult female but has yellow patches on the head and throat and yellow lesser wing coverts. Nonbreeding female has a brownish back, grayish underparts, and buffy wing bars. Both sexes have white undertail coverts. Length: 13 cm, wingspan 23 cm.

American goldfinches are associated with weedy fields, cultivated lands, open deciduous and riparian woodland, forest edge, second growth, shrubbery, orchards, and farmlands (AOU 1998). Nests usually are in small trees or bushes, 0.3-10 meters above ground, sometimes in thistles near the ground ( Terres 1980). See Watt and Dimberio (1990) for information on the structure of successful nests.

Except during the breeding season, usually travels and forages in flocks.

Nesting occurs relatively late for a songbird. In most areas, egg laying occurs primarily in late June, July, and August, sometimes in May or into September, with a peak in June and July, but some populations in California and Baja California nest from April to early July. Clutch size is 4-6 (usually 5). Incubation lasts 12-14 days. Young leave the nest about 11-17 days after hatching. Young depend on one or both parents for food for about 3 weeks after fledging.

Brown-headed cowbirds are brood parasites that sometimes lay eggs in American goldfinch nests. However, the cowbird young rarely survive. Probably this is because goldfinches feed mostly seeds to their nestlings, and this diet is inadequate for cowbird development.