The American goldfinch (Spinus tristis) is a small North American bird in the finch family. It is migratory, ranging from mid-Alberta to North Carolina during the breeding season, and from just south of the Canada–United States border to Mexico during the winter. The only finch in its subfamily to undergo a complete molt, the American goldfinch displays sexual dichromatism: the male is a vibrant yellow in the summer and an olive color during the winter, while the female is a dull yellow-brown shade which brightens only slightly during the summer. The male displays brightly colored plumage during the breeding season to attract a mate. The American goldfinch is a granivore and adapted for the consumption of seedheads, with a conical beak to remove the seeds and agile feet to grip the stems of seedheads while feeding. It is a social bird and will gather in large flocks while feeding and migrating. It may behave territorially during nest construction, but this aggression is short-lived. Its breeding season is tied to the peak of food supply, beginning in late July, which is relatively late in the year for a finch. This species is generally monogamous and produces one brood each year. Human activity has generally benefited the American goldfinch. It is often found in residential areas, attracted to bird feeders which increase its survival rate in these areas. Deforestation also creates open meadow areas, which are its preferred habitat. Taxonomy The American goldfinch was one of the many species originally described by Carl Linnaeus in the landmark 1758 10th edition of his work, Systema Naturae, where he classified it in the genus Fringilla. It was later placed in the genus Spinus, a group containing New World goldfinches and siskins. In 1976, Spinus was merged into the genus Carduelis as a subgenus. Recent studies have resurrected the genus Spinus. Its closest relatives are the lesser goldfinch (S. psaltria), Lawrence's goldfinch (S. lawrencei), and the siskins. Although it shares a name with the European goldfinch, the two are in separate genera and are not closely related. Carduelis is derived from carduus, the Latin word for 'thistle'; the species name tristis is Latin for 'sorrowful'. There are four recognized subspecies of the American goldfinch: The eastern goldfinch (S. t. tristis) is the most common of the subspecies. Its summer range is from southern Canada to Colorado, and east to the Carolinas. Its winter range is