The American Goldfinch is a granivore and adapted for the consumption of seed heads, with a conical beak to remove the seeds and agile feet to grip the stems of seed heads while feeding. However; It is a social bird, and will gather in big flocks while feeding and migrating. This birds may behave territorially during nest construction, but this aggression is short-lived. Its breeding season is tied to the peak of food supply, starting in late July, which is relatively late in the year for a finch. This species is generally monogamous, and produces one brood each year.