The American goldfinch (Carduelis tristis) is a small bird, a little smaller than a sparrow, with a wingspan of less than nine inches. In summer the males are boldly colored, with a bright yellow body and black wings, tail, and top of the head. The females have less conspicuous colors, with an olive body and dark tail and wings, with two distinctive white wing bars.
Their favorite seed plants are thistles, but they will eat seeds from a variety of plants, including asters, goldenrods, and dandelions.
Pairs of goldfinches begin nesting when thistle, milkweed, or cattail down is available with which to line their nests.