Lesser Goldfinch — a small, cheerful songbird with a big personality: The Lesser Goldfinch is one of the smallest finches in North America, measuring only about 4–4.5 inches long — yet it’s incredibly active and energetic. These birds can imitate the songs of other species, including American Robins, Barn Swallows, and even Western Tanagers. Their long, bubbly song is a mix of trills, warbles, and borrowed tunes. Their diet is almost entirely seeds, and they especially love sunflower and thistle