Birds of Brooklyn: American Goldfinch
The American goldfinch is among the most colorful and musical birds in the New York City area, and it’s easy to spot and hear as it flies over open green spaces like Prospect Park, Green-Wood Cemetery, and Brooklyn Botanic Garden. Like most members of the finch family, the goldfinch sings as it flies, and birders can identify it simply by its undulating flight pattern and its flight song. And of course, there's its characteristic coloring. Unlike most birds, which molt once a year, the goldfinch molts completely twice a year—once in August, like most birds, and again in early spring, when the male acquires that brilliant gold and black plumage. (The female is a more subdued yellow.)
The relationship between a bird and a specific type of plant could never be closer than it is between the American goldfinch and thistles. The goldfinch’s diet consists largely of thistle seeds, which gives it some interesting advantages. For instance, when the brown-headed cowbird, a nest parasite, lays an egg in a goldfinch nest, the cowbird hatchling cannot survive on the goldfinch's vegetarian diet and therefore fails to thrive at the expense of its nest-mates, as it does in other species' nests.
More: Read about the gray catbird, a local bird that meows and mimics car alarms.
The goldfinch also utilizes the down from thistle plants to line its nest. This bird probably nests later than any other species in the United States simply because it is waiting for the thistle plants to bloom and produce their downy seed heads.
Goldfinches are attracted to bird feeders, where they love to feed on—guess what?—thistle seeds. You may see them on a specially designed thistle-seed feeder any time of the year, sometimes upside down, picking at the small black seeds. They are an especially cheerful site during a bleak winter. Though they generally do migrate, some remain here year-round. In June, July, and August, you can also see them in weedy, thistle-filled fields, often in pairs or sometimes in a flock. No matter when or where you see a goldfinch, it is sure to brighten your day.