Wilderness Underfoot: American goldfinch

StoryImage( ‘/Images/Story//Auto-img-118894265017239.jpg’, ”, ‘A monogamous pair – American goldfinches, Carduelis tristis, male (front) and female (rear). These birds are widespread across most of the U.S. During summer, they may be found in southern Canada, and during winter in northeastern Mexico. They prefer open woodlands and shrubby fields, and are also found in suburban areas around bird feeders. You can attract American goldfinches to your yard with black oil sunflower seed and nyjer (thistle) seed.’);

Whenever you spot a bright yellow and black bird that looks as if it may be an escaped pet canary, chances are you’ve actually found an American goldfinch. A male American goldfinch, to be exact. The female is actually a much duller olive color (and so is the male during winter months). This finch is often called a wild canary because of its appearance.

Late summer and early autumn is an active time for American goldfinches, many of which are now in the middle of their breeding season. Few other birds rear their young this late in the year.

Males begin the breeding season by establishing territories and courting females with elaborate displays of flight. After mating, the female builds a nest lined with soft thistle down, spider webs, and other silky fibers. She lays four or five pale blue eggs that hatch in about 12 days. Only two weeks later, the fledglings leave the nest and quickly learn to fend for themselves.

Although these birds are generally monogamous, in warmer areas where it is possible to raise two broods during breeding season, females will sometimes dump their poor mates in search of more attractive prospects.

After breeding season, and for the rest of the year, American goldfinches are more gregarious, spending much of their time in large flocks.

The beaks of American goldfinches are specially adapted for extracting seeds from wildflowers such as thistles and sunflowers, and from trees such as alders, elms and cedars. They may occasionally eat insects, which they also feed to their young nestlings before moving on to harder seeds.

The bright yellow color of the male American goldfinch comes from beta-carotene found in the plant materials that they consume in the spring, after moulting their drab winter plumage. Beta-carotene is the chemical that helps give carrots, cantaloupes, and orange or yellow peppers their color, and helps intensify the colors in leafy green vegetables. When consumed by animals, beta-carotene is a powerful antioxidant that is converted into vitamin A. Therefore, it should come as no surprise that in male American goldfinches, bright yellow color is an indication of good health and vigor, which is attractive to females. from the Sept. 5 – Sept. 11, 2007, issue

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