BY KIERAN LINDSEY, PhD

There’s been a marked decline in the number of sunspots over the past decade or so. That’s what NASA scientists say, and I have no reason to doubt their research findings. Luckily, I haven’t observed any reduction in the terrestrial version of this phenomenon. Hardly a day has passed lately when I’ve not been blinded by the solar flare of a male American goldfinch (Carduelis tristis) as it escapes, briefly, the gravitational pull of a patch of vegetation.

Actually, urban gardens and other leafy oases have a fairly loose grip on goldfinches, and they regularly venture out beyond the edge. It’s just that the male’s lemon-colored plumage glows against the inky green shade of conifers and summer hardwood foliage, or a cornflower blue sky, making them even more eye-catching than when the backdrop is amber waves of grain… or weedy native grasses. The undulating flight pattern only adds to the illusion of a plasma flash.

Found throughout the majority of North America for at least part of the year, and in about a third of the continent year-round, these smallish (4-5”) birds are regular visitors to backyards. In fact, suburban sprawl, which has proven quite harmful to many wild species—neotropical migrant birds in particular—has been a boon for these devoted granivores. Goldfinches flock to places where thistle, sunflower, dandelion, cosmos, and aster seeds can be found, and development creates the perfect habitat for them and their favorite foods. The popularity of bird feeders hasn’t hurt either, since they provide seed-eaters with a competitive edge over birds who prefer other dining plans.

Also known as the wild canary, this species is sexually dimorphic, meaning gender can be distinguished by some physical feature — in this case, plumage. As is so often the case among wild birds, the female American goldfinch’s wardrobe is understated compared to her mate. The sunny palette is still present, but her hue of choice is a dull or olive-tinged yellow, and her wings are a shade or two lighter although similarly marked.

Boy or girl, the gold in those feathers comes from carotenoid pigments in their diet. It’s the same process and components that causes flamingo (Phoenicopterus and Phoenicoparrus spp.) feathers to be pink, coral, or orange — the wild ones get their color from the red algae and aquatic invertebrates they consume, while captive birds rely on fortified flamingo chow. Without carotenoids in their diet, flamingos would become a much paler version of the iconic plastic subspecies, and goldfinches would go from 24 to 10 karat.

You are what you eat, and so are goldfinches.

Even though it’s converted into an amazing variety of forms—thistle seeds, bluegrass, Brussel sprouts, mangos, caviar, cheese, chicken chests, and hamburgers—when you get down to basics, we’re all eating sunshine. It just shines more brightly through some of us than others.

Learn more about the birds who call Lafayette Park home!

© 2011 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work , just ask first). Thanks to these photographers for making their work available through a Creative Commons license (from top to bottom): Hal Trachtenberg, Frank Boston, and Maia C.