365 Urban Species. #051: American Goldfinch

[urbpan]

photo by cottonmanifesto

Urban species #051: American goldfinch Carduelis tristis

During the spring and summer, the male American goldfinch is bright lemon yellow, with a black cap on the front of its head. The rest of the year, the male and female look similar: dull olive with black wings marked with white wing bars.

The goldfinch lives almost entirely on seeds. Seeds of plants that gardeners consider weeds provide most of its diet. The large plant family Asteraceae contains many important weeds that goldfinches and other birds feed on, including common urban plants such as dandelion and thistle. Because these seeds are most abundant in the late summer and fall, the goldfinch has adapted to have the latest breeding season of our songbirds. As for winter food, Cities landscaped with the right plants can provide it for them: birch and alder seeds do the trick. Of course, humans feed goldfinches as well, buying feeders specially designed for them. These are filled with the sterilized seed from a Ethiopian plant (in the Asteraceae family) called niger, but often sold as "thistle." American goldfinches are the among the five most common birds reported to the Massachusetts Audubon Society's eBird program.

The American goldfinch is the state bird of the most densely populated state, New Jersey, and also Iowa and Washington. There are at least five other species of Cardeulis finches in North America, including the lesser goldfinch (C. psaltria) of the southwest, and the common redpoll.


Photo by urbpan. Male American goldfinch in breeding plumage (this entry edited to add it), in May.

Comments

[ankhanu.livejournal.com]

I could be wrong, but based on the examples of dandelion and thistle, the current name of Compositae is Asteraceae. Current family names of plants end in -aceae. Asteraceae is a rather specious family with a lot of vegetative and floristic characters represented, I could see how it could be called Compositae.

I didn't realize the goldfinch's late breeding season, though, I suppose if I'd thought about it, it would have made complete sense :P

[urbpan.livejournal.com]

Ah, thank you. Some of my botanical references are on the old side. It doesn't look like they've completely discarded "compositae," but Asteraceae is more current. I'll change it.

[daisynerd.livejournal.com]

Happened upon this by accident. I realise it is from a while ago but thought you might be interested to know that the daisy family is one of eight that have two alternative names sanctioned under the International Code of Botanical Nomenclature. So both Asteraceae and Compositae are right. Just showing how much of a daisynerd I am.

[urbpan.livejournal.com]

Thanks, daisynerd! It's nice to get a message saying I was right, for a change! ;)

[phlogiston-5.livejournal.com]

Yay! Its the state bird of NJ! My backyard is chock full of Goldfinches in late August and early September, when the Zinnias and Coneflowers in my garden start to senesce (both of which are in the Asteraceae). I did not know that the males became duller in the winter months. Neato.

[brush-rat.livejournal.com]

Okaaaaay. So, Mr. smart guy, how do they change color?

[urbpan.livejournal.com]

In the spring their dull feathers are replaced with their bright breeding plumage when they molt. Presumably their hormones regulate the production of pigment on the new feathers (as the hormones regulate when they molt). They don't really change color, they grow feathers of a different color. All birds molt, but only some have breeding plumage that's different from non-breeding. This site goes into goldfinch plumage and molting pretty obsessively.

Some birds (house sparrows and starlings, for example) change plumage gradually as the colored ends of their feathers wear away.