As you might remember, my Photo of the Week last week was an image of a fledgling meadowlark I’d found in mid-September. At the time, I’d talked about how surprised I was to see such a young bird so late in the season. Well, last Friday, Eliza Perry, one of our Hubbard Fellows, called me to say she’d just found a nest full of tiny birds – did I want to come take a look? Of course I did.
American goldfinch chicks sit in a nest about three feet off the ground in a tall thistle (Cirsium altissimum) plant. Platte River Prairies, Nebraska.
I’m pretty sure what Eliza found was an American goldfinch nest. The bills and markings on the birds look right, and we spotted an adult goldfinch nearby. However, the best supporting evidence was that the nest was located in a thistle plant (a native thistle species, by the way) and had thistle down in the nest cup. There is a strong tie between American goldfinches and thistles. Unlike most other bird species which feed their young on insects, goldfinches instead feed them regurgitated seeds – especially those of thistle plants. In fact, they often delay their nesting until those thistle seeds have ripened. Here is a link to photographer/naturalist Stan Tekiela’s post on this topic, if you’re interested in learning more about the topic.
These birds are even further behind the meadowlark in their development, and it’s already getting pretty cold overnight, so the nestlings’ chances for survival might seem slim. Of course, the difference between the meadowlark and the goldfinches is that the goldfinches have adults around to help them. Both have a challenging fall and winter ahead of them, but nothing others of their species haven’t dealt with countless times before, I guess.
A better view of the nest placement within the tall thistle plant.
Thanks to Anne Stine, our other Hubbard Fellow, who graciously helped hold equipment for me as we photographed the nest. Because of the very bright early afternoon sun, I had Anne hold a diffuser near the nest to reduce the harshness of the sunlight while I held a small flash unit to better illuminate the birds. We worked quickly and got out of the way so the parents could resume their feeding duties.
The Prairie Ecologist 
The American Goldfinch is one of the latest nesting songbirds, primarily because they very often do rely on maturing thistle for both nesting and food. Within the species of course, someone has to fill in the right side of the curve!
http://www.allaboutbirds.org/guide/american_goldfinch/lifehistory
Great photos of the nestlings! Goldfinches are a highlight of the autumn.
Goldfinches are wonderful and bizarre in many ways. They nest so late, because they just have to have thistle down in the nest and thistle seed to feed the chicks. Then the chicks leave their droppings all over the rim of the nest. Why? Other birds parents go to the trouble of hauling the sacs of poo away from the nest. But (as your fine photo seems to show) goldfinch nests are identifiable by their gross-to-us nest edges. Perhaps the “edge of poo” is a deterrent to some threat to the chicks?
I think the parents eat/remove the droppings for the first few days of the nestling period, but it is indeed odd that the nests become so dirty during the latter stages of nestling development. I wonder if it has something to do with their diet (being predominantly vegetarian) making the feces less problematic, or if like you suggest it has something to do with parasites that may not be active earlier in the breeding season. Sounds like a neat research project!
1. Linguistic factoid: The specific epithet for this bird – tristis – means sad, in Latin. Nothing about this bird’s appearance or behavior seems sad to me, but I believe this name refers to the mournful sound of its call, which reminds me of a high-pitched version of a sigh or sob of a mourner at a funeral.
2. On a cheerier note: Thistles are simply amazing small wildlife plants, rather like the oaks among tree species. There is a huge diversity of insects that depend on eating their leaves, roots, seeds, nectar or sap, and the plants withstand it quite well, thank you. There is a book devoted to the topic of thistle insects in England, where what are a couple of weedy thistles (bull and “Canada” thistles) on this continent serve as the same sort of banquet table for native insects in Europe.
On young birds this time of year- yesterday in my yard in NW Indiana, I found a headless (and dead) bird. The tail feathers were beginning to grow out and were about 1 cm long with yellow tips. Cedar Wax wing was my best guess at ID. That species is here year round, so not as surprising to have a young bird this time of year.
On Thistles for wildlife- observations as I collected seeds this past week on Cirsium discolor, yes there is a great diversity of insects consuming a diversity of parts of the plant. Praying mantises are there too and several larvae within the seed head. I suppose if it existed, James would have mentioned it, but does anyone know a good source for information on our North American thistle/insect associations? Also got a good show of a sphinx moth nectaring on Cirsium muticum last week too.
No work on American thistle insects that I know of.
And, don’t you just love those big, plump, deep purple seeds of C. muticum?
Thank you for showing us these beautiful birds. I hope they make it too.