|Male Goldfinch molting for winter|
All birds molt but American Goldfinches do it in style. The brilliant lemon yellow that is so common in summer is now becoming a blotchy olive-yellow. In a few weeks, the birds will have completed their molting and the yellow of their feathers will be replaced by a drab olive-brown. Male goldfinches will become almost indistinguishable from the females, with the exception that the females will have a grayer cast to their olive-brown color.
Some goldfinches migrate south for the winter but most stay in our area. It's a good thing for the males to change color. With fewer leaves on the trees, the males become harder for predators to spot.
Goldfinches do not have the ability to change color in the same way a chameleon does to match its surroundings. For goldfinches, the change in color is triggered by hormonal changes affecting carotenoid pigments. Some researchers believe that the length of daylight or differences in the bird's diet may contribute to the hormonal changes.
The change in color isn't limited to their feathers. The bills of the both sexes also change color, from an orange yellow in summer to a dark bill in winter. The darker appearance is the result of melatonin deposition, possibly because of hormonal changes. The young have a dark bill even before they leave the nest.
After winter ends, male goldfinches replace their drab feathers with the lemon yellow that we enjoy seeing in summer. The brighter the male during breeding season in June, the greater he'll impress a female and mate.
Cold-weather goldfinches can be identified by their conical bill, pointed notched tails, wing bars and lack of streaking. They are acrobatic and active, often clinging to dried sunflowers, black-eyed susans or coneflowers well into the fall.
Try this trick to attract goldfinches: Instead of cutting back your raggedy-looking coneflowers, let them stand so the seed cones can mature. Coneflowers are prized by goldfinches. It's not uncommon to see a goldfinch grasping onto a stem, often hanging upside down, to extract seeds from the cone. When the seeds disappear from the cone, then you can cut the coneflowers to the ground for winter.
Goldfinches are found mainly in weedy fields and floodplains or other overgrown areas where plants such as sunflower, aster and thistle are common. Of course, feeders will bring them to the backyards, where they shelter and nest in shrubs and trees.
The birds fly with a bouncy rollercoaster pattern, often calling while flying.
Goldfinches nest later in the summer than most other birds. They wait until mid- to late summer when milkweed, thistle and other plants have produced their fibrous seeds.
They choose to nest in maple, oak or other deciduous trees (or pine trees) about 30 feet above the ground. The nest is an open cut of rootlets woven so tightly that it can hold water. The female lashes the foundation to supporting branches and lines it with fluffy material taken from the same plants fro which the birds feed. It takes a female about six days to complete the nest. Clutch size is two to seven eggs; incubation lasts 12 to 14 days. The chicks hatch in another 11 to 17 days.
Goldfinches are strict vegetarians. Only inadvertently will they swallow an insect.
The best way to attract goldfinches to your backyard is to provide a nyjer seed feeder. These feeders are tube shaped with small ports sized to keep the seed from falling out. Fill the feeder with nyjer seed (which mistakenly is called "thistle seed") or with a "finch mix" that contains both nyjer and tiny fragments of sunflower seed. If you use the mix, don't be surprised to see an occasional Downy Woodpecker feeding from the feeder!
Goldfinches also will come to tube feeders filled with black oil sunflower seed.
The birds compete for food, and they put on a great show as they chase each other and vie for space on the feeder.