Goldfinches are the one songbird species I get every winter. About 10 years ago and earlier they used to devour Nyger seed each winter and I could barely keep up with demand. But in the last few years fine hulled sunflower seeds have become their favorite and that’s what I fill my thistle feeders with nowadays. Their bills are sharp enough to pull the sunflowers through the slits of the thistle feeders, but they have to work at it which means I don’t have to fill my feeders as often.
In the summer the male American Goldfinches sport brilliant yellow and black feathers, but they molt into drab golden-brown feathers in winter and the males and females blend together at the feeders—especially from a distance.
Goldfinches prefer tube feeders but will also visit hopper and platform feeders and you’ll even see them feeding on the ground. They are plant seed eaters so at the feeders they prefer Nyger and sunflower seeds.
If you have a flock of goldfinches make sure to take a peek at them with binoculars from time to time. You might find that there are also Pine Siskins and/or Common Redpolls feeding along with them and it can be hard to distinguish the different species from a distance.