Everyone loves the bright yellow American Goldfinch, right? They molt twice a year, unlike most birds, so the outstanding male changes from sunshine yellow to a dull greenish-yellow, just like the female, for the winter months. That's why it seems that they've all gone away, although they stick around Kentucky all year.
I used to put out a separate feeder filled with nyger thistle for them, but they would never eat it. I even bought a new feeder and new thistle, thinking it had gone bad, but they still ignored it. They do enjoy sunflower seeds though.
I've seen a great increase in Goldfinches in our yard since we started planting zinnias and native wildflowers though. Goldfinches are seed eaters, of course. Most seed eating birds will also catch insects for their chicks, to give them extra protein and perhaps calcium. Goldfinches, however, have adapted to a completely vegetarian diet, feeding only seeds to their chicks. They also nest latter in the summer, when a good supply of seeds are available. If a Cowbird lays her egg in their nest, the chick doesn't live long because it can't survive on a diet of only seeds.
I love watching them sway on the zinnia stems in the wind, as they pull off the petals to reach the tiny little zinnia seeds at the base of the flower. The little yellow ring at the top is the true flower of zinnias, and grows higher as the season progresses, leaving seeds at the bottom.
They also like the tiny seeds in black-eyed Susans, coneflowers, bee balm, and cup plants, so I don't dead head these plants when they finish blooming.
Although they aren't native plants, zinnias are quickly becoming one of my favorite flowers. They are brightly colored, and attract colorful birds and insects. Even Hummingbirds come to drink the nectar from them, which really surprised me, since they don't have the traditional long neck I expect hummers to favor.