The breeding season is gearing up for a bird that is one of the latest nesters. American goldfinches don't start building their nests until late July into August. They use thistle down to build their cup nests and the thistles aren't ripe until late summer.
In the morning when I have the windows open, I can hear the males displaying rambunctiously with their "potato chip, potato chip, potato chip" calls. They fly up and down like a roller coaster trying to impress the females.
Male goldfinches wear cheery bright yellow plumage that is unmistakable as they visit gardens. Some gardeners might not be pleased when they eat petals from flowers, but I have planted my prairie garden just for wildlife. They can eat as many coneflower and ox-eye petals as they please. That guarantees a goldfinch visit to my yard.