The bird world quiets down by late summer - but not the American goldfinch, one of the most common backyard birds. September brings the chatter of young goldfinches as they follow their male parent. They beg noisily, perched with head thrown back and trembling wings.
Most songbirds switch their diet to high-protein insects when feeding their young, and they nest earlier when insects are most bountiful. For example, chickadees that keep bird-feeders busy in winter disappear in summer as they forage for insects not birdseed.