Cornell Lab of Ornithology now I've learned Cornell University's Ornithology Department's web site All About Birds All About Birds American goldfinch American Goldfinches American goldfinches male counterpart website Brown-Headed Cowbird allaboutbirds.org allaboutbirds.org American goldfinch American Goldfinch American goldfinch American Goldfinch American goldfinches American Goldfinch website About the Goldfinch says Cornell Lab of Ornithology’s All About Birds very late breeding season now I've learned Brown-Headed Cowbird Cornell University's Ornithology Department's web site Brown-Headed Cowbird American Goldfinch’s nest American Goldfinches Brown-Headed Cowbird American Goldfinch Brown-Headed Cowbird website Cornell Lab of Ornithology American Goldfinch’s nest post on the American Goldfinch American Goldfinch American Goldfinch American goldfinches website Brown-Headed Cowbird Cornell University's Ornithology Department's web site American Goldfinches American Goldfinches American Goldfinch very late breeding season Brown-Headed Cowbird male counterpart