ClipArt ETC
"Cygnus columbianus. Common American Swan. Whistling Swan. Bill with a yellow spot or blotch in front of eye, usually small, sometimes wanting. Bill less lengthened and expanded terminally than in C. buccinator, the nostrils across the middle; the distance from the anterior angle of the eye to the hind edge of the nostril more than thence to the end of the bill. Tail-feathers normally 20." Elliot Coues, 1884

Whistling Swan

"Cygnus columbianus. Common American Swan. Whistling Swan. Bill with a yellow spot or blotch in front…