©Delores J. Knowles 2007 -- Black Swans (Cygnus atratus) are mostly black feathered, with a line of white flight feathers of the wing edges that sometimes show when at rest, and are conspicuous in flight. The bill is bright red, with a pale bar and tip; and legs and feet are greyish- black. Cobs (males) are slightly larger than pens (females), with a longer and straighter bill. Cygnets (immature birds) are a greyish-brown with pale- edged feathers. Photographed in Polk County, Florida.