They are monogamous breeders that share incubation duties and cygnet rearing between the sexes. Black Swans can be found singly, or in loose companies numbering into the hundreds or even thousands.
Black Swans are popular birds in zoological gardens and bird collections, and escapees are sometimes seen outside their natural range. Black Swans are primarily black-feathered birds, with white flight feathers. The bill is bright red; and legs and feet are greyish-black. Cobs (males) are slightly larger than pens (females), with a longer and straighter bill. Cygnets are a greyish-brown with pale-edged feathers.
Its wing span is between 1.6 and 2 metres . Black Swans were once thought to be sedentary, but the species is now known to be highly nomadic. There is no set migratory pattern, but rather opportunistic responses to either rainfall or drought.
Black Swans, like many other water fowl, lose all their flight feathers at once when they moult after breeding, and they are unable to fly for about a month. During this time they will usually settle on large, open waters for safety. The current global population is estimated to be up to 500,000 individuals.