The Mute Swan (Cygnus olor) is a species of swan & is a member of the family Anatidae. It is native to Europe & Asia. It is also an introduced species in North America, Australasia & South Africa. The name ''mute'' derives from it being less vocal than other swan species. Mute swans are 125 - 170 cm (49 - 67 in) in length with a 200 - 240 cm (79 - 94 in) wingspan. They may stand over 120 cm (47 in) tall on land. Males are larger than females & have a larger on their bill. Males (known as cobs) weigh approximately 12 kg (26 lb) & females (known as pens) weigh approximately 9 kg (20 lb). Mute Swans have white plumage & an orange bill bordered with black. It is recognisable by its pro nounced atop the bill. Young birds, called cygnets, have white, grey or buff colored down & their bill is greyish-black. Mute Swans nest on large mounds that they build with waterside vegetation in shallow water on islands in the middle or at the very edge of a lake. They are monogamous & often reuse the same nest each year, restoring or rebuilding it as needed. Male & female swans share the care of the nest. Mute swans eat a wide range of vegetation, aquatic plants, oilseeds, wheat & occasionally insects & amphibians.