The mute swan (Cygnus olor) is a species of swan and a member of the waterfowl family Anatidae. It is native to much of Eurosiberia, and (as a rare winter visitor) the far north of Africa. It is an introduced species in North America – home to the largest populations outside of its native range – with additional smaller introductions in Australasia and southern Africa. The name 'mute' derives from it being less vocal than other swan species. Measuring 125 to 170 cm (49 to 67 in) in length, this large swan is wholly white in plumage with an orange beak bordered with black. It is recognisable by its pronounced knob atop the beak, which is larger in males.
Description & appearanceAdults of this large swan typically range from 140 to 160 cm (55 to 63 in) long, although can range in extreme cases from 125 to 170 cm (49 to 67 in), with a 200 to 240 cm (79 to 94 in) wingspan. Males are larger than females and have a larger knob on their bill. On average, this is the second largest waterfowl species after the trumpeter swan, although male mute swans can easily match or even exceed a male trumpeter in mass. Among standard measurements of the mute swan, the wing chord measures 53–62.3 cm (20.9–24.5 in), the tarsus is 10–11.8 cm (3.9–4.6 in) and the bill is 6.9–9 cm (2.7–3.5 in).
The mute swan is one of the heaviest flying birds. In several studies from Great Britain, males (known as cobs) were found to average from about 10.6 to 11.87 kg (23.4 to 26.2 lb), with a weight range of 9.2–14.3 kg (20–32 lb) while the slightly smaller females (known as pens) averaged about 8.5 to 9.67 kg (18.7 to 21.3 lb), with a weight range of 7.6–10.6 kg (17–23 lb). While the top normal weight for a big cob is roughly 15 kg (33 lb), one unusually big Polish cob weighed almost 23 kg (51 lb) and this counts as the largest weight ever verified for a flying bird, although it has been questioned whether this heavyweight could still take flight.
Young birds, called cygnets, are not the bright white of mature adults, and their bill is dull greyish-black, not orange, for the first year. The down may range from pure white to grey to buff, with grey/buff the most common. The white cygnets have a leucistic gene. Cygnets grow quickly, reaching a size close to their adult size in approximately three months after hatching. Cygnets typically retain their grey feathers until they are at least one year old, with the down on their wings having been replaced by flight feathers earlier that year.
All mute swans are white at maturity, though the feathers (particularly on the head and neck) are often stained orange-brown by iron and tannins in the water.
Voice, singing & callThe mute swan is less vocal than the noisy whooper and Bewick's swans; they do, however, make a variety of grunting, hoarse whistling, and snorting noises, especially in communicating with their cygnets, and usually hiss at competitors or intruders trying to enter their territory. The most familiar sound associated with mute swan is the vibrant throbbing of the wings in flight which is unique to the species, and can be heard from a range of 1 to 2 km (0.6 to 1 mi), indicating its value as a contact sound between birds in flight. Cygnets are especially vocal, and communicate through a variety of whistling and chirping sounds when content, as well as a harsh squawking noise when distressed or lost.
Distribution & habitatThe mute swan is found naturally mainly in temperate areas of Europe then across the Palearctic as far east as Primorsky Krai, near Sidemi.
It is partially migratory throughout northern latitudes in Europe and Asia, as far south as north Africa and the Mediterranean. It is known and recorded to have nested in Iceland and is a vagrant to that area, as well as to Bermuda, according to the UN Environment Programme chart of international status chart of bird species, which places it in 70 countries, breeding in 49 countries, and vagrant in 16 countries. While most of the current population in Japan is introduced, mute swans are depicted on scrolls more than a thousand years old, and wild birds from the mainland Asian population still occur rarely in winter. Natural migrants to Japan usually occur along with whooper and sometimes Bewick's swans.
The mute swan is protected in most of its range, but this has not prevented illegal hunting and poaching. It is often kept in captivity outside its natural range, as a decoration for parks and ponds, and escapes have happened. The descendants of such birds have become naturalised in the eastern United States and Great Lakes, much as the Canada goose has done in Europe.
Hunting & foodDer Höckerschwan lebt von Wasserpflanzen und den daran befindlichen Kleintieren (Muscheln, Schnecken, Wasserasseln), die er mit seinem langen Hals unter Wasser durch Gründeln erreicht. Hierbei erreicht er Tiefen von 70 bis 90 Zentimetern. An Land frisst er auch Gras und Getreidepflanzen. Dies kommt vor allem im Spätwinter vor, wenn die Unterwasservegetation nicht mehr ausreichend Nahrung bietet. Sie bevorzugen dabei vor allem Rapsflächen. Grünland wird dagegen von Schwänen nur selten als Nahrungsfläche genutzt.
Breeding, mating, chicks, juveniles & raiseMute swans can be very aggressive in defence of their nests and are highly protective of their mate and offspring. Most defensive attacks from a mute swan begin with a loud hiss and, if this is not sufficient to drive off the predator, are followed by a physical attack. Swans attack by smashing at their enemy with bony spurs in the wings, accompanied by biting with their large bill, while smaller waterbirds such as ducks are normally grabbed with the swan's bill and dragged or thrown clear of the swan and its offspring. The wings of the swan are very powerful, though not strong enough to break an adult man's leg, as is commonly misquoted. Large waterfowl, such as Canada geese, (more likely out of competition than in response to potential predation) may be aggressively driven off, and mute swans regularly attack people who enter their territory.
Mute swans lay from four to ten eggs, and the female broods for around 36 days, with cygnets normally hatching between the months of May and July. The cygnets do not reach the ability of flight before an age of 120 to 150 days: this limits the distribution of the species in the northern edge of its range, as the cygnets must learn to fly before the waters freeze.