Swan (Mute)

For centuries, mute swans were known as 'birds royal' because only the king or a few specially favoured subjects could keep them. They were often served up, roasted, at banquets - a roast swan must have required a very large plate!


Picture of mute swans and their cygnetsOrder: Anseriformes

Family: Anatidae

Species: Cygnus olor

IUCN Status: Least Concern

Population trend: increasing

Distribution: found throughout the UK. Also in a few areas across northern Europe, eastwards to Mongolia. Introduced to North America, South Africa, Australia and New Zealand.

Habitat: large freshwater areas, such as rivers, lakes and canals. Also estuaries, especially in winter.

Description: adults all white; young are grey to begin with, and develop brown feathers which they keep until their second year. Reddish-orange bill, with a black knob of skin at the base.

Size: length:- 1.5m. Wingspan:- 2.25m. Weight:- male, 10kg, female, 8kg.

Life-span: most swans do not live more than 7 years in the wild. They can live up to 50 years.

Food: underwater plants, grasses and cereal crops.




Mute swans which live in Britain, Ireland and France are mainly resident and usually do not travel very far. Some birds leave their breeding territories and gather together in small winter flocks on nearby lakes and estuaries. Mute swans in some parts of Germany and Scandinavia migrate from their inland breeding lakes to spend the winter along the Baltic coasts, where the weather is less severe. The distance the swans have to fly depends on how cold the winter is. In milder winters, the birds may stay on their breeding lakes, the movement of their paddling feet preventing the water from freezing over.

The male mute swan, known as the cob, fiercely defends the territory that he and his mate, the pen, share . If an intruder, such as another male swan, dares to invade his terrritory he uses a threat posture, raising his wings and back feathers, while lowering his head and moving powerfully through the water. This display usually frightens away the intruder.

Food and feeding

An adult swan eats about 4kg of aquatic vegetation every day. It reaches these underwater plants by plunging its long neck into the water, or 'upending', tail in the air. To help with the digestion of these plants in its gizzard, or second stomach, the swan swallows grit which grinds up the food.

As well as eating water plants, the swan may also graze on grasses and grains it finds in fields of cereal crops. Sometimes it may eat small fish, frogs and insects.


Mute swans pair for life and they mate and begin buiding a nest in March and April. Pair bonding takes place from the age of two although swans are not generally mature until three years old and may breed at this age if there is a territory available. The nest is built on the ground, near to water, in an undisturbed place.

The cob collects reeds and sticks, bringing them to the female so she can arrange them. The nest is often a very big platform-like structure, and may be the pair's old nest which has been rebuilt and used year after year. Although the cob and pen look very similar at first glance, they can be told apart by looking at their beaks. In the spring and summer the cob's bill is a brighter colour than the pen's, and the black knob is more bulbous. The cob is never far from his mate on the nest, keeping an eye out for intruders. If a potential predator gets too close, he will hiss at them (mute swans are quiet birds on the whole, but are not really mute!) and if necessary will charge at them with flapping wings.

The pen lays 5 - 8 large, greenish-brown eggs, one every two days. She does most of the incubation, which starts as soon as the last egg has been laid. This allows all the young to hatch at the same time, after 36 days. Soon after hatching, the young swans, called cygnets, covered with fluffy, grey down, leave the nest. Their parents pull up water plants for them to eat, and they snap up invertebrates (minibeasts) from the surface of the water.

The cygnets stay with their parents until the next winter by which time they are losing the brown plumage that replaced the grey down. It will be a full year before they are completely white, and they are ready to breed when they are three or four years old.

Mute Swans and humans

For centuries, mute swans were known as 'birds royal' because only the king or a few specially favoured subjects could keep them. They were often served up, roasted, at banquets - a roast swan must have required a very large plate!

Flight feathers from the female swan were used as writing implements then known as 'pen quills' and later as 'quill pens', until the 'quill' was left out and only the word 'pen' remained. So our present-day ballpoints etc. take their name from the female swan!

Over the last 30 - 40 years, the mute swan population has fluctuated. Many swans living on rivers where coarse fishing is popular died because they were swallowing lead fishing weights with their food. Lead is very poisonous. Since 1987, the use of lead weights has been banned in the UK and its swan population has recovered.  Another hazard for swans is carelessly discarded fish hooks and lengths of nylon fishing line - both can cause a swan to suffer a painful death.


Image: Swan (Mute) by Tony Hisgett


The graceful mute swan is Britain's largest bird and one of the heaviest flying birds in the world. There are six other species of swan in the world, but the mute is the only resident one you will see in Britain i.e. it stays in Britain all the year round. During the winter months you may also see the whooper swan and Bewick's swan. Whooper swans visit the north and west of Britain in large numbers, arriving in the late autumn and remaining until the spring, when they fly on up to their breeding grounds in the Arctic. Bewick's swans come in from Siberia and occupy the eastern and southern parts of England. In some areas, both these visiting swans can be seen together. Large numbers gather together in three main groups; on the Derwent Floods in Yorkshire, the Ouse Washes of East Anglia and at Slimbridge in Gloucestershire.

Different swans

Swan Heads from left to right: adult Bewick / adult whooper  / adult mute

The mute swan is easy to distinguish from the whooper and Bewick's swans, but when the last two are seen together at a distance, it can be difficult to spot the difference between them. However, the whooper is larger than the Bewick's and has more yellow on the bill.