The mute swan (Cygnus olor) is a large bird in the swan family, Anatidae. It is found throughout much of Eurasia and is a rare winter visitor to northern Africa. Mute swans have been introduced to North America, where they have the largest populations outside their native range. Smaller populations also exist in Australasia and southern Africa. The term “mute” refers to their quieter nature compared to other swan species.
Mute swans typically measure between 125 and 160 cm in length. They are entirely white with an orange beak that has a black border. Males are larger and have a bigger knob on their beaks than females. On average, these swans are the second largest waterfowl species after the trumpeter swan, although some male mute swans can weigh as much as or more than male trumpeters. Mute swan wingspans measure between 200 and 240 cm.
In studies from Great Britain, male mute swans, called cobs, weigh between 9.2 and 14.3 kg, with an average weight of 10.6 to 11.87 kg. Females, known as pens, are slightly smaller, weighing 7.6 to 10.6 kg, with an average of 8.5 to 9.67 kg. Mute swans can fly at speeds of up to 88.5 km/h (55 mph) and reach speeds of about 48 km/h (30 mph) when taking off.
Young mute swans, called cygnets, are not bright white like adults. Their bills are dull greyish-black, not orange. The down can be white, grey, or buff, with grey or buff being most common. Cygnets grow quickly and reach near adult size in about three months. They usually keep their grey feathers for at least a year, with their wings losing down earlier that year.
All mature mute swans are white, but their feathers can get stained orange-brown from iron and tannins in the water.
Mute swans build their nests on large mounds made of plants in shallow water on islands in lakes. They are monogamous and often reuse the same nest each year, repairing it as needed. Both parents help care for the nest, and once cygnets are able to fly, families often gather to find food. They eat a variety of vegetation, both underwater and on land, including crops like oilseed rape and wheat. In winter, they can cause damage to crops, not just by eating but also by trampling with their large feet. They may also eat some aquatic insects, fish, and frogs.
Unlike black swans, mute swans are very territorial. Usually, only one pair lives on smaller lakes, but they can form colonies in places with plenty of food.
Mute swans communicate less than the louder whooper and tundra swans, but they still make various sounds.
