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Swan

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Swans are large birds belonging to the genus Cygnus. They are part of the Anatidae family, which also includes ducks and geese.

Mute swan family with five cygnets
Mute swan family with five cygnets

Swans are the largest waterfowl in existence. They are also among the largest birds capable of flight in their environments. Because of their significant size and weight, they often require large areas of open water or land to take off and land successfully.

Schwanflug22
Schwanflug22

Scientists classify them within the tribe Cygnini. Some researchers consider them a distinct subfamily called Cygninae.

Physically, swans possess several unique traits that distinguish them from their relatives. They have much larger bodies, feet, and necks than geese.

Whooper-swan
Whooper-swan

Most adults have a patch of unfeathered skin located between their eyes and their bills. In species like the mute swan, males have a fleshy lump at the base of the upper mandible called a knob. This knob is larger in males and can change size depending on the season. While both sexes look similar in plumage, males are generally heavier and larger than females. The males are called cobs, while the females are known as pens.

There are six living species of swan recognized today. These species are often categorized by their plumage and geographic location. Northern Hemisphere species typically have pure white feathers. In contrast, Southern Hemisphere species often show mixed black and white patterns.

Black Swan in Australia
Black Swan in Australia

The Australian black swan is almost entirely black, except for white flight feathers on its wings. The South American black-necked swan has a white body but a black neck and pink legs.

Black-necked Swans (Cygnus melancoryphus), near Chacao, Chile (25184819835)
Black-necked Swans (Cygnus melancoryphus), near Chacao, Chile (25184819835)

Their bills also vary, with subarctic species having black bills with yellow, while others feature red and black patterns.

Swans have a specialized way of feeding on aquatic resources. They are almost entirely herbivorous, meaning they eat mostly plants. They obtain food by up-ending or dabbling in the water to reach roots, tubers, stems, and leaves.

Trumpeter Swaw (Cygnus buccinator) RWD1
Trumpeter Swaw (Cygnus buccinator) RWD1

Although they lack teeth, their beaks have serrated edges that function like small, jagged teeth. These edges allow them to consume aquatic plants, algae, molluscs, small fish, frogs, and worms. This specialized anatomy is a common trait among the Anatidae family.

Socially, swans are known for their strong pair bonds. Many species mate for life and may even bond before reaching sexual maturity.

Courting swan on Danube
Courting swan on Danube

For example, trumpeter swans can live up to 24 years and may form monogamous bonds as early as 20 months of age. While "divorce" can happen, it is relatively rare. In mute swans, the divorce rate is only 3% for successful breeding pairs. Unlike many other waterfowl, male swans actively help construct nests and take turns incubating the eggs.

Swans with nest and eggs at Lake Constance
Swans with nest and eggs at Lake Constance

These nests are built on the ground near water and can reach about one metre in width.

The history of swan classification dates back to 1764. This was when the French naturalist François Alexandre Pierre de Garsault introduced the genus Cygnus. The fossil record shows that swans have a long and diverse history. The largest swan ever discovered was the extinct Cygnus falconeri. This flightless giant lived on the islands of Malta and Sicily during the Pleistocene. It may have reached a length of over 2 metres from its tail to its bill.

Cygnus chathamensis mounted skeleton
Cygnus chathamensis mounted skeleton

Scientists believe its extinction was caused by extreme climate changes or the arrival of new predators.

Swans are distributed across most temperate environments globally. They are rarely found in tropical regions and are absent from tropical Asia, Central America, and Africa. Some species are migratory, moving between different habitats to find food or better weather. The tundra swan is wholly migratory, while the mute swan is a partial migrant.

Bewick's Swans at Big Waters
Bewick's Swans at Big Waters

This movement patterns allow swans to inhabit a wide variety of ecosystems, from the Arctic tundra to the southern parts of South America.

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🖼️ Images & Media (16)
File:Mute swan family with five cygnets.jpg
Mute swan family with five cygnets.jpg
File:Schwanflug22.jpg
Schwanflug22.jpg
File:Whooper-swan.jpg
Whooper-swan.jpg
File:Courting swan on Danube.jpg
Courting swan on Danube.jpg
File:Swans with nest and eggs at Lake Constance.jpg
Swans with nest and eggs at Lake Constance.jpg
File:The swan attacks man.Hokkaido-toyako,人を襲う洞爺湖の白鳥P6200258モザイク.jpg
The swan attacks...
File:Black Swans mating in Lake Burley Griffin-2 (5549171039).jpg
Black Swans mating in Lake Burley...
File:Trumpeter Swan × Whooper Swan with hybrid cygnets, Kalamazoo, Michigan 31393340.jpg
Trumpeter Swan × Whooper Swan with hybrid...
File:Cisne (Cygnus olor) en el Palacio de Nymphenburg, Múnich, Alemania30.JPG
Cisne (Cygnus olor) en el Palacio de...
File:Black Swan in Australia.JPG
Black Swan in Australia.JPG
File:Black-necked Swans (Cygnus melancoryphus), near Chacao, Chile (25184819835).jpg
Black-necked Swans (Cygnus...
File:Cygnus cygnus EM1B1735 (50023626141).jpg
Cygnus cygnus EM1B1735 (50023626141).jpg

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