Swans

 

 

 

 

 

 

 

 

 

When Swedish naturalist Carl Linnaeus (1707-1778) in 1758 published the 10th edition of Systema Naturae, he named the whooper swan Anas cygnus, the specific name being a Latinized form of the classical Greek word for swans, kyknos. In 1764, swans were moved to the genus Cygnus, instigated by French naturalist François Alexandre Pierre de Garsault (1693-1778).

Swans are the largest members of the family Anatidae (ducks, geese, and swans), and they are among the largest flying birds, reaching a length of over 1.5 m and weighing up to 15 kg, with a wingspan of more than 3 m. The largest species was the extinct Cygnus falconeri, a flightless giant that once lived on islands in the Mediterranean.

Adult male swans are called cobs, females pens, and young swans cygnets. A flock of swans is called a bevy or a wedge.

The name swan is derived from Indo-European swen (‘to sound’ or ‘to sing’), referring to the whooper swan (below).

 

 

In 1984, the mute swan was elected the national bird of Denmark – an appropriate choice, as it is very common. This was not always the case. In the 1800s, swans were hunted in Denmark, and by 1920, only three or four pairs were breeding in the vicinity of Copenhagen. Swans were protected in 1926, and the mute swan soon began spreading across the country.

In the breeding season, swans are usually strongly territorial, but in areas, where the living conditions are especially favourable, it may change behaviour and in some cases start breeding colony-like. One such case took place in Ringkøbing Fjord, western Jutland, Denmark, in the 1970s. A huge amount of nutrients from the surrounding rivers, especially Skjern Å, was led into the fjord, causing a strong increase in the growth of water plants, which constitute the preferred food of swans.

On three islets in the fjord, together called Klægbanken, the first breeding of mute swans took place in 1953, and in 1958 the number had risen to 10 pairs. In the following years, the number increased dramatically. In 1960, 74 nests were counted on the islets, and in 1969 181 nests, but only two years later, this number had more than doubled, and a maximum of 725 nests were counted in 1978. This development was surveyed in detail by a friend of mine, biology student Jörn Eskildsen. (Source: J. Eskildsen 1979. Kolonidannelse hos Knopsvane 1 & 2 (‘The forming of a colony of mute swans, 1 & 2’). – Master thesis, Copenhagen University)

When the forming of the colony took place, the swans in the fjord changed behaviour from being strongly territorial to breeding in colonies. In some cases, the nests were situated only a few metres from each other.

During a number of years, the breeding swans on Klægbanken constituted the largest ‘swan colony’ in the world, and 585 nests were still present in 1980. However, already the following year, the number had fallen to only 45 nests. This dramatic decrease was caused by a total collapse of the underwater vegetation in Ringkøbing Fjord in 1979 and the following years. The result of leading large amounts of nutrients into the fjord for several years was that water plants like widgeon grass (Ruppia) was overgrown by epiphytes, especially algae. This meant that in only a couple of years the fjord, as a feeding area for plant-eating birds, changed from being of enormous importance to being of minor importance.

Following an improved sewage treatment in the surrounding towns, the underwater vegetation in the fjord has become stabilized, causing the number of breeding mute swans on Klægbanken to increase again, and in 2024 the number was 229 pairs.

As opposed to the whooper swan (below), the mute swan is not very vocal, hence the appellation mute. Occasionally, it emits a spinning krrrrr, and in flight its wings produce a singing sound.

The specific name is the classical Latin term for swan.

In his fairy tale The Ugly Duckling, Danish poet Hans Christian Andersen (1805-1875) relates the fate of a cygnet, which is ostracized by its fellow fowl in a farmyard, where it has been hatched together with ducklings. It has to undergo much suffering, before it realizes that it has matured into a beautiful swan. In reality, this story is about the fate of Andersen himself.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

It was named due to its very powerful, sonorous call, and often several birds call in unison. Incidentally, its name is pronounced ‘hooper swan’, although the word whooper alone is pronounced ‘wooper’. In his book Ornithologiae libri tres (‘Ornithology, Book Three’), from 1676, English naturalist Francis Willughby (1635-1672) refers to the whooper swan as “the Elk, Hooper, or wild Swan”.

It is a widespread and common bird, breeding in shallow lakes and forest bogs, from Iceland eastwards across Scandinavia, Finland, and northern Asia to Kamchatka, southwards to Kazakhstan, Mongolia, and extreme northern China.

During the last 50 years, it has been expanding southwards. Today, it is a common breeding bird in southern Sweden, and breeds regularly in Ireland, Scotland, Germany, Denmark, Poland, Latvia, and Estonia.

It is partly resident in Iceland, Norway, and Sweden, but the vast majority of the population is migratory, spending the winter in western and southern Europe, around the Black, Caspian, and Aral Seas, in eastern China, and in Korea and Japan. In Denmark, up to 60,000 birds spend the winter, and the country constitutes one of the most important wintering areas for the species in the world.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bewick’s swan resembles the whooper swan (above), but is notably smaller, and the yellow patch at the base of the bill is smaller.

If you regard these birds as a single species, it breeds in Arctic areas of Alaska and Canada, and in the northernmost parts of Siberia. The wintering areas of the whistling swan include several separate areas in western Canada, United States, and Mexico, and the central part of the Atlantic coast. Eastern populations of Bewick’s swan spend the winter in eastern China, Korea, and Japan, whereas western populations migrate to western Europe.

The total population of the whistling swan is around 200,000, and is slightly increasing. The population of Bewick’s swan is much smaller, less than 50,000, but is probably stable.

In 1803, American President Thomas Jefferson (1743-1826) ordered two army captains, Meriwether Lewis (1774-1809) and William Clark (1770-1838), to undertake an expedition across the western part of the North American continent, from the Mississippi River to the Pacific Ocean. During their 3-year long expedition, Lewis described countless plants and animals, many of which were new to science, including the tundra swan. The whistle-like call of the bird prompted Lewis to name it whistling swan.

The specific name refers to the Columbia River, the type locality of the whistling swan.

Bewick’s swan was named in 1830 by English naturalist William Yarrell (1784-1856) in honour of English engraver Thomas Bewick (1753-1828), who specialized in illustrations of birds and other animals. He is best known for the work A History of British Birds, which contains many fine wood engravings. He also illustrated several editions of Aesop’s Fables.

 

 

 

 

 

The global population is estimated at over 500,000 individuals.

The black swan is depicted on the state flag and the coat of arms of Western Australia.

The bird plays a significant role in the mythology of the Nyungar people of south-western Australia. It is said that the ancestors of the Nyungar were once black swans which were transformed to people.

The specific name is Latin, meaning ‘clothed in mourning’, derived from ater (‘black’).

 

 

 

 

 

The total number is unknown, but the population in Argentina is estimated at over 50,000 individuals.

It is a bit larger than the tundra swan, with a length of up to 1.2 m, a wingspan of up to 1.7 m, and a weight of up to 8.7 kg.

The specific name is derived from Ancient Greek melas (‘black’) and koryphe (‘head’).