Swan (Cygnus atratus)

Swan (Cygnus atratus)

The Swan is known around the world for its beauty, elegance, and grace.

The swan is a genus of waterfowl that has the ability to swim and fly with incredible speed and agility. This bird is also very intelligent, devoted to its mate, and highly aggressive about defending its young. They are a common sight in temperate and colder climates around the globe.

Swan (Cygnus atratus)

Swans love to live together as a family unit and mate for life ( ©john hambleton/Shutterstock.com)

An Incredible Bird: 4 Swan Facts!

  • The English word swan is also shared with the German and Dutch. It likely has its roots in the older Indo-European word swen, which means to sound or to sing.
  • The black swan is often cited as a symbol of rare and unexpected events due to the fact that ancient writers theorized it did not exist. This was assumed to be true until after the discovery of black swans in Australia, which are actually quite common in the region.
  • This bird is much faster on land than you might suspect with speeds of 22 miles an hour. In the water, it can also achieve speeds of around 1.6 miles per hour by paddling its webbed feet. But if they stretch out their wings, then swans can let the wind carry them at much higher speeds while also saving energy.
  • These birds feature prominently in human mythologies and arts around the world. Some of the most famous stories involve metamorphosis and transformation. A Greek legend claims that the god Zeus once disguised himself as a swan. The famous 19th century Tchaikovsky ballet Swan Lake, which derived from Russian and German folk tales, is the story of a princess transformed into a swan by a curse. And of course, the Hans Christian Andersen fairy tale The Ugly Duckling is about a duck that transforms into a swan.

The scientific name for the genus of swans is Cygnus (the word derives from the Greek and Latin words for swan). There are six living species of swans and many other known from the fossil record. These include:

  • Black Swan (Cygnus atratus): Found in the southwestern and eastern Australian wetlands, this large swan is capable of growing to 56 inches in length and having a wingspan of 6.6 feet. It is known for its dark plumage, white flight feathers, and red bills.
  • Black-Necked Swan (Cygnus melancoryphus): Members of this species have dark head and neck feathers, a dash of white behind their eyes, and a bump at the base of their beaks which appears by their third or fourth year. They live in South America and can be found in Argentina, Brazil, Chile, and Uruguay.
  • Coscoroba Swan (​Coscoroba coscoroba): A relatively small-sized swan, this avian is capable of growing to 61 inches with a wing span of 155 cm. It can be found in Argentina, Bolivia, Brazil, Chile, Paraguay, and Uruguay.
  • Mute Swan (Cygnus olor): Members of this subspecies have a pristine white plumage and an orange bill with a black base. They are monogamous and build nests at the edge of bodies of water or at their center which they repair as needed. They are capable of reaching 32 lbs in weight.
  • Trumpeter Swan (Cygnus buccinator): Recognizable by its pristine white plumage and black bill, this avian is capable of reaching 28 lbs in weight. Considered North America’s largest waterfowl, it is also capable of growing to 5 ft 11 inches with a maximum wingspan of 8 ft 2 inches.

Additional species include the Tundra Swan (Cygnus columbianus) and the Whooper Swan (Cygnus cygnus). These birds belong to the waterfowl family (scientific name Anatidae) along with ducks and geese.

Evolution

According to experts swans spread north of the equator between the Miocene (23 – 5.3 million years ago) and the slightly warmer Pleistocene ( 5.3 – 2.58 million years ago) period.

During this period, the earth progressively cooled. Cockatoos, crows, dabbling ducks, plovers, ostriches and owls also made an appearance during this period.

The Bird’s Appearance

Swimming gracefully through the water, these birds are an impressive spectacle whose characteristics include a large body, a long and curved neck, and big feet. Each species has different colored plumage. The common mute swan is almost completely covered in white feathers except for an orange bill and some black markings on the face. The trumpeter swan has white feathers and a black bill, whereas the tundra and whooper swan both have a mixture of black and yellow on the bill. The black-necked swan, as the name implies, has black feathers all along the neck, plus a black bill, a red knob around the bill, and white markings around the eyes. The black swan is entirely covered in black feathers with a bright red bill and pale tip.

These birds rank as the largest waterfowl and among the largest birds in the world. The longest species is the trumpeter swan, which measures nearly 5.5 feet with a wingspan of some 10 feet. The heaviest species is the 30-pound mute swan (which sometimes weighs as much as 50 pounds), but even though it’s formidable, this extra weight is a problematic characteristic that makes it more difficult to fly. They compensate for it with weaker honeycomb-like bones. Males (called cobs) are generally larger than females (called pens), but the characteristics of their plumage are remarkably similar.

Swan (Cygnus atratus)

Two white swans. (©Ira Kalinicheva/Shutterstock.com)

The Bird’s Behavior

Swan (Cygnus atratus)

Swans form close lifelong bonds (©Teemu Tretjakov/Shutterstock.com)

Among these birds’ most remarkable social characteristics are the intense bonds they form with one mate for life. Unlike many other species of birds (even the closely related geese and duck), this has a few distinct advantages. First, it allows the pair to learn from their reproductive failures and develop better strategies. Second, the couple will share several duties, including the construction of nests, which they build out of grasses, branches, reeds, and other vegetation. This makes them far more effective than they would be on their own. Third, because of their long migratory routes, they have less time to acquire a mate, so the lifelong bond actually saves them time.

Even though it makes logical sense for the couples to remain faithful to each other for their entire lives, even swan fidelity has its limits. Cheating seems to occur with some regularity among female black swans, perhaps as a backup reproductive strategy. It is estimated that one of every seven eggs from this species is the result of adultery. If the couple fails to produce any young at all, then it is possible for swans of any species to break up with each other and find a new mate.

These birds are quite defensive animals that will do anything to protect their young. To drive off threats, they will engage in a display called busking, which involves hissing, snorting, and flapping with their outstretched wings. Due to their relatively weak bones, this display is largely a bluff that has little force behind it, but it doesn’t stop them from gloating. After driving off a predator, they make a triumphant sound. They also communicate through a variety of other vocalizations that emanate from the windpipe or the breastbone, including in some species a geese-like honk. Even the so-called mute swan can make hissing, snoring, or grunting sounds.

After the breeding season, the bird migrates to warmer climates in the winter by flying in diagonal V formations with around 100 individuals. When the lead bird tires, another one takes its place at the front. These birds can be either partially migratory or wholly migratory depending on where they nest. The fully migratory species typically live in colder climates and may travel the same route thousands of miles every year toward warmer climates.

The Bird’s Habitat

These birds are endemic to ponds, lakes, rivers, estuaries, and wetlands all over the world. Most species prefer temperate or Arctic climates and migrate during the colder seasons. The common mute swan is native to Europe. It was later introduced into North America (where it flourished), New Zealand, Japan, and South Africa. The tundra swan, as the name implies, inhabits the Arctic regions of North America and Asia but migrates as far south as Texas and northern Mexico in the winter. Other species include the whooper swan of Eurasia, the trumpeter swan of North America, the black-necked swan of South America, and the black swan of Australia.

Diet

This bird is an herbivorous animal that feeds exclusively on roots, leaves, stems, shoots, and other plant matter. When swimming in the water, it feeds via a method called dabbling in which it flips upside down and reaches down with its long neck to the vegetation at the bottom of the floor. The bird can also come up onto land in search of food.

Predators and Threats

Swan (Cygnus atratus)

oxes are rather fond of swan eggs and may even attempt to take a mouthful or more out of an adult, too (©RT Images/Shutterstock.com)

These birds large sizes, fast speeds, flying ability, and rather aggressive behavior (at least when threatened) are a deterrent for most predators, but the old, ill, and young (especially the eggs) are sometimes preyed upon by foxes, raccoons, wolves, and other carnivorous mammals. Habitat loss, pollution, and overhunting have all posed a persistent threat, but they can adapt quite well to human habitations, and the cultivation of ponds and lakes for local wildlife has kept population numbers high. In the future, swan habitat and migratory patterns will be affected by climate change.

The Bird’s Reproduction, Babies, and Life span

Swan (Cygnus atratus)

Baby cygnets are quite capable of swimming once they’ve hatched, however, nothing beats a ride on a doting parent’s back (©iStock.com/Lemanieh)

Swan courtship involves a series of elaborate bonding rituals such as bill dipping, synchronized swimming, and head contact (when their curved necks form a heart shape). Swans also dance, make noises, and spend time with each other. The black swan of Australia even has special feathers to help them attract a mate. Some swan species mate for life.

Once the pair copulates, the female pen lays a clutch of about three to eight unmarked eggs in the nest (the black swan is the only species that lays multiple clutches per year). She spends most of the time incubating the eggs while the male stands guard nearby, but the male will sometimes join in on incubation duties as well. This allows the female time to feed on extra food and rebuild her fat stores.

The incubation period typically lasts a month. Once they hatch, the young baby cygnets have short necks and a thick down of feathers. They are capable of running and swimming almost immediately, but the parents still keep careful watch over the brood and sometimes give the young baby cygnets a ride on their back. The birds sport a mottled gray or brown appearance for at least the first two years of life. They reach full sexual maturity after three or four years and have a full life expectancy of some 20 years in the wild and up to 50 years in captivity.

Population

Thanks to years of protection, the swan genus as a whole is in excellent health. According to the IUCN Red List, which tracks the population status of many animals around the world, every single species of the swan is listed as least concern, which is the best possible conservation prognosis. Population numbers, though not known with precise accuracy, appear to be stable or increasing around the world. The trumpeter swan endemic to North America once fell to as little as 100 birds in 1935, but it has since been rehabilitated.

Birds in the Zoo: Where to find Swans

Even though it’s a common sight around the world, the swan is a very popular feature at many American zoos, usually floating around the ponds. The trumpeter swan is kept at the Minnesota Zoo, Maryland Zoo, and the Lincoln Park Zoo in Chicago. The tundra swan can be found at Zoo New England. A black-necked swan known as Swanton is also an exhibit at the Denver Zoo.