The tundra swan (Cygnus columbianus) is a small swan with two taxa found in the northern hemisphere. These taxa are often considered to be the same species, but are sometimes split into two species: Bewick’s swan (Cygnus bewickii) and the whistling swan (C. columbianus). Bewick’s swan is found in the Palearctic, across much of Eurasia and North Africa. The whistling swan is found in the Nearctic, in North America.
The tundra swan is the smallest of the Holarctic swans and most of their body, including their neck, is white. Their diet mainly consists of aquatic vegetation, but they’ll also eat grains and crops. They ahem very few natural predators, although breeding females and young can be at risk of predation from foxes.
Despite their small size, tundra swans are widespread. The whistling swan is most common swan species of North America and tundra swans are listed as Least Concern on the IUCN Red List. Despite this, they are at risk from habitat loss and are affected by water pollution. They are also targeted by hunters, which is the main cause of death in adult swans.
Tundra Swan History and Taxonomy
The two different taxa of these swans are Bewick’s swan (Cygnus bewickii) and the whistling swan (C. columbianus). Swans from eastern Russia are sometimes separated into the subspecies C. c. jankowskii, although many include them in C. c. bewickii. Tundra swans are also sometimes separated in the subgenus Olor with the other Arctic swan species.
The scientific Cygnus columbianus comes from Cygnus, which is the Latin for “swan”, and columbianus comes from the Columbia River.
Bewick’s swan was named in 1830 by William Yarrell after the engraver Thomas Bewick, who specialised in illustrations of birds and animals.
Tundra Swan Characteristics
Tundra swans are the smallest of all Holarctic swans, measuring between 115 and 150 cm (45 and 59 in) in length, with a wingspan between 168 and 211 cm (66 and 83 in). They weigh between 3.4 and 9.6 kg (7.5 and 21.2 lb).
The tundra swan has an entirely white plumage, including their neck. Some tundra swans live in waters that contain large amounts of iron ions, such as bog lakes, and sometimes the head and neck plumage of these swans can acquire a golden or rusty hue.
They have black feet, a dark brown iris and a bill that is mostly black. There is a thin salmon-pink streak running along the mouthline. Among mature tundra swans, their black beak extends up their forehead. In some swans, a yellow spot, resembling a teardrop, can be found below their eye.
Males and females are sexually monomorphic and look very similar. These swans have a long neck, which is held high and stretched out. Their head is round and they have a short tail with short black legs.
Tundra swans are often mistaken for trumpeter swans or whooper swans. However, tundra swans can be distinguished by their straight neck, which is different from the neck kink of trumpeter swans or the “s” shape of whooper swans.
Bewick’s and Whistling Swan Differences
While Bewick’s swans and whistling swans look very similar, there are a few features that can be used to differentiate them from each other.
Bewick’s swans are smaller than whistling swans, measuring between 115 and 140 cm (45 and 55 in) with a wingspan of around 51.9 cm (20.4 in). They weigh 3.4 to 7.8 kg (7.5 to 17.2 lb). Their tarsus measures 9.2 to 11.6 cm (3.6 to 4.6 in) in length, the bill 8.2 to 10.2 cm (3.2 to 4.0 in).
Whistling swans, on the other hand, measure between 120 and 150 cm (47 and 59 in) in length and weigh between 4.3 and 9.5 kg (9.5 and 21 lb). Each wing measures 50 to 57 cm (19.7 to 22.4 in) long. Their tarsus measures 9.4 to 11.4 cm (3.7 to 4.5 in) in length, and the bill is between 9.1 and 10.7 cm (3.6 and 4.2 in) long.
Whistling swans have a blacker bill than Bewick’s swans, with just a small yellow spot at the base. Bewick’s swans also have an individual bill pattern with is unique to each swan, which is often used by scientists to distinguish birds when studying them.
Tundra Swan Lifespan
The lifespan of tundra swans is between 15 and 20 years in the wild. In captivity, however, their lifespan is longer, between 20 and 25 years. They are more likely to die in the first three years of life, with their annual mortality rate is 25 to 50% during this time. During and after their third year, their annual mortality rate is 10 to 15%.
The most common causes of death in the adult tundra swan is lead poisoning, avian cholera, hunting, drowning and starvation.
Tundra Swan Diet
Tundra swans are herbivores. In the summer, they mostly consume aquatic vegetation, such as grasses (mannagrass and seagrass), sieges and smartweed. They will also eat flowers, stems, roots, and tubers. The rest of the year, they eat leftover grains and other crops such as potatoes, which are foraged in open fields after harvest. These swans will occasionally feed on some invertebrates such as shellfish, too.
The tundra swan forages mainly in the day and does so by dipping their heads underwater, and stretching out their long necks to obtain food up to 1 m under the surface. They use their sharp beaks to dig up plants by their roots, or tear plants out of the ground using their webbed feet as paddles.
Tundra Swan Behavior
Tundra swans are mostly active during the day. They are social and interact with other swans within their population, but are closest in family units. A family unit will usually consist of both parents, their 3 to 7 cygnets from that year, and occasionally young from previous years.
Swans are socially dominant. In large flocks made up of multiple swan families, the most dominant family is not necessarily the largest unit, but is determined by each member’s ability to gain resources. Swan units with more dominance have greater access to food and resting areas. Once dominance is established for a family, their social rank is maintained throughout the winter.
Male tundra swans will often fight other males, particularly when it comes to protecting their families. Unmated birds are much lower down the social rank and so are unlikely to engage in aggressive encounters. However, an unmated bird can establish dominance, and their social rank increases with their years in the flock.
Tundra swans use calls to communicate with other flock members. They are particularly vocal when foraging in flocks on their wintering grounds. These calls are a high-pitched honking which sounds like,“woo-oh” or a “kow-hooo”.
Tundra swans are a migratory species. Migrating flocks can be made up of 100 swans or more, and are made up of family groups. They leave the nesting areas in late summer and concentrate in nearby estuaries, before southward migration begins in mid-autumn.
Bewick’s swan start to arrive on the breeding grounds around mid-May, and leave for winter quarters around the end of September. Whistling swans arrive at their breeding grounds in late-May and leave for winter quarters about October.
Tundra Swan Reproduction
Tundra swans breed yearly, in late May through late June. They are a monogamous species and are not known to change mates within their lifetime, with both parents helping to raise their young.
When courting, the swans face each other, then quiver, spread their wings, and call out loudly. While calling, they bow their heads up and down to express interest. The reproductive success of a tundra swan can help establish dominance in the social structure. The greater the number of young from the previous year that are paired with a mate upon their arrival at their wintering site, the greater their dominance within groups of family units.
During the mating season, nests with a diameter of between 122 to 183 cm and a depth of 61 cm are built, made of moss, dead leaves, and grasses. The warmer the temperature at the breeding site, the more eggs that are produced, although the average is between 3 and 7 eggs. Eggs are laid one at a time, every 1.5 to 2 days, and are creamy white, smooth and circular in shape. They usually measure about 107 mm by 66 mm.
The incubation period ranges from 31 to 33 days, with the female doing most of the incubating. When the female is absent, the male sits on the eggs. They have a precise mechanism of changeover. The parent swan that is leaving the eggs stands and pokes downwards at the eggs a few times, and then walks off. Then, the parent that is returning to the nest quickly sits on the eggs. Whichever parent is not sat on the eggs, sits nearby to watch for predators.
When hatched, the hatchlings, called cygnets, are born fully feathered and weigh about 180 g. The downy young are silvery gray above and white below. Their eyes are opened, and they are able to leave their nests immediately. However, they cannot fly until they are between 60 to 75 days old.
Once the eggs have hatched, the parental roles are not distinct and both parents look after the cygnets equally. However, cygnets follow their mother, keep closer to her, and interact with her more than the father. Both parents tend to stay close to each other and their offspring during the pre-fledging period.
Cygnets do not leave their parents until they are at least 2 years of age. They are able to reproduce by the age of 3, but may not begin breeding until the age of 4 or 5. Sometimes siblings rejoin their family, with or without a mate.
Immature tundra swans are grayish but, in their second winter, they moult into the adult plumage. Young swans have pinkish-gray legs, which turn a dull black as they get older. Their beak is also pinkish-gray and turns pure black with age.
Tundra Swan Location and Habitat
Tundra swans are widespread and native to parts of North America, Europe, Asia, Africa, and the Caribbean. Bewick’s swan is found across much of Eurasia and North Africa, while the whistling swan is found across North America. As their name suggests, tundra swans breed in the tundra of the Arctic and subarctic, where they inhabit shallow pools, lakes and rivers.
Tundra swans are a migratory species. The whistling swan consists of two populations: the western population and the eastern population. During the summer breeding season, the western population inhabits the southwestern coast of Alaska, from Point Hope to the Aleutian Islands, and above the Arctic circle of Canada. During the wintering season, they migrate towards the Arctic slope of Alaska to the California Central Valley.
The eastern population inhabits the Pacific Ocean during the summer breeding season and then migrates southward through Canada, and into the Great Lakes region of North America. During the wintering season, they inhabit Maryland, Virginia, North Carolina, South Carolina, Georgia, and Florida.
Bewick’s swans travel from their breeding grounds across the coastal lowlands of Siberia around the end of September, migrating via the White Sea, Baltic Sea and the estuary of the Elbe to winter in Denmark, the Netherlands and the British Isles. Some birds also winter elsewhere on the southern shores of the North Sea. Bewick’s swans that breed in eastern Russia migrate via Mongolia and northern China to winter in the coastal regions of Korea, Japan, and southern China, south to Guangdong and occasionally as far as Taiwan.
Tundra swans are mostly found in freshwater lakes, pools, grasslands, and marshes at an elevation below 60 m. They prefer to reside in aquatic habitats, such as wetlands close to agricultural fields, where there is plenty of food for them. During the migration period, they are found in rivers and lakes along their migratory pathway.
While they fly, tundra swans have been observed as high as 8,229.6 m above ground.
Tundra Swan Conservation Status
Tundra swans are considered to be abundant across their range. The whistling swan is the most common swan species of North America, and, although less is known about Bewick’s swan populations, it is also thought they are fairly common across their range.
Despite this, the tundra swan population is declining. This is due to habitat destruction and water pollution, which affects their food sources both in the summer and winter. The main cause of death in the tundra swan is hunting, with at least 10,000 tundra swans being killed each year. The United States allows hunting of tundra swans in eight states. Despite it being illegal to hunt Bewick’s swan, they are often found with lead shots in their body.
The IUCN lists the tundra swan as Least Concern.
Tundra Swan Predators
Tundra swans have very few natural predators. The main threat is to breeding females and hatchlings, which can be preyed on by Arctic foxes, brown bears, red foxes, golden eagles and parasitic jaegers.
Tundra swans spend their time in flocks to avoid predation. The larger the flock, the more swans there are to look out for predators and the safer the swans are. During the breeding season, the males keep a look out for predators to protect the females and the young.
Tundra swans have a heightened sense of vision and hearing, which are helpful in avoiding predation. This also helps them keep aware of other flock members, and scan for food.
Tundra Swan Importance
Tundra swans are important to their environment as they help to spread plants as they migrate. For example, they use the pondweed as a food source during migration, and then disperse the pondweed, causing its population to expand.
Tundra swan feathers are often used by humans for coats, pillows, blankets, mattresses, and winter clothing. Their excrement can also be used as a fertilizer to help with crop and grass growth.
Tundra Swan FAQs
Where do tundra swans live?
Tundra swans are widespread in the Northern Hemisphere and can be found in North America, Europe, Asia, Africa, and the Caribbean. They are mostly found in freshwater lakes, pools, grasslands, and marshes, where there is plenty of food for them to eat.
Do tundra swans migrate?
Tundra swans do migrate. As a migratory species, they leave the nesting areas in late summer and begin their southward migration in mid-autumn. When migrating, they congregate in large flocks. Tundra swans with breeding grounds in different parts of the world also migrate to different parts of the world.
Is there more than one species of tundra swan?
This is up for debate. Some believe there is only one species of tundra swan, with two taxa, but others believe the two taxa are separate species. These species are known as Bewick’s swan (Cygnus bewickii) and the whistling swan (C. columbianus). They are located in different parts of the world and even look slightly different, but are similar enough to belong to the same genus.
Are tundra swans white?
Tundra swans are almost entirely white. Their whole plumage, including their neck, is white. In fact, the only parts of their body that are not white are their legs and feet, their bills and their eyes!
Young tundra swans are grey, but molt and develop their white plumage as they age.