Tundra Swans
The Tundra Swans (Cygnus columbianus) – also known as the Whistling Swan or American Swan in North America – is a small migratory swan that occurs naturally in the northern continents of the world, including Europe, Asia, and North America. The Eurasian race is commonly referred to as the Bewick’s Swan.
In North America, the Tundra Swan is the most widespread of the swans that occur in this region.
The slightly smaller females are commonly referred to as “pens” (females) and the males are known as ” cobs.” Swan chicks are called “cygnets”
Alternate (Global) Names
Albanian: Mjelma e vogël … Armenian: ???? ????? … Czech: labu malá, Labut malá, Labu? malá … Chinese: ???, ??? … Danish: Pibesvane, Tundrasvane … Dutch: Fluitzwaan, Kleine Zwaan … German: Pfeifschwan, Zwergschwan … Greek: ?????????? … Finnish: Pikkujoutsen … French: Cygne américain, Cygne de Bewick, Cygne siffleur, Cygne siffleur ou Cygne de Bewick … Irish: Eala Bewick … Hungarian: Kis hattyú … Icelandic: Dvergsvanur … Italian: Cigno minore … Japanese: amerikakohakuchou, kohakuchou, Ko-hakuchou … Korean: ?? … Norwegian: Dvergsvane … Polish: labedz czarnodzioby, ?ab?d? czarnodzioby, ?ab?d? czarnodzioby (?ab?d? ma?y) … Portuguese: cisne pequeno, Cisne-pequeno … Romansh: cign pitschen … Russian: ???????????? ??????, ?????? ????????????, ????? ?????? … Slovenian: mali labod … Spanish: Cisne Chico, Cisne de Tundra, Cisne Silbador, Cisne silbón, Cisne Silvador … Serbian: ???? ????? … Swedish: Mindre sångsvan, Tundrasvan … Turkish: Küçük Ku?u, Küçük Ku?u, Tundra Ku?usu … Ukrainian: ????????????? ??????
Subspecies and Distribution:
The Bewick’s Swan and Whistling / Tundra Swan are usually regarded as conspecific (of, or belonging to, the same species), but some consider the Bewick’s Swan a separate and full species.
- Whistling or Tundra Swan (Cygnus columbianus columbianus – Ord, 1815) – Nominate Race
- Range: Tundra of Arctic North America; winters in western and coastal eastern USA.
- Bewick’s Swan (Cygnus columbianus bewickii or Cygnus bewickii – Yarrell, 1830)
- Range: Kola Peninsula east throughout arctic northern Siberia; winters in Western Europe, south of Caspian Sea and east China, Korea and Japan.
- [Cygnus columbianus jankowskii] – Proposed subspecies previously placed on CITES Appendix II; however, eventually removed as it is not officially recognized. Most authorities include it in Cygnus columbianus bewickii .
- Range: Eastern Russia – roughly east of the Taimyr Peninsula
Description
The Tundra Swans is the smallest of the swans that occur in the northern continents of the world. They weigh between 7.5 – 21 lbs (3.4 – 9.6 kg), with an average weight of 16 lbs (7.3 kg) for males and 14 lbs (6.4 kg) for females.
They measure 45–59 in (115–150 cm) in length; have a wingspan of 67–77 in (170–195 cm); and a tarsus measuring about 3.7–4.5 in (9.4–11 cm) in length. The bill is about 3.6–4.2 in (9.1–11 cm) long.
The Tundra Swan has a relatively short neck, which give it the appearance of a large white goose.
The adult plumage is entirely white; however, those swans that inhabit waters rich in iron ions (such as bog lakes), the head and neck plumage may show a golden or rusty hue. The feet are generally black – although in the Bewick’s race specifically rarely yellowish feet have been observed. The bill is mostly black, with a thin orangey streak running along the mouthline and – depending on the subspecies – more or less yellow on the upper half of the upper beak. The eyes are dark brown.
Gender ID: Females are slightly smaller than the males, but are otherwise identical in appearance.
Juveniles: The down of chicks is silvery grey above and white below. Immatures have a white plumage mixed with some dull grey mostly on the head and upper neck, which often are entirely light grey. The first summer plumage is mostly white and during the second winter, they attain the adult plumage. Their bills are black with a large flesh-colored patch on the upper half of the upper bill below the usually black nostrils. The feet are dark grey with a flesh-colored hue.
Subspecies ID:
The Tundra Swan is larger than the Bewick’s Swan and has a mostly black bill with a small a yellow spot of variable size at the base. However, there are color variations with more or less yellow, or pink instead of yellow or black – especially in Bewick’s Swans.
The North American Trumpeter Swan (C. buccinator) is much larger than the Tundra Swan and has a longer bill which is all black, except for the flesh-colored mouthline, which is stronger than that of the Tundra Swan.
The Tundra Swan is also similar in appearance to the Mute Swan
In flight, the Tundra Swans may be differentiated from their relatives by their shorter necks; quicker wingbeats; and different calls.
Distribution
Summer / Breeding Range:
The Tundra Swan, as suggested by its name, spends the summer on tundra lands in or near the arctic and subarctic tundra.
Those occurring in North America breed in coastal Alaska and islands eastwards over northern Canada to Baffin Island. In fact, about 60% of the global population of Tundra Swans breed in Alaska, with the greatest density occurring around coastal western areas.
The Eurasian Race (Bewick’s Swan) breeds in Western Siberia.
Breeding Habitat: Tundra Swans breed on near lakes, ponds, shallow pools along coast, and wide slow-flowing rivers with emergent vegetation and pondweeds; as well as in open, moist, low-lying sedge-grass or moss-lichen Arctic tundra. They rarely nest in shrub tundra and avoid forested areas.
Wintering Range:
In North America, Tundra Swans winter along the Pacific coast – from southern Alaska to California, and may move inland – such as the Californian Central Valley and even as far east as Utah and south to Texas and northern Mexico. Populations along the Atlantic coast winter mainly from Maryland to South Carolina, but may move as far south as Florida.
Eurasian populations mostly winter in Western Europe.
Winter Habitat: Often winter near the coast and in the vicinity of agricultural fields, which represent a major source of food during the winter months. Usually found in shallow tidal estuarine areas, grassland, brackish and freshwater marshes, shallow lakes, ponds, rivers and flooded pastures.
Worldwide Distribution
Tundra Swans are native to the following countries:
Austria; Azerbaijan; Belgium; Bulgaria; Canada; China; Croatia; Cuba; Czech Republic; Denmark; Estonia; Finland; France; Germany; Greece; Greenland; Hungary; Iceland; India; Iran, Islamic Republic of; Iraq; Northern Ireland; Israel; Italy; Japan; Kazakhstan; Korea, Democratic People’s Republic of; Korea, Republic of; Latvia; Libyan Arab Jamahiriya; Lithuania; Luxembourg; Macedonia, the former Yugoslav Republic of; Mexico; Mongolia; Nepal; Netherlands; Norway; Oman; Pakistan; Poland; Puerto Rico; Romania; Russian Federation; Slovakia; Slovenia; Sweden; Switzerland; Taiwan, Province of China; Turkey; Turkmenistan; Ukraine; United Kingdom (Wales, England and Northern Ireland); United States
They are vagrants (non-breeding) to:
Algeria; Antigua and Barbuda; Belarus; Bermuda; Cuba; Gibraltar; Guam; Hawaii; Jordan; Kyrgyzstan; Northern Mariana Islands; Portugal; Saint Pierre and Miquelon; northeastern Siberia; Spain; United Arab Emirates; Virgin Islands, U.S.
They may also occur in:
Montenegro; Serbia
Migration:
The Tundra Swans travel on specific routes with specific stop-over sites from their Arctic breeding ranges to the temperate wintering grounds. They usually fly in V formation at altitudes of about 8 km (nearly 27,000 ft) (Ref. National Geographic).
Small groups of them arrive on their breeding grounds (usually between early March to late June); where breeding pairs will separate from the flock and disperse to their favored nesting sites. Some may nest in small groups in optimum habitats.
After breeding, between late June and September, Tundra Swans will undergo a molt which will leave them flightless for about a month. During this time, they will usually father in flocks on open waters as they would be vulnerable to predation on land.
In mid-October, family groups will usually start their migration to their wintering grounds. They may remain at their usual stop-over sites (such as shallow ponds, lowland and mountain lakes [i.e., Great Lakes region], reservoirs, riverine marshes, shallow saline lagoons and sheltered coastal bays and estuaries) for as long as the weather conditions are favorable. Most arrive in their wintering range by November / December.
Behavior
During the breeding season, these swans sleep on land; but in the winter, they typically sleep on water.
Outside the breeding season, Tundra Swans are generally quite sociable and gather in large flocks of hundreds or even thousands. When breeding, however, they tend to be aggressive and territorial; and usually spread out to nest. Although some flocks may still occur consisting of non-breeding adults and birds that are too young to breed.
They usually forage by day and roost at night on open water.
The Diet of Swans and Feeding Swans
Calls / Vocalizations
Tundra Swans make high-pitched honking calls that sound similar to those of the black goose (Branta). They are particularly noisy when foraging in flocks. They make loud excited calls when other swans arrive or leave. While in flight, the Bewick’s Swan makes low and soft ringing bark bow-wow calls; while the Tundra Swan makes high-pitched bark-like sounds: wow-wow-wow.
The Whooper and Trumpeter Swans make deep hooting and a higher-pitched French horn-like honk vocalizations, which serves as one method of identification
Breeding
Tundra Swans typically breed in freshwater marshes, ponds, lakes and along slow-flowing rivers with ample food supplies and few disturbances.
They form monogamous pair bounds and remain with their mate until one of them dies; and even then the surviving mate may not mate again for years or may indeed never pair up again.
The breeding season usually starts in the late spring upon their arrival at the nesting grounds. Upon arrival in the breeding territory, the pair will engage in courtship behavior, which includes bobbing their heads and facing each other with quivering wings.
The nesting season is timed to take advantage of readily available food supplies. Tundra Swans usually start nesting at the end of May. The female chooses the nesting area, while the male defends it. Swan pairs are most likely to return to the same nesting site if they were able to raise young successfully there in the past.
Even they are not colonial breeders, Tundra Swans may nest close together in optimum breeding habitats.
Pairs will either build a new nest or repair the nest that they have used in previous years. The nest construction or restoration of an existing nest may take up to two weeks. The male uproots aquatic vegetation, grasses and sedges, and transfers it to the female, who will first pile it up high and then uses her body to form a depression to place her eggs in. The interior is lined with down and feathers. It is usually situatedon elevated ground to reduce to the risk of flooding, . They defend a large territory around their nest.
The female lays 2 – 7 creamy white eggs (usually 3-5), which are incubated for 29 – 30 days for the Bewick’s Swan and 30 – 32 days for the Tundra / Whistling Swans. Very rarely, the male may help brooding the eggs. In most cases, it is the female who broods the eggs, while the male remains nearby to defend the nest against intruders and predators. During the incubation period, the female leaves the nest only for short periods to feed on nearby vegetation, bathe and preen her feathers – however, before doing so, she usually covers the eggs with nesting material to conceal them. The male will also remain nearby to deter predators. If a perceived predator approaches the nest, either one of the parents will give a warning call to alert the other of the danger. They may lay a second clutch if the first eggs or cygnets are lost.
The young hatch about 29 – 32 days later. The hatchlings’ eyes are open and they are covered with down. They are able to leave the nest within 24 hours of hatching and have the ability to swim and feed.
The juvenile Tundra Swan learn to fly about 60 – 75 days after hatching and the young of theBewick’s Swan fledge as early as 40–45 days after hatching. The young remain with their parents for the first winter migration. The offspring of previous years may join them on the wintering grounds.
Tundra Swans reach reproductive maturity when they are about 3 – 4 years old; however, they will usually find their mates before the age of 2, mostly during the winter season. They start breeding when they are 3 – 7 years old.
Post-Nesting
In late September, the young swans take daily practice flights in preparation for the winter migration. These flights are initially short, but get longer as the young grow stronger.
Swans commence their journey south to their wintering areas just before the water begins to freeze. They often remain in pairs or small family groups. Juveniles stay with their parents throughout the winter and migrate back with them to their breeding territory in spring. When the offspring is about one year old then, the parents will get started on their next brood and at this point, they will drive their offspring away.
The young swans remain together in sibling groups until they are about two years old, at which time, they themselves commence their search for mates. Some may return to their parents after the breeding season. Their family bonds are generally strong.
Diet / Feeding
What they eat …
Tundra Swans primarily feed on the seeds, roots, and stems of aquatic plants, such as mannagrass (Glyceria), pondweeds (Potamogeton), marine eelgrass (Zostera) and Glyceria. sedges, reeds (Phragmites and Typha) as well as herbaceous tundra vegetation.
They will also feed on the occasional small invertebrate, including mollusks and arthropods, and polycheate worms.
They also eat some grass growing on dry land.
Swans feed primarily on aquatic plants; but they also eat grain, grasses and crop foods, such as wheat, potatoes, sugar beets and carrots – especially in the winter when other food sources aren’t readily available.
Only young cygnets (immature swans) eat aquatic insects and crustaceans, as they have a higher requirement for protein than the adults. As they get older, their diet changes over to a plant diet, which includes aquatic vegetation and roots.
How they eat …
They forage mainly by day both on land and in water. They are usually observed feeding in flocks.
In shallow water, Swans may use their strong webbed feet to dig into submerged mud and, like mallards, they tip up – plunging the head and neck underwater – to expose and feed on roots, shoots and tubers.
They feed in waters by uprooting plants and snapping off the leaves and stems of plants growing underwater.
Swans also forage by swimming picking up plant material from the water’s surface or water’s edge. On land, they feed on grains and grasses.
Cygnets feed on invertebrates and aquatic vegetation stirred up by their foraging parents. Ducks and other water birds also often follow swans to forage on exposed plant matter and aquatic insects.
- The Diet of Swans and Feeding Swans
Lifespan
The oldest recorded Tundra Swan was over 24 years old. However, average life expectancy of the Tundra Swan living in the wild is about 10 years, as about 15% of adults die each year from various causes, such as hunting, lead poisoning and predation.
Status / Threats and Conservation
Status / Conservation
Tundra Swans are common within most of their range. In North America, it is the most common swan species. In the late 19th century, its numbers were estimated to be almost 170,000.
The western populations appear to be undergoing a slow decline, probably caused by habitat conversion in their wintering areas. However, the eastern population appears to have increased somewhat in the late 20th century. Globally, their numbers seem to have risen slightly and their numbers appear to be stable over most of its range. This species is not considered threatened by the International Union for Conservation of Nature (IUCN) due to its large range and population.
In 1972, the Tundra Swan population was estimated to be about 146,000. The Eurasian Bewick’s Swan was estimated at 16,000-17,000 about 1990, with about 20,000 birds wintering in East Asia. The Iranian population consists of no more than 1,000 individuals dispersed to several sites.
The Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies to the Tundra Swan.
Threats
- Hunting: It is generally protected, except for limited hunting seasons in certain areas. The main cause of adult mortality is hunting. About 4,000 Tundra swans are legally shot each year, and it is estimated that another 6,000 – 10,000 are killed by poachers. During the post-breeding season, Tundra Swan undergoes a molt that renders them flightless for about a month. During this time, many of them are killed for food or their own.
- Lead poisoning caused by the ingestion of lead shots also results in significant mortality.
- Habitat destruction and pollution lead to a reduction of aquatic vegetation in their winter habitats. Toxic mining wastes in the Silver Valley, Idaho in the United States also resulted in the death of migrating tundra swan.
- Predation: Nesting females, their young, and eggs are preyed upon by foxes, weasels, wolves, raccoons, bears, people, and seabirds, such as jaegers and gulls. Nesting parents will usually leave their nest when large predators are in sight to not draw attention to their nest.
Species Research by Sibylle Johnson
Swan Information and Photos … Listing of Swan Species … Photos of the Various Swan Species for Identification
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