Tundra Swan

Informazioni

The Tundra Swan, also known as the Whistling Swan (North America) or Bewick's Swan (Eurasia), is a medium-sized swan species. It is characterized by its pure white plumage, long neck, and a black bill with a variable yellow patch at the base. It is a migratory species, breeding in the Arctic tundra and wintering in more temperate regions.

Dimensioni e longevità

Lunghezza

115-150 cm

Apertura alare

170-195 cm

Peso

3.4-9.6 kg

Longevità

Up to 20 years in the wild

Dieta

Herbivore

Caratteristiche fisiche

Piumaggio

Adults are entirely pure white. Juveniles have a greyish wash, particularly on the head and neck, which fades to white by their first winter.

Forma del becco

Relatively short and stout compared to other swans, entirely black with a prominent yellow patch at the base of the upper mandible. The size and shape of the yellow patch are highly variable and can be used for individual identification, especially in the Bewick's Swan subspecies.

Colore degli occhi

Dark brown

Colore delle zampe

Black

Caratteristiche distintive

The most distinctive feature is the black bill with a yellow patch at the base. The extent of the yellow varies geographically and individually. It has a relatively short neck compared to the Mute Swan, and typically holds its neck straight. The call is a distinctive 'whooping' or 'barking' sound.

Aspetto giovanile

Juveniles have a greyish-brown wash over their white plumage, particularly on the head and neck, and their bill is pinkish-grey with a black tip, gradually acquiring the adult black and yellow pattern over their first year.

Cambiamenti stagionali

No significant seasonal plumage changes, as they maintain their white plumage year-round. However, plumage can become stained with iron-rich water, appearing rusty on the head and neck.

Dimorfismo sessuale

Males (cobs) are generally slightly larger than females (pens), but plumage is identical.

Come identificare

1. 1

   Bill coloration

   Look for a black bill with a distinct yellow patch at the base. The size and shape of this yellow patch are key. In North America, the yellow is often a small spot (Whistling Swan). In Eurasia (Bewick's Swan), the yellow patch is typically larger and more variable, often extending further along the culmen.

2. 2

   Neck posture

   Tundra Swans typically hold their long neck straight and erect, unlike the S-curve of the Mute Swan.

3. 3

   Size

   They are smaller than Mute and Trumpeter Swans, but larger than geese. This can be difficult to judge without a direct comparison.

4. 4

   Vocalizations

   Listen for their characteristic 'whooping' or 'barking' calls, especially in flight. This is a reliable identifier, distinguishing them from the silent Mute Swan and the bugling Trumpeter/Whooper Swans.

5. 5

   Juvenile plumage

   Young birds have a greyish wash and a pinkish-grey bill with a black tip, which helps distinguish them from adult swans.

Habitat e areale

Biomi

Tundra, wetlands, marshes, shallow lakes, estuaries, coastal lagoons, agricultural fields (during migration and winter).

Areale geografico

Holarctic. Breeds in the Arctic tundra of North America (Alaska, Canada) and Eurasia (Siberia). Winters in temperate regions of North America (Pacific and Atlantic coasts, Great Lakes) and Eurasia (Western Europe, Caspian Sea, East Asia).

Fascia altitudinale

Primarily lowlands, from sea level up to a few hundred meters.

Ambienti preferiti

Shallow freshwater and brackish wetlands, including tundra ponds, lakes, rivers, and coastal marshes for breeding. During migration and winter, they utilize larger lakes, estuaries, flooded fields, and coastal bays.

Comportamento

Periodo di attività

Diurnal, primarily active during daylight hours for feeding and other activities.

Abitudini alimentari

Primarily herbivorous, feeding on aquatic vegetation such as submerged leaves, stems, tubers, and roots, which they obtain by dabbling or up-ending in shallow water. They also graze on grasses and agricultural crops (e.g., waste grain, potatoes) in wintering areas.

Comportamento sociale

Highly social, especially outside the breeding season. They form large flocks during migration and in wintering grounds. Breeding pairs are territorial.

Tipo di volo

Strong, direct flight with powerful, slow wingbeats. Flies in V-formations or in long, undulating lines during migration. Can be quite vocal in flight.

Migrazione

Long-distance migratory. Breeds in the Arctic and migrates south to temperate wintering grounds. North American populations (Whistling Swan) migrate to the Atlantic and Pacific coasts and the Great Lakes region. Eurasian populations (Bewick's Swan) migrate to Western Europe, the Caspian Sea, and East Asia. Migration occurs in large flocks, often at high altitudes.

Territorialità

Breeding pairs are territorial, defending their nesting sites and immediate foraging areas. In winter, they are gregarious and less territorial, though disputes over prime feeding spots can occur.

Riproduzione

Stagione riproduttiva

Late May to early June in the Arctic, after the snowmelt.

Abitudini di nidificazione

Nests are large mounds of vegetation (moss, sedges, grasses) lined with down, typically built on elevated ground near water, such as small islands, hummocks, or shorelines of tundra ponds and lakes. Both parents participate in nest building.

Dimensione della covata

3-5 eggs (range 2-7)

Descrizione dell'uovo

Typically 3-5 eggs, dull white or creamy, sometimes stained. Oval to sub-elliptical in shape.

Periodo di incubazione

31-32 days, primarily by the female.

Periodo di involo

60-75 days. Cygnets are precocial and can swim and feed shortly after hatching, but remain with parents for protection and guidance.

Cure parentali

Both parents care for the young (cygnets). The male guards the nest and territory, while the female incubates. After hatching, both parents lead the cygnets to foraging areas and protect them until they fledge and often through their first winter migration.

Dove trovarlo

Consigli sul campo

1. Scan open water bodies. Look for large white birds on open water, especially during migration and winter. Use binoculars or a spotting scope for detailed bill examination.
2. Listen for calls. Their distinctive 'whooping' calls are often the first indication of their presence, especially when they are flying overhead or in dense fog.
3. Observe feeding behavior. Watch for them dabbling or up-ending in shallow water to feed on submerged vegetation. They often feed in groups.
4. Check for yellow on bill. Carefully observe the bill for the presence and extent of the yellow patch at the base. This is the most crucial field mark for distinguishing them from other swan species.
5. Visit known wintering grounds. Consult local birding guides or eBird for known wintering concentrations in your region, as they often return to the same sites annually.

Specie simili

Fatti rapidi

Primary Diet:

Aquatic vegetation, roots, tubers, some grains

Migration Status:

Long-distance migratory

Sociality:

Highly social outside breeding season

Key ID Feature:

Black bill with yellow patch at base

Vocalization:

Whooping or barking calls

Curiosità

• The Tundra Swan is divided into two subspecies: the Whistling Swan (Cygnus columbianus columbianus) in North America and the Bewick's Swan (Cygnus columbianus bewickii) in Eurasia. The primary difference is the extent of yellow on the bill.
• They undertake one of the longest migratory journeys of any waterfowl, traveling thousands of kilometers between their Arctic breeding grounds and temperate wintering areas.
• The yellow patch on the bill of Bewick's Swans is so variable that it can be used by researchers to identify individual birds, much like a human fingerprint.
• Despite their large size, Tundra Swans are surprisingly agile in flight and can reach considerable altitudes during migration.
• They often form strong pair bonds that can last for many years, and both parents are dedicated to raising their cygnets.

Classificazione scientifica

Regno

Animalia

Phylum

Chordata

Classe

Aves

Ordine

Anseriformes

Famiglia

Anatidae

Genere

Cygnus

Specie

Cygnus columbianus

Esplora Tundra Swan