Bean Goose

Informazioni

The Bean Goose (Anser fabalis) is a large goose species belonging to the 'grey goose' genus Anser. It is characterized by its dark brown body plumage, orange legs, and a black bill with a variable orange or yellow band. It is a migratory species, breeding in the Arctic and subarctic regions of Eurasia and wintering further south in temperate zones. Historically, two main groups were recognized: the Taiga Bean Goose (Anser fabalis fabalis group) and the Tundra Bean Goose (Anser fabalis rossicus group), which are now often treated as separate species (Anser fabalis and Anser serrirostris, respectively). This description focuses on Anser fabalis sensu stricto, the Taiga Bean Goose.

Dimensioni e longevità

Lunghezza

68-90 cm

Apertura alare

140-174 cm

Peso

1.7-4.0 kg (males typically larger, 2.2-4.0 kg; females 1.7-3.3 kg)

Longevità

Up to 15-20 years in the wild

Dieta

Herbivore

Caratteristiche fisiche

Piumaggio

Adults have dark brown upperparts, head, and neck, contrasting with paler grey-brown underparts. The flanks are darker, often with faint barring. The rump and undertail coverts are white. The primary and secondary flight feathers are dark, giving the wings a dark appearance in flight. The overall impression is a dark, robust goose.

Forma del becco

The bill is relatively long and heavy, entirely black with a distinct orange or yellow band across the middle. The extent and color of this band are variable and important for subspecies identification. The nail at the tip of the bill is black.

Colore degli occhi

Dark brown.

Colore delle zampe

Bright orange.

Caratteristiche distintive

Key features include the dark brown body, orange legs, and the black bill with a variable orange/yellow band. The head and neck are uniformly dark brown, lacking the white forehead patch of some other goose species. In flight, the dark underwing and dark primaries are noticeable.

Aspetto giovanile

Juveniles are similar to adults but have duller plumage, often with a slightly scaly appearance due to paler feather fringes. The bill coloration is less distinct, often with a duller, less vibrant orange/yellow band, and may be more uniformly dark initially. Legs are also duller orange.

Cambiamenti stagionali

No significant seasonal plumage changes. Plumage remains consistent throughout the year, though wear and tear can make feathers appear slightly paler or more worn by late summer.

Dimorfismo sessuale

Males (ganders) are generally larger and heavier than females (geese), but plumage is identical. Size difference is often subtle and not reliable for field identification of individuals.

Come identificare

1. 1

   Overall Plumage

   Look for a uniformly dark brown body, head, and neck, contrasting with white undertail coverts. No white forehead patch or black belly bars.

2. 2

   Bill Coloration

   Observe the bill carefully: it is black with a distinct orange or yellow band across the middle. The extent and color of this band are crucial for distinguishing from Tundra Bean Goose.

3. 3

   Leg Color

   Note the bright orange legs, a consistent feature across all ages and sexes.

4. 4

   Size and Shape

   A large, robust goose with a relatively long neck and a heavy bill. Taiga Bean Geese are generally larger and longer-necked than Tundra Bean Geese.

5. 5

   Vocalization

   Listen for the deep, resonant 'ung-unk' or 'ga-ga-ga' call, which is lower-pitched than most other grey geese.

6. 6

   Habitat and Behavior

   In winter, look for them grazing in agricultural fields, often in mixed flocks with other geese. In flight, observe their V-formation and dark underwings.

Habitat e areale

Biomi

Taiga (boreal forest), tundra, wetlands, agricultural fields.

Areale geografico

Breeds across the taiga zone of northern Eurasia, from Scandinavia eastward through Siberia. Winters in temperate Europe (e.g., Germany, Netherlands, UK, Poland, Hungary) and Asia (e.g., China, Korea, Japan).

Fascia altitudinale

Primarily lowlands, especially during wintering, but can be found in higher elevations in breeding areas if suitable habitat is present.

Ambienti preferiti

During breeding, they prefer open taiga forests, bogs, marshes, and tundra with scattered trees, often near lakes, rivers, or ponds. In winter, they utilize agricultural fields (stubble fields, pastures, winter cereals), grasslands, and wetlands, often roosting on large bodies of water.

Comportamento

Periodo di attività

Diurnal. Feeds during daylight hours, often roosting on water bodies at night.

Abitudini alimentari

Strictly herbivorous. Feeds primarily on grasses, sedges, mosses, berries (especially cranberries and blueberries), and aquatic vegetation during the breeding season. In winter, their diet shifts to agricultural crops such as spilled grain (barley, wheat, oats), potatoes, sugar beet tops, and young shoots of winter cereals. They graze in fields, often in large flocks.

Comportamento sociale

Highly social, especially outside the breeding season. Forms large flocks during migration and in wintering grounds, often mixing with other goose species like Greater White-fronted Geese. During breeding, they are more territorial and form pairs or small family groups.

Tipo di volo

Strong, direct flight with powerful wing beats. Flies in V-formations or irregular lines during migration, typical of large geese. Can be quite agile when taking off or landing.

Migrazione

Long-distance migratory. Breeds in the Arctic and subarctic and migrates south to temperate regions for the winter. Migration occurs in large flocks, typically from September to November and again from March to May. Specific routes vary by breeding population.

Territorialità

During the breeding season, pairs establish and defend a nesting territory around their nest site. Outside of breeding, they are gregarious and not territorial, forming large feeding and roosting flocks.

Riproduzione

Stagione riproduttiva

May to July, with egg-laying typically in late May to early June.

Abitudini di nidificazione

Nests are usually built on the ground, often in a sheltered spot near water, such as under a bush, in tall grass, or on a small hummock in a bog. The nest is a shallow scrape lined with plant material and down plucked from the female's breast.

Dimensione della covata

3-9 eggs, typically 4-7.

Descrizione dell'uovo

Typically 4-7 eggs, though clutches can range from 3 to 9. Eggs are creamy white to yellowish-white, becoming stained during incubation. They are oval-shaped.

Periodo di incubazione

27-29 days.

Periodo di involo

40-50 days. Goslings are precocial and leave the nest shortly after hatching, but are dependent on parents for protection and guidance until they can fly.

Cure parentali

Both parents care for the goslings. The female incubates the eggs, while the male stands guard nearby. After hatching, both parents lead the goslings to feeding areas and protect them from predators. Family groups remain together until the next breeding season.

Dove trovarlo

Consigli sul campo

1. Scan large flocks. Bean Geese often mix with other goose species. Carefully scan large flocks of geese in wintering fields to pick out the distinctive bill and leg coloration.
2. Listen for calls. Their deep, resonant calls are often the first indication of their presence, especially in foggy conditions or at a distance.
3. Observe bill details. The specific pattern of black and orange/yellow on the bill is the most critical identification feature, especially when distinguishing from the Tundra Bean Goose. A good spotting scope is invaluable.
4. Visit known wintering sites. Consult local birding resources or eBird for known wintering sites in your region. These areas often have designated viewing points.
5. Look for family groups. In late winter and early spring, family groups (parents with their offspring from the previous year) can often be observed together.

Specie simili

Fatti rapidi

Type:

Waterfowl

Diet:

Herbivore

Habitat:

Taiga, Tundra, Wetlands, Agricultural fields

Migration:

Long-distance migratory

Sociality:

Highly social outside breeding season

Bill Color:

Black with orange/yellow band

Leg Color:

Orange

Curiosità

• The name 'Bean Goose' is thought to derive from its historical habit of feeding on spilled beans in agricultural fields.
• Recent taxonomic revisions have split the Bean Goose into two or more species, primarily the Taiga Bean Goose (Anser fabalis) and the Tundra Bean Goose (Anser serrirostris), based on genetic, morphological, and vocal differences.
• Bean Geese are known for their strong pair bonds, which often last for many years.
• They are among the earliest geese to migrate north to their breeding grounds in spring, often arriving when snow is still present.
• Different populations of Bean Geese show distinct migration routes and wintering areas, highlighting their adaptability to various environments across Eurasia.

Classificazione scientifica

Regno

Animalia

Phylum

Chordata

Classe

Aves

Ordine

Anseriformes

Famiglia

Anatidae

Genere

Anser

Specie

Anser fabalis

Esplora Bean Goose