[order] Anseriformes | [family] Anatidae | [latin] Anser serrirostris | [UK] Tundra Bean Goose | [FR] Oie des moissons | [DE] Tundrasaatgans | [ES] Ánsar Campestre | [IT] Oca granaiola | [NL] Toendrarietgans

Toendrarietgans determination

copyright: ShenstoneBirder

Averaging only slightly smaller than Greylag Goose but not so bulky, with less weight in the rear half of body. Large, tall, rather long-billed and long-necked, essentially brown goose, with very dark head and neck obvious in flight. At long range and in poor light, difficult to separate from other grey geese but noticeable length of dark head and neck, upright stance, and uniform upperwing in flight, characteristic. High head carriage, bulk, uniform dark plumage tone, lack of forewing contrast, rather long, deep orange-marked bill, and orange legs all diagnostic at closer ranges. Confusion with large, dark individuals of Pink-footed Goose possible, but Bean Goose never shows grey upperparts and differences in bare-part colours afford certain distinction of typical birds.

Conspicuous differences in habitat characterize the various subspecies. More southerly breeders within west Palearctic (mostly nominate fabalis), extending in places to south of subarctic, unique among indigenous geese in nesting within dense coniferous forest or birch scrub. At times also on upland stony tracts with only scattered trees, usually near stream, pool or lake. Subspecies rossicus prefers more conventional Anser habitats on wet low tundra and Arctic Ocean islands, but habitat overlaps in some areas with nominate fabalis. Winter movements extend less far west than in other Anser; in normal winters, only small proportion reach grassy wetlands in oceanic climates. Fields under crops or fallow, steppe, floodlands, rivers, and coastal shallows used on passage and in winter.

Anser fabalis breeds in Fennoscandia and northern Russia, and winters patchily in western, central and south-east Europe, which probably holds >50% of its global wintering population. Its European wintering population is large (>390,000 individuals), and underwent a large increase between 1970-1990. Although there were declines in a number of countries-notably the Czech Republic-during 1990- 2000, key wintering populations in Germany and the Netherlands were stable or increased, and the species was stable overall.

Grasses, cereal grains, and other agricultural crops; mainly by grazing on arable and pastureland in winter. On breeding grounds, feeds on green parts of plants, flowers and fruits, seeds, and rootstocks.

This species has a large range, with an estimated global Extent of Occurrence of 10,000,000 km˛. It has a large global population estimated to be 800,000-840,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]

Nests in low hummocks and banks free from snow and post-thaw flooding. often at base of tree or among bushes. Usually close to water but could be up to 1 km away. Normally well dispersed, though sometimes forming loose colonies. Previous year's nests re-used with new lining. The nest consists of low mound of grasses, dead leaves, moss, and other vegetation, with shallow cup lined with down, particularly after laying. Building: mostly by female, though male may help, using material within reach of nest. The clutch size is 4-6, sometimes 3 or up to 8, in one brood per season. Eggs probably laid at 24-hour intervals. after hatching the eggshells left in nest.
Incubation continues for 27-29 days and is performed by females and starts after the lat egg is laid. She covers eggs with down when she is leaving the nest. The young are hatching synchronous. The young are immediately Self-feeding. Both parents care for young in defending them against predators. When still very young the chickens are brooded by female at night.
The young fledge in about 40 days. Young remain with parents during the first autumn and winter, migrating with them in spring but will be independent before they return back to breeding grounds. Age of first breeding normally 3 years.

Migratory, winters mostly on coastal plains in NW and Central Europe and E Asia. Sporadically in more southern latitudes during cold winters.