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Tundra Bean Goose (Anser serrirostris) & Whooper Swan (Cygnus cygnus)

Scientific classification

Kingdom:Animalia

Phylum:Chordata

Class:Aves

Order:Anseriformes

Family:Anatidae

Genus:Anser

Species:A. serrirostris

Binomial name

Anser serrirostris

 

The tundra bean goose (Anser serrirostris) is a goose that breeds in northern Siberia. This and the taiga bean goose are recognised as separate species by the American Ornithological Society and International Ornithologists' Union, but are considered a single species by other authorities (collectively called bean goose). It is migratory and winters further south in Asia. The taiga and tundra bean goose diverged about 2.5 million years ago and established secondary contact ca. 60,000 years ago, resulting in extensive gene flow.

 

Rather large, dark gray-brown goose with typically small orange patch on bill, and orange legs. In flight lacks contrasting pale forewing areas of Pink-footed Goose and Graylag Goose. Not always safely told in the field from Taiga Bean Goose, but Tundra averages a shorter and thicker bill, vs. the longer, more sloping bill of Taiga. Breeds on tundra and winters in farmland and wetlands, where it associates readily with other geese.

 

The length ranges from 68 to 90 cm (27–35 in), wingspan from 140 to 174 cm (55–69 in) and weight from 1.7–4 kg (3.7–8.8 lb).[2] In the nominate subspecies, males average 3.2 kg (7.1 lb) and females average 2.84 kg (6.3 lb).[2] The bill is black at the base and tip, with an orange band across the middle; the legs and feet are also bright orange.

 

The upper wing-coverts are dark brown, as in the white-fronted goose (Anser albifrons) and the lesser white-fronted goose (A. erythropus), but differing from these in having narrow white fringes to the feathers.

 

The voice is a loud honking, higher pitched in the smaller subspecies.

 

The closely related pink-footed goose (A. brachyrhynchus) has the bill short, bright pink in the middle, and the feet also pink, the upper wing-coverts being nearly of the same bluish-grey as in the greylag goose.

 

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Whooper Swan (Cygnus cygnus)

 

[order] Anseriformes | [family] Anatidae | [latin] Cygnus cygnus | [UK] Whooper Swan | [FR] Cygne chanteur | [DE] Singschwan | [ES] Cisne Cantor | [IT] Cigno selvatico | [NL] Wilde Zwaan | [IRL] Eala Ghlórach

 

spanwidth min.: 205 cm

spanwidth max.: 235 cm

size min.: 140 cm

size max.: 160 cm

Breeding

incubation min.: 31 days

incubation max.: 42 days

fledging min.: 78 days

fledging max.: 96 days

broods 1

eggs min.: 3

eggs max.: 5

 

 

Physical characteristics

 

Size is similar to the Mute Swan, but there are noticeable differences. Whooper Swans have a yellow and black beak, a more rigid neck bearing in activiy as well as at rest, and, finally, their wings produce a musical sound when they fly. Their feathers are entirely white and their webbed feet are black. Juveniles show a greyish brown plumage. After one year, they get their adult one.

The Whooper Swan can also be mistaken for the Bewick Swan whose he's very close. There are two ways to differentiate them: the Whooper Swan is much bigger, with a longer neck and a more angulous head, and the beak's yellow/black layout is different. While the Whooper's Swan beak looks globally yellow with just a black tip, the Bewick's Swan's one is mainly black with a yellow base, sometimes half yellow, half black. Unlike the Mute Swan, it never raises its wings above its back when it swims and its neck is straighter.

 

Habitat

 

Winters on low agricultural land, generally not far from coast. Breeds in northern zones, on shallow fresh waters: pools, lakes and rivers in wooded country. Rarely in tundra.

 

Other details

 

Cygnus cygnus breeds mainly in Iceland, Fennoscandia and northern Russia, but winters patchily across much of Europe, which constitutes >50% of its global wintering range. Its European wintering population is relatively large (>65,000 individuals), and was stable between 1970-1990. Although there were declines in a handful of countries during 1990-2000, most European wintering populations-including key ones in Denmark and Germany-were broadly stable or increased, and the species underwent a large increase overall.

Whooper Swans nest mainly in Eurasian boreal regions. They split in three distinct groups. The most occidental one, with a stable population of about 16 000 individuals, nests in Iceland. The central one nests in Scandinavia and Occidental Russia. It is estimated at 59 000 individuals, regularly increasing. The most oriental group is located in Siberia. Its population, estimated at 17 000 individuals, is probably decreasing. These groups migrate south beginning autumn with the first cold days. The occidental group leaves Iceland for the British Isles, North Sea and Channel coasts, as far as the farthest point of Brittany. The oriental group sets up on Caspian and Black Sea shores. The Scandinavian group is the one that has the shortest migration. During winter, Whooper Swans, like Bewick Swans, spend a great deal of time grazing.

 

Feeding

 

Essentially vegetarian. It eats aquatic plants and uses all parts of it (stems, leaves, roots, shoots). It also graze in prairies, like geese. It may eat small invertebrates, but it's a minor part of their diet.

 

Conservation

 

This species has a large range, with an estimated global Extent of Occurrence of 10,000,000 km². It has a large global population estimated to be 180,000 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]

 

Breeding

 

Pairs unite for lifetime. Males are very active in nest building. Their nest is bulky and made essentially with stems and leaves. The bottom is covered with twigs, leaves and feathers. In April-May, the female lays 4 to 7 eggs and sits on for 5 to 6 weeks. Chicks are precocious and are carried on the female's back under the male's aggressive watch and protection. Taking flight occurs 87 to 90 days after hatching.

 

Migration

 

Migratory. Part of Icelandic population remains in winter. Migrates southwards to temperate areas, sporadically in more southern latitudes in cold winters; vagrant to USA and Pakistan.

 

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Uploaded on October 6, 2021
Taken on March 8, 2020