Lesser White-fronted Goose (Anser erythropus)

Lesser White-fronted Goose

[order] ANSERIFORMES | [family] Anatidae | [latin] Anser erythropus | [authority] Linnaeus, 1758 | [UK] Lesser White-fronted Goose | [FR] Oie naine | [DE] Zwerggans | [ES] Ansar Careto Chico | [NL] Dwerggans

Subspecies

Genus Species subspecies Region Range
Anser erythropus EU n

Genus

The waterfowl genus Anser includes all grey geese and sometimes the white geese. It belongs to the true geese and swan subfamily (Anserinae). The genus has a Holarctic distribution, with at least one species breeding in any open, wet habitats in the subarctic and cool temperate regions of the Northern Hemisphere in summer. Some also breed further south, reaching into warm temperate regions. They mostly migrate south in winter, typically to regions in the temperate zone. Numerous fossil species have been allocated to this genus. As the true geese are near-impossible to assign osteologically to genus, this must be viewed with caution. It can be assumed with limited certainty that European fossils from known inland sites belong into Anser. As species related to the Canada Goose have been described from the Late Miocene onwards in North America too, sometimes from the same localities as the presumed grey geese, it casts serious doubt on the correct generic assignment of the supposed North American fossil geese. The Early Pliocene Branta howardae is one of the cases where doubts have been expressed about its generic assignment.[citation needed] Similarly, Heterochen = Anser pratensis seems to differ profoundly from other species of Anser and might be placed into a different genus; alternatively, it might have been a unique example of a grey goose adapted for perching in trees.

Physical charateristics

Small, grey-brown goose. White patch at base of pink bill. Black belly patches. Yellow eye-ring at close range. Similar spp. White-fronted Goose A. albifrons larger, longer necked with bigger bill and less steeply sloping forehead. Adult less dark and has smaller white blaze on face and lack bright yellow eye-ring. Juvenile lacks pale eye-ring. Difficult to distinguish in flight except by longer neck and bill and relatively shorter wings. Voice Fast bouncing dyee yik. Hints Search flocks of other geese, particularly A. albifrons. Walks faster than A. albifrons and is consequently often found near the front of feeding flocks.

Listen to the sound of Lesser White-fronted Goose

[audio:http://www.planetofbirds.com/MASTER/ANSERIFORMES/Anatidae/sounds/Lesser White-fronted Goose.mp3]

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 115 cm wingspan max.: 135 cm
size min.: 56 cm size max.: 66 cm
incubation min.: 25 days incubation max.: 28 days
fledging min.: 30 days fledging max.: 40 days
broods: 1   eggs min.: 3  
      eggs max.: 7  

Range

Eurasia : North

Habitat

In de winter, wanneer de dwergganzen in Nederland verblijven, eten ze gras. Daartoe zoeken ze vooral goed bemeste weilanden op, met mals gras dat goed verteerbaar is en voldoende voedingsstoffen levert om de koude te overleven.

Reproduction

The Lesser White-fronted Goose breeds in the sub-arctic/low-arctic zone from northern Scandinavia in the west to eastern Siberia in the east, with the range’s centre of gravity lying in central Siberia. Within the western Palearctic the Lesser White-fronted Goose breeds in the Scandinavian mountain ranges. In Russia, the species used to breed in a belt extending from the Kola peninsula to the Bolshezemelskaya tundra, but at present it is suggested that a viable breeding population is found only in the Bolshezemelskaya tundra.

The range in Fennoscandia has contracted markedly during the twentieth century. The distributions in the western and eastern parts of the range have become fragmented: in northern Scandinavia only small groups (loose associations of a few pairs/families) are found in Finnmark, and the situation in Russia is likely to be the same.

Feeding habits

The species is strictly herbivorous, foraging on a variety of plants along lake and river margins and in marshes. During pre-nesting in northern Norway the geese feed on saltmarshes.

Video Lesser White-fronted Goose

httpv://www.youtube.com/watch?v=p4vfaMa_StM

copyright: youtube


Conservation

This species is listed as Vulnerable because it has suffered a rapid population reduction in its key breeding population in Russia, and equivalent declines are predicted to continue. The Fennoscandian population has undergone a severe historical decline, and has not yet recovered.
The breeding and wintering population of Lesser White-fronted Goose in the western Palearctic has undergone an alarming decline (more than 90%) and range contraction in the second half of this century, and this is apparently continuing. The east Palearctic population is now estimated at c.6,000 birds, based on mid-winter counts. Hence, it is realistic to assume that the population decline has affected the whole of the world population and that the total has declined to fewer than 50,000 individuals, a figure which must be treated as an absolute maximum (Europe fewer than 1,000 wintering; Caspian region possibly 30,000 and almost certainly far fewer; eastern Palearctic 6,000).

The Fennoscandian breeding population was estimated at more than 10,000 individuals in the first half of the twentieth century, but since then the population has crashed, and by 1992 numbers were estimated at c.50 pairs. In Sweden the population is considered close to extinct. In the early 1990s, 30-60 birds gather in a post-moulting site in Porsanger Fjord in Norway (August-September).

Drastic reductions in population size and range have also been recorded in northern Russia since the middle of the twentieth century, and in European Russia the population is estimated at 3,500-5,500 individuals, but this information has to be regarded as a best guess only.

From surveys on the breeding grounds the total population is estimated in Russia to exceed 100,000 individuals; the population in Taimyr has been stable during recent decades. However, these figures have not been confirmed by recent winter counts, as only c.30,000 were accounted for in the Caspian region in the 1980s. Some question the high estimate and state that in many regions of central Siberia and northern Russia the population has decreased. The far east Siberian population has declined sharply in recent decades.
Lesser White-fronted Goose status Vulnerable

Migration

Migratory, main wintering areas on coastal plains of Caspian and Black Seas and in E China.
In Hungary, the last birds of winter/spring are usually seen in late March. In western Finland and Norway the first birds usually arrive in early May and migration continues until early June. The geese arrive on the breeding grounds from late May to mid-June and leave the breeding areas from mid-August through September. In Siberia, non-breeding birds undertake a moult-migration to areas north of the breeding range, while non-breeders in Fennoscandia moult at high altitudes. The first autumn influx of birds in Hungary usually occurs in September.

The autumn staging areas and winter quarters of the Scandinavian population are poorly known. Autumn and spring staging areas are found in Hungary, and from late autumn to early spring small numbers are observed in Romania, Bulgaria and Greece. Further to the east, staging areas are found in the Ob valley in Kazakhstan, and major wintering grounds are found in Azerbaijan, and possibly in Iran and Iraq. Massive shifts in winter distribution have occurred in the Caspian region within the last 30-40 years. Wintering areas in Iran have been abandoned, and the status of wintering sites in Iraq is unknown. Spring staging areas are poorly known. In western Finland, small flocks stage in May. Recent use of satellite tracking has enabled important staging areas to be located on the Kanin peninsula, Russia. Potentially important staging areas have been found in Brandenburg, Germany, S.W. Lithuania, the Azov Sea and in northern Kazakhstan. There is unconfirmed information that further staging areas exist in the Baltic republics.

Distribution map

Lesser White-fronted Goose distribution range map

Literature

Title Phylogeography and conservation genetics of the lesser white-fronted goose (Anser erythropus)
Author(s): Ruokonen, Minna
Abstract: Analyses of mitochondrial control region sequences..[more]..
Source: Academic Dissertation of the Faculty of Science, University of Oulu, 2001

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Title A note on the Lesser White-fronted Goose Anser erythropus in Sweden and the result of a reintroduction scheme.
Author(s): Von Essen L.
Abstract: The Lesser White-fronted Goose has been a
fairly ..[more]..
Source: ARDEA 79 (2): 305-306.

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