thumb|Greater white-fronted goose in California

thumb|Greater white-fronted geese, [[Texel, Netherlands (2013)]]

The greater white-fronted goose (Anser albifrons) is a species of goose, closely related to the smaller lesser white-fronted goose (A. erythropus). The greater white-fronted goose is migratory, breeding in northern Canada, Alaska, Greenland, and Russia, and winters farther south in North America, Europe, and Asia. In the United Kingdom and Ireland, it has been known as the white-fronted goose; in North America, it is known as the greater white-fronted goose (or "greater whitefront"), and this name is also increasingly adopted internationally.

  • The mantle and scapulars of A. a. flavirostris have narrow, indistinct pale fringes creating a uniform appearance to the birds' upperparts, whereas A. a. albifrons has noticeable whitish fringes creating obviously barred upperparts.
  • The tertials of A. a. flavirostris have indistinct pale fringes, whereas these pale fringes are more noticeable on A. a. albifrons
  • The lesser and median upperwing coverts of A. a. flavirostris have narrow, indistinct pale fringes, creating a rather uniform appearance to the wing, whereas on A. a. albifrons, these fringes are prominent and broad, creating wing bars.
  • The greater coverts of A. a. flavirostris are dark grey, with a narrow white tip, forming a narrow wing bar; on A. a. albifrons, they are blue-grey, with prominent white tips, forming a bold wing bar.
  • The flank line is narrow and white on A. a. flavirostris, but broad and bright white on A. a. albifrons
  • The tail of A. a. flavirostris is dark brown, with a very narrow white tip and sides; that of A. a. albifrons is dark grey, and the white tip and sides are at least double the width of the corresponding areas on A. a. flavirostris.
  • The bill of A. a. flavirostris is orange-yellow with a dark nail, compared with the bright-pink bill of A. a. albifrons, which has only a hint of dark on the nail; in addition, the bill of the former is longer and appears slimmer than that of the latter.

The belly barring on adult birds is on average more extensive on A. a. flavirostris than on A. a. albifrons, but the individual variation in both forms renders this of limited use as an identification feature.

Taxonomy

The greater white-fronted goose is divided into five subspecies. The nominate subspecies, the European white-fronted goose (A. a. albifrons) breeds in the far north of Russia and winters further south and west in Europe and Asia.

Three other restricted-range subspecies occur in northern North America: Gambel's white-fronted goose (A. a. gambeli) in interior northwestern Canada and wintering on the coast of the Gulf of Mexico, slightly larger than the nominate form, the Pacific white-fronted goose (A. a. frontalis), and the tule goose (A. a. elgasi) in southwest Alaska, the largest and longest-billed of all, both wintering in California. All these subspecies are similar in plumage, differing only in size..

Distribution

<!-- are 14 years enough ? -->

thumb|Egg, Collection [[Museum Wiesbaden]]

The North American midcontinent birds of the subspecies A.&nbsp;a. gambeli – which in 2010 had a fall population around 710,000 birds – breeds from the Alaska North Slope across the western and central Canadian Arctic. The Pacific white-fronted goose of the American Pacific coast, which in 2010 numbered approximately 650,000 birds, and the tule geese, which are estimated to number 10,000 birds, nest in western Alaska. The midcontinent geese gather in early fall on the prairies of western Saskatchewan and eastern Alberta, spending several weeks feeding before heading to wintering areas near the Gulf of Mexico, into northern Mexico.

Origin of migration

Midcontinental white-fronted geese in North America have many breeding areas and each group in each breeding area differs in its migration time and wintering location. The six breeding areas include interior Alaska and Alaska's North Slope, western Northwest Territories, western Nunavut, central Nunavut, and eastern Nunavut. These spatial differences lead to different departure times for white-fronted geese leaving their breeding areas. Birds from interior Alaska start migrating earlier during autumn and fly farther south to winter. The RSPB estimates that 1.3% of the world's population of Greenland White-fronted Geese can be found there each October.

<gallery widths="200" heights="200">

White-fronted.goose.750pix.jpg|European white-fronted goose (A. a. albifrons) at the Slimbridge Wildfowl and Wetlands Centre

Anser albifrons in flight at Llano Seco.jpg|In flight

Anser_albifrons_hm.jpg|Illustration from Hume and Marshall's Gamebirds of India, Burmah, and Ceylon

Greater White-fronted Goose from the Crossley ID Guide Britain and Ireland.jpg|ID composite

</gallery>

References

  • White-fronted goose facts on the website of RSPB
  • Greater white-fronted goose at "All About Birds" (Cornell Lab of Ornithology)
  • White-fronted Goose – Anser albifrons – USGS Patuxent Bird Identification InfoCenter