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  ScienceZoologyBirdsOrder Anseriformes
 
the two types of snow gooseSnow Goose

Anser caerulescens [an ser sE roo' les sens]

Description

Snow geese have an average weight of 1-2 pounds, an overall body length of about 27 inches, and a wingspan of about 17 inches. Males and females are similar in appearance, but males are usually larger.

Snow geese come in two basic "color schemes" -- snow white and blue. Both "kinds" of snow geese have black wing tips, red feet and legs, a pink bill, and a black "grin patch" (a patch of skin surrounding the base of the bill), but basic colorations of the two are different -- an adult "snow snow goose" is snowy white, while an adult "blue snow goose" is blue/gray. Immature "snows" are dirty white in color with black wing tips, while immature "blues" are slate gray with little or no white. It was once thought that the two color variations were different species of geese, but they are not. They interbreed with one another, and are found together throughout their range. The colors appear to be genetically determined. Individual snow geese tend to choose mates that resemble their parents, but "mixed" breeding is not uncommon.

Distribution and Habitat

range of the snow gooseSnow geese breed in the northeast Arctic regions of North America, from northern Baffin Island, west to Bathurst Island, north through Ellesmere Island, and east to northwest Greenland (red on the map). Their main wintering grounds are along gulf coast of Louisiana and Texas, from the Mississippi Delta to Corpus Christi (blue on the map). In recent years, colonies have also been seen in Missouri, Illinois, Kansas, Oklahoma, Nebraska, and Iowa, as well as in eastern Mexico and southern New Mexico.

Breeding grounds typically consist of low grassy tundra with flat basins. Snow geese prefer coastal lagoons, marshes, tidal flats, and estuaries, but have been seen on prairies and agricultural lands. They are seldom found more than 25 or 30 miles from water.

Reproduction

Like most other species of geese, snow geese are monogamous and usually form life-long pair bonds.

Mating takes place during the south-to-north migration. Nesting occurs in June, with nesting colonies numbering into the tens of thousands. The nest is usually a shallow depression in the ground lined with bits of dry vegetation and down from the mother. The female lays one egg per day until she reaches a full clutch of three to five. Incubation takes about 25 days, during which period the male guards the nest and the mother. Both parents care for the young, which fledge in 45 to 49 days.

Snow geese frequently nest near snowy owl nests, probably for partial protection from predation.

Behavior

Snow geese travel in large flocks madeof many family units and fly during both day and night. They tend to return to the same nesting areas year after year.

Males are territorial toward other males, as are females toward other females.

Diet

Snow geese eat roots, leaves, grasses, and sedges.

Scientific Classification

Phylum Chordata
Subphylum Vertebrata
Class Aves
Order Anseriformes
Family Anatidae
Subfamily Anserinae
Genus & Species Anser caerulescens


Animal Diversity Web http://animaldiversity.org/accounts/Anser_caerulescens/

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  The Robinson Library > Science > Zoology > Birds > Order Anseriformes

This page was last updated on October 02, 2015.

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