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Home > Research > Waterfowl Bio's and Biology >

Snow Geese

Common Names: blue goose; wavie, brant

In the early 1900’s hunting snow geese was severely restricted due to low population numbers. However, these days the snow goose is one of the most abundant species of waterfowl in the world. In North America the massive increase in agricultural productivity has increased winter food availability to snow geese in the form of waste grain and other food products in agricultural fields. This is resulting in a huge population boom. Now, instead of restrictive hunting, a spring conservation hunt takes place every year in an attempt to manage the ever growing population that is threatening to destroy its own breeding and wintering habitats through overpopulation.

Identification

Snow geese are a mid-sized goose with a distinctive blackish patch that looks like a grin or smile on its bill. Average male is about 756 mm long and weighs about 2.5 kg. Females are generally slightly smaller being an average of 728 mm long and weighing about 2.2 kg.

Unlike ducks, male and female snow geese have the same colored plumage which doesn’t change throughout the year. Snow geese are dimorphic. This means that they can be one of two colors. In this case, there is a white morph and a blue morph. Genetic analysis tells us that these two color morphs are actually the same species. Up until 1983 it was thought that white snow geese and blue snow geese were separate species.

White morphs are white all over, except for gray primary coverts and back primaries. Sometimes their head looks a rusty orange, but this is staining from digging or grubbing in mud that contains iron oxides for food, not a feather color. They have dark pink feet and legs and a rose-pink bill.

Blue morphs actually aren’t blue, they just look like it. On closer inspection their body is mostly dark gray-brown with a white head and foreneck. .

Ross’s goose is very similar to white morph snow geese, but are smaller with a smaller more rounded head , short neck, and a stubby bill with no ‘grinning patch’.

Distribution

During breeding season, snow geese are usually found in large, dense colonies along the coast and islands of arctic and sub-arctic North America (above the tree line) from northeastern Russia to northwestern Greenland.

There are actually 3 fairly separate breeding/wintering populations of snow geese classified as western, mid-continent and eastern. Each of these populations usually migrates south in parallel lines of longitude to their wintering grounds.

Major wintering populations are found the central valleys of California (western population), the Gulf Coast of Louisiana and Texas (mid-continent population) and the Atlantic coast from New Jersey to North Carolina (eastern population).

Habitat

Snow geese breed and nest in sub-arctic and artic tundra close to ponds, shallow lakes, streams or islands. Colonies in the high arctic can be found far inland in areas of rolling terrain, but more commonly are sited in low lying wet meadows. The geese favour areas with small bumps and ridges as these areas are the first to clear of snow and don’t flood in the spring thaw.

In the winter, snow geese like estuarine marshes, marine inlets, shallow tidal waters, marshes (fresh and brackish), lakes, grasslands and cultivated fields.

Food

Snow geese are mostly herbivorous (i.e. they mostly eat plants). They will grub in to the dirt to pull out plant roots and tubers as well as grazing on surface vegetation and waste grains.

Main foods eaten in breeding season are leafy parts of grasses, sedges, rushes, willows as well as other aquatic plants. They also eat rhizomes, tubers and roots of grasses, rushes, sedges, forbs and shrubs.

During migration and in the winter, they eat seeds, stems, leaves, rhizomes, stolons, tubers, and roots of aquatic plants such as grasses, sedges, rushes. They also eat grain, the stems of young agricultural crops, horsetail stems and berries.

Reproduction

Snow geese keep the same partner for life. If one of the partners dies, the other will re-mate. It is very rare that pairs separate when both partners are alive. Generally snow geese pair bond at about 2 years of age during the spring.

They nest on dry ground as the snow melts, usually close to rocks or small shrubs that provide some shelter as well as close to small ponds if available. The initial nest is a scrape made in the ground by the female. As she lays more eggs, she adds nesting material like grass, seaweed, small branches and a large amount of down feathers from her breast.

Eggs are laid at about 33 hour intervals. It is not uncommon for the first egg to be abandoned with the female finishing her laying somewhere else. Usually 2 – 6 eggs are laid in total.

Only the female incubates. The time she spends incubating increases as she lays her eggs. Eggs hatch about 23 days after she starts incubating continuously. Hatching out of all the eggs takes from 15 to 36 hours. Both parents lead the goslings from the nest within 24 hours of hatching. Goslings feed themselves, starting within the day they leave the nest. Both parents stay with the young through their first winter and finally break up when they return to the breeding grounds.

Conservation and Management

Snow geese are protected as a migratory game bird under the Migratory Birds Convention. With the increasing population of snow geese, attitudes have changed from conserving them to managing population numbers to minimize habitat damage. In 1999, the Arctic Tundra Habitat Emergency Conservation Act was passed in the US. This act allows the hunting of snow geese in the spring after traditional hunting season have been closed. There is also a spring conservation hunt in Canada that was established in 1998.

Information on the snow goose comes from:

Bellrose, F.C. 1976. Ducks, geese and swans of North America, 2nd edition. Stackpole Books, Pennsylvania.

Johnsgard, P.A. 1978. Ducks, geese and swans of the world. University of Nebraska Press, Nebraska.

Mowbray, T.B., F. Cooke, and B. Ganter. 2000. Snow goose (Chen caerulescens). In The Birds of North America, No. 514 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.