Snow geese are poor man’s swans. Slightly smaller than Canada geese, they are gleaming white with black wing tips. Moving in family groups of up to half a dozen, they form large flocks to feed on marsh grasses and newly sprouted winter rye in farm fields. Geese are birds trying to be sheep and will graze happily on anything green.
The snow geese in this area are almost exclusively Greater Snow Geese.(Chen caerulescens atlantica) as opposed to their smaller and more abundant Lesser Snow Goose (Chen caerulescens caerulescens) cousins. Lesser Snow Geese are rarely seen along the Atlantic, but very common along the Mississippi and Central flyways in the heart of North America.
Any flock of snow geese, Greater or Lesser, will contain a proportion of blue geese. Blue geese, with white heads and blue-gray bodies, were once thought to be a closely-related species and given the poetic scientific name Chen hyperborenis, meaning “goose from beyond the north wind”--this was before hardy explorers with an ornithological bent journeyed north to above the Arctic Circle and actually observed the birds on their nesting grounds. Blue and snow geese paired indiscriminately and broods had both snow and blue goslings. Blue geese were determined to be a genetic color variant or morph and the species name was retired. Blues and snows vary in relative proportions, depending on environmental factors favoring one morph or the other. Currently, snows seem to be in the ascendancy, with over 90% of the birds being the white morph.
Snow geese, due to their resemblance to swans, have been protected from hunting (nobody wants to shoot an angel by mistake), and populations, especially in the Lesser Snow Goose, have exploded to the point where over-grazing orgies (called eat-outs) at the nesting grounds are destroying the sparse vegetation, endangering the goose population as well as other species using the same tundra habitat. Increased bag limits and longer seasons for hunters seem causing some leveling-off in the population.
Greater Snow Geese are the farthest-north breeding waterfowl in North America. Summer breeding grounds range north from the Foxe Basin (the northern arm of Hudson Bay) to Elsmere Island, the farthest north of the Canadian Archipelago. Their wintering range is the mid-Atlantic Coast from New Jersey to the Carolinas. While Greater Snow Geese on most of the Delmarva come from Hudson Bay north, birds wintering along salt water come from a separate breeding population in western Greenland. Snow Geese have serrated edges to their bills, allowing for greater traction in pulling plant roots and tubers, their main diet. In the past few years, snow geese have been moving into farm fields to graze on waste grains and green cover crops such as rye or winter wheat. Watching a flock move across a field covered in sprouted rye reminds me of a party, groups come and go, aggregating and breaking up like conversation groups at a cocktail party and there is an overall background conversation buzz of honks and gabbles. Snow geese mate for life; young unattached adults meet and court their new mates on the wintering grounds. Adults who have lost mates do the same. Mixing and mingling on the wintering grounds serves to keep the population genetics mixed up—geese return to the females’ nesting areas. This may be a party in more than just metaphor.
