By David Spector Gazette Contributing Writer
As the nights chill in October and November, vast numbers of waterfowl pass over us on their routes from prairie and arctic breeding grounds to the Atlantic coast. Most familiar to many people are the Canada geese, honking as they fly south in long diagonal lines and chevrons. The persistent observer can occasionally see or hear other species also moving south.
The angle between adjacent birds in a formation and the tendency of birds to take the lead in a group vary among formation-flying species. Snow geese are known for their wave- like flight formations, which can help to identify this species, even at a distance at which plumage details cannot be seen. At night, the barking calls of snow geese, higher pitched than the honking of Canada geese, also help identify them.
Seen well, an adult snow goose’s mostly white plumage, with black on the outer wing, justifies its name. A snow goose coming in for a landing is typically not a graceful sight; this species often loses altitude with a seemingly out-of-control rocking motion that could be likened to the falling of a large snowflake. The sight of many thousands of these birds tumbling down onto a field or marsh makes me think “blizzard goose” might also be appropriate.
Such goose blizzards are a rare sight here in Massachusetts. Millions of snow geese breed across the arctic regions of North America (and even into Greenland and Siberia), and hundreds of thousands winter along the mid-Atlantic coast. Many snow geese fly just to the west of Massachusetts. Observers who spend a lot of time scanning the autumn sky, nonetheless, may be rewarded by the sight of some snow geese passing high over western Massachusetts, on their way from stopovers in the St. Lawrence River and Lake Champlain regions to the coastal marshes of New Jersey and points south.
People who prefer to see their birds on land need not despair of seeing snow geese locally. Sometimes a snow goose or two shows up amid a flock of Canada geese feeding in a corn field; careful scanning of such flocks sometimes reveals snow geese and other less-common species. Much less frequently, substantial flocks of snow geese stop over in the Connecticut Valley. Flurries of white geese are sometimes grounded by a change in weather. A sudden snow or rain during migration season can ground birds that usually pass high over us. Such a squall is the cue for birdwatchers to get out and search fields and ponds for locally uncommon species forced down by the weather.
Snow goose populations have fluctuated dramatically. In the 19th and early 20th centuries this species was uncommon, probably much less common than at the time of European settlement of North America. In western Massachusetts the bird was quite rare. Robert Morris’ Birds of Springfield and Vicinity, published in 1901, mentions only two occurrences of individual snow geese; in 1937 Aaron Bagg and Samuel Eliot writing in their classic Birds of the Connecticut Valley of Massachusetts could add only three more records of flocks and one of an individual bird.
Over the past several decades the numbers of snow geese and other Arctic geese have increased. Indeed, the population has grown to such an extent that these geese now have the potential to damage the limited habitat left to them by human development, by overgrazing on their plant food. Snow geese, unlike most grazers, often pull up the underground parts of the plants that they eat.
As the population has grown, so too have the numbers of stragglers slightly outside the normal migratory pathways of the species. Now snow geese are an annual though still uncommon occurrence here. Anyone who takes the effort to watch and listen throughout the fall has a chance of seeing them.
David Spector is a former board president of the Hitchcock Center for the Environment and teaches biology at Central Connecticut State University. Hear a recording of snow goose calls.
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