By mid-November on the Maine coast, the great migration of shorebirds is complete and the warblers and other songbirds have departed (weeks ago) for their overnight exodus to the tropics. The leaves have fallen, but ice has yet to form on lakes and rivers. Just when it seems that all is dead, dying, or ready to freeze, the ducks arrive. They flow into the Atlantic in a steady stream from the Arctic, some from boreal lakes and others from the cold northern sea. They travel hundreds of miles to the relatively warmer waters of the Maine coast, where food is still plentiful. Some will stay; others will continue their migration south.
Their arrival is another beat in the seasonal rhythm, and a fairly predictable one. Take, for example, the goldeneyes of the Penobscot. Every year they appear in the first two weeks of November at a bend in the river at Bangor, just above the rapids of Treats Falls, site of the old waterworks and dam. At first it’s just a few males, but by month’s end there could be 20-30 common and Barrow’s goldeneyes all hanging out in that one stretch of river. True to their name, they have a striking yellow eye punctuated with a white comma on a field of iridescent black.
All day long, their yellow eyes search for prey and they dive to the river bottom, their feet propelling them three to ten feet deep. What are they eating here, so close to the city? Freshwater mussels, probably. Snails, insect larvae, fish, algae, maybe. They tear and crush invertebrates, shells and all, with their mighty jaws. None of these foods contain much energy, so the birds must consume large amounts.
The Penobscot is one of several locations in Maine where the rare Barrow’s goldeneye congregates. The eastern population is estimated at around 7,000 birds, but only around 250 overwinter in Maine. Sometimes they range up to Old Town or down to Belfast, or even up along the Kenduskeag Stream in downtown Bangor. Goldeneyes are also common on the Harraseeket River in Freeport, and the Kennebec. These ducks have learned over time that these are the places with abundant food, and so they stay faithful to their winter homes.
Other migrants have similar site fidelity. Harlequin ducks, also rare, leave Greenland, Iceland, and eastern Canada to winter in the waters around Isle au Haut in outer Penobscot Bay. Some pairs, still united since their summer breeding days, even return to the same ledge year after year. The harlequins are quite colorful, with blue and chestnut accents on the standard black and white. They dive in the rocky surf, foraging among the rocks and seaweed for small shrimp, periwinkles, and other invertebrates.
The goldeneyes and harlequins are among the twelve species of sea ducks, known to scientists as the tribe Mergini, found in Maine. Most migrate from northern breeding grounds. A few, like common eiders, are here year-round, and some, like mergansers, only come to the coast in winter after inland lakes have frozen. The mergansers on the Penobscot stay a bit south of the goldeneyes, and can be seen from the Bangor and Brewer waterfronts on years the river doesn’t freeze.
Eiders are here year-round, and a King eider might appear amid their rafts. Long-tailed ducks, with shades of gray amid their black and white, are common. Scoters—black, surf, and white-winged—are small, mostly black. The surf scoter has a white patch on the back of its neck, and an orange, black, and white bill.
The smallest of the tribe but just as boldly patterned, buffleheads find safety in numbers. Their summer home is in the boreal forest, where they nest in holes made by northern flickers. In the winter, they bob like apples in the bay.
Sea ducks wait a few years to mate, live a relatively long time, and don’t produce a lot of chicks, so survival of adults is important to the overall population. On their breeding grounds, they are threatened by fossil fuel extraction, pollution, and habitat changes.
A recent analysis by U.S. Fish and Wildlife Service biologists found that four of the most common species wintering along the eastern coast of the United States—long-tailed duck, white-winged scoter, surf scoter, and black scoter—may be declining, while the status of the common eider is uncertain. “The apparent negative trends, combined with the fact that sea duck life histories are among the most poorly documented of North American waterfowl, have led to concerns for these species and questions about the impacts of human activities, such as hunting, as well as catastrophic events and environmental change,” they wrote in the Journal of Fish and Wildlife Management.
Like other migratory creatures that survive a long journey, sea ducks are cause for celebration. There’s a good chance that in any given ice-free cove or current, sea ducks are swimming, diving, floating, waiting to be wondered at.
Sea ducks are easy to find—in any cove or harbor not frozen over—and observe, even for the nearsighted or inexperienced. Looking for ducks in tidal rivers, harbors, and coves is one of the joys of winter. When the rest of life seems frozen, hibernating, or dead, the ducks are a reminder that no one lives in isolation, unconnected to the rest of earth. On the Penobscot River, the goldeneyes will leave sometime in April, a bittersweet refrain in the yearly song of arrival and departure.
Catherine Schmitt is Communications Director for the Maine Sea Grant College Program at the University of Maine. She is the author of A Coastal Companion: A Year in the Gulf of Maine from Cape Cod to Canada.