Imagine a winter sunset, beginning around three in the afternoon. The beach is empty, the sharp wind cuts like a knife.The ocean churns, tossing back spray tinged in tones of gold, peach and lavender.
Clouds, pewter and silver, are reflected in the swash, while deep green swells roll in, one after another, with nothing much but sea foam between the frozen beach and Spain. Then, low, the first flock shows, a thin, dark, undulating line just above the horizon. It is a broken line at first, then a double tributary led by a clump of dark dots. Soon more lines form: some high in the sky, some distant, some close, appearing and disappearing in the trough of the wave. More and more pass as the minutes tick by, the sun sinking slowly.
The dark line is now a river, a mighty stream of almost uncountable birds. Then, a flock flies right overhead, black and white plumage gilded by the pale winter sun, a haunting, multi-voiced “oodleoodle-ehwhooo” echoing above. The Long-tailed Ducks are on their evening commute.
LONG-TAILED DUCKS are not your average barnyard fowl. They are sea ducks, foraging far from land during the day and roosting in quieter near-shore waters by night. They are surprisingly small in the hand, about 16 inches long and only weighing about a pound and a half. Only the males show the distinctive tailfeathers that give the species its name. With two long, sharp black plumes, the male can be 21 inches from bill-tip to tail-end. Females are not quite as showy, though they are also beautifully patterned.
They nest in the high Arctic around the globe, and as ice fills the north, Longtails fly south. Although the ocean off New England in December seems forbidding to us, to these hardy birds it is balmy weather: their Miami Beach, their Caribbean. It is also their dating game, where pair bonds are re-established or new ones made.
Humans feel cold easily, but birds are vastly tougher and more athletic than even the most dedicated Olympian. Their feathers are the ultimate word in insulation. They add layers of fat to fuel long journeys, and their strength and resilience is astounding. The cold of high altitudes or icy seas doesn’t faze them. What they must have is food. Far more than temperature, available food rules their journeys. They have no agriculture, no cupboards, no refrigerators. They don’t cook. The ocean is their shopping mall, their great restaurant. Seeking food is their job, and they will go to work wherever they can find it.
Nantucket’s shoals are a major food source for many species, fish as well as birds. Long-tails can dive as deep as 200 feet below the surface, “flying” under water using mainly their wings for propulsion. They eat small clams or mussels on the ocean bottom, planktonic creatures in the water column, or sometimes feed in wrack floating on the waves. Tiny sand shrimp, periwinkles, vegetation and small crabs can also form part of their diet. In our area gaminid amphipods are their mainstay. Laterally-compressed crustaceans without a carapace, only a few millimeters long, they look rather like an unappetizing cross between a squashed flea and a truncated shrimp. But when those are on the menu and plentiful, birds gather by the thousands.
Long-tails were themselves a staple on the menu of Nantucketers during the Great Depression, and are still a game bird in the United States and Canada. But today, they are not much hunted except as a tradition in some indigenous cultures.
Judging by the recipe jokes they are probably not too palatable. Preparation involved soaking the bird overnight in a baking-soda solution, weighted down with a brick, then long baking in a slow oven, after which the bird is discarded and the brick eaten instead.
So other factors influence their population. Like many other water birds they were affected by DDT and DDE, and tests have shown them to contain high levels of the contaminants cadmium, selenium, lead and mercury, particularly in the Great Lakes region. But as a highly-mobile species with an offshore lifestyle, much is still unknown.
On Nantucket we begin to look for Long-tails by early November, with a peak, in some years, around Thanksgiving. They winter along both coasts of North America, but have become scarce in the Pacific and are on the watch list in Alaska. Numbers here are highly
variable. Sometimes the sight from shore is a river, sometimes a trickle only visible using a high-power telescope. In some years, even a couple of handfuls can be few and far between. Where they go, how many there are on the planet: these are mysteries still.
Researchers have discovered, however, that climate is a factor in the shifting habitat and habits of Longtailed ducks. There is a direct correlation between their movements and an oceanic phenomenon known as the North Atlantic oscillation. Not as well-known as Pacific celebrities El Nino and La Nina, the NAO is a similar shift of warm and cold water currents which affect our weather. Water temperature and weather affect the growth and species composition of sea creatures. This affects the birds making their living eating them.
A positive NAO brings Long-tailed Ducks closer to our shores. Periodically they have appeared in the hundreds, in the thousands, even in the hundreds of thousands. As many as half a million birds were estimated in peak years. Birders’ minds boggled at the numbers. How do you count them? The ducks fly in discrete groups of long ragged lines with one or two birds in the lead and the rest of the clan following behind. A line might contain a dozen birds, or two dozen, or a clump of 50 or 100. So, observers count the clumps. But when the clumps are an endless river, how can
they be counted? The answer is to do a point count and time the duration.
For a number of years in the 1980s and again in the early 2000s literally hundreds of thousands of these sea ducks streamed past Great Point in the early morning, commuting along the north shore from their bedroom in Nantucket Sound to the shoals 30 to 50 miles south of the island. There they spent the day feeding in the cold, rough waters that churned up their food in world-size quantities. In the late-winter afternoons they flew back, streaming along Nantucket’s south shore like a continuous river of bird life until past sunset and into the night.
In a negative NAO, the picture changes. Last year one birder sat for an hour at the end of Madaket Road, counting little rivulets of six, of a dozen, of 20, of 50, until the total count reached just over 500. Where were the Long-tails? Are they somewhere else? Are they endangered, crashed, gone? No one knows. But birders will keep watching, and hoping that they will continue, increase and return again to give us that almost mystical experience of watching rivers of Long-tails silhouetted against a winter sky.
Virginia Andrews writes the weekly “Island Bird Sightings” column for The Inquirer and Mirror and is a regular feature writer for Nantucket Today.
