With a furious, leaden sky spilling its guts overhead and curtains of rain making the air a thing of liquid, an epic gale was raking the Maine coast. Ferocious winds were coming in from the ocean and raising enormous breakers, which crashed into foam that was flung to shore in a bitter mist. It was dead low tide, but the long, low boulders offshore disappeared beneath frenzied walls of dishpan-gray water and dreary foam that surged and fell and rose again.

In the midst of this maelstrom there was life. Small flocks of sea ducks—chunky eiders, slimmer goldeneyes, oldsquaws all white against the pewter sea—were riding out the storm just beyond the surf line. Every few seconds their world tilted violently as another great wave rose beneath them and the water became nearly vertical; then it slid past to its roaring death, and the ducks calmly slipped down its back side. Once, when an especially big wave rose and crested early, breaking over their heads, they all turned bill-first into it, as though by command, and vanished beneath the boil, only to roll to the surface again on the other side. It was, I suppose, just another day on the winter sea for them.

For me as an observer standing on shore, leaning hard into the gale and soaked to the skin despite the best efforts of modern synthetics, it was a humbling realization of the gulf that separates humans from the inhabitants of the winter ocean. This is no idyllic place of sailboats and puffy clouds, but a bitter, harsh place where life treads the thin edge.

So why, then, should any creature capable of fleeing before winter—and certainly that includes birds—elect to stick it out in so uncompromising an environment? The reason, of course, is that the winter sea is brutal by human standards, but not by those of, say, an eider. The sea provides shelter and food, and the bird's physical and behavioral adaptations provide the cushion of comfort and safety that allow it to thrive in the face of winter's worst challenges.

In fact, the seacoast in winter is one of the most exciting places for a naturalist. Ocean birds are the most visible attraction; sea ducks from the Arctic, pelagics blown inshore by strong winds, hardy shore birds, and blizzards of gulls.

Where the tide exposes mud flats, or the shore is gentle enough for a beach, one is likely to find sanderlings skittering in synchronization with the waves; farther north on the rock-bound coast, or on jetties in the south, look for purple sandpipers the color of the sea, and ruddy turnstones whose orange legs are the only reminder of their springtime elegance.

On the beach itself, and in the shifting dunes just beyond, another community of birds endures the cold weather. Flashing their black-and-white wings like tiny explosions, snow buntings cascade along with the wind, having traveled south from the islands of the Arctic Ocean. With them come a handful of other rarities, including a few Lapland longspurs, which have traded their dramatic breeding plumage of black and russet for a camouflaging mix of ocher, brown, and rust that merges seamlessly with the withered vegetation of the back dunes. Most common of all are the horned larks, their frugal brown relieved by the faintest hint of yellow on the throat and belly, tiny feather "horns" tickled by the sea breeze.

There are mammals here, too, most notably meadow voles and shrews where the ground cover is thickest. And with the prey come the predators; the winter coast is the hunting ground of harriers and rough-legged hawks, northern shrikes, and short-eared owls. In an invasion year, any piece of wide-open coastline is liable to have a snowy owl, starkly white and yellow-eyed, perching on old pilings or jetty walls or the lightpoles of beachside parking lots, waiting for a rodent to make the mistake of showing itself. For the exceptionally lucky, the winter shore may also hold a glimpse of a huge gyrfalcon, white or gray or charcoal-black, bringing a piece of the Far North south on its powerful wings, like an embodiment of the wind.