Only about 3,000 harlequins are found in the East, while the West Coast population approaches 300,000. And it just so happens that Newport County is one of the few places to see these aquatic entertainers on the East Coast.

Audra Cook, a Montana wildlife guide, was visiting her mother in Mattapoisett, Mass., when the pair decided to drive to Middletown to look for harlequin ducks. Spying a flock frolicking in the surf, Cook and her mother, Alicia Crabbe, set up their telescope and settled in to watch the colorful birds at play. “Harlequin ducks are the perfect example of art in nature,” says Cook. “I might see one or two in Yellowstone, but it’s nothing like the numbers you see here.”

Harlequins have been called the clown prince of waterfowl, as much for their boldly patterned plumage as for their entertaining antics diving in the rough surf. They’re also the rarest duck species in the eastern United States. South of Maine, the most reliable place to find them is Newport County, where they attract bird-watchers and photographers from near and far.

Dressed in patches of slate blue and chestnut, with white slashes and spots, harlequin ducks spend the winter by the dozens at Sachuest Point National Wildlife Refuge in Middletown and Beavertail State Park in Jamestown, and in smaller numbers at Brenton Point in Newport and Sakonnet Point in Little Compton. They begin arriving in late October and can be seen every day until early April — especially in the surf zone, where waves crash among large boulders.

“What seems to attract people to harlequins is that they’re just such a spectacular-looking bird. Their plumage colors are out of this world,” says Peter Paton, an ornithologist at the University of Rhode Island. “It’s the combination of their attractiveness, their rarity, and that there aren’t a lot of places to get good looks at them.”

During Thanksgiving weekend, a steady stream of visitors paused to look for the ducks at an observation platform overlooking Island Rocks on the east side of Sachuest Point. A group of eight harlequins played close to shore with a large group of black scoters and common eiders — two common species of sea ducks — while about 20 more harlequins paraded in the surf and occasionally dived for a meal.

Moments later, Albert Sanford from Attleboro, Mass., arrived at the observation platform with his camera and long telephoto lens. He visits Sachuest several times each year to photograph wildlife, and he is especially attracted to the harlequins. “I just love their patterns and colors,” he says. “But they’re tricky to shoot. They’re always in the turbulent waters. Rarely do they sit still on the rocks.”

At the refuge’s visitor center, an illustration of a harlequin duck graces the cover of the bird checklist, and one is featured prominently in a mural on the wall. Volunteer Charlie Rhoads says that harlequin ducks attract a wide variety of visitors. Birdwatching clubs from Massachusetts and Connecticut make regular trips to seek them out. (“We had a club from Connecticut here just last week,” Rhoads says.) And non-birders often notice the ducks in the mural and wander off to find them on the water.

While their appeal is obvious, not a lot is known about the harlequin ducks. Eastern populations breed in the summer along rushing streams in northern Quebec and Labrador, and winter along the coast of New England and the Canadian Maritimes. Only about 3,000 harlequins are found in the East, while the West Coast population approaches 300,000. No one seems to know why their numbers are so low in the East.

Little is known about what the ducks eat during their wintertime visits to Newport County. Rick McKinney, a wildlife ecologist for the Environmental Protection Agency in Narragansett, has studied the birds extensively and even tried to dive into the waters where the birds feed to see what they may be consuming. But he didn’t learn much. “I had a helluva time trying to find out what they eat,” he says. “It’s almost impossible to spend any time in the rocky surf where they prefer to forage. My guess is that they’re rooting around in the seaweed attached to the rocks where there are some amphipods and snails. And occasionally I have seen one come up with some kind of crab, but I didn’t find any crabs when I sampled down there.”

Paton and McKinney say the birds are very strong underwater swimmers. (They would have to be, considering their preference for diving in the surf zone.) But that’s not to say that the conditions aren’t treacherous for the birds. McKinney saw a report of a necropsy on several dead harlequins that concluded that the birds had experienced numerous broken bones during their lives. “They obviously had been tossed around in their habitat pretty often,” he says. “I wouldn’t be able to survive in that. But they have this uncanny ability to dodge the waves and go under when they need to and exploit that habitat.”

McKinney has surveyed the birds in Rhode Island waters every winter since 2005, and has found that in recent years even more harlequins are turning up at Beavertail than at Sachuest. The feeding habitat is similar, he says, so it’s unclear why the bulk of the local population has shifted, though there are still plenty of birds at both sites. “To a duck that’s flown a thousand miles from its breeding habitat to its wintering habitat, the few miles between Sachuest and Beavertail may not mean much,” he says. “To us, they’re two places far apart. But the birds might see them as being part of the same place and they move back and forth.”

At Beavertail, the birds are most often found close to the southern point or in the waters along the east side of the park. Regardless of where you see them, most observers have a reaction like that of Alicia Crabbe. “I don’t know how they survive in that surf,” she muses. “But they sure are fun to watch.”