I love these guys. Purple sandpipers are my favorite shorebirds. Let me count the reasons.

One, they’re purple. In an avian world of yellows, blues and reds, these guys go with a color more royal. However, they’re not really purple. They’re more slate-colored with a purplish tinge. That’s no accident. They blend in with the color of wet granite and can magically disappear in the surf zone.

Two, they’re hardy. They breed about as far north in the arctic as any bird can survive, picking little critters out of the seaweed at the water’s edge. On their breeding grounds, they supplement with insects, spiders, berries and seeds in the tundra soils. In Maine, they stay in the seaweed, probing for food even when being doused by surf.

Three, they love Maine. As with many arctic species, they have a circumpolar range. They can be found in Scandinavia, and winter along the Northern European coast. In North America, they winter from Labrador all the way down the Mid-Atlantic coast. Some Canadian breeders even hopscotch over Greenland and Iceland to winter along the coast of Great Britain. But up to half of this continent’s entire population chooses Maine as its winter home.

Four, they’re bold. In general, arctic species don’t recognize humans as threats. They tolerate close approach by people and just about anything that doesn’t look like an arctic fox. And, for reasons I can’t fathom, they seem oblivious to eagles. I’ve watched eagles fly over a flock and the birds didn’t even flinch. I’ve see them foraging on rocks just a few feet away from a perched eagle. They’re the honey badgers of the sandpiper world.

Five, they’re appealingly plump, as if their diet consisted of crustaceans, mollusks and Haagen-Dazs. They are stockier than most shorebirds, looking almost like small pigeons, but with long down-curved bills.

Six, they’re social. It’s rare to see just one. They move around in small flocks, and sometimes big flocks. At high tide when their prey is underwater, they roost on shoreline rocks, moving around just enough to avoid the bigger waves. In fact, that’s the easiest way to find them. Look for a rock with pimples. If it’s cold and windy, focus on the leeward side of shoreline boulders as they huddle out of the breeze.

Seven, they exhibit high moral character. They are monogamous, and both parents raise the young. In fact, some studies show the male taking most of the responsibility. When danger approaches the chicks, the parents execute a maneuver called the “Rodent Run” to draw off predators. It’s similar to the broken wing display performed by a killdeer, but they raise one wing, fluff their feathers and run while squeaking like a mouse.

Eight, they’re declining. A warming planet and lost habitat have reduced their numbers and put them on watch lists of concern in North America.

Since we have up to half of the North American continent’s purple sandpipers wintering along our shoreline, why do most people not see them? They don’t know where to look. Just about any flock of shorebirds flying in winter will be purples. Some sanderlings winter over, but they confine themselves mostly to the beach. Purple sandpipers stay mostly on the rocks. I’ve seen them on sand only once in my life.

Purple sandpipers love Maine’s rocky coastline, and they can be found from Kittery to Calais. On any winter tour of Acadia National Park, I expect to find them. They particularly like Seawall in Manset and the area around Thunder Hole. On Schoodic Peninsula, they appear on the rocks adjacent to the park loop road, and they huddle in the surf zone at Schoodic Point. You, however, should stay out of the surf zone!

We will see purple sandpipers on a boat trip next month. The Island Heritage Trust in Stonington is chartering the Isle au Haut Ferry for another winter birding adventure on March 26. You’re invited. Harlequin ducks are the chief target, plus all of the other wintering sea ducks, but we’ll see our fair share of sandpipers, too.

This is the fourth year for this exceptional trip, and I’ve discovered that the sandpipers favor certain spots along the route. I know where they are, but I don’t announce it ahead of time. Rather, from a mile away I will squint through my binoculars, announce their presence, and then bask in the glory as people wonder how I could have seen them from so far. I know, I’m devious that way.

Bob Duchesne serves as vice president of Maine Audubon’s Penobscot Valley Chapter. He developed the Maine Birding Trail, with information at mainebirdingtrail.com. He can be reached at duchesne@midmaine.com.