A Boothbay Register/Wiscasset Newspaper staffer sent us a number of beautiful photos last week that happened to be of our favorite duck species, the common eider (yes, we did include it in our book “Maine’s Favorite Birds.”) One of Maine’s hardy year-round residents, the common eider is an exclusively marine duck.

Adult male common eiders are a strikingly sharp white and black while the females sport an exquisite, muted ruddy-brown scalloping on the body.

As they float together upon the surf, they give the impression of spilled salt and pepper. One of the easiest ways to identify common eiders is to check out the profile of their head. Their distinctive, long-sloping forehead and bill is unlike any other commonly occurring Maine waterfowl species.

Many ducks occur in flocks, but common eiders are particularly fond of staying in close proximity to each other, occasionally forming flocks that number in the hundreds.

During winter, a scan of just about every bay and rocky ledge along the coast of Maine will yield the sighting of a group of bobbing white-and-black male and brown female eiders.

These birds dive down for mussels, sea urchins, star fish, crabs and other small marine creatures, swallowing them whole and letting their muscular gizzards grind them up. They regurgitate the non-digestible parts later.

Mainers are fortunate; not only are we near the southern limit of nesting for common eiders (a few make it down to coastal Massachusetts) but we also have some of the highest densities of nesting birds on our islands.

Also, we host a large number of wintering eiders from farther north. In fact, Damariscove Island, right offshore from Boothbay Harbor, hosts one of the state’s largest breeding populations of common eiders.

Females make nests on the ground, under bushes or in grass. They pluck the insulating down feathers from their breasts to make a warm cushion, within which the 3-5 eggs are nestled and incubated by the female.

In some countries (common eiders also occur across northern Europe and in Siberia), some of the down from each nest is harvested to use for use as insulation in coats and blankets. When the chicks hatch, they are almost immediately led to the water by the female, who may combine her chicks with other females and their chicks.

These females may include non-breeding females called “aunts.” Several of the females watch over the young and try to protect them from marauding gulls – for whom a small eider chick would make a tasty meal.

Common eiders that come from farther north to spend winter mostly migrate back north, following the coast.

However, a small population breeds in the St. Lawrence of Quebec and has developed an unusual migratory route that takes them directly across inland Maine. Occasionally, these flocks are downed by bad weather on inland lakes and river.

Years ago, a flock ran into a storm while trying to migrate through the night and crash-landed in parking lots and roads in front of stunned drivers. The birds mistook the reflective surface of asphalt for water. Sadly, many of the birds died from the impact.

Since common eiders don’t occur in most of the U.S., bird enthusiasts from away find it exciting to be able to see these birds that we often take for granted.

Next time you’re taking visiting friends and family for a ride along Maine’s beautiful coast, be sure to point the salt-and-pepper birds, one of many species that makes Maine so special.

Dr. Jeff Wells is the senior scientist for the Boreal Songbird Initiative. During his time at the famed Cornell Lab of Ornithology and as the Audubon Society's national bird conservation director, Dr. Wells earned a reputation as one of the nation's leading bird experts and conservation biologists. Jeff's grandfather, the late John Chase, was a columnist for the Boothbay Register for many years. Allison Childs Wells, also formerly of the Cornell Lab of Ornithology, is a widely published natural history writer and a senior director at the Natural Resources Council of Maine. Together, they have been writing and teaching people about birds for decades. The Maine natives are authors of the highly acclaimed book, “Maine's Favorite Birds.”