Over four years ago, on an early April afternoon while hiking around La Salle Lake on La Salle Lake State Recreation Area’s “Challenge Trail,” I reached an area of the trail that offers a bird’s eye view of the east end of the lake. Standing beneath gorgeous towering red pines growing like sentinels atop the mountain-like ridges that surround the lake, the panorama takes one’s breath away.
As I looked at portions of the still frozen lake far below me through the limbs of leafless deciduous trees and shrubs, I became aware of curious and unfamiliar sounds coming from the mouth of La Salle Creek. As I focused on the area where the creek flowed gently into La Salle Lake, I could see that it was entirely ice-free; perhaps half the size of a football field in all.
The interesting hog-like sounding vocalizations that emanated from the lake completely dumbfounded me, and so I crept closer, downslope, in search of a clearer vantage. On the ridge’s steep incline I soon found a natural bench that provided me a corridor of unobstructed viewing of the lake and the mouth of the creek.
Scattered across the entire width of the lake where the ice was absent were a couple of dozen birds comprised of a single species of waterfowl that I didn’t immediately recognize on account of not only their appearance, but the confounding grunting sounds they produced. The birds resembled common loons from afar, but their vocalizations were anything but. At long last, after studying the birds with the naked eye, it dawned on me that the large, “loon’ish” looking ducks were common mergansers. And all of them drakes.
I would argue that common mergansers, though their name bespeaks of widespread familiarity, are not all that widely known. A species resigned to mostly large lakes and rivers of North America’s northern latitude during the breeding season, common mergansers are big and beautiful cavity nesting ducks.
Although males of the species do indeed bear a striking resemblance to our state bird, the common loon, common mergansers are not a close relative of loons at all. Loons are bigger, heavier, and have greater wingspans than do common mergansers, yet, that withstanding, common mergansers are among the largest species of duck in North America. With a total body length of over 2 feet, a wingspan of nearly 3 feet, and a weight of nearly 4 pounds, common mergansers are indeed large ducks.
Interesting of the species, too, is that this big duck nests in tree cavities, particularly abandoned woodpecker holes, as well as inside of some artificial nest boxes (the hooded merganser is a cavity nester, too). Other nesting locations sometimes used by common mergansers include crevices in rocks, lighthouses, old buildings, chimneys, and holes in banks.
With a penchant for mature forests where cavity trees are more plentiful and available, the common merganser is at home throughout Minnesota’s forestlands where large lakes and rivers are also abundant. Places like the Boundary Water Canoe Area Wilderness provides almost unlimited breeding and nesting habitat for common mergansers. Those of you who have ventured into the wilderness in the summertime have undoubtedly encountered common mergansers numerous times, especially hens and their broods of ducklings.
Lake Bemidji and other lakes throughout northwest Minnesota also host breeding and nesting common mergansers. In fact, a year ago the New York Times ran a story about one special common merganser hen that was leading around a brood of 76 ducklings on Lake Bemidji. The impossibly large family of ducks, which really wasn’t the offspring of the lone hen in the story, can actually be explained by an unusual phenomenon whereby a single hen is left the responsibility of raising the broods of other hens in a sort of, “duck daycare” system.
Undeniably uncommon in some places, common in others, the common merganser, an attractive species of duck found here in the Land of 10,000 Lakes, is a bird once observed are likely never forgotten as we get out and enjoy the great outdoors.
Blane Klemek is a Minnesota DNR wildlife manager. He can be reached at firstname.lastname@example.org.