Freeport Digby County Nova Scotia: Community Events

Creatures of the Cove

By Roger Outhouse, Chairperson of the Bay of Fundy Discovery Centre Assoc.

This month features a very striking sea bird in the form of the White-winged Scoter or Melanitta fusca by its scientific name. This is the largest of the three types of diving scoters. The females are slightly smaller than the males which weigh up to 3 to 4 pounds (1.3 - 1.7kg). The male is a striking black color with a distinctive teardrop shaped white patch around the eye. The wedge shaped bill is orange with a black hump at the base. Females are more dark brown and possess a less conspicuous white spot on the head. This same faded spot can also be present in immature males. Both sexes have a large white speculum on the secondary wing feathers that show as a stripe when they are swimming in the water but are amazingly large and showy when the birds are in flight; hence the name White-winged Scoter.

No one really knows a lot about the migrations and behaviors of these ducks. They are thought to number between half a million to one million North American wide. The reason why we are not more confident of the numbers is scientific population counts are done from aircraft and the three types of scoter species look enough alike that they do not count the types separately. During the 70's scientists noted a dramatic drop in population (estimated by some as a 50% decline). Although no hard evidence explains the situation many speculate that the deterioration of habitats and food contaminated by toxins may be responsible. Another suggestion is that since they often winter in bays and inlets they are prone to oil spills and discharges from ships. Some authors now speculate that these ducks are making somewhat of a comeback, due in part to the invasion of the dreaded zebra mussel. Mussels are a popular meal for these ducks and since this troublesome specie has been introduced by ships to North America's freshwater habitats it has virtually exploded in horrific numbers. Fortunately the scoter ducks are a great help to humans as we wage war with this new threat to our ecosystems.

While the White-winged Scoter feeds mainly on insect larvae and small crustaceans in their freshwater breeding areas they have a rather long list of foods on their coastal wintering grounds. Clams, mussels, snails, periwinkles, crab, shrimp, starfish, urchins, aquatic vegetation, and even the occasional fish round out their menu. They typically feed in shallow bays in depths ranging from 5 to 20 meters and while they swallow small prey while under water they will bring larger animals to the surface where they swallow them whole.

Scoters winter along the Pacific Ocean (from Alaska to California), the Atlantic Ocean (from Newfoundland to Texas) and smaller numbers along portions of the Great Lakes. By May or even June, they migrate from the wintering grounds to inland lakes in the Northeastern boreal forests of Canada and Alaska. A few even nest in the prairies. When possible the birds build nests in the worst thickets imaginable well back from the shoreline. This discourages predators and in particular gulls which account for huge mortality rates among the eggs and hatchings. Female White-winged Scoters return year after year to the same nesting sites. They lay from 5 to 16 pink or creamy buff colored eggs. The females incubate the eggs while the males depart for better feeding areas. Once the females have the young to the point where they can fly on their own, all the birds join the males.

Large flocks of these ducks are an inspiring sight as their beautiful white flashing wings propel them along as they barely skim the waves of the turbulent Bay of Fundy. For such a populous creature it is amazing that we have yet to discover much about its life history and it remains a mystery to the present day.