Sea Ducks on the Move

"Unruffled" is definitely not a fitting description for sea ducks. These feisty waterfowl migrate in spring and fall between inland breeding areas and wintering habitats along our coasts. Their flyway routes are often surprising. The harlequin duck, for example, migrates more east and west than north and south.

From mollusc eaters to fish feeders, from tree hollow nesters to colonial breeders, sea ducks are arguably the most diverse and interesting group of waterfowl.

Sadly, many of their populations are in decline. Common mergansers, black scoters, common goldeneyes, and white-winged scoters are among the sea duck species in Canada whose populations may be in trouble. Such threats as habitat loss and chemical contaminants are probably to blame.

Waterfowl biologists have identified the need for concerted research, monitoring, and management action to solve the sea duck crisis. They need to know more about the ecology, population dynamics, and threats to the health of these beloved birds.

Range data based on the following sources: The Audubon Society Encyclopedia of North American Birds (1995), Birds of Canada (1995), and North American Birds (Peterson Multimedia Guides, 1996)

A bright orange knob above the bill and a pearly blue crown on the head of the male in breeding plumage earn the king eider its royal name.

Perfectly adapted to Arctic climes, it plunges 55 metres deep in near-freezing waters in pursuit of molluscs, sea anemones, and other invertebrates. Ducklings leave their nest a day after hatching and go straight to sea, swimming, diving, and feeding themselves from the start.

• Range: The king eider breeds in Canada, Russia, Alaska, and Greenland. Its main North American population breeds in the western Canadian Arctic and northern Alaska, wintering in the Bering Sea. A smaller population breeds in the eastern Canadian Arctic and winters off Newfoundland, Labrador, and Greenland.
• Migration: Spring migration starts early, with flocks moving north over mainly frozen seas by April. Most wintering birds remain far north, but strays have reached Florida, Louisiana, Kansas, and southern California.
• Habitat: The king eider nests in a hollow in the ground on arctic tundra, rocky shores, and lakesides far inland from the coast. It comes ashore only in the breeding season, spending the rest of the year in northern seas, often among pack ice.
• Status: Estimated at 370,000, the western population has declined by 40 to 75 per cent since the 1960s. The status of the eastern population is unknown.
• Threats: Wintering birds are threatened by oil spills, coastal development, and the closure of open water leads in ice floes. Contaminants may impact on breeding success and hatchling survival.

This stunningly marked little duck prefers rushing rivers, where it dives and walks against the current, poking its bill among stones to catch mayfly and caddis-fly larvae. It gets its name from a character in Italian comedy with an oddly painted face and patterned costume.

• Range: Western harlequins breed in Alaska, the Yukon, British Columbia, Alberta, and the northwestern United States. They winter from the Aleutian Islands south to Alaska, British Columbia, and the U.S. northwest. Eastern harlequins breed in Quebec, New Brunswick, Labrador, and Newfoundland. They winter from southern Newfoundland to the New England states with some northerly breeders wintering in Greenland as well.
• Migration: Mostly a short-distance traveller, the harlequin migrates in small flocks between inland nesting sites and nearby coasts.
• Habitat: Rushing mountain rivers and surf-pounded coasts are the usual haunts of the harlequin duck. It nests along shallow, fast-moving streams and occasionally along quiet tundra ponds and glacial lakes.
• Status: The western population is stable at 200,000 to 300,000 birds. With fewer than 2,000 individuals, the endangered eastern population has plunged from as many as 10,000 birds in this century.
• Threats: Logging, mineral exploration, hydroelectric projects, scarcity of nesting sites, and the impact of acid rain on insects eaten by harlequins are threats in the breeding range. Oil spills and other contaminants from shipping are problems in wintering areas. The accidental killing of harlequins during the hunting of other waterfowl is another major concern.

Conservation: The eastern population is listed as endangered. It receives legal protection from hunting in Ontario, Quebec, Atlantic Canada, and the eastern United States.

White patches on the male surf scoter’s head earn this sea duck the nickname “skunk-headed coot.” It uses its huge bill to chomp down great quantities of molluscs. The stomach of one surf scoter contained 574 periwinkles.

• Range: Breeding in the boreal forest and taiga regions from eastern Alaska to Labrador, the surf scoter winters along the Pacific coast from Alaska to Mexico and along the Atlantic coast from Newfoundland to Florida.
• Migration: The bird migrates in flocks, flying high between inland breeding areas and coastal wintering habitats. It stops en route to rest on inland lakes.
• Habitat: Nesting in a hollow in the ground in tundra or forest along northern lakes, ponds, and slow-moving rivers, the surf scoter winters on ocean coasts in shallow estuaries and bays.
• Status: Estimates of between 257,000 and 756,000 birds indicate a population decline.
• Threats: The surf scoter is threatened by oil spills, coastal development, contaminants in the food chain, hydroelectric projects, aquaculture, and possibly overhunting.

Mergansers are the only Canadian ducks that specialize in eating fish. Their streamlined bodies and long, saw-like bills are perfectly designed for the underwater pursuit of prey. Even ducklings catch fish within a day of hatching.

• Range: The western population breeds in British Columbia, Alberta, and the northwestern United States. It winters from British Columbia south to California. The larger eastern population breeds from Manitoba to Nova Scotia and south to the Gulf of Mexico. It winters in New England, southern Ontario, and Michigan south to the Texas coast.
• Migration: This mainly short-distance migrant travels in between breeding and wintering areas in early spring and late fall.
• Habitat: Nesting in tree hollows along wooded lakes, ponds, rivers, and swamps, the hooded merganser depends on woodpeckers to dig its nesting cavities. It will also use artificial nesting boxes. It winters on coastal estuaries, as well as woodland swamps and ponds.
• Status: The population size is uncertain but probably surpasses estimates of 270,000 to 385,000 birds. The eastern population is stable and possibly increasing.
• Threats: The hooded merganser is threatened by oil spills, coastal development, chemical contaminants, the digging of channels, and sedimentation. Loss of nesting sites to logging and the impact of acid rain on prey are special concerns.

Conservation: Population declines due to past deforestation and loss of tree hollows have been reversed thanks to artificial nesting boxes.

Named in honour of geographer Sir John Barrow and for the rich, yellow colour of its eyes, this sea duck is also called a “whistler” because of the loud, musical sound produced by its wings.

• Range: Most Barrow’s goldeneyes breed west of the Rocky Mountains, from Alaska to Oregon. Smaller populations breed in Eastern Canada and Iceland. Western birds winter in coastal waters from Alaska to Puget Sound, from Oregon to California. Eastern birds winter in the St. Lawrence Estuary and in smaller estuaries from the Maritimes to New England.
• Migration: Barrow’s goldeneye is one of the first ducks to migrate north in spring to inland breeding grounds and south in fall to coastal wintering areas.
• Habitat: Nesting in tree hollows in forested country around inland rivers, lakes, and ponds, Barrow’s goldeneye winters in shallow bays, estuaries, and other coastal waters.
• Status: Estimated at 70,000 to 150,000, the western population appears to be stable or slightly declining. The eastern population has decreased by 30 per cent, with some 3,000 birds in Quebec and 2,000 in Iceland.
• Threats: Wintering birds are threatened by oil spills, coastal development, chemical contaminants, and loss of food sources. Deforestation, industrialization, and mineral exploration could impact on breeding grounds.

A male oldsquaw seen in summer and winter could easily be mistaken for two different birds. This long-tailed duck is unique among waterfowl because it has two distinct but equally beautiful plumages. A champion diver, it has been caught in fishing nets 70 metres deep. It is also the noisiest of our waterfowl — a flock of oldsquaws sounds like a pack of baying hounds.

• Range: The most common and widespread sea duck, the oldsquaw breeds throughout the Arctic, nesting to the northern limits of land. It winters on coasts from the Bering Sea to California and from Labrador to North Carolina.
• Migration: A late fall and early spring migrant, the oldsquaw flies high over land but low over sea. Huge numbers migrate north through the Bering Strait in spring.
• Habitat: The oldsquaw nests on low tundra, hills, forest edges, and barren ground near lakes or pools. It spends most of the year on the open ocean, often among pack ice far from shore.
• Status: Numbering in the millions, oldsquaw populations appear to be stable in the east but declining in the west at 2 per cent a year, or 70 per cent since the 1960s.
• Threats: Urbanization, industrialization, fowl cholera, lead-shot poisoning, oil spills, and capture in fishing nets are all threats to oldsquaws.

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