Scoters

Black Scoter (Melanitta nigra)
White-Winged Scoter (Melanitta fusca)
Surf Scoter (Melanitta perspicillata)

Description: Scoters are common sea ducks on Whatcom County waters, particularly abundant during winter months when the velvet black males and dark-chocolate brown females are often seen swimming offshore in large groups, or “rafts”. The drakes, or males, of the three different species - black, surf, and white-winged scoters – can be recognized by the distinctive bills and white head markings. Requiring a running start, scoters are strong, low flyers across the water.

Distribution: Scoters winter along the Pacific coast from as far south as Baja, Mexico north to Alaska's Aleutian Islands. Surf scoters are also seen on the Atlantic coast of North America, while black scoters and white-winged scoters are circumpolar, with populations extending to Europe and Asia.

Surf scoters are widely distributed along Whatcom County shorelines and all three species can be seen wintering around Drayton Harbor and Birch Bay. In spring, numbers are particularly abundant along Point Whitehorn and Cherry Point as migrating scoters stop to join the feast on smelt and herring spawn.

Reproduction: Although many non-breeding surf scoters stay in Whatcom County for the summer, breeding pairs fly north to boreal and tundra regions of Alaska and Canada. Scoters build nests on the ground at the edges of lakes, rivers and wetlands with each species having slightly different preference of nesting habitat. Scoters form pair bonds in winter areas or during spring migration, which are maintained and defended by males until incubation of eggs begins, at which point males fly off.

Ecology: Often seen swimming along the surf, scoters dive for blue mussels, crabs, clams and other invertebrates. Unlike the dabbling marsh ducks, diving sea ducks have a life cycle more oriented to adult survival than high reproduction. Adults generally live longer, but they don’t breed until at least two years old. In addition, adults may not breed in some seasons, and they lay fewer eggs in a clutch. These birds have high fidelity to their breeding, molting and wintering areas, so they are slow to rebuild populations or colonize new areas.

Scoters, like other waterfowl, undergo a complete molting annually in which they lose their primary feathers and are flightless for a month. Compared to other waterfowl, sea ducks - and scoters in particular - are not well studied. Researchers are trying to learn more about the scoters breeding, migration and molting patterns - critical times when the birds are stressed and vulnerable.

Economic Value: Scoters are hunted by native tribes for subsistance in Canada and Alaska and recreationally along flyways in the U.S. Harvest on the Atlantic flyway constitutes 80 percent of the 30,000 scoters shot each year.

Wildlife watching - bird-watching in particular - is the fastest growing activity in the country and a major attraction for the growing tourism economy of our area.

Current Status:

The Puget Sound's scoter population is estimated to have declined by 50% in the last two decades A large scale die-off in the 1990's occurred in Southeast Alaska and although the cause is unknown, contaminants are suspected. Reasons for decline in Puget Sound are not known, but possibilities include:

• Vulnerability to oil spills: Scoter populations concentrate in nearshore areas where spills typically occur. Birds caught in oil nearly always die due to hypothermia or poisoning.
• Susceptibility to toxins accumulating in their foods: Cadmium, lead and PCP's are filtered by shellfish, then eaten by the diving duck, accumulating in the fatty tissue.
• The decline of spawning forage fish means less roe available to migrating scoters

The status of scoters is representative of sea birds in general. Although some sea bird populations have remained stable, others, such as the long-tailed duck and marbled murrelet have declined more than 90%.

The lack of information about scoters makes it difficult to determine the exact reasons for their decline so researchers are using new technology such as satellite tracking to learn more.

Sources:

Seattle Audubon Society BirdWeb
http://www.birdweb.org/birdweb/

Alaska Department of Fish and Game
http://www.state.ak.us/adfg/wildlife/duck
/scoter/surf.htm#cite

Terrance Wall Birds of Whatcom County:
Status and Distribution. 1995

Puget Sound Water Quality Action Team.
Puget Sound's Health. 2002.

Photo's by Tim Bowman, USFWS
http://www.seaduckjv.org/index.html

For More Information:

Whatcom County
Marine Resources Committee
(360) 676-6876
http://whatcom-mrc.wsu.edu/MRC/index.htm