Rate of Decline: 75 percent in 40 years
Global Population: 1.3 million
Continental Population: 506,000 now, 2 million 40 years ago
Watch List Status: 
Appearance: The male is a black, gray, and white duck smaller than a Mallard. The head, chest, and rump are black; the back is gray; and the belly and wing-stripe are white. The female is brown with a white facial mask and a white belly and wing-stripe similar to that of the male.
Vocalization: A wide variety of vocalizations during active courtship, otherwise pretty quiet.
Listen (© Lang Elliot, Nature Sound Studio).
Habitat: Breeds along lakes and large ponds in large open tundra complexes. Winters in large lakes and along ocean coasts, usually in large
"rafts" or flocks.
Range: Circumpolar. In North America, breeds mostly in Alaska and eastern Canada; winters in Great Lakes (when they don’t freeze) and just off the Atlantic and Pacific Coasts.
Feeding: Feeds on small bivalves, snails, crustaceans, aquatic insects and larvae, and aquatic plant seeds. Selects feeding locations high in nutrient content, including discharge outlets for sewage treatment plants, secondary lagoons that process effluent, unprotected aquaculture beds, and water intakes at power plants. Usually a daytime feeder, but will forage during the night in the fall and winter if disrupted by recreational small-boat traffic during the day. The population explosion of the non-native zebra mussel has provided a new source of food for wintering and migrating birds in the Great Lakes. These recent dietary changes have caused them to ingest higher concentrations of organic contaminants and heavy metals.
Reproduction: The nest site requires substantial cover from tall grasses or sedges, and it must be on ground that is not subject to summer flooding. The female hollows out a cavity and lines it with grasses and down feathers. The young are relatively mature at hatching, with a full layer of natal down. Crèching, in which birds care for unrelated offspring, is relatively common for this species. Produces a single brood per season with a clutch size range of 5-13 eggs (usually 8-9).
Conservation Issues & Efforts:
- Threats: With global warming, the Greater Scaup’s open tundra breeding grounds are undergoing dramatic changes, notably earlier melting of permafrost and invasion by formerly more southern species, including woody plants and nest predators. In the Great Lakes, invasive species such as zebra mussels are out-competing the natural prey species upon which Greater Scaup have always relied. Along the coasts, these birds are very sensitive to oil spills and other water quality issues that affect shellfish.
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Outlook: Greater Scaup may turn out to be among the species most at risk from climate change, and its long-term fate will likely hang on how this issue is dealt with during the next decade.
What Can You Do:
- Conserve Wetlands
Support wetlands conservation programs such as the Clean Water Act, North American Wetlands Conservation Act (NAWCA), and Farm Bill conservation programs such as the the Wetlands Reserve Program (WRP), and “swampbuster” (the rule that restricts wetlands from being converted to agriculture). Encourage governments at all levels to enact and enforce wetlands protection and water quality laws and regulations.
- Help Halt Global Warming
Back strong federal, state, and local legislation to cap greenhouse emissions, and spur alternative energy sources. Conserve energy at home and at work (http://www.audubon.org/globalWarming/BePartSolution.php).
- Stop Invasive Species
Work with county agricultural officials to help fight the spread of non-native annual grasses. Support strong federal, regional, state, and local regulations and research and management to combat non-native, invasive species.
- Patrol Beaches
Join beach watches to look for oiled birds or other signs of coastal pollution. Lobby with local, state, and federal officials to maintain wildlife-friendly beaches and clean coastal waters.
For more Information:
References:
Kaufman, Kenn.
Guía de campo a las aves de Norteamérica. New York: Houghton Mifflin Company, 2005.
Kessel, B., D.A. Rocque, and J.S. Barclay (2002). Greater Scaup (
Aythya marila).
The Birds of North America Online (A. Poole and F. Gill, Eds.). Philadelphia: The Birds of North America, Inc. Retrieved from The Birds of North America Online database:
http://bna.birds.cornell.edu/BNA/account/Greater_Scaup/
