Appearing like flecks of black, white, and brown floating low in the water, a raft of Lesser Scaup can look like a rough patch on a wind blown lake. Common from Alaska to Nicaragua, this diving duck has many names, including blackhead, bullhead, blackjack, and river bluebill. Although closely related to the Greater Scaup, with which it was considered one species before 1838, the Lesser Scaup usually flocks by itself and prefers fresh over saltwater.

The Lesser Scaup’s breeding range stretches from Alaska to Ontario and dips southward through the Great Plains to northern New Mexico. Nearly 66% of all Lesser Scaup breed in Canada’s boreal forest region. This diving duck winters across a broad range from Washington south into Nicaragua, and from Central California east through Texas. The winter range also covers almost the entire eastern United States south of a line roughly from Texas through the Great Lakes to southern New England.  

 

A legend for the range map to the right can be found here.

The Lesser Scaup is among the most abundant ducks in North America, but it has been declining significantly over the last 30 years. In 2006, combined winter estimates of Lesser and Greater Scaup set a record low—37% under the long-term average. Between 1966 and 2003, Breeding Bird Surveys recorded significant population declines, especially in the southern and central ranges. Statistical analyses reveal that the Lesser Scaup’s population is becoming older, and has fewer females. The U. S. Fish and Wildlife Service lists the Lesser Scaup as a “game bird below desired condition” and a “conservation management concern.” Alabama, Idaho, and Wyoming consider it a “species of conservation concern.”

 

An explanation of the Annual Indices graph displayed to the right can be found here.

Invasive plants, landfills, wetland drainage, and water level control have fundamentally altered the Lesser Scaup’s migrating and wintering habitat. Siltation and the westward spread of fish, which the scaup do not eat, have reduced the prey on which Lesser Scaup depend. Zebra mussels in the lower Great Lakes provide an alternative food source, but this invasive mussel competes with native prey, and concentrates pollutants, which the scaup ingest. Increased lumber and petroleum extraction also impact the boreal forest, where this scaup breeds.

 

In coordination with the North American Waterfowl Management Plan, conservation groups like Ducks Unlimited seek to investigate population declines and preserve more open-water wetlands. The Important Bird Areas project has targeted key migrating sites for the Lesser Scaup, like eastern Lake St. Clare and the lower Detroit River, both in Michigan.

The logging of boreal forests is driven by consumer demand for paper. Buy paper products high in post-consumer recycled content and reduce the number of catalogues and magazines you receive. Visit the Boreal Songbird Initiative to learn more.

 

Become familiar with the issues surrounding mercury emissions that poison waterfowl like the Lesser Scaup and share your concerns with your state and federal representatives.

 

Consider purchasing a Federal Duck Stamp to help provide for the protection of and research on Lesser Scaup.

 

For more actions you can take, including Audubon activities, please visit our resources page.

Learn more about the Lesser Scaup through Ducks Unlimited .

 

Visit our resources page for more information about this species.

Austin, J. E., et al. 2000. “Declining scaup populations: issues, hypotheses, and research needs.” Wildlife Society Bulletin 28:1 (2000) 254-263.

 

Austin, J. E., C. M. Custer, and A. D. Afton. 1998. Lesser Scaup (Aythya affinis). In The Birds of North America, No. 338 (A. Poole and F. Gill, Eds.). The Birds of North America, Inc., Philadelphia, PA.

 

Badzinski S. and S. Petrie. “Diets of Lesser and Greater Scaup During Autumn and Spring on the Lower Great Lakes.” Wildlife Society Bulletin 34:3 (October 2006) 664–674.

 

Chipley, Robert M., George H. Fenwick, Michael J. Parr, and David N. Pashley. The American Bird Conservancy Guide to the 500 Most Important Bird Areas in the United States. New York: Random House, Inc. 2003.

 

Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, New York. 2000.