Lynn M. Stone / Tundra swan (Cygnus columbianus) flock on brackish river at sunset with Canvasback (Aythya valisineria) duck flock in flight. Chesapeake Bay, Maryland, USA. February.

Lynn M. Stone / Canvasback duck (Aythya valisinereria) drake paddling on Choptank River, where the species winters, Chesapeake Bay Eastern Shore, Maryland, USA. February.

Lynn M. Stone / Canvasback duck (Aythya valisineria) female in flight over Choptank River, where the species winters, Chesapeake Bay Eastern Shore, Maryland, USA. February.

Lynn M. Stone / Canvasback duck (Aythya valisineria) and Redhead duck (Aythya americana) hybrid, this drake has orange eyes, intermediate between red of Canvasback and yellow of Redhead and intermediate light gray co...

Lynn M Stone / Canvasback duck (Aythya valisimeria) drake wintering on Choptank River, Eastern Shore of Chesapeake Bay, Maryland, USA

Lynn M Stone / Canvasback duck (Aythya valisimeria) hen wintering on Choptank River, Eastern Shore of Chesapeake Bay, Maryland, USA

Lynn M Stone / Canvasback duck (Aythya valisimeria) drake, wintering on Choptank River, Eastern Shore of Chesapeake Bay, Maryland, USA

Lynn M Stone / Canvasback duck (Aythya valisimeria) drakes, bird on right showing aggression toward other drake, wintering on Choptank River, Eastern Shore of Chesapeake Bay, Maryland, USA

Lynn M Stone / Canvasback duck (Aythya valisimeria) drake emerging from dive, wintering on Choptank River, Eastern Shore of Chesapeake Bay, Maryland, USA

Barry Mansell / Canvasback duck (Aythya valisineria), male. Captive. Occurs in North America.

Visuals Unlimited / Canvasback (Aythya valisineria) female swimming on a golden pond in Victoria, British Columbia, Canada.

Visuals Unlimited / Canvasback (Aythya valisineria) male swimming on a golden pond in Victoria, British Columbia, Canada.

Gerrit Vyn / Canvasback Duck (Aythya valisineria) male on a prairie pond. Alberta, Canada. May.

Lynn M Stone / Canvasback Duck (Aythya valisineria) head portrait of male; captive.

Lynn M Stone / Canvasback duck (Aythya valisineria) male on water, captive. North America

David Kjaer / Canvasback duck (Aythya valisineria) female, Captive, UK, from North America

David Kjaer / Canvasback duck (Aythya valisineria) Male, Captive, UK, from North America

David Kjaer / Canvasback duck (Aythya valisineria) Male, Captive, UK, from North America

Roger Powell / Canvasback pair (Aytha valisineria) swimming together, Washington WWT, Tyne & Wear, UK.

Rod Williams / Canvasback duck {Aythya valisineria} male with female behind, captive, from North America

Rolf Nussbaumer / Male Canvasback (Aythya valisineria) preening, Rockport, Texas, USA. December 2003

Rolf Nussbaumer / Male Canvasback (Aythya valisineria) Rockport, Texas, USA. December 2003

Tom Vezo / Canvasback duck {Aythya valisineria} resting, Long Island, NY, USA.

Barrie Britton / Canvasback duck (Aythya valisineria) female camouflaged on nest in reed bed, Canada

Tom Vezo / Canvasback duck (Aythya valisineria) male resting on water, Long Island, New York, USA

Terry Andrewartha / Canvasback duck {Aythya valisineria} on water, UK

David Welling / Canvasback ducks {Aythya valisineria} resting together, Alaska, USA

Tom Vezo / Flock of Canvasback duck (Aythya valisineria) roosting on water, Long Island, New York, USA

E.J. Peiker/ BIA / Canvasback (Aythya valisineria) male, Arizona

Steve Gettle / Canvasback (Aythya valisineria) male and female flying, North Dakota

Tim Zurowski / Canvasback (Aythya valisineria) male, California

Tim Zurowski / Canvasback (Aythya valisineria) female, California

Tim Zurowski / Canvasback (Aythya valisineria) male flapping wings, California

Jan Wegener / Canvasback (Aythya valisineria) drake, British Columbia, Canada

Steve Gettle / Canvasback (Aythya valisineria) male in breeding plumage, Saginaw Bay, Michigan

Steve Gettle / Canvasback (Aythya valisineria) duck drake paddling, Michigan

Donald M. Jones / Canvasback (Aythya valisineria) spring courtship flight, central Montana

Donald M. Jones / Canvasback (Aythya valisineria) spring courtship flight, central Montana

Michael Quinton / Canvasback (Aythya valisineria) drake, Alaska

Donald M. Jones / Canvasback (Aythya valisineria) flock flying during spring migration, central Montana

Tom Vezo / Canvasback (Aythya valisineria) duck, flock coming in to land, sunrise, Long Island, New York

Jim Brandenburg / Canvasback (Aythya valisineria) duck diving underwater in search of food, North America

Jeff Foott / Canvasback (Aythya valisineria) male bathing, Utah

Jeff Foott / Canvasback (Aythya valisineria) male and female, Utah

E.J. Peiker/ BIA / Canvasback (Aythya valisineria) male, Arizona

E.J. Peiker/ BIA / Canvasback (Aythya valisineria) male, Arizona

E.J. Peiker/ BIA / Canvasback (Aythya valisineria) female, Arizona

Tim Zurowski / Canvasback (Aythya valisineria) male, California