The canvasback duck (Aythya valisineria) is a species of diving duck found in North America. It gets its name from the coloration and texture of its back and wings, which resemble canvas fabric.
Naming and Classification
The canvasback belongs to the genus Aythya in the family Anatidae. This family contains ducks, geese, and swans. The species name valisineria refers to one of the canvasback’s preferred foods, wild celery (Vallisneria americana).
The canvasback was first scientifically described by Carl Linnaeus in 1758 in the 10th edition of his Systema Naturae. Linnaeus gave it the binomial name Anas valisineria. In 1822, William Elford Leach moved the species to the genus Aythya.
There are two theories about the origin of the name “canvasback”:
- The male’s back appears as white as a canvas sail on a boat.
- The feathers resemble the rough surface of canvas fabric.
The second theory is considered more likely to be the origin of the name. The canvaslike texture comes from the male’s black, gray, and white vermiculated (wormlike) feather patterns.
Description
The canvasback is a large diving duck species. It measures 19-24 inches (48-61 cm) long with a wingspan of 34 inches (86 cm). Males weigh 3-3.75 lbs (1.4-1.7 kg) while females are slightly smaller at 2-2.5 lbs (0.9-1.1 kg).
Other key identification features include:
- Long sloping bill that is blackish blue and about 2.5 inches (6.4 cm) long
- Red eyes
- White belly
- Gray sides
- Black breast and rump
- Pale gray wings
Females have a light brown head and neck and lack the male’s dramatic plumage patterns. Immature birds resemble adult females until their second year.
Range and Habitat
Canvasbacks breed in the Prairie Pothole Regions of central North America. This area encompasses parts of Canada and the northern United States including Minnesota, North Dakota, South Dakota, Montana, Manitoba, Saskatchewan, and Alberta.
They prefer to nest over water in emergent marsh vegetation near ponds and wetlands. Favored plants include bulrushes, cattails, and reeds.
During winter, canvasbacks migrate south and congregate on coastal bays, estuaries, and lakes. On the Atlantic Coast, they are found from Maine to Florida. On the Pacific Coast, they range from Alaska to Baja California in Mexico.
Some key wintering grounds include:
- Chesapeake Bay
- Long Island Sound
- Lake St. Clair between Michigan and Ontario
- San Francisco Bay
Diet
Canvasbacks are omnivorous. Their diet consists of both plant and animal foods. Some key foods include:
- Roots, stems, leaves, and seeds of aquatic plants – Especially wild celery, pondweeds, widgeongrass
- Insects – Mayflies, caddisflies, midges
- Crustaceans – Crayfish, crabs
- Mollusks – Snails, mussels, clams
- Fish eggs and larvae
The canvasback’s bill is specially adapted for digging roots and tubers out of the muddy bottom. Its broad, 2.5 inch long bill acts like a shovel. Wild celery tubers make up the majority of the canvasback’s diet in some areas.
Breeding
Canvasbacks become sexually mature by 2 years old and form monogamous pairs during the breeding season. Peak breeding occurs from late March through May.
The female builds a nest lined with down and vegetation in marshy areas over shallow water. Nesting near water provides protection from predators. Ideal water depth is less than 4 feet deep.
She lays 6-12 pale greenish buff eggs and incubates them for 24-29 days. The eggs hatch one per day. The ducklings leave the nest shortly after hatching.
The female cares for the young while the male leaves after mating. The ducklings fledge at 45-55 days old but may stay with the female for up to 3 months.
Population Status
Canvasback populations declined significantly in the early 20th century due to hunting and wetland loss. Their numbers fell to a low of about 504,000 in 1970.
Conservation efforts including hunting restrictions and wetland protection programs have allowed canvasback numbers to rebound. Current populations estimate around 750,000 birds.
Canvasbacks are protected under the Migratory Bird Treaty Act but can be legally hunted during designated hunting seasons.
Fun Facts
- Nicknames for the canvasback include “bluebill”, “bullneck”, and “king of ducks”
- Canvasbacks can dive to depths up to 10 feet to find food
- They migrate in V-shaped flocks but often spend winter gathered in large rafts of thousands of birds
- The male’s “canvas” plumage stands out and attracts females during courtship
- Their legs are located far back on the body, which is good for diving but makes walking on land more difficult
Conclusion
The canvasback duck gets its distinctive name from the canvas-like appearance of its plumage. This is created by intricate vermiculated patterns in black, gray, and white. Besides inspiring its name, the male’s back also plays an important role in courtship displays to attract a mate.
This species depends on abundant aquatic vegetation for food. Loss of wetland habitat contributed to population declines in the past. But protected breeding grounds and wintering sites have now allowed canvasback numbers to recover.
An iconic North American duck, the canvasback remains a favorite among hunters and birdwatchers alike. Its adaptions for diving help it thrive in shallow ponds and flooded fields where it dabbles through mud for roots and tubers.
Scientific Name | Aythya valisineria |
---|---|
Common Name | Canvasback |
Identification | 19-24 inches long; pale gray body, sloping black bill, black breast, white belly; male has distinctive black, gray, and white “canvas” pattern on back |
Habitat | Nests in shallow prairie marshes. Winters on coastal bays, lakes, and ponds. |
Diet | Omnivorous – eats roots, stems, leaves of aquatic plants as well as mollusks, crustaceans, insects, and fish |
Status | Populations recovered to ~750,000 birds after declines in the 1900s |
The canvasback duck is a fascinating bird with unique adaptations to its wetland lifestyle. Its versatile bill allows it to feed on both plant and animal foods. Watch for canvasbacks on your next visit to a lake, marsh, or bay to catch a glimpse of their distinctive profile and canvas-colored back plumage.
References
- Baldassarre, G. (2014). Ducks, geese, and swans of North America. JHU Press.
- Bellrose, F. (2010). Ducks, geese and swans of North America. Stackpole Books.
- Kear, J. (2005). Ducks, geese and swans: general chapters, species accounts (Anhima to Salvadorina). Oxford University Press.
- Sibley, D. (2014). The Sibley guide to birds (2nd ed.). Knopf Doubleday Publishing Group.
- Cornell Lab of Ornithology. Canvasback duck life history. Retrieved from https://www.allaboutbirds.org/guide/Canvasback