Canvasback

The canvasback (Aythya valisineria) is a species of diving duck, recognized as the largest of its kind in North America. It boasts a distinctive wedge-shaped head and a long, elegant neck. The adult male, or drake, is characterized by a chestnut red head and neck, a black breast, and a white body with fine vermiculation. The female, or hen, displays a more subdued palette with a light brown head and neck, and grayish brown body. Both sexes have black bills and bluish-gray legs and feet.

Identification Tips

To identify the canvasback, look for its unique head shape and the male's striking red eyes, particularly vibrant in the spring. The male's chestnut head contrasts with its white body, while the female's muted tones blend with the marshes. The canvasback's profile is sloped, setting it apart from other ducks.

Habitat

Canvasbacks breed in North American prairie potholes and prefer nesting over water in permanent prairie marshes surrounded by emergent vegetation. In winter, they seek brackish estuarine bays and marshes with abundant vegetation and invertebrates.

Distribution

During migration, canvasbacks travel through the Mississippi Flyway to the mid-Atlantic United States and the Lower Mississippi Alluvial Valley, or along the Pacific Flyway to California's coast. Some have been recorded as far as the United Kingdom.

Behaviour

Canvasbacks are known for taking new mates each year, pairing in late winter. They are strong divers and agile fliers, often seen stretching their wings on the water's surface.

Song & Calls

The canvasback's vocalizations are less documented in this context, but like many ducks, they likely have a range of quacks and calls used for communication, especially during mating season.

Breeding

The canvasback's bulky nest is built from marsh vegetation and lined with down. They have a clutch size of 5–11 greenish drab eggs, and the chicks are precocial, able to leave the nest shortly after hatching. Canvasbacks may lay eggs in other nests, and their nests can be parasitized by redheads.

Similar Species

The canvasback can be confused with the redhead duck, but the canvasback's sloping profile and larger size are distinguishing features.

Diet and Feeding

Canvasbacks primarily feed on plant material, diving for seeds, buds, and tubers, with a preference for wild celery and sago pondweed. They have adapted to changes in food availability, shifting their diet to include more animal matter like Baltic Clams when necessary.

Conservation status

The canvasback has experienced population fluctuations, with low numbers in the 1980s raising concern. However, populations have since increased, though they remain vulnerable to drought and wetland drainage. Conservation efforts focus on protecting key breeding and feeding grounds.