I have oftentimes attempted to imagine what it would have been like to be an early 19th century explorer from Europe who had the opportunity to provide names to animals for the first time. Sometimes, the common names of animals can be quite fitting; at other times, not so much. The common name of a migratory species of waterfowl that I will be writing about today falls into that latter category … maybe just because I have nary an artistic bone in my body.
The canvasback (Aythya valisineria) is a migratory species that spends the summer breeding primarily in the western Midwestern states through western Canada into southeastern Alaska. During the colder winter months, it can be found sea to shining sea in the southern half of the United States, including throughout the entire state of Texas. Nearly any body of water is utilized as habitat, although it generally prefers waters that are at a minimum depth of three feet.
As I mentioned, the common name for the canvasback can be a bit confusing. Apparently, the early Europeans thought that the back of this large duck was “canvas-like” in appearance. Yes, the back can superficially resemble a blank canvas with its smoky gray, lightly mottled coloration in both sexes. Males and females also have black tails as well as long, black bills. But males have a dark, maroon colored neck and head with a black breast while the female has a more subtle rusty colored neck, breast and head. Both sexes also have a characteristic sloping profile; whereas other duck species have a more rounded slope on the front of the skull (like that of a rollercoaster), the canvasback has more of a 45-degree slope to its skull.
The canvasback’s body size has been recorded to a length of 24 inches, while the wingspan is right at three feet. Males average nearly three pounds in weight while females top out around two and one-half pounds. These proportions make this species the largest of the five species of Aythya that occur in Texas.
This species of waterfowl is known as a diving duck which means that rather than just submerge its head and forebody under water to retrieve food, it dives and swims along the bottom of the waterway to feed. Being an omnivorous species, crustaceans make up approximately 80% of its diet during the breeding season while during migration and winter aquatic plants and crustaceans are fed upon at equal proportions. Unlike other members of this genus, this species only dives down to a maximum of seven feet below the surface to forage; other members can dive as deep as 40 feet.
This variety of aquatic bird prefers to live in small colonies, although during the breeding season it chooses to nest solitarily. This nest is constructed exclusively by the female and is generally built along marshy areas in strands of vegetation, although occasional nests are built on dry land. Canvasbacks are a monogamous species that breeds during the summer months and lays between seven and 12 two and one-half-inch long grayish or greenish eggs that are incubated by the female. This incubation period is generally just under a month, after which time the almost self-reliant young will leave the nest. They can feed themselves but are protected by the mother. Hatchlings begin to take flight as early as two months of age. This species typically only produces one brood annually.
Studies have shown that the population dynamics of this species have stabilized over the past two decades. It can be quite abundant in many areas. The main concern for the conservation of this species is the loss of nesting habitat.
Michael Price is owner of Wild About Texas, an educational company that specializes in venomous animal safety training, environmental consultations and ecotourism. Contact him at firstname.lastname@example.org.
This article originally appeared on San Angelo Standard-Times: Canvasback ducks call Texas home during the winter