Aythya valisineria

Although this duck’s rufous-red is one of its most striking field marks, the male Canvasback is not the only duck in North America with this pattern of coloration. In many parts of its range, this species occurs side by side with the closely-related Redhead (Aythya americana), and a couple field marks must be noted in order to distinguish the two. The Canvasback is slightly larger (20-24 inches), has a longer bill, and is much lighter on the back and flanks. Males have a red head and white body (resembling a sheet of blank canvas from a distance), while females are mostly light grayish-brown. The Canvasback breeds primarily in the northern Great Plains, the northern Rockies, western Canada, and Alaska. Most Canvasback populations migrate south in winter to the southern two-thirds of the United States and into Mexico. In its wintering range, this species is more common inland than the Redhead. Canvasbacks breed in lakes, ponds, marshes and bays. In winter, this species utilizes similar habitats as it does during the breeding season. In summer, Canvasbacks eat both aquatic plants and animals, such as small insects and mollusks; in winter, they feed primarily on plant matter, particularly the wild celery plant (Vallisneria americana) from which this species derives its scientific name. One of several species of “diving ducks” in North America, Redheads may be observed submerging themselves to feed on aquatic plant matter. In winter, they may also be observed in large flocks on coastal bays and lagoons. This species is primarily active during the day.

Threat Status: Least concern

Canvasbacks breed in the prairie pothole region of central North America, from Colorado and Nevada north through Canada to central Alaska. Breeding populations seems to be moving farther northward in recent years. The winter range is from Pacific coast across the central prairie states to the southern Great Lakes and south to Florida, Mexico, and Baja California. The largest winter concentrations of canvasbacks are found in Lake St. Clair, the Detroit River and eastern Lake Erie, Puget Sound, San Francisco Bay, the Mississippi River delta, the Chesapeake Bay and Currituck and Pamlico sounds in North Carolina.

Biogeographic Regions: nearctic (Native )

Breeds North America; winters to s Mexico.

Canvasbacks breed from central Alaska and northern Yukon to western
Ontario and south to southeastern Alaska; and locally in inland areas to
northeastern California across to northern Utah, central New Mexico,
northernwestern Iowa, and southern Ontario. They winter from along the
Pacific Coast from the central Aleutians and southeastern Alaska south
to Baja California; from Arizona and New Mexico to the Great Lakes; and,
along the Atlantic Coast from New England south to the Gulf Coast and
Mexico [3,8]. Canvasbacks also occasionally winter in Cuba, Bermuda,
and Guatemala [12].

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This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

1 Northern Pacific Border
2 Cascade Mountains
3 Southern Pacific Border
4 Sierra Mountains
5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
8 Northern Rocky Mountains
9 Middle Rocky Mountains
10 Wyoming Basin
11 Southern Rocky Mountains
12 Colorado Plateau
13 Rocky Mountain Piedmont
14 Great Plains
15 Black Hills Uplift
16 Upper Missouri Basin and Broken Lands

AL AK AZ AR CA CO CT DE FL GA HI ID IL IN IA KS KY LA ME MD MA MI MN MS MO MT NE NV NH NJ NM NY NC ND OH OK OR PA RI SC SD TN TX UT VT VA WA WV WI WY

AB BC MB NB NF NT NS ON PE PQ SK YT

MEXICO

North America; Northern Cape Cod and extending south into the Gulf of Mexico

Gulf of Maine, Gulf of Mexico, North West Atlantic

Canvasbacks breed in the prairie pothole region of central North America, including the United States from Colorado and Nevada north through British Columbia, Alberta, Saskatchewan, Manitoba, the Northwest Territories, the Yukon, and central Alaska. Breeding populations seems to be moving farther northward in recent years. The winter range is from the coastal Pacific Northwest across central prairie states to the southern Great Lakes and south to Florida, Mexico, and Baja California. Largest winter concentrations of canvasbacks are found in Lake St. Clair, the Detroit River and eastern Lake Erie, Puget Sound, San Francisco Bay, the Mississippi River delta, the Chesapeake Bay and Currituck and Pamlico sounds in North Carolina.

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDS: central Alaska, central Yukon, northern Northwest Territories (Mackenzie Delta), and southeastern Manitoba south to northern California, western Nevada, northern Utah, northern Colorado, Nebraska, and Minnesota. WINTERS: southern British Columbia, northwestern Montana, northern Colorado, northern Tennessee to eastern Great Lakes, Chesapeake Bay, eastern Massachusetts, and Quebec, south to central Mexico, Gulf states, northern Florida; rarely Hawaii. In the U.S., the highest winter densities occur in the Chesapeake Bay region and at the Bitter Lake NWR in eastern New Mexico (Root 1988). Over 25% of the continental population winters in Louisiana. Winter populations in the Atlantic flyway are more concentrated than those in Mississippi flyway (Serie et al. 1983). About 83% of the western North American population overwinters for 4-6 months in California, primarily in San Francisco Bay (Reinecker, 1985, Calif. Fish Game 71:141-149).

Canvasbacks are sometimes called the "aristocrat of ducks" for their elegant appearance. Canvasbacks are the largest diving duck (Aythya) species. Males are slightly larger, from 51 to 56 cm in body length and 863 to 1,589 g mass. Females are from 48 to 52 cm in body length and 908 to 1,543 g in mass. Canvasbacks are distinguished by their large size and characteristic long, sloping profile and wedge-shaped head that is held erect on their long necks. Canvasback breeding plumage, which they keep for most of the year, is striking. Males have rich, reddish-brown heads and necks, black breasts, and white wings, sides, and belly. The rump and tail feathers are black. The feet and legs are dark grey and the bill is black. Female breeding plumage is much more subdued, but similar to males; the head and neck are brownish, the wings, sides, and belly are white or gray, and the tail and breast are dark brown. Non-breeding males and females, and immature individuals, are generally brownish overall. Canvasbacks are sometimes confused with their close relatives: Aythya americana, Aythya marila and Aythya affinis.

Range mass: 863 to 1589 g.

Range length: 48 to 56 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger; sexes colored or patterned differently; male more colorful

Canvasbacks are sometimes called the "aristocrat of ducks" for their elegant appearance. Canvasbacks are the largest diving duck (Aythya) species. Males are slightly larger, from 51 to 56 cm in body length and 863 to 1,589 g mass. Females are from 48 to 52 cm in body length and 908 to 1,543 g in mass. Canvasbacks are distinguished by their large size and characteristic long, sloping profile and wedge-shaped head that is held erect on their long necks. Canvasback breeding plumage, which they keep for most of the year, is striking. Males have rich, reddish-brown heads and necks, black breasts, and white wings, sides, and belly. The rump and tail feathers are black. The feet and legs are dark grey and the bill is black. Female breeding plumage is much more subdued, but similar to males; the head and neck are brownish, the wings, sides, and belly are white or gray, and the tail and breast are dark brown. Non-breeding males and females, and immature individuals, are generally brownish overall. Canvasbacks are sometimes confused with their close relatives: redheads, greater scaup and lesser scaup.

Range mass: 863 to 1589 g.

Range length: 48 to 56 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger; sexes colored or patterned differently; male more colorful

Length: 53 cm

Weight: 1248 grams

In the breeding season canvasbacks are found in areas with small ponds, slow moving rivers, and dense vegetation. Most breeding occurs in areas of central Canada characterized by aspen woodlands, grasslands, and potholes. Canvasbacks prefer breeding in small lakes and ponds or marshes with dense emergent vegetation, such as cattails and reeds. During spring and fall migration and winter canvasbacks are found in aquatic areas with high densities of food availability, including estuaries, large freshwater lakes, coastal bays and harbors, and large river deltas. During migration they may also use flooded fields, farm ponds, and wetlands.

Habitat Regions: temperate ; saltwater or marine ; freshwater

Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water

Wetlands: marsh

Other Habitat Features: estuarine

More info for the term: cover

Canvasbacks select stands of emergent vegetation for nesting cover [7].
Canvasback broods seek the most open, the largest, and the deepest
potholes for their development [1].

More info for the term: marsh

Breeding/nesting habitat - Canvasbacks breed and nest on large marshes,
ponds, sloughs, and potholes [1]. Pairs occupy the larger, deeper ponds
for feeding, resting, and courting but use the smaller, shallower ponds
for nesting. These ponds are usually less than an acre and are
encircled by bands of cattails and bulrushes. Brood ponds are
intermediate in size between those used for feeding and for nesting but
contain considerable marsh vegetation [1].

Canvasbacks usually nest over water 6 to 24 inches (15-60 cm) deep
[1,3]. They sometimes build their nests on muskrat houses and rarely on
dry ground. They attach the nest to surrounding plants or build it on a
mat of floating dead plants, generally 3 to 60 feet (0.9-18.3 m) from
the edge of open water [3,7].

Migration and winter habitat - Large lakes of 150 acres (61 ha) or more,
marshes, and rivers with submerged beds of pondweed are favored during
migration. Canvasbacks winter primarily on estuaries, sheltered bays,
coastal lagoons, and sometimes on deep freshwater lakes [3,8].

More info for the terms: cover, fresh

Canvasbacks are found on marshes or large lakes scattered throughout
boreal forests, on mixed prairies, and on the drier shortgrass prairies
[1]. Within these plant associations, canvasbacks often inhabit shallow
prairie marshes surrounded by bulrushes (Scirpus spp.), cattails (Typha
spp.), sedges (Carex spp.), reeds (Phragmites spp.), and other similar
emergent vegetation [1,8].

Canvasback nests are often located in pure stands of hardstem bulrush
(Scirpus acutus) or in hardstem bulrush mixed with cattail, burreed
(Sanguisorba spp.), or sedges [1,7]. In prairie pothole areas, cattails
are commonly used for nesting cover. At Lousana, Alberta, 29 percent of
canvasback nests were among flooded willows (Salix spp.); at Redvers,
Saskatchewan, 9 percent were among willows. On the Saskatchewan Delta,
most nests were located in reed [1].

During winter, beds of wild celery (Vallesniria spp.) in fresh water
habitats are heavily utilized by canvasbacks as are pondweeds
(Potamogeton spp.), widgeongrass (Ruppia maritima), and eelgrass
(Zostera marina) in more brackish areas. In the interior of the
continent, lakes and marshes with heavy growths of pondweeds and wild
celery provide major concentration points for canvasbacks [8].

REFERENCES :
NO-ENTRY

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This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

More info for the term: bog

K047 Fescue - oatgrass
K048 California steppe
K049 Tule marshes
K050 Fescue - wheatgrass
K051 Wheatgrass - bluegrass
K054 Grama - tobosa prairie
K057 Galleta - three-awn shrubsteppe
K063 Foothills prairie
K064 Grama - needlegrass - wheatgrass
K065 Grama - buffalograss
K066 Wheatgrass - needlegrass
K067 Wheatgrass - bluestem - needlegrass
K068 Wheatgrass - grama - buffalograss
K069 Bluestem - grama prairie
K070 Sandsage - bluestem prairie
K072 Sea oats prairie
K073 Northern cordgrass prairie
K074 Bluestem prairie
K075 Nebraska Sandhills prairie
K076 Blackland prairie
K077 Bluestem - sacahuista prairie
K078 Southern cordgrass prairie
K079 Palmetto prairie
K080 Marl - everglades
K088 Fayette prairie
K092 Everglades
K094 Conifer bog
K105 Mangrove

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

FRES10 White-red-jack pine
FRES11 Spruce-fir
FRES16 Oak-gum-cypress
FRES17 Elm-ash-cottonwood
FRES23 Fir-spruce
FRES28 Western hardwoods
FRES36 Mountain grasslands
FRES37 Mountain meadows
FRES38 Plains grasslands
FRES39 Prairie
FRES40 Desert grasslands
FRES41 Wet grasslands
FRES42 Annual grasslands

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This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

95 Black willow
106 Mangrove
222 Black cottonwood - willow
235 Cottonwood - willow

Systems

• Terrestrial
• Freshwater
• Marine

In the breeding season canvasbacks are found in areas with small ponds, slow moving rivers, and dense vegetation. Most breeding occurs in the aspen parklands of central Canada, characterized by aspen woodlands, grasslands, and potholes. Canvasbacks prefer breeding in small lakes and ponds or marshes with dense emergent vegetation, such as cattails (Typha), bulrush (Scirpus acutus), reeds (Phragmites communis), and rivergrass (Scholochloa festucacea). During spring and fall migration and winter canvasbacks are found in aquatic areas with high densities of food availability, including estuaries, large freshwater lakes, coastal bays and harbors, and large river deltas. During migration they may also use flooded fields, farm ponds, and wetlands.

Habitat Regions: temperate ; saltwater or marine ; freshwater

Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water

Wetlands: marsh

Other Habitat Features: estuarine

Depth range based on 249 specimens in 1 taxon.

Environmental ranges
  Depth range (m): 0 - 0
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Comments: Marshes, ponds, lakes, rivers and bays. Winters on deep, freshwater lakes and rivers as well as on sheltered bays and estuaries (AOU 1983).

Nests in emergent vegetation in freshwater marshes, including those bordering lakes, ponds, or rivers; study in Manitoba indicated need for secure nesting site in a diversified wetland complex containing a variety of size, permanency, and cover types (favored different conditions for acitivities such as nesting, feeding, and brood rearing) (Stoudt 1982). Sometimes nests on old muskrat house or on dry ground. Females typically breed in their natal area.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Begins migrating northward in February from coastal U.S. Reaches northern nesting areas in April (late May or early June in far north). In fall may begin migrating southward October-November. Upper Mississippi River is an important staging area for populations wintering in different areas (Serie et al. 1983).

Canvasbacks are omnivorous, eating both plants and animals as they are available. In winter and migration they mainly eat aquatic plants, especially the underwater roots. They may also take small snails and clams during this time. In the breeding season canvasbacks eat aquatic plants and animals, including the seeds, buds, leaves, and roots of aquatic plants and Gastropoda, Tricoptera, Odonata, Ephemeroptera, and Tendipedidae. Canvasbacks forage in small to very large groups (over 1000) and mainly in the morning and evening. They can dive to more than 5 meters deep for 10 to 20 seconds. They take food in a variety of ways, including diving, stripping plants with their feet or beaks, and grabbing prey from the water surface or air. In a dive they use their strong, cone-shaped heads to probe and pull-up submerged plants.

The scientific name of canvasbacks comes from their favorite winter food, the aquatic plant Vallisneria_americana, or wild celery.

Animal Foods: insects; mollusks

Plant Foods: leaves; roots and tubers; wood, bark, or stems; seeds, grains, and nuts

Canvasbacks dive in shallow water, usually 3 to 12 feet (0.9-3.6 m)
deep, for food. Their diet generally consists of about 80 percent
vegetative matter [3]. In the northeastern United States, canvasbacks
prefer seeds and vegetative parts of wild celery; in the Southeast and
the West they primarily consume pondweeds. They also feed on bulrush
seeds, widgeongrass, eelgrass, arrowhead (Sagittaria spp.) and coontail
(Ceratophyllum demersum). Animal matter consumed by canvasbacks mostly
consists of mollusks, insects, fish, and mud crabs [1,3,10].

Management of food resources on canvasback staging areas must emphasize
wild celery and other plants that produce tubers, such as arrowhead and
pondweeds [10].

Canvasbacks are omnivorous and opportunistic. In winter and migration they mainly eat aquatic vegetation, including buds, roots, tubers, and rhizomes. They may also take small snails and clams during this time. In the breeding season canvasbacks eat aquatic plants and animals, including seeds, buds, leaves, rhizomes, tubers, and roots and snails, caddisfly larvae (Tricoptera), damselfly and dragonfly nymphs (Odonata), mayfly nymphs (Ephemeroptera), and midge larvae (Chironomidae). Outside of the breeding season canvasbacks forage in small to very large groups (over 1000 individuals) and mainly in the morning and evening. These diving ducks can dive to more than 5 meters depth for 10 to 20 seconds, although they usually dive from 0.5 to 2 meters deep. They take food in a variety of ways, including diving, stripping plants with their feet or beaks, and grabbing prey from the water surface or air. In a dive they use their robust, cone-shaped heads to probe and excavate submerged plants.

The scientific name of canvasbacks comes from their favorite winter food, the aquatic plant Vallisneria americana, or wild celery.

Animal Foods: insects; mollusks

Plant Foods: leaves; roots and tubers; wood, bark, or stems; seeds, grains, and nuts

Primary Diet: omnivore

Comments: Feeds on aquatic plants; pondweeds, wild celery, water lilies, seeds of grasses, wild rice, CYPERUS, SAGITTARIA, SCIRPUS, etc.; rhizomes, tubers, and seeds figure prominently in winter diet. Also eats some animal food; mollusks, aquatic insects, small fishes, etc. Feeds by diving from surface of water.

Canvasbacks form large groups in the non-breeding season, which can have a substantial effect on local aquatic ecosystems. Canvasbacks are infected by a variety of diseases and parasites

Other canvasbacks and two other duck species will lay their eggs in canvasback nests, a form of parasitism called "nest-parasitism." The most important nest parasites of canvasbacks are their close relatives Aythya americana, they are also parasitized by Oxyura jamaicensis. Canvasback nests with redhead eggs in them are more likely to have the canvasback eggs damaged, be abandoned by the parents, and the ducklings are less likely to survive.

Commensal/Parasitic Species:

• renal coccidia (Eimeria_truncata)
• malaria (Plasmodium_circumflexum)
• blood parasite (Leucocytozoon_simondi)
• blood parasite (Haemoproteus_nettionis)
• parasitic trematodes (Typhlocoelum_cucumerinum)
• bird fleas (Ceratophyllus)
• bird lice (Austromenopon_leucoxanthum)
• ticks (Ixodidae)
• ticks (Argasidae)
• leeches (Hirudinea)
• redheads (Aythya_americana)
• ruddy ducks (Oxyura_jamaicensis)

Canvasback eggs and young are preyed on by a variety of nest predators, including Procyon lotor, Mephitis mephitis, Vulpes vulpes, Mustela vison, Mustela erminea, Corvus brachyrhynchos, Pica hudsonia, Corvus corax, and Larus californicus. Adults and fledglings are preyed on by raptors as well as large terrestrial and aquatic predators, including: Mustela vison, Canis latrans, Larus marinus, Haliaeetus leucocephalus, Bubo virginianus, Nycticorax nycticorax, Chelydra serpentina, and Esox lucius.

When a female notices a predator near her nest, she silently swims away to distract attention. If the young are hatched, the female uses a warning call so that the young swim into thick vegetation. Outside of the breeding season canvasbacks form large groups to help protect against predation. Predation accounts for up to 60% of duckling mortality.

Known Predators:

• raccoons (Procyon_lotor)
• striped skunks (Mephitis_mephitis)
• red foxes (Vulpes_vulpes)
• mink (Mustela_vison)
• ermine (Mustela_erminea)
• American crows (Corvus_brachyrhynchos)
• black-billed magpies (Pica_hudsonia)
• common ravens (Corvus_corax)
• California gulls (Larus_californicus)
• coyotes (Canis_latrans)
• great black-backed gulls (Larus_marinus)
• bald eagles (Haliaeetus_leucocephalus)
• great horned owls (Bubo_virginianus)
• black-crowned night herons (Nycticorax_nycticorax)
• snapping turtles (Chelydra_serpentina)
• northern pike (Esox_lucius)

More info for the terms: cover, marsh

The heaviest nest destruction by predators commonly occurs during the
egg-laying period when the hen is off the nest [7]. Raccoons are the
most common predators of canvasback nests. In 1973 one study reported
that this predator was responsible for 60 percent of all canvasback
nests destroyed in the Minnesota potholes in Manitoba [1]. Skunks are
the second most important mammalian predator of canvasback nests in the
prairie breeding grounds. They are especially destructive in years when
water recedes from marginal marsh cover, leaving nests stranded on dry
ground, or when low water at the beginning of the nesting season
necessitates placing nests out of the water. Coyotes, foxes, minks,
weasels, crows, and magpies also prey upon canvasback nests [1].
Additionally coyotes, foxes, minks, and weasels prey on ducklings and
adults.

Canvasbacks form large foraging groups in the non-breeding season, these large numbers of animals feeding on aquatic plants and animals can have a substantial effect on local aquatic ecosystems. Canvasbacks are infected by a variety of diseases and parasites, including renal coccidia (Eimeria truncata), malaria (Plasmodium circumflexum), blood parasites (Leucocytozoon simondi and Haemoproteus nettionis), parasitic trematodes (Typhlocoelum cucumerinum), bird fleas (Ceratophyllus), bird lice (Austromenopon leucoxanthum), and ticks (Ixodidae and Argasidae). In some areas canvasbacks are also parasitized by leeches (Hirudinea).

Canvasback females may lay their eggs in the nests of other canvasback females, making them intra-specific nest parasites. Canvasbacks are also subject to nest parasitism by redheads (Aythya americana) and ruddy ducks (Oxyura jamaicensis). Male canvasbacks are important in protecting new nests from nest parasitism, they drive away other species aggressively. Because redheads often lay their eggs in canvasback nests about 1 week after incubation begins, aggressive encounters between canvasbacks and nest parasites at the nest often result in egg loss through breakage. Canvasback eggs are about five times as likely to crack as redhead eggs. Parasitized nests are more likely to be abandoned and ducklings from parasitized nests have lower survival rates than those from non-parasitized nests.

Commensal/Parasitic Species:

• renal coccidia (Eimeria truncata)
• malaria (Plasmodium circumflexum)
• blood parasite (Leucocytozoon simondi)
• blood parasite (Haemoproteus nettionis)
• parasitic trematodes (Typhlocoelum cucumerinum)
• bird fleas (Ceratophyllus)
• bird lice (Austromenopon leucoxanthum)
• ticks (Ixodidae)
• ticks (Argasidae)
• leeches (Hirudinea)
• redheads (Aythya americana)
• ruddy ducks (Oxyura jamaicensis)

Canvasback eggs and young are preyed on by a variety of nest predators, including raccoons, striped skunks, red foxes, mink, ermine, American crows, black-billed magpies, common ravens, and California gulls. Adults and fledglings are preyed on by raptors as well as large terrestrial and aquatic predators, including: mink, coyotes, great black-backed gulls, bald eagles, great horned owls, black-crowned night herons, snapping turtles, and northern pike.

When a female notices a predator near her nest, she silently swims away to distract attention. If the young are hatched, the female uses a warning call so that the young swim into thick vegetation. Outside of the breeding season canvasbacks form large groups to help protect against predation. Predation accounts for up to 60% of duckling mortality.

Known Predators:

• raccoons (Procyon lotor)
• striped skunks (Mephitis mephitis)
• red foxes (Vulpes vulpes)
• mink (Neovison vison)
• ermine (Mustela erminea)
• American crows (Corvus brachyrhynchos)
• black-billed magpies (Pica hudsonia)
• common ravens (Corvus corax)
• California gulls (Larus californicus)
• coyotes (Canis latrans)
• great black-backed gulls (Larus marinus)
• bald eagles (Haliaeetus leucocephalus)
• great horned owls (Bubo virginianus)
• black-crowned night herons (Nycticorax nycticorax)
• snapping turtles (Chelydra serpentina)
• northern pike (Esox lucius)

More info for the terms: cover, marsh

Fire can remove canvasback nesting cover [5]. Large-scale autumn
burning may have a detrimental effect upon marshes by reducing the
retention of drifting snow, which adds heavily to spring run-off. The
ability of marsh vegetation to catch and hold snow is vital to marsh
survival [17].

Fire can also improve the habitat for canvasbacks. Fire often removes
excessive accumulations of fast-growing hydrophytes, permitting better
waterfowl access and growth of more desirable duck foods [16].

Pair bonding - Canvasback pair bonding takes place in late winter. Most
canvasbacks arrive on their breeding grounds already paired [12].

Nesting - Canvasbacks begin to nest in late April or early May [1].
Even in the subarctic, canvasbacks nest almost as early as in the
northern prairies [1]. The nesting season generally lasts from April to
June [1,12].

Clutch size/incubation - Determining the clutch size in canvasback nests
is complicated by the effect of redhead (Aythya americana) parasitism on
the number of host eggs. When redheads lay in canvasback nests, host
clutches are reduced in size. Clutches usually consist of 7 to 12 eggs
and average 9 1/2 in nonparasitized nests. Clutches are somewhat
smaller in parasitized nests [1,8]. Female canvasbacks seldom lay eggs
in the nests of other species but commonly parasitize the nests of other
canvasback hens [1].

The incubation period normally lasts about 24 days but sometimes as long
as 29 days [7,8]. The inclusion of eggs laid by other females sometimes
results in several unhatched eggs being left in the nest at the time of
general hatching [8].

Fledging - Fledging requires about 56 to 68 days [8].

Age at sexual maturity - Canvasbacks become sexually mature their first
winter [7,8].

Molting - Drakes begin to gather on molting grounds shortly after
females start incubation. Most have completed their prenuptual molt by
mid-October or early November. Hens begin to molt after leaving their
broods in the fall [7].

Migration/Fall - Canvasbacks begin to migrate into the Northern Great
Plains in early September. Numbers slowly build up to late October,
followed by rapid departures in early November. Canvasbacks in the east
arrive in the Great Lakes States in early October, reach peak numbers by
early November, and decline rapidly to wintering numbers by the end of
the month. Canvasbacks arrive on their winter grounds adjacent to the
central Gulf Coast in late November. Farther south on the lower Texas
coast, however, they arrive almost a month earlier [1]. They arrive on
winter grounds in central California in late October, and numbers
steadily increase through November and December. On winter grounds in
southern California, canvasbacks do not appear until late November and
rapidly increase in numbers through December [1].

Migration/spring - Canvasbacks begin departing many of their winter
areas in early February. On most winter areas, there is a steady
departure lasting almost to mid-April. On lakes midway to their
breeding grounds, canvasbacks appear in small numbers in late February,
with populations rapidly increasing through March. Canvasbacks begin to
arrive on the southern margins of their breeding grounds in the Great
Plains in early April [1].

Canvasbacks are generally quiet ducks, although they do use a variety of distress calls and emit a variety of coos and rattles as part of courtship behaviors. They use visual signals in courtship, through their displays.

Communication Channels: visual ; acoustic

Canvasbacks are generally quiet ducks, although they do use a variety of distress calls and emit a variety of coos and rattles as part of courtship behaviors. They use visual signals in courtship, through their displays.

Communication Channels: visual ; acoustic

The oldest wild canvasback captured was 22 years and 7 months old, the next longest recorded lifespan in a wild canvasback was 16 years 11 months.

Range lifespan
Status: wild: 22.6 (high) years.

The oldest wild canvasback captured was 22 years and 7 months old, the next longest recorded lifespan in a wild canvasback was 16 years 11 months. Annual survival rates for adults have been estimated at 82% for males and 69% for females. Canvasback mortality is documented as a result of hunting, collisions, toxin ingestion, and exposure during cold weather.

Range lifespan
Status: wild: 22.6 (high) years.

Maximum longevity: 29.5 years (wild)

Canvasbacks usually have a single mate each breeding season, although they may have a different mate in each breeding season. Courtship begins during the spring migration and continues on the breeding grounds. During the height of courtship, females may be surrounded by 3 to 8 males in "courting parties." Females choose their mate from these groups. There are a variety of courtship displays used between mates: the neck-stretch, incite behavior, a male sneak approach, kinked-neck, head-throw, and turning the back of the head.

Mating System: monogamous

Females choose the same home ranges for their nesting sites each year. Nests are started as early as late April, but nesting peaks in mid to late May and may continue into June. Pairs lay one brood per year, although they will re-nest if the first brood is destroyed. Nests are built in emergent vegetation above water, although they will occasionally build nests on land as long as it is in a protected area. They prefer medium to large sized, shallow wetlands with extensive emergent vegetation for breeding. Females lay from 5 to 11 smooth, elliptical, greenish drab eggs. Average reported clutch sizes vary regionally, but range from 6.6 to 8.3 eggs per nest. Clutch sizes may be affected by nest parasitism, with parasitized nests having smaller clutches. One egg is laid per day and the female begins to incubate the eggs a few days before the last egg is laid. Eggs are incubated for 24 to 29 days. Young are able to swim and forage soon after hatching. Young fledge at 56 to 68 days after hatching. In late August or September young canvasbacks form groups in preparation for migration. Canvasbacks are capable of breeding in the year after hatching.

Breeding interval: Canvasbacks breed once yearly.

Breeding season: Canvasbacks nest from April to June, with a peak in mid to late May.

Range eggs per season: 5 to 11.

Range time to hatching: 24 to 29 days.

Average time to hatching: 25 days.

Average birth mass: 44.7 g.

Range fledging age: 56 to 68 days.

Average age at sexual or reproductive maturity (female): 1 years.

Average age at sexual or reproductive maturity (male): 1 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate)

Females build nests and line them with plants and down feathers. Male canvasbacks are protective of their mate and the nest for the first few weeks that the eggs are being incubated. After that, they abandon the females and their nests. Young canvasbacks can swim and feed themselves as soon as their feathers dry after they hatch, although their mother will protect them against cold weather. Within a day after hatching the female and her brood abandon the nest and move into larger lakes and ponds with lots of vegetation. Females remain with their broods until close to migration in the fall. For broods that hatch late in the year, though, that may be at only 2 to 3 weeks old.

Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Protecting: Female); pre-independence (Protecting: Female)

Canvasbacks are seasonally monogamous. Courtship begins during the spring migration and continues on the breeding grounds. Males and females generally remain with a partner during the season, although occasional males have extra pair copulations or abandon a first mate for a second. Females use courtship displays to assess male quality, especially male ability to compete for food and space. During the height of courtship, receptive females are periodically surrounded by 3 to 8 males in "courting parties." There are a variety of courtship displays: the neck-stretch, incite behavior, a male sneak approach, kinked-neck, head-throw, and turning the back of the head. All are used to start and enforce the pair bond.

Mating System: monogamous

Females choose the same home ranges for their nesting sites each year. Nests are started as early as late April, but nesting peaks in mid to late May and may continue into June. Pairs lay one brood per year, although they will re-nest if the first brood is destroyed. Nests are built in emergent vegetation above water, although they will occasionally build nests on land as long as it is in a protected area. They prefer medium to large sized, shallow wetlands with extensive emergent vegetation for breeding. Females lay from 5 to 11 smooth, elliptical, greenish drab eggs. Average reported clutch sizes vary regionally, but range from 6.6 to 8.3 eggs per nest. Clutch sizes may be affected by nest parasitism, with parasitized nests having smaller clutches. One egg is laid per day and the female begins to incubate the eggs a few days before the last egg is laid. Eggs are incubated for 24 to 29 days. Young are able to swim and forage soon after hatching. Young fledge at 56 to 68 days after hatching. In late August or September young canvasbacks form groups in preparation for migration. Canvasbacks are capable of breeding in the year after hatching.

Females choose the same home ranges for their nesting sites each year. Nests are started as early as late April, but nesting peaks in mid to late May and may continue into June. Pairs lay one brood per year, although they will re-nest if the first brood is destroyed. Nests are built in emergent vegetation above water, although they will occasionally build nests on land as long as it is in a protected area. They prefer medium to large sized, shallow wetlands with extensive emergent vegetation for breeding. Females lay from 5 to 11 smooth, elliptical, greenish drab eggs. Average reported clutch sizes vary regionally, but range from 6.6 to 8.3 eggs per nest. Clutch sizes may be affected by nest parasitism, with parasitized nests having smaller clutches. One egg is laid per day and the female begins to incubate the eggs a few days before the last egg is laid. Eggs are incubated for 24 to 29 days. Young are able to swim and forage soon after hatching. Young fledge at 56 to 68 days after hatching. In late August or September young canvasbacks form groups in preparation for migration. Canvasbacks are capable of breeding in the year after hatching.

Breeding interval: Canvasbacks breed once yearly.

Breeding season: Canvasbacks nest from April to June, with a peak in mid to late May.

Range eggs per season: 5 to 11.

Range time to hatching: 24 to 29 days.

Average time to hatching: 25 days.

Average birth mass: 44.7 g.

Range fledging age: 56 to 68 days.

Average age at sexual or reproductive maturity (female): 1 years.

Average age at sexual or reproductive maturity (male): 1 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate)

Females build nests and continue to line them with plants and down feathers throughout the nest-building and incubation period. Male canvasbacks are protective of their mate and the nest, especially in the first week after incubation starts. After that time they begin to spend less time defending the nesting area from predators, other canvasbacks, and redheads. During incubation males abandon their mates and nests. Young are precocial at hatching and are able to swim as soon as their feathers dry. Females brood the young when the weather is cold, however. Within a day after hatching the female and her brood abandon the nest and move into larger bodies of water with abundant emergent vegetation. Females remain with their broods until close to migration. For broods that hatch late in the year, though, that may be at only 2 to 3 weeks old. Females do not feed their young, but they do protect them.

Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Protecting: Female); pre-independence (Protecting: Female)

Clutch size is 7-12 (usually 9-10). Incubation lasts 23-29 days, by female (Terres 1980). Nestlings are precocial and downy. Young are tended by female, first fly at 10-12 weeks (Harrison 1978). Commonly lays one or more eggs in nests of conspecifics, but this is a relatively unsuccessful reproductive tactic; parasitic female may or may not also lay eggs in her own nest (Sorenson, 1993, Auk 110:57-69). Nests commonly are parasitized by redhead in some areas.

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There are 6 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 6
Specimens with Barcodes: 8
Species With Barcodes: 1

Canada

Rounded National Status Rank: N5B,N4N : N5B: Secure - Breeding, N4N: Apparently Secure - Nonbreeding

United States

Rounded National Status Rank: N5B,N5N : N5B: Secure - Breeding, N5N: Secure - Nonbreeding

Canvasbacks are protected as migratory gamebirds in the United States, Mexico, and Canada. They are not considered threatened or endangered currently. Populations are affected by hunting pressure, habitat degradation, pollution, and collisions with cars or stationary objects. Hunting pressure is most intense during fall migration. In 1999 approximately 87,000 canvasbacks were taken by U.S. hunters. Because canvasbacks eat vegetation in aquatic sediments, they are susceptible to the toxins that accumulate in those sediments. This is especially true in areas of high industrial activity, such as the Detroit River.

IUCN Red List of Threatened Species: least concern

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

Canvasback is noted in the Audobon Society's Blue List as a species of
special concern [20].

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 2008
  Least Concern
• 2004
  Least Concern

Canvasbacks are protected as migratory gamebirds in the United States, Mexico, and Canada. They are not considered threatened or endangered currently. Populations are affected by hunting pressure, habitat degradation, pollution, and collisions with cars or stationary objects. Hunting pressure is most intense during fall migration. In 1999 approximately 87,000 canvasbacks were taken by U.S. hunters. Because canvasbacks eat vegetation in aquatic sediments, they are susceptible to the toxins that accumulate in those sediments. This is particularly true in areas of high industrial activity, such as the Detroit River.

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Rounded Global Status Rank: G5 - Secure

Global Short Term Trend: Unknown

Comments: After record low levels in 1988, there were indications of a population rebound in San Francisco Bay in the early 1990s (see Miles and Ohlendorf 1993). Overall, reproductive success was excellent in the mid-1990s (USFWS).

Global Long Term Trend: Decline of 50-70%

Comments: Wintering population in the U.S. and Canada declined by 57% from 1955 to 1974. Breeding population index declined from the mid-1970s until at least the late 1980s; spring breeding index for the eastern population was below the USFWS management objective in the 1980s (USFWS 1988, Di Silvestro 1986).

Comments: Has suffered from loss of breeding habitat (drained and cultivated). Susceptible to lead poisoning due to ingestion of shot while feeding (this threat should gradually disappear with lead shot ban). Declines in the western U.S. are not directly attributable to contaminants acquired by populations wintering in San Francisco Bay; however, evidence of high and increasing Se levels and elevated Hg levels warrant future monitoring (Miles and Ohlendorf 1993).

More info for the term: cover

Fire can be used to remove fast-growing, undesirable species and
increase desirable canvasback foods such as pondweed [15]. Controlled
burning can also be used to create nesting edge for ducks. Removal of
dense vegetation and woody encroachment is vital if prairie marshes are
to remain in this successional state [17]. According to Ward [17],
spring burning in marshlands is primarily done to remove vegetation and
create more nesting edge. Summer fires are used to create more
permanent changes in the plant community.

Burning should be completed well before or after the nesting season to
avoid destroying nesting cover and nests of canvasbacks [17]. Land
managers who burn during the nesting season should consider partial
burns. Partial burns will probably have less impact on total vegetation
changes but should result in higher recruitment of waterfowl than would
complete burning [18].

More info for the term: series

Of all the extensively distributed game ducks in North America, the
canvasback is the least abundant [1]. The canvasback population has
decreased due to habitat loss and overhunting [8]. In the 1930's the
population decreased after a series of drought years prevented any
reasonable breeding success. During the 1960's and 1970's the extensive
drainage of prairie marshes resulted in a decline in canvasbacks to an
estimated 500,000 individuals by the mid 1970's; a 50 percent reduction
of numbers estimated 20 years earlier. Canvasbacks have also been lost
due to oil spills in key wintering areas [12]. Current population
numbers were not found in the literature.

Desertion of canvasback nests is a far greater problem than in most
other waterfowl species. Hens desert their nest because of flooding or
brood parasitism by redheads and other canvasbacks. Heavy rains on
small potholes or wind tides on large marshes often raise the water
faster than the hens are able to build up the nest platforms [1].

REFERENCES :
NO-ENTRY

Management Requirements: See Marcy (1986) for specifications for the construction and placement of wire nest baskets.

There are no adverse effects of canvasbacks on humans.

Canvasbacks are important members of healthy, aquatic ecosystems. They are also an important game species and are one of the best studied duck species.

Positive Impacts: food ; research and education

There are no adverse effects of canvasbacks on humans.

Canvasbacks are important members of healthy, aquatic ecosystems. They are also an important game species and are one of the best studied duck species.

Positive Impacts: food ; research and education