[order] Anseriformes | [family] Anatidae | [latin] Anas discors | [UK] Blue-Winged Teal | [FR] Sarcelle à ailes bleues | [DE] Blauflügelente | [ES] Cerceta Aliazul | [IT] Anatra aliazzurre americana | [NL] Blauwvleugeltaling

Blauwvleugeltaling determination

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The male breeding plumage has a blue-gray head with large white crescent behind bill. Cinnamon-brown body feathers, patterned with fine black marks. White patch on rear flank. Upper wing with light blue patch with white rear border. Back of wing iridescent green. In eclipse plumage its gray-brown overall, without white patches. Faint outline of white face crescent. The female is recognized by gray-brown overall, with small white area at base of bill. Bill dark. Light blue upper wing patch with narrow white border. Back of wing mostly brown, with little green. Juveniles are similar to adult female.

Blue-winged teal inhabit shoreline more often than open water and prefer calm water or sluggish currents to fast water. They inhabit inland marshes, lakes, ponds, pools, and shallow streams with dense emergent vegetation. In coastal areas, breeding occurs in salt-marsh meadows with adjoining ponds or creeks. Blue-winged teal use rocks protruding above water, muskrat houses, trunks or limbs of fallen trees, bare stretches of shoreline, or mud flats for resting sites. Blue-winged teal winter on shallow inland freshwater marshes and brackish and saltwater marshes. These teals build their nests on dry ground in grassy sites such as bluegrass meadows, hayfields, and sedge meadows. They will also nest in areas with very short, sparse vegetation. Blue-winged teal generally nest within several hundred yards of open water; however, nests have been found as far as 1 mile (1.6 km) away from water. Where the habitat is good, they nest communally.

Breeds in North America, mainly in prairie region, from British Columbia east to Newfoundland, south to California, New Mexico, Texas, Tennessee, and North Carolina; locally further south. Exceptionally, pair (status unknown) bred Denmark 1986. Some records probably refer to escapes, but at least 10 recoveries of ringed birds proving that transatlantic vagrancy does occur. Most records Britain and Ireland (annual). Also recorded in Iceland, Faeroes, Channel Islands, France, Belgium, Netherlands, Germany, Denmark, Norway, Sweden, Finland, Poland, Switzerland, Spain, Portugal, Balearic Islands, Italy, Greece, Egypt, Algeria, Morocco, Azores, Canary Islands.

Blue-winged teal are surface feeders and prefer to feed on mud flats, in fields, or in shallow water where there is floating and shallowly submerged vegetation plus abundant small aquatic animal life. They mostly eat vegetative matter consisting of seeds or stems and leaves of sedge, grass, pondweed, smartweed, duckweed, widgeongrass, and muskgrass. The seeds of plants that grow on mud flats, such as nutgrass, smartweed, millet, and rice cut-grass are avidly consumed by this duck.One-fourth of the food consumed by blue-winged teals is animal matter such as mollusks, crustaceans, and insects.

This species has a large range, with an estimated global Extent of Occurrence of 11,000,000 km². It has a large global population estimated to be 6,100,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]

The onset of courtship among immature blue-winged teal often starts in late January or early February. In areas south of the breeding grounds, blue-winged teal are more active in courtship during the spring migration than are most other ducks. Blue-winged teal are among the last dabbling ducks to nest, generally nesting between April and mid May. Few nests are started after mid-July. Time of nesting can vary from year to year as a result of weather conditions. Blue-winged teal generally lay 10 to 12 eggs. Delayed nesting and renesting efforts have substantially smaller clutches, averaging 5 to 6 eggs. Clutch size can also vary with the age of the hen. Yearlings tend to lay smaller clutches. Incubation takes 21 to 27 days. Blue-winged teal ducklings can walk to water within 12 hours after hatching but do not fledge until 6 to 7 weeks. Blue-winged teal are sexually mature after their first winter. During incubation, the drake leaves its mate and moves to suitable molting cover where it becomes flightless for a period of 3 to 4 weeks.

Blue-winged Teal are highly migratory and are, for the most part, absent from the majority of North America during the cold months of the year. They winter more extensively in South America than any other dabbler. They begin migrating later in spring than other dabblers, with birds arriving on the coast as early as March, but mostly not before April and May. Single males arrive first, with pairs and unpaired females following. Males migrate again from mid-July to mid-August, moving to larger marshes to undergo their molt. Fall migration starts in early August, and most birds are gone by mid-October.