Blue-winged teal

Spatula discors (Anas discors)

Blauwvleugeltaling / Blauflügelente / Sarcelle à ailes bleues

Spatula discors (del Hoyo and Collar 2014) was previously placed in the genus Anas.

The blue-winged teal is a small dabbling duck from North America. The blue-winged teal is 40 cm (16 in) long, with a wingspan of 58 cm (23 in), and a weight of 370 g (13 oz). The adult male has a greyish blue head with a white facial crescent, a light brown body with a white patch near the rear and a black tail. The adult female is mottled brown, and has a whitish area at base of bill. Both sexes have sky-blue wing coverts, a green speculum, and yellow legs. They have two molts per year and a third molt in their first year. The call of the male is a short whistle; the female's call is a soft quack.

These birds feed by dabbling in shallow water at the edge of marshes or open water. They mainly eat plants; their diet may include molluscs and aquatic insects.

Blue-winged teal are generally the first ducks south in the fall and the last ones north in the spring. Adult drakes depart the breeding grounds well before adult hens and immatures. Most blue-winged teal flocks seen after mid-September are composed largely of adult hens and immatures. The northern regions experience a steady decline in blue-winged teal populations from early September until early November. Blue-winged teal in central migration areas tend to remain through September, then diminish rapidly during October, with small numbers remaining until December. Large numbers of blue-winged teal appear on wintering grounds in Florida, Louisiana, and Texas in September.

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 (Polygonum spp.), duckweed (Lemna spp.), Widgeongrass, and muskgrass (Chara spp.). The seeds of plants that grow on mud flats, such as nutgrass (Cyperus spp.), smartweed, millet (Panicumspp.), and Rice Cut-grass (Leersia oryzoides), are avidly consumed by this duck. One-fourth of the food consumed by blue-winged teal is animal matter such as mollusks,crustaceans, and insects.

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern (IUCN, 2012).

More information: http://www.iucnredlist.org/details/22680229/0

Taxonomy

Usually placed in Anas like most dabbling ducks, it stands well apart from such species as the mallard and together with the shovelers and their relatives forms a "blue-winged" group that may warrant separation as genus Spatula (del Hoyo and Collar 2014).

Blue-winged teal in aviculture

Written by Dan Cowell

Very common both in the wild and in North-American collections, the Blue-winged Teal is known by two subspecies the Atlantic (A. d. orphna) and the Prairie (A. d. discors). Both subspecies are very similar to one another and probably interbreed. The Atlantic Blue-wing breeds in the tidal marshes along the Atlantic coast from Canada to the Carolinas and winters in the West Indies and South America. However, some birds remain resident year round in the middle seciton of the range. The Prairie Blue-winged Teal breeds in the central plains of North America, from Canada to New Mexico and Texas. Winters from the Gulf Coast States to norhtern South America.

The Blue-winged Teal is mostly all brown, with males having a slate-blue head with a white crescent in front of the eye. The speculum is metallic green below the light blue forewing for which this species is named. Hens resemble Cinnamon Teal hens, but lighter. The bill is black; legs and feet are yellow.

This small duck is fairly easy to breed and keep in aviaries. The hens begin to build nests close to a water source in thick cover in late May. Clutches consists of between 7 and 10 eggs and are incubated for 24 days. Some hens will use a ground box if provided. They fledge at six weeks and are able to breed their first year.

This species is very similar to the Cinnamon Teal (Anas cyanoptera) and will cross with this species if care is not taken to keep the two seperate (mainly extra hens and drakes). Not has hardy as other North American species, shelter must provided during the Winter months. Some birds may become quite tame, while others will remain shy and wary, always hiding in the cover. Larger species may tend to pick on this species, so house only with species of similar size. 

Above: adult male and female  Blue-winged teals

Above: adult female Blue-winged teal

Above: adult male Blue-winged teal

Above: adult female (front) and male (back) Blue-winged teals

Above: adult female (front) and male (back) Blue-winged teals

Above: adult male Blue-winged teal