Anas is a genus of dabbling ducks. It includes mallards, wigeons, teals, pintails and shovelers in a number of subgenera. Some authorities prefer to elevate the subgenera to genus rank. Indeed, as the moa-nalos are very close to this clade and may have evolved later than some of these lineages, it is rather the absence of a thorough review than lack of necessity that this genus is rather over-lumped. The phylogeny of this genus is one of the most confounded ones of all living birds. Research is hampered by the fact the radiation of the two major groups of Anas ? the teals and mallard groups ? took place in a very short time and fairly recently, roughly in the mid-late Pleistocene. Furthermore, hybridization may have long played a major role in Anas evolution, with within-subgenus hybrids regularly and between-subgenus hybrids not infrequently being fully fertile. The relationships between species are much obscured by this fact, and mtDNA sequence data is of dubious value in resolving their relationships; on the other hand, nuclear DNA sequences evolve too slowly to resolve the phylogeny of the subgenus Anas for example. Some major clades can be discerned. For example, that the traditional subgenus Anas, the mallard group, forms a monophyletic (in the loose sense, i.e. non-holophyletic) group has never been seriously questioned by modern science and is as good as confirmed (but see below). On the other hand, the phylogeny of the teals is very confusing. For these reasons, the dabbling duck lineages more distantly related to mallard group (which includes the type species of Anas) than the wigeons should arguably be separated in their own genera. These would include the Baikal Teal, the Garganey, the spotted black-capped Punanetta group, and the shovelers and other blue-winged species. Whether the wigeons, which are very distinct in morphology and behavior, but much less so in mtDNA cytochrome b and NADH dehydrogenase subunit 2 sequences, should also be considered a distinct genus Mareca (including the Gadwall and Falcated Duck) is essentially the one remaining point of dispute as regards the question which taxa should remain in this genus and which ones should not.
Listen to the sound of Blue-winged Teal
Copyright remark: Most sounds derived from xeno-canto
|wingspan min.:||63||cm||wingspan max.:||69||cm|
|size min.:||37||cm||size max.:||41||cm|
|incubation min.:||23||days||incubation max.:||27||days|
|fledging min.:||35||days||fledging max.:||27||days|
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.
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.
Video Blue-winged Teal
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.
from true metabolizable energy feeding trials?