Down feather

Down is a fine thermal insulator and padding, used in goods such as jackets, bedding (duvets and featherbeds), pillows and sleeping bags.

[3] All parrots have powder down, with some species (including the mealy amazons) producing copious amounts.

[8] The loose structure of down feathers traps air, which helps to insulate the bird against heat loss[5] and contributes to the buoyancy of waterbirds.

Species that experience annual temperature fluctuations typically have more down feathers following their autumn moult.

This process performs the dual function of helping to insulate the eggs and exposing the female's brood patch—an area of bare skin, rich in blood vessels, which transmits heat very efficiently.

[14] Mutations in the genes that control the formation of down feathers have been recorded in a German White Leghorn chicken flock.

The Hopi rub eagle down feathers over rattlesnakes collected for Snake Dances, in an effort to soothe and calm the reptiles.

[19] Historically, much of the down used for the flies came from the wing and tail of the marabou stork; these feathers were also popular with the millinery and dressmaking trades.

Russian documents from the 1600s list "bird down" among the goods sold to Dutch merchants,[23] and communities in northern Norway began protecting the nests of eider ducks as early as 1890.

The first collection is made roughly halfway through the incubation period, when some 0.75 oz (21 g) of high quality down is removed per nest.

[29] Although the down feathers of various species of wildfowl, gulls and other seabirds have historically been used for insulation, most now come from domestic geese.

[30] A portion of the world's supply of down feathers are plucked from live birds,[31] a practice condemned as cruel by animal welfare groups.

[32] The precise percentage of down harvested in this manner is uncertain; while some references report that it is only a small fraction of the total (less than 1% in 2011),[31] a 2009 Swedish documentary reported that it might be as much as 50–80% of the total supply, a figure supported by IKEA and an industry representative, but disputed by organizations within the industry.

[35] Although live-plucking is illegal in Canada, the United States and Europe, it is known to occur in two European countries (Poland and Hungary) and in China.

IKEA and clothing manufacturer Patagonia have altered product lines to eliminate the use (or possible use) of live-plucked down.

Pillows provide the most common source of exposure, though mattresses, comforters, outerwear and upholstery can also cause problems.

[40] A Finnish study has shown that true feather allergies are rare, with most issues caused by dust mites.