Swedish yellow ducks, or "Svensk gul anka," live exclusively in Sweden. This domesticated waterfowl species thrived prior to 1950, then underwent a population decline significant enough for the country to believe they had gone extinct by the 1970s.
Duck breeder Mans Eriksson of Svalov, a town in southwestern Sweden, created the first Swedish yellow ducks sometime prior to 1920 by crossing Swedish blue ducks with mottled, yellowish ducks he purchased in the nearby town of Molle.
Khaki Campbell Ducks
Although Eriksson claimed in a 1940 magazine article that he crossed Swedish blue ducks with a "white race," the Svenksa Lanthonsklubben ("Swedish Native Poultry Society") believes he may have used other ducks, Khaki Campbells, in the breeding process.
Swedish yellow ducks range from pale yellow to brown in color, with females showing consistent uniformity. The male sports a dark gray to brown head and a greenish-blue bill. The female's bill tends to be brownish-blue.
Suspected Extinction and Rediscovery
Swedish yellow ducks disappeared from known breeding farms by the 1970s, but a single farmer in the town of Billinge kept the breed alive.
Recent Population Increase
As few as 110 Swedish yellow ducks existed in 2001. That number rose to 145 by 2004, thanks to a renewed breeding program targeting population increase.
By Johnny Galluzzo, eHow Contributor