The Ameraucana breed and "Easter egger" hybrids of the United States, which also lay blue or green eggs, both derive from the Araucana.

Castelló believed the birds to belong to a new species, and reported his observations at the First World's Poultry Congress in The Hague in 1921.

[5]: 17 [6] In modern times, the Ameraucana breed, a derivative of the Araucana, also lays blue eggs, while hybrid birds carrying the dominant oocyan gene may in the United States be called "Easter eggers".

It has been variously attributed to hybridisation with Tinamus solitarius, a species of tinamou (dismissed as "erroneous" by Helmut Sick);[7]: 347 [8] to genetic mutation;[9]: 349  and to the action of a retrovirus soon after the domestication of the chicken.

[11] Blue-egg chickens from South America were introduced to the British Isles at various times in the early twentieth century.

There has been a long and inconclusive debate about the origin of the Araucana and whether it derives from chickens brought by Europeans after Columbus reached the Americas in 1492, or if it was already present.

A report published in 2007 on chicken bones found on the Arauco Peninsula in south-central Chile suggested pre-Columbian, possibly Polynesian, origin.

[22] A total of twenty plumage varieties are listed for the Araucana by the Entente Européenne d’Aviculture et de Cuniculture.