araucana

Araucana is a distinctive breed of domestic chicken originating from the Araucanía region of south‑central Chile. The breed is best known for producing blue or green‑black eggs, a trait caused by the presence of the dominant Dominant (D) allele which results in the deposition of biliverdin pigment in the eggshell. Araucanas were brought to Europe in the 19th century and later introduced into North America, where they have been valued both for their unique egg colour and for their ornamental appearance.

The stock displays a characteristic broad, rounded head with feathered wattles and a hooked comb that is usually a muted grey or brown. Body plumage is generally a dark chocolate brown with a glossy sheen, though feather patterns can range from spotless to speckled. Males typically weigh 2.7–3.3 kg and females 2.3–2.9 kg. A notable feature is the presence of a blue feathered shank, which is one of the few true flesh‑colour variations in domestic fowl.

Araucanas are primarily raised for their eggs; blue eggs can yield a higher yolk content and are commercially desirable for certain markets. They are also kept for show purposes and as ornamental birds in hobbyist flocks. The breed has been listed as vulnerable by the American Livestock Breeders Association and by the Australian Chickens and Hen Society, owing to a limited gene pool and the specialised requirements for feathered wattles and shanks.

Crossbreeding with other Iranian or American breeds such as Ike and New Hampshire has been undertaken to stabilize the blue‑egg trait while increasing productivity. Conservation efforts focus on preserving the pure Araucana genetics and mitigating the risks of inbreeding depression.