Which chicken breed is known for laying blue eggs?

The Araucana is the chicken breed best known for laying blue-shelled eggs. It originated in Chile and is associated historically with the Mapuche people of the Araucanía region.

The blue color comes from a dominant genetic trait often called the oocyan gene. Unlike a brown egg’s pigment, which is mainly deposited on the shell’s surface, the blue-green pigment is incorporated into the shell as it forms. Crosses involving brown-egg breeds can therefore produce olive or green eggs.

Araucanas may have distinctive ear tufts and can be rumpless, meaning they lack a tail and tailbone. These features are linked to genetic variants, and not every bird displays both traits. Breed standards also differ between countries, so the appearance of an Araucana can vary.

Ameraucanas, developed partly from Araucana stock, also lay blue eggs, and mixed-breed “Easter Eggers” may produce blue, green, or other tinted eggs. Those are legitimate neighbouring facts, but when a quiz asks for the classic blue-egg chicken breed, Araucana is the standard answer. Blue shells do not indicate a major nutritional advantage over ordinary eggs.