The Araucana is one of many breeds of chicken. A breed is defined as a stock of animals within a species having a distinctive appearance and typically having been developed by deliberate selection. What are accepted as a breed is defined in text descriptions called a Standard of Perfection (SOP) which are maintained by various associations. For poultry, the associations tend to be country based and do not always have consistent definitions for the same breed. In the United States, the American Poultry Association (APA) and the American Bantam Association (ABA) are the two major associations. In comparison, the Poultry Club of Great Britain has a standard for a breed which is also called Araucana, but the characteristics defined in the standard are a far cry from the APA or ABA Araucana standard.
Getting back to the question at hand. Determining if a chicken is of a breed or not is from a combination of attributes absent of color. That is to say, if you look at the silhouette of the chicken in question, it should more or less fit the silhouette of a known Araucana. There are a few characteristics which are unique to the Araucana and those are rumpless, tufts, and laying blue eggs. However tufts and laying blue eggs are not really so cut and dry. Araucana most certainly should possess the blue egg gene but due to their history (see the Araucana Club of America for historical information) many will also have some brown egg genes which result in birds that can lay a blue to greenish egg, blue being preferred. Tufts are another cloudy aspect as the gene for producing tufts has variable expression and it is lethal in the homozygous state. This means that there will always be non tufted, double tufted, single tufted, and miss matched tufted Araucana.
Historically, the Araucana has been confused with a closely related breed, the Ameraucana, as well as a non-standard breed commonly referred to as the Easter Egger. This confusion was impart at the fault of hatcheries who have and often still do, missable non Araucana as true Araucana. However, comparison of the bird’s silhouette and comparison to the written standard should quickly rule out an Ameraucana or Easter Egger. The trouble is that not everyone that keeps chickens is familiar with the standard for the Araucana, and often when someone is sold a chicken and told it is something that it may not be, the misconception is perpetuated. When it comes down to it, there is no easy way to answer the question, especially since the Araucana is a newer breed and may be found in various stages of adherence to the SOP. To truly determine if a chicken is an Araucana, one must assess the bird and the stock the bird came from against the SOP and make a judgement call.
