The Araucana is a challenging breed that combines several unusual traits of tufts (peduncles), rumplessness (no tail) and blue eggs.
Tufts are not similar to the muffs and beards in other breeds, like the Ameraucana. Instead tufts appear as upturned feathers, somewhat similar to curls, that protrude near the ear on the birds, and are best when they tilt backwards like handlebars. Unfortunately, this trait is lethal when present in chromosomes from both parents as the chicks will die in-shell – which is why buying eggs from an Araucana breeder can be challenging: not all of the eggs purchased will hatch. This is something you must take into account before purchase, as an Araucana flock will always be a mixture of tufted and clean-faced birds . There is also a wide variability in the size and shape of tufts, but a bird with large showy tufts makes an unforgettable impression!
Rumplessness the Araucana’s second unique trait. This appears on the bird literally as though they are missing a tail and the downside here is neither do they have even an oil gland. Luckily though, this is not lethal but as a an autosomal dominant gene if one parent has the gene, then their their offspring will also get the gene but it does not mean that it will express itself as rumplessness. Instead what could happen is that half of the group will be tailed, and oddly at that, and the other half will have some degree rumplessness and there may be one or two that are truly rumpless. This first set will not be show worthy but since the rumpless genes now exist, successive breedings will eventually eliminate the undesired “tail” genes.
Still the lack of movable tails creates difficulty for fertilization as the rooster uses the weight of the tail to make contact with the hen’s cloaca (hens neither have a clitoris nor vagina ; roosters do not have a penis). To improve this situation, some breeders trim or pull out the feathers around the vent to aid in physical contact or mate a rumpless bird to a tailed bird in an effort to enhance fertility; none of these methods are necessary experience has shown.
Finally, the third and the most notable trait of the Araucana is the laying of blue or turquoise-colored eggs. The blue color comes from another autosomal dominant gene, this time caused by the deposit of liver bile pigment throughout the egg. As it is “throughout” the egg, that means that the inside of the eggshell is as blue as the outside as it is deposited simultaneously with the calcium carbonate that creates the egg shell.
In contrast, the color for brown eggs is deposited by the shell gland as a thin layer on the outside of the egg shell just before laying, which is why in brown eggs, there is a a layer of white on the inside; the Araucana’s blue eggs is blue inside and out. If you cross a blue egg-laying bird like the Araucana with any brown laying-bird, the shell will be blue but a brown coating over the egg surface will occur as well, which is why you see many shades and tints of brown eggs, including olive, green and even pink.
As a last note, it is relatively common to find Araucanas which do not lay pure blue eggs and have brown shell genes. If this happens, use the birds for breeding which have the bluest of eggs, so that the mixed-colored eggs are slowly weeded out of your program.