GENETICS
The blue mutation of the yellow naped Amazon is the result of a recessive mutation. A typical green Amazon carries a mixture of blue and yellow in its genes resulting in a visually green bird. For a baby to be blue rather than green, it must be missing the yellow gene. Likewise, a bird missing the blue gene would be visually yellow in color. If a bird is missing both yellow and blue genes, it will appear white in color.
In the case that one parent is missing the yellow gene, the baby will appear as a normally colored green bird. However, this baby will have altered genes allowing it to have the possibility of producing a blue offspring if paired correctly. A bird that is visually green with one blue parent is referred to as a “split to blue”.
The combinations below show the percentage of possible outcomes in babies for blue mutation yellow naped Amazon parrots, depending on pairing of the parents.
Blue x Blue = 100% chance of blue baby
Blue x split = 50% chance of blue baby
50 % chance of split baby
Blue x normal = 100% chance of split baby
Split x split = 50% chance of split baby
25% chance of blue baby
25% chance of normal baby
Split x normal = 50% chance of split baby
50% chance of normal baby
The first three combinations produce either blue or split babies. The fourth combination (split x split), has only 1 in 4 chance of resulting in a blue baby. The fourth and fifth combinations provide the possibility of normal babies. Currently, there is no way to determine if these normal colored babies are “split to blue” or “normal” unless they produce a blue baby when pared accordingly.
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True Blue Aviaries is currently working with the molecular ecologist Taylor Hains of University of Chicago and a few other bird breeders. Our aim is to devise a genetic test to determine which normal looking green birds actually carry the mutated gene which would allow them to produce a blue offspring. Also, using genetic data, we are examining the relatedness in the captive yellow nape population.
