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THE COLOUR INHERITANCE

OF GOULDIAN FINCHES

PART 2: CHEST

THE CHEST COLOUR INHERITANCE

OF GOULDIAN FINCHES

 
Gouldian Finches come in three accepted chest-colour mutations: 1.Purple chest:  The purple chest is autosomal dominant. Both male and female can be double-factor (DF) or single-factor  (SF) for purple chest. Gouldian Finches can never be “split” for purple chest, they either have it and show it, or they don’t have it at all.                  Purple chest can occur in combination with any head or body colour. 2.White chest:  In the white chest there is an almost complete reduction of the paeomelanin in the plumage, which results is clearly shown in the feathers of the chest. The blue structure in the feathers is retained, but the loss of the light-absorbing melanin no longer reflects the blue structure. The light rays which are falling on the plumage are reflected and so the original purple chest is now white.  The reduction of the phaeomelanin is also noticeable in other feather zones. The back gets a slightly lighter shade. Likewise the yellow belly plumage appears also in a lighter yellow colouring. We can also see the colour changes to a bright orange colouring in the orange-headed gouldian Finches, because of the reducing the phaeomelanin. The white chest appearance only takes place through the reduction factor of phaeomelanin. The white-chest factor inherits autosomal recessive to its wild allele and inherits independently to blue factor and orange- head factor. Both male and female can either be double-factor (DF) and express the white chest. They also can be a single-factor (SF) and “split” for white chest, without expressing it. Visible they are purple-chest and “split” for the white chest colour. White chest can occour in combination with any head or body colour, except Dilute and Pastel (= males) gouldian finches. They are showing a purple chest.
3.Lilac chest: The first lilac chest gouldian finch was reported in 1978. An English breeder had been bred two white chested gouldian finches and got a male with the appearance of a lilac chest. For a long time this phenomenon has not been confirmed as a mutation and was also not popular. The lilac chest was considered dangerous to the purity of normal gouldian finches and thought it should be eradicated. In 1986 it was reported that several breeders in the United Kingdom were able to establish the lilac chest. A further report from 2005 confirmed that the lilac chest was bred worldwide and also accepted as a mutation. The characteristic of the lilac chest mutation is a partial reduction of phaeomelanin. This is mainly noticed in the colour of the chest, which has turned into a lilac-like colour. NOTE: (1.) To the purple chest is the lilac chest autosomal recessive heritable. (2.) To the white chest is the lilac chest autosomal dominant heritable. Why is that? The lilac-chested gene is probably an allele of the white chest.
Lilac chest can occur in combination with any head or body colour. To show a lilac chest, the gouldian finch must either be double-factor  (DF) for a lilac chest, or be single-factor (SF) for lilac chest and single-factor  (SF) and also "split" for white breast.  A gouldian finch with the single factor for lilac breast and likewise single factor for purple chest, is visible a purple-chested gouldian finch which is "split" for a lilac chest. In addition to (2.): While this phenomenon is really a genetically white chest but shows a light lilac colour it is also called a "rose chest". Note: If crossing for many generations gouldian finches with a “bad white chest”, sometimes there offsprings can likewise show a light chest colour.
A black-headed; dilute green Gouldian Finch with a “Blue Chest”  Around 1970 the blue-chested appearance was first reported. The blue chest occurs due to lack of eumelanin. Only phaeomelanin with the structural blue colour are present. This appearance is reported as an autosomal recessive mutation, but that it is a true established mutation is currently not proven. Also later some breeder report about blue-chested Gouldians. Currently we called it modification, maybe a result of influence of the environment, administer of medicals, false nutrition etc. can be the reason of a modification. The blue-chested appearance is not to seen in context with the lilac or dirty-white chest. Lilac or dirty-white chest must be seen in context with the white chest.
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