Article kindly provided by Ron Fisk

All rights reserved. No part of this publication may be replaced, stored or transmitted in any from, or by any means without the prior permission in writing from the author, Ron Fisk.

Most of the experienced breeders would know all about genetics, so hopefully these following notes will assist those who may not. The Gouldian is no different in their genetic make up as that of other birds regardless of what some might think. Following are a list of facts, some we should know and others we need to know, if we are breeding the Gouldian Finch. The white-breasted birds are recessive to all mutations known at present. The lilac-breasted is dominant to the white-breasted. The black-headed, orange-headed and white-breasted are all recessive to the normal red-headed, and the black-headed is sex linked, whereas the other two are autosomal recessive.

In the Terminology of Aviculture, when a bird inherits a single recessive mutant gene, it is said to be split for the mutation concerned. The slash “/” symbol is used to represent this term. It separates the visual appearance from the recessive mutations being carried in hidden form. When a bird inherits two mutant recessive genes, it shows the effect of the mutation and is given the name of the mutation, i.e. white-breasted. Each gene is responsible for controlling various factors in the bird, including the colour characteristics which can be dominant, partially dominant, pied recessive or sex linked, in their manner of inheritance.

RECESSIVE MUTATIONS
The “Wild Colour” type of the Gouldian is dominant to all other types, except the pied. If only one of a pair of genes is mutated, the bird will still appear as a normal colour Gouldian, but will carry the mutant gene e.g. yellow, blue etc. Such birds are “Split” for the mutant colour. If two of these birds are paired, the mutant colour will eventually appear amongst their progeny.

SEX LINKED MUTATIONS
In birds, the sex chromosomes of the male are indicated by “XX” and the female by “XV”. If a gene occurs on the X chromosome of the female, it is said to be sex linked.
Males have two sex linked genes, whereas females have only one. Consequently, males can be split for a sex linked colour whereas females cannot. There is no such thing as a split/European yellow hen. Hens are either the sex linked colour in appearance or normal.

DOMINANT MUTATIONS (pied factor)
There is one mutation that will be dominant to the normal “wild Colour” bird, this is the pied factor. The pied factor can be present as a single factor or a double factor that is where both genes are effected respectively. This cannot be distinguished by appearance, but by the number of pied progeny. Theoretically a double factor pied, when paired to a normal wild colour will throw only pied young. A single factor will throw a percentage of pied young.

PARTIALLY DOMINANT MUTATIONS (dark factor)
This mutation does not actually change the colour of the bird, but the depth of the colour. Unlike the pied mutation, single or double dark factor birds can be distinguished by the difference in their colour. Although the depth of colour in a birds plumage is the obvious difference. In order to advance in colour breeding, it is necessary to know all about the rules of inheritance. This gives the breeder the knowledge to make the appropriate matings, in order to produce specific desired results. It is important to know the exact pedigree of the parents. To be successful in breeding the Gouldian finch, it is desirable to house them in a disease free environment and away from other finches.

SOME NOTES ON THE EUROPEAN YELLOW MUTATION
I believe this mutation to be a sex linked, partially dominant mutation. I prefer the names of, dilute, yellowback and yellow-bodied (for want of better names), instead of single-factor and double-factor. The reason is, when the partially dominant (dark factor) mutation, and the pied (single and double-factor) mutations establish themselves more thoroughly in our Gouldian population. I can see an immense amount of confusion ahead.

PAIRING RESULTS