An Excerpt by Don Crawford from © Australian Birdkeeper 1991, (p.32)
Revised edition © ABK Publications 2005, (p.63)
There are three basic head colours in the Gouldian. These are Black, Red and Yellow. Ideally the various head colours should not be indiscriminately bred together. By doing so a number of motley blackish red or blackish yellow headed birds are produced. This is especially prevalent in hen birds. When selecting for head colour breeding special attention should be paid to the hens to be bred with. Black-headed hens especially should be a rich deep velvety black with absolutely no signs of a red or yellow feather showing through.
The only reasons for crossing head colours should be to, one, improve the quality of the finch itself. That is, if all the Yellow-headed birds in the aviary are of poor quality ie. too small or have poor fertility then they should be mated through your other head colours to rectify these deficiencies.
Buying good quality Yellow-headeds may seem a better solution but remember that a lot of problems can be brought into your established stock by new arrivals so only bring them in when absolutely necessary and be sure to follow the quarantine measures… or disaster will most certainly follow.
The second reason would be to breed a mutation in the three head colours. That is, if for example, all your Dilute-backed Gouldians are Black-headed, then to produce Red-headed Dilutes they have to be paired to Red-headed birds.
The Red-head is sexlinked dominant. The Black-head is sex-linked recessive. The Yellow-head is autosomal recessive.
A Red-headed Gouldian has a red-tipped beak. The Black-headed can have a red-tipped beak or a yellow-tipped beak and the Yellow-headed has a yellow-tipped beak.
The normal Black-headed Gouldian has a red-tipped beak. However, when a Gouldian inherits both characteristics for black and yellow headedness the black will mask the yellow. That is to say, it is a Yellow-headed bird with a black head and not simply a Black-headed split to Yellow-headed. Therefore because it is Yellow-headed it has a yellow-tipped beak. A Black-headed Gouldian split to Yellow will have a red-tipped beak.