Aussie Finch Forum

Hi Graham,

While I agree with the basics of what you are saying,
that a yellow headed bird can carry a black gene, and it will only be in males.

I disagree that you can have yellow which is split for black, it will always be a RH which is split for BH which also has the 2 yellow genes attached and therefore will express the yellow colour.

As you would well know the Yellow gene is autosomal recessive, meaning that it merely co-exists with the other 2 head colours.

Therefore yellow can never exist on its own and can never be split for anything.

Every Yellow-headed Gouldian male I have here (about 20 of them) is split to black-headed. I know this for certain because they all have a black-headed parent. I pair them up as if they are split to black-headed & they produce breeding outcomes as expected of YH split BH. They are YH not RH - I also have some RH males split to YH and BH. They also produce progeny "by the book" for that genotype.

Black-headed is also a recessive gene - sex-linked recessive. YH split BH is just as real as BH split YH.

Again, there are plenty of examples of recessive forms of many species in aviculture being split to other mutations. eg Blue Gouldian split to white-breasted.

Tiaris wrote: 10 Dec 2017, 13:02 You can get Yellow split to black in males only as black is sex-linked recessive (so no female splits). These will have a red-tipped bill exactly the same as a pure black.
A yellow-billed black is actually a yellow and a black both occurring simultaneously in the same bird. In these, the darker black head colour totally masks any yellow on the head.

Thanks Graham ...thought I was going crazy...