Aussie Finch Forum

There was a breeder in the UK who bred the Dark Factor Gouldian, the Dark Factor is sex linked so when mixed with blue it should produce Cobalt blue(SF) and Mauve(DF) backed Gouldians.

It's the dark factor with Blue that creates Cobalt & Violet in Indian Ringnecks, and the cinnamon mixed with the Dark Factor & Blue that creates Sky Blue and Mauve so I don't see why it shouldn't happen in Gouldians one day.

You can read more here http://www.australianfinchsociety.co.uk/" onclick="window.open(this.href);return false; click on articles and then dark factor by Graham Tulk, The article was written in 2001 and the Author died in 2002, There's no record of what happened to the birds but hopefully one day the mutation will appear in Austraila.

i was interested to know that with the dark factor the double factor appeared in both cocks and hens...and that 2 double factors could be paired together....this mutation would be great if it appeared in Oz

Simba the dark mutation exists in many bird species, to many Aussie "birdies" probably one of the earliest examples we would encounter would be the budgies with dark green / olive and cobalt / mauve (green and blue based respectively). I cannot speak for ringnecks but based on that article it is not a sex linked characteristic in Gouldians, likewise in budgies. It is co dominant (or more correctly partially dominant) but it is independent of sex inheritance.

In the yellow back (Euro Yellow) is co dominant, the gene is located on the Z chromosome, thus a cock can be single factor or double factor, because it has two Z chromosomes. However a hen can only be single fccator but will always look yellow as she has only one Z chromosome and therefore no normal gene on the other the other Z.

In the dark factor the same principle applies. Lets say the dark factor is on chromosome 5 (who knows which one it's really one). Every bird gets two 5s, one from each parent (unlike Zs and Ws where the W can come only from the mother). Each chromosome can carry either the normal gene or the dark gene. If both 5s have normal then you get normal. If one 5 has a normal and the other dark you get a dark green (or cobalt) bird. If both 5s have the dark gene then it is an olive (or mauve) bird.