The Modifier Gene

There has been much debate lately regarding the Dark Factor Gouldian – are they or are they not, a real colour morph with a Single and Double Factor involved? I for one, held the belief that I was absolutely working with a Co-Dominant Single and Double Factor Mutation! After many years of disappointment not producing a Double Dark Factor Olive, the only answer was they are not Dark Factor but… what are they? as they sure were a lot darker than any normal that I possessed.

Gouldian carrying the modified gene
This bird is carrying the modified gene, which I previously thought was a ‘Single Dark Factor Green’

Obviously, I needed to do some research, leading me to an interesting article by genetic expert Dr Terry Martin, who believes that out there in bird world is a gene that can change feather colour to a darker shade, called a Modifier Gene!

These genes as the name suggest changes or alters something. In this case it is the feather colour on the wild type normal Gouldian Finch. Martin, also mentioned another Modifier gene that had the ability to reduce the feather colour called ‘Intensity Reducing Factor’ (as put forward by Bergman in 1999). This reduces the colour of the feather, meaning that there could be more than one Modifier gene, in our birds.

I find this very helpful information. Peter Bergman also believes this Modifier carry the genetics of Dominant. Obviously, they have proven there is more than one Modifier involved in the feather make up of a bird. My interest is strictly focused on the Modifier that will intensify the colour of my normal Gouldians.

Sure I am disappointed that I have not got the Dark Factor as most breeders will be. If you look at the positive of what the Modifier can do to intensify feather colour totally improving our normal, also the mutations would benefit without a dramatic colour change, only slightly intensifying the beauty of the natural colour they possess, then it is a worthwhile exercise!

Gouldian carrying the modified gene
Another Gouldian carrying the modified gene

Graham Bull is also of the belief that what we as Dark Factor breeders are working with is a gene modifier. Graham would not comment unless he had a vast understanding on this subject. So, until the Dark-Factor shows itself, we should take advantage of what we have and never lose faith that a true Double Dark Factor Olive could turn up in someone’s aviary!