Dark Factor Gouldians
By Graham Tulk

Early in 1994, I bred a young Gouldian finch from a pair of normal green series Gouldian finches. When this young bird moulted out it seemed different. It was a brighter bird; its deeper cleaner colours set it apart. This bird looked different to other Gouldians that I had bred in the past. The subsequent progeny proved it genetically different. This bird and its progeny, I now know carry the "Dark Factor" gene. From the research I have carried out, this colour phase in Gouldian finches is new and is not established in aviculture anywhere else in the world. I think it is also the first time that a new mutation in Gouldian finches has been discovered and established in the U.K.

I have built a family of birds around this bird over the last few years. This was difficult and slow to start with, as my options, genetically, were limited. This was due, in the early years, to the small numbers of birds that carried the necessary genetic information that I had to work with. It was not always easy to decide which was the best way to proceed. I needed to maximise the genetic material whilst not breeding too close too often.

The Gouldian finches I breed are all parent reared and have been for a number of years. This way of breeding Gouldians (in Europe they call this method, Nature bred) has suited my style of bird keeping. I suppose that this tended to slow things down, but perhaps that was not such a bad thing with the number of related birds in the earlier part of the breeding programme. It enabled me to build in some genetic diversity over a period, without having too many closely related birds hanging around with no real breeding potential within the programme.

The more of the new colour variants that I bred, the more I needed cage space to hold on to the foundation birds that I had already bred. Cage and flight space always being at a premium, especially as I breed with one pair per enclosure, typically 1.5m x 0.5m x 0.5m. I therefore needed to make decisions about the other species that I kept and bred in order that I could develop the breeding programme further. The many other species of seed eating birds that I have been keeping and breeding have been disposed of, to make available the extra accommodation needed. They included a small group Crimson Seedcrackers, pairs of Red crested finches, Rhodospingus finches, Nonparial and Indigo buntings, Queen Whydahs. Along with a breeding group of Red-hooded Siskins, which had produced over 80 birds in the last seven years. I do still have my African Silverbills. At present I am reluctant to dispose of them, although I have intentionally not bred many over the last couple of years.

I have bred sufficient Gouldians in this new colour break to be able to state that this new colour phase is an "Incomplete Dominant" "Dark Factor". It appears in both single dark factor (dark green/laurel) and double dark factor (olive) in the green series. This is, in effect, a depth of colour gene known as the dark factor gene. This gene is not responsible for the colour i.e. green or blue, only the depth of that colour and works independently of other colour genes.

From the black-headed green series (normal) I have bred black-headed, dark green (single dark factor) and olive (double dark factor) in purple breasted, lilac breasted and white breasted.

I have now extended the breeding program into the blue and yellow series and both red and yellow-headed green series. The blue series should prove interesting as a single dark factor blue, (dark blue or cobalt) and double dark factor blue (mauve) should be possible. I do now have some single factor dark blues but they have yet to moult out. There are also young dark greens coming through in red headed and yellow headed green series. The yellow series is a bit more complex, I also have young bred from double factor yellows (no dark factor) X olive, but more work is needed to evaluate all the possibilities.

The dark factor colour phase could be applied to all existing colour variations that exist today and in effect triple the number of colour variants available to Gouldian breeders. As this is a dominant gene, it is only in a visual form, in single or double factor. Dominant genes are visual and cannot be present in a hidden form on the chromosomes, as a recessive gene can be, in the form known as a split.

I have included a table of matings and expectations and this table applies across the board independent of colour.

I realise that colour variants are not everyones cup of tea. My main interest in Gouldians has been in trying to produce the very best black-headed normals for over 25 years. I go back to 1958 with Gouldians so I really do appreciate the wild form of this outstanding species. In saying that I have over the years kept and bred many of the colour variants, as they have become available. This has enabled me to understand the genetics of the modern day Gouldian and its development as a cage bird. Even so, I never expected that I would breed a new mutation and have the pleasure of trying to establish it in all its colour forms.

I have stated in the past that in my opinion the Gouldian is a bird that has genes that are prone to mutate. It is found naturally in four established head colours. Red head is the dominant red colour phase. Yellow head is the Recessive yellow colour phase and in my opinion, it is incorrect to call it orange. Black head is the sex linked melanistic phase this exists in both the red and yellow forms. Genetically the two Black headed forms are recognised by the tip of the beak being red or yellow. These four head colours make it the only multi-morph Estrildid. It is amongst the small number of bird species in which this phenomenon exists. There are many examples of species that have established two colour phases. Indeed a number occur within the species mandate of the Australian Finch Society. The Crimson finch and the Pintailed Parrot-finch can be used as an example. Both species have red and yellow colour forms or morphs established in the wild. These naturally occurring colour variants show part of the continuing evolutionary process of these species.

Colour variants are a naturally occurring phenomenon and can only exist in numbers if they are well established. In the wild, this is difficult, as natural selection is far more random than in a captive-breeding programme. Time is nature's tool and species are evolving and developing to fill the niches open to them. How long the Gouldian has been evolving is open to question. It could be many thousands of years, it may even be millions, who knows. What we can be certain of is that it is an ongoing process in the wild. Mother Nature does not stand still.

In captivity the birds we keep, live and breed in far different circumstances to their wild cousins. Captive breeding programs have established the various colour variations as they have come along. By establishing these genes the breeders of Gouldians, or indeed any species, where genetic change has been established, will be able to reproduce any of the established colour variants in a controlled breeding programme. The downside is that unwanted colour variants can be reproduced when a colour variation is well established amongst captive stocks. For example white-breasted and blue variations occur from time to time from hidden (recessive) genes. This can be a surprise when colour variants are bred from apparently normal looking birds.

Colour combinations are not a new problem for Gouldian breeder however, as the 54 different matings from combining the four head colours has been with us from the beginning; these additional genetic developments just make the Gouldian far more interesting.

Conclusion:

It has been a slow job to get this far, but it is very exciting, as many of the young birds that are now coming through will be new dark factor variations. I am also considering taking on a few pairs of Bengalese, as some of the Gouldians that I really need youngsters off, are not always satisfactory or reliable parents, but is that their fault or mine?

50% Dark Green (SDF)

50% Normal

25% Olive (DDF)

50% Dark Green (SDF)

25% Normal

50% Dark Green (SDF)

50% Olive (DDF)