A KNOWLEDGE OF GENETICS HELPS WHEN BREEDING VIOLET BUDGERIGARS

Text and Photographs by Pantcho Tomas

At the risk of being too pedantic, I would like to add to John Scull's article `Violet Budgerigars' which appeared in the August/September Issue (Volume 9 Issue 4). Most important, is that people who are colour-blind are going to have difficulty breeding Violet Budgerigars as they will not be able to identify the various tones of violet. The violet factor in Budgerigars is a modifying gene rather than a true colour. As such it can be present in every variety and colour, even Albinos where it can give the impression of a pink budgerigar. The striking Visual Violet is generally a combination of the violet factor plus one dark factor in the blue series, ie. a Violet Cobalt. It is autosomal dominant in its mode of inheritance, therefore, a bird cannot be split for violet. When a Violet Cobalt is paired to a Cobalt, the violet factor will be passed on to 50% of the young. This means that a Violet Skyblue or a Violet Mauve may eventuate. Violet Skyblues are often very similar in colour to a Cobalt and cannot be verified with certainty. However, if the colour of the two long tail feathers is studied, it will be seen that a Violet Skyblue shows distinct violet tones, while a Cobalt is dark navy blue. A Violet Mauve carries a violet tinge over its entire body, particularly in the rump area. Some Blue Budgerigars have violet coloured feathers and bloom on the back of their head or near their cheek patches. Unfortunately, this is not confirmation of the violet factor. Birds carrying violet show its presence by having modified tail feather colours and also by carrying a violet bloom on the leading edge of the primary flight feathers. Of course, this does not apply to Violet Greys which have an added depth to their grey colouring. Green series birds with the violet factor are different in colour to Normal green birds (except Greygreens). The colour of a violet light green is usually half way between a Normal Light Green and a Dark Green. A Violet Dark Green is a rather dull colour somewhere between a Normal Dark Green and Olive. The addition of violet to olive produces a very dark bronze colour. This looks best on Clearwings where the contrast between body colour and the yellow wings is most striking. It would probably have a similar effect in Spangles. Identifying the violet factor in Green series birds is not easy and there is always an element of uncertainty. It can be carried for many generations to suddenly appear when blue mates are used, a fact testified to by most Clearwing breeders. As with Blue birds, its presence can be detected by colour modifications in the tail feathers and by a distinctive bloom in the flight feathers. The story of Violet Budgerigars does not end here. Being dominant in its mode of inheritance, the violet gene can be present in both single­factor and doublefactor forms. Doublefactor Violet Cobalts (also Visual Violets) are something else to behold. If you are impressed with ordinary single-factor Visual Violets, then wait until you see these, as they are an even richer violet. The doublefactor Violet Skyblue is also a Visual Violet very similar in appearance to a singlefactor Violet Cobalt. The influence of the violet factor is interesting and also baffling when incorporated into Mauves. Whether in single or doublefactor forms, the colour can vary from Violet, Dark Blue, Greyblue, or even Grey. Verification is possible through the violet coloured cheek patch common to Blue Budgerigars.

TABLE I- Pairings to produce Visual Violets (Violet Cobalts)
VISUAL VIOLET

SKYBLUE	COBALT	MAUVE
25% Violet Skyblue	12.5% Violet Skyblue	25% Violet Cobalt
25% Skyblue	2.5% Skyblue	25% Cobalt
25% Violet Cobalt	25% Cobalt	25% Violet Mauve
25% Cobalt	25% Violet Cobalt	25% Mauve
	12.5% Mauve
	12.5% Violet Mauve

Pairing a Visual Violet to any shade of Blue, produces the same number of Visual Violets, that is 25% or 1 in 4. The incorporation of a Green bird, split for Blue into these pairings is complicated by the existence of two different genetic types of Dark Green, ie. Type 1 and Type 2. It is not simply a matter of halving the calculated expectations.

TABLE 2 - Using other Violet Factor Blues in Breeding Visual Violets
VIOLET SKYBLUE

SKYBLUE	COBALT	MAUVE
50% Violet Skyblue	25% Skyblue	50% Violet Cobalt
50% Skyblue	25% Violet Skyblue	50% Cobalt
	25% Cobalt
	25% Violet Cobalt

VIOLET MAUVE

SKYBLUE	COBALT	MAUVE
50% Cobalt	25% Cobalt	50% Mauve
50% Violet Cobalt	25% Violet Cobalt	50% Violet Mauve
	25% Mauve
	25% Violet Mauve

NOTE: As the violet factor is autosomal dominant in its mode of inheritance, these figures can be halved to calculate the percentage of cocks and hens.

TABLE 3 - Pairing together Two Visual Violets (Both Singlefactor)
VIOLET COBALT

VIOLET COBALT

6.25% Skyblue

12.5% Violet Skyblue (SF)

6.25% Violet Skyblue (DF and Visual Violet)

12.5% Cobalt

25% Violet Cobalt (SF and Visual Violet)

12.5% Violet Cobalt (DF and Viual Violet)

6.25% Mauve

12.5% Violet Mauve (SF)

6.25% Violet Mauve (DF)

Theoretically, 43.75% (almost half) of the nest of nine chicks will be Visual Violets, but of three different genetic types. That is, 6.25% doublefactor Violet Skyblues, 25% singlefactor Violet Cobalts and 12.5% doublefactor Violet Cobalts. These will be indistinguishable and can only be verified with further breeding. If you do happen to breed a doublefactor Violet Cobalt (about one chance in ten) and also manage to identify it, then lucky you.

HOW TO USE THE TABLES
Using the tables is simple and will enable you to achieve any goal you wish to set when breeding Violets. For example, consider the situation where you have one Visual Violet (ie. a Violet Cobalt) and would like to breed more. You may have Skyblues, Cobalts and Mauves at your disposal, but are unsure of which to use. Table 1 is of help here as it shows that when paired to any shade of Blue, your initial Visual Violet should produce 25% Visual Violets. You will also produce a number of Cobalts which do not carry the violet factor. If by chance you breed a Violet Skyblue, then you are in a position to breed more Visual Violets in the next generation. You may choose to pair this to either a Cobalt or a Mauve and Table 2 will provide you with the expected theoretical outcome. The use of Mauves and Violet Mauves is particularly beneficial in producing a large proportion of Visual Violets when you have Skyblues and Violet Skyblues. The most common pairing by newcomers to the breeding of Violets is that of Visual Violet to Visual Violet. The outcome of this pairing is shown in Table 3 and produces nine different colour variants. Many of these are indistinguishable except to the most experienced breeder, so a newcomer would have little chance. In fact, a newcomer is far better off to stay with pairings in Table 1 and 2, where the different violet factor birds can be identified with some certainty. By pairing together two violet factor birds (not necessarily Violet Cobalts) you can create doublefactor Violets. These add another level of complication when predicting theoretical outcomes, as seen when Table 3 is compared to Table 1. When a Green series bird is added, give up. There are potentially 18 different genetic types when a Violet Cobalt is paired to a Violet Dark Green. Hopefully, you can now see how a knowledge of genetics does help when breeding Violet Budgerigars. This does not preclude the use of Green series birds, as they can be a valuable asset. However, you are advised to limit their use until the concepts described in Tables 1, 2 and 3 have become second nature.

ACKNOWLEDGEMENTS
In preparing this article I would like to thank the following people for making their birds available for photography - Ray Annesley, Ross Christie, Ken McLean, Fred Annesley, Jill Balfour and Brian King. In addition, I wish to thank Bob Gorman for his many years of tireless tuition.

Our thanks to Australian Birdkeeper Magazine.



Spangle Violet , Opaline Violet , Yellowface Violet