I've really been wondering how the dark factor works.. So I you pair a light green budgie (no dark factor) with a Dark green budgie (1 dark factor) will there be any light green chicks? or will they all be dark green? what about pairing a budgie with 2 dark factors with a budgie with 1 dark factor and so on?

 

Thanks,

Corina

Extract from other topics on this forum

 

Originally posted by Kaz in ‘Breeding Expectations Tables’ .

 

　

 

THE DARK FACTOR

by Keith Leedham taken from April 1992 Budgerigar World

 

An excellent subject for discussion is the pairing of two dark factor birds. Before we do this let us restate what we know about colors. The two basic colors are Green and Blue plus their dilutes. Yellow and White have three shades. Light Green, Skvblue, Light Yellow and Skyblue White have no dark factor. Dark Green, Cobalt, Dark Yellow and Cobalt White carry one dark factor whilst Olive Green, Mauve, Olive Yellow and Mauve White carry two dark factors.

 

The above colors can be modified by the Grey or Violet genes, although the three shades still exist within the modified colors. A practical consideration is that from experience and observation the continual pairing, generation after generation, of two dark factor birds' results in the reduction in size of the resulting program.

 

All budgies have a level of "dark factor" ranging from no dark factor, one dark factor, or two dark factors. Wild budgies have no dark factor. Dark factor basically darkens the blue in the body feathers. (In budgies totally lacking normally colored feathers, such as albinos and lutinos, the budgie's dark factor will be present but unknown). A green (yellow-based) budgie with no dark factor will be the original very bright green; this variety is called "green" or "light green." One dark factor will result in a darker green; this variety is called "dark green." Two dark factors will result in a deep olive drab green color; this variety is called "olive." A blue (white-based) budgie with no dark factor will be the original bright sky blue; this variety is called "sky blue." One dark factor will result in a slightly darker blue; this variety is called "cobalt." Two dark factors will result in a deep grey bluish color (more grey than blue); this variety is called "mauve." Within each level of dark factor is room for some variation in darkness. One sky blue may look a little darker than another sky blue and one olive budgie may look a little lighter than another olive budgie. But usually there is no mistaking which dark factor category a budgie falls into, and the pictures below can be used as a guide.

 

Basic Genetics:

Dark factor - semi-dominant

Normal - recessive

 

There are only two alleles that determine the darkness of a budgies body color: the normal gene and the dark factor gene. The dark factor gene is semi-dominant to the recessive normal gene. This means that a budgie that has one dark factor and one normal gene looks different from a budgie that has two dark factor genes.

A skyblue has no dark factor, a cobalt has 1 dark factor and a mauve has 2 dark factors. A violet is a blue with 1 dark factor (cobalt) plus the factor for violet.

 

Table of expectations

The following table shows the theoretical expectations from various pairings.

 

KEY: Lt=No Dark Factor, D=One Dark Factor, DD=Two Dark Factors

 

Pairings Expectations

Lt x Lt =100% Lt

Lt x D =50% Lt, 50% D

D x D =25% Lt, 50% D, 25% DD

Lt x DD 100% D

D x DD =50% D, 50% DD

DD x DD =100% DD

 

 

The offspring in this table can be of either sex irrespective of the dark factor genes carried by either parent. It is also noticeable that in general the progeny carrying two dark factors are smaller than the birds carrying none. Of course there are always exceptions to this type of observation.

 

Many fanciers may well recall various exceptional birds carrying either one or two dark factors. If the aim is to produce birds that have a single dark factor, I have found it to be more beneficial to pair a single dark factor bird with a bird carrying no dark factor. This will produce a theoretical 50% of the progeny carrying the single dark factor, and normally without reducing the overall size of the bird.

 

 

Edited May 21, 200915 yr by KAZ

the best article and easiest to understand in my opinion is an article by Neville Collins. He is a member of the forum.

 

A Simple Explanation of the Dark Factor

I shall attempt to explain how the dark factor works without going into any complicated reasons

 

All budgies have a dark factor rating. It is either 0, 1 or 2. This affects the base colour regardless of what mutation the birds are

 

0 dark factors appear as sky blue or light green

1 dark factor appears as cobalt or dark green

2 dark factors appear as mauve or olive

 

If you pair two birds with 0 dark factors together the chicks will also have 0 dark factors. It doesn’t matter whether they are both sky blues or both light greens or one of each

 

If two birds with 1 dark factor are paired together the result will be 50% 1 dark factor, 25% 0 dark factor and 25% 2 dark factors

 

If two birds with 2 dark factors are paired together all the chicks will also have 2 dark factors

 

If a 0 dark factor bird is mated to a 1 dark factor bird the result will be 50% with 0 dark factors, 50% with 1 dark factor

 

If a 1 dark factor bird is mated to a 2 dark factor bird the result will be 50% 1 dark factor, 50% 2 dark factors

 

If a 0 dark factor bird is mated to a 2 dark factor bird the result will be 100% 1 dark factor chicks

 

Mutations like albinos, lutinos, greys and others where the dark factor rating may not be visible still have a dark factor rating but it might be only possible to tell what it is by breeding.

 

e.g. If a mauve cock bird (2 dark factors) was mated to a lutino hen and the chicks were all dark greens and/or cobalts (1 dark factor) it would prove that the lutino’s dark factor rating was 0. If however the chicks were a mixture of cobalts, mauves, dark greens and olives, the lutinos rating would be 1 dark factor. If they were all mauves & olives her rating would be 2 dark factors.

 

Mating a bird with 2 dark factors with a bird with any other rating can not possibly produce chicks with 0 dark factors. Also mating a bird with 0 dark factors with a bird with any other rating can not produce chicks with 2 dark factors. This means that a sky blue cannot have a mauve parent and an olive can not have a light green parent.

i agree with the above

Check out our FAQ, I think Pearce's explanation is very similar to that or that one but we have all this information in the FAQ section under Mutations .

Thank you Linda_S and Pearce

 

I understand perfectly now, Pearce's explanation was very easy to understand the first one kinda gave me a headache lol and also thanks to KAZ and Neville for posting the articles

Or you could try a colour coded version of the Dark Factor article found here http://www.geocities.com/Heartland/2761/ar.../dkfactors.html