We have been fortunate in being given a series of upcoming articles by Don Burke of Burke's Backyard and rare budgerigar breeder. Don has offered us some articles he has written and I am about to post three.

 

 

PUTTING A FACE ON CLEARWINGS

 

 

The hardest part of breeding clearwings is to put a decent face (forehead “blow”, directional feather, plus a long, wide mask) on a bird with good clear wings and decent body colour.

 

I have started some work on faces, but I don’t have sufficient statistics yet to be certain of what is going on. However, Warren wants an article so here goes on some half-baked ideas.

 

The Directional Feather Gene

There are two aspects here: having the gene for directional feather and having the length of directional feather.

 

 

My preliminary observations are that the gene for directional feather is a sex-linked recessive. So it is much the same as cinnamonwing or opaline. So if you cross a male modern showbird homozygous for the directional feather gene to a female pure primitive bird (e.g. a clearwing), all of the young females should have some directional feather, no matter how subtle it is and all of the young males should have none.

 

But all of the males are split for directional feather. If you cross a modern female showbird to a pure primitive-headed clearwing, expect 100% primitive heads on the babies. All of the females from this cross are more or less useless, since they won’t carry the directional feather gene, but all of the males will be split for directional feather.

 

Length of Directional Feathers

I am not at all sure of which gene is working here. Nonetheless, this is a genetic volume control issue* That is, some gene controls the length of directional feathers (perhaps it also controls the length of all head feathers). Volume controls on this gene control the length of the directional feathers. Since volume controls are at play, blending inheritance is the result. So matings of long directional feathers to short directional feathers should more or less give medium length ones.

 

That is, what you see is what you get, genetically speaking. This is the sort of thing that we used to refer to as modifier genes – except that modifier genes, in general, don’t exist. If they did you would get segregation of feather lengths in babies, but you don’t. Modifier genes are a furphy that needs to be put to rest once and for all.

 

So, select by eye for better length directional feathers and ignore the genetics as there is none at play that affect the outcome.

 

How to Pick the Presence of the Directional feather Gene Itself

This took me a while to work out. In clearwings, the effect was so subtle that, for years, I missed it. Now, what I do is to hold the bird in my hand and look at it from above and behind the head. As you look, you should notice that the front of the head should be wider than the middle or the rear. This is a certain sign that the gene is present. You will mostly see it in females due to the sex linkage.

 

In the crude drawing that I have done, I have greatly exaggerated the difference to show what to look for.

 

Blow

This appears to be largely a sex-limited gene. That is, it is visible mostly in males. Sex limiting genes create primary and secondary effects in sexual dimorphism: they create the peacock’s tail, body and facial hair in male humans, penises in most male animals, breasts in human females etc.

 

If I am correct, extreme forehead blow in females may indicate a masculinised female. That is, her hormones may be out of whack and she may not breed well. In other words, don’t expect too many females that can erect their forehead feathers like a male can. Technically speaking, these birds with blow are the first truly crested budgies. What we call cresteds merely have a facial feather whorl which is common in horses, cattle and some species of uncrested birds (especially parrots).

 

A truly crested bird has long, erectile feathers that are erected to indicate mood swings or for general communication. As with cockatoos, you can eventually produce females with a true crest, but I suspect that it won’t be easy.

 

Blow appears to be another volume control gene in this case affecting the existing erectile blow behaviour in male budgies. A feather length gene is also involved and this, too, is a volume control issue.

 

So:

1.Don’t expect too much blow in hens

2.But do expect that hens may produce it in their sons

3.Select really hard for it in all males. In males it is never hidden.

4.Expect blending inheritance. Non blow lines crossed with full blown lines should produce partial blow in the males only.

 

Mask

I really don’t know much about this at all. Obviously length and width of feathers are involved. It could be a volume control gene – i.e. blending inheritance issue. The strong ability for reversion worries me. Masks tend to fall back to very short in so many babies. Makes you wonder if something else is going on.

 

Anyway, long to short mask tends to produce medium masks, so clearly volume controls are at work somehow.

 

*New discoveries about gene actions have shown that the normal set up for most, if not all, genes is that the gene itself has volume control sections. That is a gene for say brown colour in bears can have its volume turned down and this produces the white polar bear. The gene for dilute in budgies can have its diluting effect turned up so that you get a blackeyed yellow. The pied gene can be turned up to get a reverse pied. Skin colour in humans is probably the result of volume controls too. Where volume controls are involved, you get blending inheritance rather than the segregation of genes that Mendel discovered. This explains why a white person married to a black person produces kids half way between the two in colour.

These gene controls produce banded pieds, winged pieds, and of course blue macaws. Blue macaws still possess the yellow gene, it is just re-shaped in area expression and turned down. That is, we can produce a white-faced green budgie. But not by finding a mutation, but rather by selecting for insipid yellow colour amongst greens.

 

 

 

7/3/11

 

 

http://www.bestofbreeds.net/wbo/article11.htm

Edited May 15, 201114 yr by **KAZ**

I really enjoyed this article Kaz, something to think about.