Aussie Finch Forum

Hi Guys,

This might seem like a really dumb question, but I've seen everyone talking about double factor and single factor with regards to gouldians..

What does this actually mean?? :)

Keen to know, as we've got quite a few of them and plan to breed etc!!

Cheers!
Venetta and Kylie

A Cock bird has two sex chromosones (ZZ) and a hen one (Z) chromosone and one (W) chromosone (ZW).

A colour like yellow back is called sex linked and acts on the Z chromosone only and not the W chromosone.

So if a hen has the yellow colour on it's Z chromosone then it will be visually Yellow back. (Hens can not be DF)

If a cock only has the yellow colour on one of his Z chromosones then he is SF Single Factor, if he has yellow on both his Z chromosones then he is DF Double Factor.
Purple breasted Cock Gouldians SF Yellow will have a dilute green back and a DF Yellow will have a complety yellow back.
White breasted Cock Gouldians SF Yellow will have a yellow back with a blue ring around the head, a DF will have a more intense yellow back and a white ring around the head.

Have a play around with this gentic forcaster it might help:
http://www.ikhom.com/phpBB3/birds_manua ... cies_id=29" onclick="window.open(this.href);return false;

Does being single factor actually affect the colour??

Like will the male be a yellow back if he is only single factor??

I learnt genetics a little while studying Animal Care, but that was YEARS ago... lol

The terms refer to European yellow,also called yellow back.

The gene is on the sex chromosomes and is co dominant with normal. Birds are back to front with males having two z chromosomes hens a z and a w. if a cock has one yellow gene and one normal gene (one on each chromosome) it is partially yellow ie dilute green and is called single factor. The cock with two yellow genes is yellow and double factor. Because a hen can only have a normal or yellow gene (because it only has one z chromosome) it is yellow even though a single factor.

Im away at present so can't post pics do a google search for gouldian Belgium and you'll find a site with really good pics.

natamambo wrote: Im away at present so can't post pics do a google search for gouldian Belgium and you'll find a site with really good pics.

I think this is the site natamambo is refering to:
http://users.skynet.be/fa398872/engoulm34.htm" onclick="window.open(this.href);return false;

I think my eyes are officially going to fall out of my head and then my head will explode

Try this forecaster too, can be used offline
http://clientes.netvisao.pt/carlmato/" onclick="window.open(this.href);return false;
below is another online one


EDITED.....correct link in here now....
http://www.amadinagouldove.cz/gouldian- ... e/english/" onclick="window.open(this.href);return false;

also some light reading for you.
http://www.finchinfo.com/genetics/lady_ ... /index.php" onclick="window.open(this.href);return false;

venetta wrote:I think my eyes are officially going to fall out of my head and then my head will explode

The best thing is to use the forcasters and play around witht the different options.

bluebutterfly, that second link didn't work properly??
I just checked out the offline forecaster, I like it!

I think Simba"s way of explaining it is one of the most straightforward I have read.
LML