Reverse Genetics

The following article was written by me. It was published with my permission in the National Finch & Softbill Society Journal

As many who have bred or are breeding Gouldians likely knows, there are a few different computer programs available out there which forecast the genetic possibilities of offspring depending upon what two birds are paired together. The purpose being to determine what mutations the pair can possibly produce and thus influence the likelihood of producing a specific body color mutation.

What happens if you are simply not sure, however, how to achieve a specific body color mutation? I.e., You are not sure what is necessary to be present in order to produce the specific color mutation, so you are not sure which birds must be paired together to start. I frequently have individuals contact me asking what is the best way to produce “such and such” mutation, and these individuals usually have a specific goal in mind, and they want to know - what two birds should I pair together in order to get my goal bird?

This is where reverse genetics comes in. Reverse genetics can be quite tricky if you do not understand the basic mechanisms at play with Gouldian genetics. You have to have a firm grasp on how the mutations are produced to go backwards and determine what you need to pair to them re-produce those mutations. This article will only discuss Body Color.

A few important points to note:
1. The pairings below will not necessarily only produce the specified mutation bird. There are many other possibilities each pairing could produce. These are merely examples of what pairings are capable of producing said bird. Statistics are a funny thing, and their accuracy is usually dependent upon large numbers of results. So if you have one pair producing 4 babies each clutch, there is a possibility that the first clutch will not contain the baby you are looking for!

2. You generally need to have some background knowledge of the birds you intend to pair together in order to successfully achieve the results you are looking for. Meaning, if you have no idea if your pair carries the blue mutation, you can’t expect to produce genetically blue birds.

3. I belong to the camp of people who believe blue bodied birds (blues, pastels, silvers) should not be paired together. I realize there are many individuals who do not see a problem with this, so I will note that this is my personal opinion. To be comprehensive, this list includes all possibilities, but I have starred those I would discourage.

For specific inquiries, you can always email me!
I'll start with the more exotic mutations, since that is what most people seem to be interested in.

REMEMBER: The pairings below will not necessarily only produce the specified bird. There are many other possibilities each pairing could produce. These are merely examples of what pairings are capable of producing said bird. Statistics are a funny thing, and their accuracy is usually dependent upon large numbers of results. So if you have one pair producing 4 babies each clutch, there is a possibility that the first clutch will not contain the baby you are looking for! Check out "Body Color Pairings" if you would like to know all of the potential offspring a particular pairing below could produce.

Guide to Abbreviations

RH, BH, OH

Red Head
Black Head
Orange Head

SF, DF, /

Single Factor
Double Factor
Indicates a split or recessive color is present. I.e., Normal/Blue - Normal split for Blue Body; Purple/White - Purple split for White Breast

PB, LB, WB

Purple Breast
Lilac Breast
White Breast

N, Y, B

Normal
Yellow
Blue

Silver Males

Silver males can occur in two ways. The first, is to have a genetically double factor yellow, genetically blue bodied male. This bird will appear visually silver regardless of his breast color. The second option is by having a Lilac or White Breasted, single factor yellow, blue bodied male.

The following pairings can produce Silver Males [DF Yellow]:

Silver Male x Silver Hen*
Silver Male x Yellow/Blue Hen

Pastel Male x Silver Hen*
Pastel Male x Yellow/Blue Hen

Dilute/Blue Male x Silver Hen
Dilute/Blue Male x Yellow/Blue Hen

*These pairings are not recommended.

The following pairings can produce Silver Males [SF Yellow]:

"P/-" means a Purple/White or Purple/Lilac Bird.

P/-, LB or WB SF Y/B Male x P/-, LB or WB N/B Hen
P/-, LB or WB Pastel Blue Male x P/-, LB or WB N/B Hen
P/-, LB or WB Silver Male (SF or DF) x P/-, LB or WB N/B Hen

P/-, LB or WB N/B Male x P/-, LB or WB Y/B Hen
P/-, LB or WB SF Y/B Male x P/-, LB or WB Y/B Hen
P/-, LB or WB Blue Male x P/-, LB or WB Y/B Hen
P/-, LB or WB Pastel Blue Male x P/-, LB or WB Y/B Hen
LB or WB Silver Male (SF only) x P/-, LB or WB Y/B Hen

P/-, LB or WB SF Y/B Male x P/-, LB or WB Blue Hen
P/-, LB or WB Pastel Blue Male x P/-, LB or WB Blue Hen*
LB or WB Silver Male (SF only) x P/-, LB or WB Blue Hen*

P/-, LB or WB N/B Male x P/-, LB or WB Silver Hen
P/-, LB or WB SF Y/B Male x P/-, LB or WB Silver Hen
P/-, LB or WB Blue Male x P/-, LB or WB Silver Hen*

Silver Females

Silver hens are a bit less complex than silver males. Due to yellow being sex-linked, hens only need one copy to express the yellow body color [which they inherit from their father, not their mother]. This means that there is no requirement for them to be DF Yellow + Blue bodied to express the silver color. It also means that the only pertinent genetic information they receive from their mother revolves around the blue body mutation. In short: All you need for a Silver hen is a genetically yellow blue bodied bird

The following pairings can produce Silver hens:

Silver Male x Silver Hen*
Silver Male x Blue Hen*
Silver Male x Yellow/Blue Hen
Silver Male x Normal/Blue Hen

Pastel Male x Silver Hen*
Pastel Male x Blue Hen*
Pastel Male x Yellow/Blue Hen
Pastel Male x Normal/Blue Hen

DF Y/B Male x Silver Hen
DF Y/B Male x Blue Hen
DF Y/B Male x Y/B Hen
DF Y/B Male x N/B Hen

SF Y/B Male x Silver Hen
SF Y/B Male x Blue Hen
SF Y/B Male x Y/B Hen
SF Y/B Male x N/B Hen

*These pairings are not recommended.

Pastel Males

Pastel males are the result of combining a genetically SF Yellow, Genetically blue bodied male with a purple breast. They do not occur with any other breast color. Because they only need to be SF Yellow + Blue Bodied, there are quite a few pairings out there capable of producing this mutation. Likewise, I find this mutation particularly pleasing because it can produce a large variety of offspring when paired with certain hens.

The following pairings can produce Pastel Males:

Silver Male x Blue Hen*
Silver Male x N/B Hen
Silver [only if he is SF Yellow] Male x Silver Hen*
Silver [only if he is SF Yellow] Male x Y/B Hen

Pastel Male x Silver Hen*
Pastel Male x Blue Hen*
Pastel Male x Y/B Hen
Pastel Male x N/B Hen

DF Y/B Male x Blue Hen [!Best Choice! - 50% Pastel Males, 50% Dilute/Blue Males]
DF Y/B Male x N/B Hen

Dilute [SF Y]/Blue Male x Silver Hen
Dilute [SF Y]/Blue Male x Blue Hen
Dilute [SF Y]/Blue Male x Y/B Hen
Dilute [SF Y]/Blue Male x N/B Hen

*These pairings are not recommended.

Blue Bodied Birds

Blue is an autosomal recessive mutation. To put it in every day terms: to be visually Blue, a bird must inherit one copy of the blue body gene from both parents. Thus, at the very least, both parents must be split for blue body in order to produce blue bodied chicks.

The following pairings can produce Blue Males:

Silver [only if he is SF Y] Male x Blue Hen*
Silver [only if he is SF Y] Male x N/B Hen

Blue Male x Blue Hen*
Blue Male x N/B Hen

Pastel Male x Blue Hen*
Pastel Male x N/B Hen

Dilute [SF Y]/Blue Male x Blue Hen
Dilute [SF Y]/Blue Male x N/B Hen

N/B Male x N/B Hen
N/B Male x Blue Hen

*These pairings are not recommended.

The following pairings can produce Blue Hens:

Silver [only if he is SF Y] Male x Silver Hen*
Silver [only if he is SF Y] Male x Blue Hen*
Silver [only if he is SF Y] Male x Y/B Hen
Silver [only if he is SF Y] Male x N/B Hen

Blue Male x Silver Hen*
Blue Male x Blue Hen*
Blue Male x Y/B Hen
Blue Male x N/B Hen

Pastel Male x Silver Hen*
Pastel Male x Blue Hen*
Pastel Male x Y/B Hen
Pastel Male x N/B Hen

Dilute [SF Y]/Blue Male x Silver Hen
Dilute [SF Y]/Blue Male x Blue Hen
Dilute [SF Y]/Blue Male x Y/B Hen
Dilute [SF Y]/Blue Male x N/B Hen

N/B Male x Silver Hen
N/B Male x Blue Hen
N/B Male x Y/B Hen
N/B Male x N/B Hen

*These pairings are not recommended.

Producing birds that are guaranteed Split for Blue [/Blue] is as simple as pairing a genetically Blue bodied bird to any other bird that is not visually blue!

Yellow Hens

Yellow is a sex-linked gene, so therefore females need only inherit one copy [again, which they inherit from their father] to visually appear yellow. The body color of the mother therefore does not particulary matter, so it is not necessary to list out the various combinations of hens to pair to the males below. Just understand that "Any Hen" literally means any hen.

The following pairings can produce Yellow Hens:

Silver [DF or SF] Male x Any Hen

Pastel Male x Any Hen

DF Yellow Male x Any Hen [!Best Choice! - All hens produced will be Yellow]

Dilute [SF Y] Male x Any Hen

SF Yellow Males

SF Yellow males exist in two varieties. The first are the "Dilutes" as they are called, which are genetically SF Yellow birds that are also purple breasted. The second are what I call "SF Yellow Males". These are genetically SF Yellow, with a Lilac or White Breast, thus appearing visually yellow like their DF counterparts.

The following pairings can produce Dilute [SF Yellow, PB] Males:

Silver [SF Y only] x Yellow Hen
Silver [SF or DF Y] x Normal Hen

Pastel x Yellow Hen
Pastel x Normal Hen

Blue Male x Yellow Hen

DF Yellow x Blue Hen
DF Yellow x Normal Hen [!Good Choice! - All males produced will be Dilute]

SF Yellow x Silver Hen
SF Yellow x Blue Hen
SF Yellow x Yellow Hen
SF Yellow x Normal Hen

Normal Male x Silver Hen[!Good Choice! - All males produced will be Dilute/Blue]
Normal Male x Yellow Hen[!Good Choice! - All males produced will be Dilute]

It is necessary to explain that the above pairings assume both birds are not Lilac or WB. If one is Purple/White or Purple/Lilac, you will still get visual Dilutes. If pairing two splits together, you will get some visual Dilutes, and some SF Yellow, non PB, visually yellow males. The above pairings would not work to produce visual Dilutes if both parents are visually Lilac or White Breast. That is what the following section is for!

The following pairings can produce SF Yellow [Visually Yellow, Lilac or WB] Males:

"P/-" means a Purple/White or Purple/Lilac Bird.

P/-, LB or WB Silver [SF Y only] x P/-, LB or WB Yellow Hen
P/-, LB or WB Silver [SF or DF Y] x P/-, LB or WB Normal Hen

P/- Pastel x P/-, LB or WB Yellow Hen
P/- Pastel x P/-, LB or WB Normal Hen

P/-, LB or WB Blue Male x P/-, LB or WB Yellow Hen

P/-, LB or WB DF Yellow x P/-, LB or WB Blue Hen
P/-, LB or WB DF Yellow x P/-, LB or WB Normal Hen

P/-, LB or WB SF Yellow x P/-, LB or WB Silver Hen
P/-, LB or WB SF Yellow x P/-, LB or WB Blue Hen
P/-, LB or WB SF Yellow x P/-, LB or WB Yellow Hen
P/-, LB or WB SF Yellow x P/-, LB or WB Normal Hen

P/-, LB or WB Normal Male x P/-, LB or WB Silver Hen
P/-, LB or WB Normal Male x P/-, LB or WB Yellow Hen

DF Yellow Males

In order to produce DF Yellow Males, the bird needs to inherit one copy of the yellow gene from its mother, and one from its father. This means at the very least you need a SF Yellow male x Yellow hen.

The following pairings can produce DF Yellow Males:

Silver [DF or SF] Male x Silver Hen*
Silver [DF or SF] Male x Yellow Hen

Pastel Male x Silver Hen*
Pastel Male x Yellow Hen

DF Yellow Male x Silver Hen
DF Yellow Male x Yellow Hen [!Best Choice! - All males produced will be DF Yellow]

Dilute [SF Y] Male x Silver Hen

Dilute [SF Y] Male x Yellow Hen

*These pairings are not recommended.