Genetics Introduction
Genetics can be tricky for anyone who doesn't have a background in Biology or has never taken a genetics course. For that reason I will attempt to simplify the basics and provide a "crash" course in mendelian genetics to assist those who are truly interested in learning about Gouldian genetics. Learning can be rewarding not only because of the joy you get from understanding something so complex - but also because of the freedom to produce set clutches of babies based on your knowledge of the genetics and your birds.
Gouldian genetics can be divided into three basic categories:
1. Head Color
2. Breast Color and
3. Body Color
In the Genetics Menu above, you can navigate through the three different areas to learn more about the genetics associated with each. Following the genetics information, you will find forecast charts which will break down what certain pairs are capable of producing.
For those of you who are interested in diving a little deeper to a more advanced discussion of color genetics, you can select the "Advanced Genetics" or "Reverse Genetics" option from the Genetics menu above!
Gouldian genetics can be divided into three basic categories:
1. Head Color
2. Breast Color and
3. Body Color
In the Genetics Menu above, you can navigate through the three different areas to learn more about the genetics associated with each. Following the genetics information, you will find forecast charts which will break down what certain pairs are capable of producing.
For those of you who are interested in diving a little deeper to a more advanced discussion of color genetics, you can select the "Advanced Genetics" or "Reverse Genetics" option from the Genetics menu above!
Gouldian Nomenclature
There is a lot of confusion surrounding the "Names" of the different Gouldian Finch mutations. I'll try to clear the air below, but I may just add to the confusion so if so, I apologize in advance!
Orange vs Yellow Head
A lot of people ask what is the difference between an "Orange Head" and a "Yellow Head?" - The answer is nothing. Orange is what we visually see expressed, so this is often how the bird is described. In the scientific community these birds are referred to as "Yellow" because the orange color that is expressed is actually controlled by a "Yellow" pigment. I tend to refer to these birds as "Orange Head" because there is also a "Yellow" body color and I don't want anyone to get the two confused - especially when using the various abbreviations used to describe a Gouldian Finch.
Lilac Breast
I often see people refer to a bird as "Rose" or "Pink" breasted. These are all "Lilac" breasted birds, there is no genetic difference. However - there is a difference between Lilac and "Dirty White Breasted" birds, which is likely a modification and not necessarily heritable. These birds typically have patches of purple or lilac color on an otherwise white breast. Often times the patches of color disappear with a subsequent molt. The Lilac breast color comes in various shades depending on how much phaeomelanin is suppressed - much like the variations one sees in Dilute backed Gouldian males.
Body Color
The names of the various body color mutations is where things get really hairy. Many people are pushing for the genetic nomenclature to be the standard, as it describes what is actually going on genetically, versus what we see physically, and can help eliminate some of the confusion - specifically surrounding "Pastels" and "Silvers". However, using the genetic nomenclature requires an understanding of the genetics, so it's my opinion that the colloquial names are going nowhere. Therefore it's important to understand both. The names below revolve around the base color present in the bird: Green or Blue. Pastel is what the scientific community uses to refer to the gene responsible for producing visually "dilute," "yellow," "pastel blue" and "silver" bodied birds.
SF Pastel Green
This is a "normal" bird (meaning it does not carry the blue mutation) that carries a single copy of the Pastel (or yellow) gene. SF Pastel Greens can be cocks or hens. SF Pastel Green cocks are generally called "Dilutes" or "SF Yellows" to describe their visual appearance. SF Pastel Green hens are typically just called "Yellow."
DF Pastel Green
This refers exclusively to cocks who carry two copies of the Pastel (or yellow) gene. DF Pastel Greens are generally called "DF Yellows."
SF Pastel Blue
This is a genetically blue bodied bird that also carries a single copy of the Pastel (or yellow) gene. SF Pastel Blues can be cocks or hens. SF Pastel Blue cocks have so many names in the US that it can be extremely confusing for individuals just starting out. They are most commonly referred to as "Pastel," but you will also see people refer to them as "Powder Blue," "Blue Dilute," etc. Some people even refer to "Powder Blue" as if it is a separate mutation, which it's not. To add to the confusion, SF Pastel Blue cocks can also be visually "Silver" if they are Lilac or White Breast. In these instances I've seen people refer to them as "False" or "Fake" Silvers, which is completely illogical because the birds are visually Silver, so there's nothing "False" or "Fake" about it. In this instance it almost becomes necessary to use the genetic nomenclature because you know immediately the bird is SF Pastel Blue vs DF Pastel Blue.
SF Pastel Blue hens are always visually silver, and generally called "Silver" as a result.
SF Pastel Blue hens are always visually silver, and generally called "Silver" as a result.
DF Pastel Blue
This is a genetically blue cock that carries two copies of the Pastel (yellow) gene. DF Pastel Blue cocks are always visually silver, and as such are usually referred to as "Silver."
Genetics Terms
Phenotype
This is the actual visual appearance of the animal (from now on we'll say Gouldian). So.. your bird being Red Headed, Purple Breasted and Normal (Green) backed is its "Phenotype."
Genotype
The genotype, on the other hand, is the actual genetic make up of the bird which produces its phenotype. This is where things can get tricky - because a Purple Breasted bird can be a few genotypes - it can be Purple/White, Purple/Purple, Purple/Lilac. The "/" once again denotes that the color is "split" for something else. This will make more sense once we define Double-Factor and Single-Factor (also known to biologists as either Homozygous or Heterozygous).
Single-Factor
Single factor (simplified SF) means just the opposite - the bird has only one of the genes corresponding to a particular trait. For instance - with the Yellow mutation, a male bird can either be SF or DF for the Yellow gene.
Double-Factor
Double-Factor (simplified DF) indicates that the bird is homozygous for a trait. This means it has two of the same genes corresponding to that particular trait.
Sex-Linked
When a trait is sex-linked, it means the genes appear only on the sex chromosomes. It is useful to point out that these refer to genes on the male sex chromosome since the W female chromosome does not carry any sex linked genes. In birds, these chromosomes are denoted as Z and W (whereas in humans they are X and Y) - and male birds are identified as ZZ, with females being ZW (as some may notice, this is the reverse of the situation with humans: males are XY and females are XX).
Autosomal Traits
Autosomal traits are those that are located on chromosomes other than the sex chromosomes. For example, all breast color genes are autosomal genes and are not found on the sex chromosomes.
Dominant Trait
A dominant trait is one that will appear phenotypically if one or more parents contributes that trait.
Recessive Trait
The opposite of a dominant trait, a recessive trait is one that will only be phenotypically expressed if both parents contribute the recessive trait.