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Head Color GeneticsGouldians come in three head colors: Red, Black, and Yellow (aka Orange).
The Red and Black head color can be understood as two “alleles” (varieties) of a single gene located on the male sex chromosome. Because this gene is sex linked, males can either be “single factor” or “double factor” for each, whereas females can only ever be “single factor.” The Orange Head trait is autosomal recessive. What this means in a nutshell is that birds can potentially possess one or all traits associated with head color. Sound confusing? It's not really, I promise! |
Red Head (RH)
Red Head is sex-linked dominant. Because of this, hens can only be SF and express it, while cocks can either be SF or DF for the trait. A cock that is SF for Red Head is always "split" for the Black Head trait.
Occasionally you will see hens that appear to be mostly black headed with only a small amount of color. Sometimes, they only have a few flecks of red. They are still genetically "Red" but often referred to as "Dirty" red heads or "Dirty Masked" hens. Although I am sure this would be considered a fault if showing the hen, I have not found any evidence that this phenomenon is directly heritable. It also does not appear to be related to breeding BH to RH. The two "Dirty" hens I have produced came from RH to RH pairings. In fact, the two hens in the above photos are full sisters from the same pair.
The reason for the variation in the amount of color that RH or OH hens display is not fully understood at this time. One speculation is that there are modifying genes at play in the females that affect/regulate the amount of color in the mask. Hopefully - the ongoing research at STGF will help expose the underlying factors that control the variation of female head color.
Occasionally you will see hens that appear to be mostly black headed with only a small amount of color. Sometimes, they only have a few flecks of red. They are still genetically "Red" but often referred to as "Dirty" red heads or "Dirty Masked" hens. Although I am sure this would be considered a fault if showing the hen, I have not found any evidence that this phenomenon is directly heritable. It also does not appear to be related to breeding BH to RH. The two "Dirty" hens I have produced came from RH to RH pairings. In fact, the two hens in the above photos are full sisters from the same pair.
The reason for the variation in the amount of color that RH or OH hens display is not fully understood at this time. One speculation is that there are modifying genes at play in the females that affect/regulate the amount of color in the mask. Hopefully - the ongoing research at STGF will help expose the underlying factors that control the variation of female head color.
RH Cock |
RH Hen |
"Dirty" RH Hen |
Black Head (BH)
Black Head is sex-linked recessive to RH. So like RH, hens can only be SF and express the trait while cocks can either be SF (where they are visually RH and split for BH) or DF for Black Head (visually black).
There are also "visual" black headed birds that are really genetically Yellow (aka "Orange") head. These are usually referred to as "Black Head (Yellow-Tipped Beaks)" or "BH (YTB)."
The yellow tipped beak alerts you to the fact that the bird is genetically carrying the two recessive orange head genes - described in further detail below.
There are also "visual" black headed birds that are really genetically Yellow (aka "Orange") head. These are usually referred to as "Black Head (Yellow-Tipped Beaks)" or "BH (YTB)."
The yellow tipped beak alerts you to the fact that the bird is genetically carrying the two recessive orange head genes - described in further detail below.
BH Cock |
BH Hen |
Yellow Head (YH) aka Orange Head (OH)
Please Note - The scientific term for birds that appear Orange in head color is actually "Yellow Head." This is because the pigment associated with the color we see is a yellow pigment called Lutein. However, because most people are more comfortable referring to them as "Orange Head (OH)", this is the term I will use describing them.
Orange Head is an autosomal recessive trait but also requires at least one red head allele to be present in order to be expressed (e.g., R- oo). If a bird has two orange head genes but no red head allele (it is genetically black head instead), it will have a black head with a yellow tipped beak (YTB). This occurs because the bird is genetically an orange headed bird, but it cannot express the orange color because the orange head color depends in part on the red head color for expression, and the red head color is not there. Both cocks and hens can be "split" for orange head.
Orange Head is an autosomal recessive trait but also requires at least one red head allele to be present in order to be expressed (e.g., R- oo). If a bird has two orange head genes but no red head allele (it is genetically black head instead), it will have a black head with a yellow tipped beak (YTB). This occurs because the bird is genetically an orange headed bird, but it cannot express the orange color because the orange head color depends in part on the red head color for expression, and the red head color is not there. Both cocks and hens can be "split" for orange head.
YH Cock |
YH Hen |
BH(YTB) Cock |
BH(YTB) Hen |
Body Color Mutations and Their Affect on Head Color
The different body color mutations present in Gouldians will also affect the way the bird visually expresses its head color.
The Yellow body mutation reduces the expression of melanin (black pigment). SF Yellow males will only be partially reduced, with head color appearing as a smokey grey or charcoal color. DF Yellow males will have white or off-white heads. Because hens can only ever be SF for Yellow with full expression, their heads will always appear white or off-white in color.
The Yellow body mutation reduces the expression of melanin (black pigment). SF Yellow males will only be partially reduced, with head color appearing as a smokey grey or charcoal color. DF Yellow males will have white or off-white heads. Because hens can only ever be SF for Yellow with full expression, their heads will always appear white or off-white in color.
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The Blue Body mutation (this includes blue body, pastel body, and silver body) affects the Carotene colors (Red, Orange, Yellow) - turning both RH and OH into a Salmon or Sand/Tan color depending on the breast color. Purple Breasted birds tend to be more Salmon in color, while Lilac and White Breasted birds appear more Sand or Tan in color. There is no way to visually distinguish RH from OH in the blue mutation - you have to know the bird's genetics or try a test pair to determine the head color if you do not already know it.
RH PB Blue Cock |
RH WB Blue Cock |
RH PB SF Pastel Blue Cock |
RH PB SF Pastel Blue Hen |
Head Color Pairings & Results
The following will try to break down some of the possible genetic results of the following breedings. This is only discussing head color and is not taking breast or body color into consideration. The cock and hen pairings will be listed at the top in bold, with the possible outcomes below.
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DF RH Cock x RH Hen
DF RH Cocks RH Hens |
BH Cock x RH Hen
RH/BH Cocks BH Hens |
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SF RH Cock x RH Hen
50% DF RH Cocks 50% RH/BH Cocks 50% RH Hens 50% BH Hens SF RH Cock x BH Hen 50% RH/BH Cocks 50% BH Cocks 50% RH Hens 50% BH Hens |
DF RH Cock x BH Hen
RH/BH Cocks RH Hens BH Cock x BH Hen BH Cocks BH Hens |
Remember - the Orange headed trait is autosomal recessive - which means it is inherited independently of the red and black alleles, and it will only be expressed if both recessive copies are present. However! At least one red allele must be present in order for the orange color to be visually expressed. If a bird is genetically orange headed but does not possess at least one red allele, the bird will be black headed with a yellow-tipped beak (BH YTB). Birds that are split for orange head will appear as either red or black headed birds, with no visual way to identify the orange trait being present.
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OH Cock x OH Hen
OH Cocks OH Hens /OH Cock x /OH Hen 25% OH Birds 50% /OH Birds 25% will not carry the orange trait at all *It is important with this particular breeding to point out the negative aspect of breeding two heterozygotes (two "splits") together with respect to a recessive trait. There is no way to visually distinguish the babies produced by this pairing that are split for OH from babies that do not carry the OH trait at all. The only way to verify a chick has the trait present would be a future test breed to another OH bird. The same would be true for a pairing between a /OH Cock and a non-orange hen. 50% of the babies would be split for OH while 50% wouldn't possess the trait at all - but there would be no visual way to distinguish one from the other. Intuitively, an Orange headed bird paired with a non-orange bird will produce offspring that are all split for orange head - no guess work involved with that pairing! |
/OH Cock x OH Hen (or vice-versa)
50% OH Birds 50% /OH Remember - if a bird carries both recessive copies of the OH trait, but does not possess a red head allele (it is black head instead), it will have a black head with a yellow tipped beak (YTB). This occurs because the bird is genetically an orange headed bird, but it cannot express the orange color because the orange gene depends on the red head allele for expression. This is probably because the Orange pigment we see in an OH bird relies partially on the metabolic pathways responsible for the red color in RH birds, that do not function when a bird is genetically BH (and thus, neither the red or the orange pigment can not be synthesized). That being said - when pairing a BH(YTB) bird with another bird that is not Orange head or Split for orange head, all babies produced should be understand as being genetically split for orange head. BH (YTB) Cock x OH Hen OH/BH Cocks BH (YTB) Hens OH Cock x BH(YTB)Hen OH/BH Cocks OH Hens |
There are obviously other pairings involving BH YTB birds and /OH - but the results would be similar to those outcomes already discussed above. If you would like information on a specific pairing, please feel free to email me and I will also add it to this list.