NOTE: This has been directly copy/pasted from my previous thread on the subject, so that I can update the information as more is learned about peafowl genetics.
Welcome! If you are here, I assume you have made it through Peafowl 101: Basic care, genetics, and answers(and if you haven't you may want to start there) and are ready for a second dose of knowledge. This thread is hopefully going to be very helpful to anyone who has questions about how peafowl colors and patterns transfer as well as answer a few other questions. If you have no prior knowledge, I suggest reading this twice; once to read the information and a second time to see how the bits all relate. If you have questions or comments that are NOT answered by this page, please PM me and I will work to get an answer.
A lesson in basic genetics
You may be familiar with some basic genetic ideas but in case you aren't, here's a quick overview as it relates to peafowl.
It is first important to understand the difference between a gene and an allele. A gene is the portion on a chromosome that codes for a trait. For example, you have a gene for eye color. The gene is the housing for the coding for eye color, not the quite coding itself. An allele is the coding variations of genes. An allele determines what color your eyes are (brown instead of blue). So you have a gene for eye color and the alleles of that space on the chromosome specify which color that is.
It is also important to understand genotype vs phenotype. A genotype is what genes the organism actually carries while a phenotype is what genes the organism displays. An India Blue peafowl that carries Bronze (we say Blue split Bronze) would genotypically be blue and bronze. Phenotypically, it would be a normal India Blue because Bronze is not displayed.
Before doing ANYthing with peafowl genetics, you must understand that there are only two species: Pavo cristatusand Pavo muticus*: The India Blue and the Green. The Green has 3 sub-species: Muticus, Imperator, and Specifier... however, the Green has NO color mutations to date. The India Blue has NO sub-species, but it has many color mutations. It's important to keep in mind that while 'blue' is a color, it is also the name of the species. Therefore, when someone says 'blue is the dominant color' they are not entirely accurate. A 'split' bird displays blue not because blue is dominant, but because 'Blue' is the species (the wild type) and it is only carrying the mutation.
*There is one other species of peafowl, Afropavo congensis. This is the Congo Peafowl and as it is namely wild or in zoos and is not commercially available, it does not factor into this discussion.
Lastly, you must understand sex-linked traits in birds. In humans, the chromosomes which carry gender are written XX (females) and XY (males). In birds, the chromosomes for gender are written ZZ (males) and ZW (females). Sex-linked colors in birds are displayed only if both the male's Zs have the allele, but the female only needs her 1 Z to have the allele.
Split: This indicates that the bird is carrying the color that follows. IE: A Blue split white is an India Blue carrying the white allele. In other genetics, this is referred to as "het" as in "heterozygous."
Spalding: This refers to any Pavo cristatus bred to Pavo muticus, resulting in a mixed species (hybrid) bird. Unlike most hybrids, spaldings are fertile.
Breed True: This refers to whether or not a color/pattern when bred to itself (ie, blue to blue) will produce 100% the same color.
Sex-linked: Refers to a trait (in peafowl it usually refers to color) that is transferred on the gender chromosome.
Colors Versus Patterns
In peafowl, color and pattern are two different traits and are transferred independently. I'm sure you remember this from Peafowl 101, but here is the list again.
Blue, White*, Charcoal, Bronze, Opal, Midnight, Jade, Taupe, Peach, Purple, Cameo, Sonjas Violeta
The above are (or are color mutations of) the Indian peafowl. The last four are sex-linked colors.
Green colored peafowl belong to the Muticus species, or are hybrids between Muticus and the India blues, called Spaldings. We will discuss them later.
*Please see White and Pied section below
It is important to understand that the above colors display as a phenotype. Genotypically, the birds are still India peafowl. For example, if a Bronze bird is bred to a pure blue the kids will all be Blue split Bronze despite that it looks like there is no blue in the Bronze parent. The exceptions are the sex-linked colors, which we will discuss later.
Barred wing- Wings are brown/tan and black 'striped'. This is the wild type pattern and many will not say 'barred wing'. If 'solid wing' (see below) is not indicated, barred wing may be assumed.
Solid wing (also known as Black Shoulder and abbreviated as BS)- Where the barring is on barred wing will be solid black/green/blue colors. This was the first pattern mutation.
Pied- White patches on body (result of leucism genes). This was the second pattern mutation.
White eye- The black eye of the train feathers will be white (or have white spots) in males and females are typically lighter in color (as chicks and as adults). Some birds can be white-eye without displaying white eyes. Additionally, this pattern is co-dominant. Only one parent needs to have this mutation for the offspring to have a chance at displaying it. This was the third pattern mutation.
Silver pied- Body looks white with patches of color. This is in interaction of the other three leucstic genes (white, pied, and white-eye). This is the most recent pattern mutation.
(White, see 'White and Pied' below- White is a color, but it will mask all other colors and patterns. The colors and patterns will still be present genetically.)
**Special Note: You may hear used the name "Oaten" and there have been questions about what this means. Oaten was the original name for Cameo BS, when they first appeared. People thought this was a new color, until it was determined this was just a pattern variation of a known color. There was also Jetta, an attempt to name a new color when in fact the birds were Opal with a new pattern. Thanks to ConnerHills for this information!
There are currently 185 United Peafowl Association approved varieties of peafowl and more possible.
Proper Grammar of Bird Lineage
This is quoted exactly from Brad Legg's UPA Approved Varieties page because I don't feel like rewording it: "The India varieties are listed with color first; then pattern, (if multiple patterns, then the oldest pattern is listed first with each different pattern listed in next sequence of existence). Hybrid varieties are listed with Spalding name first, then color, then pattern (if multiple patterns, then the oldest pattern is listed first with each different pattern listed in next sequence of existence)."
To understand what a 'split' bird is you have to have a grasp on what it means to carry a color. A carried color is a color the coding for which exists in the bird genotypically but is not displayed phenotypically. In order to display one of the color mutations, two copies of the mutation must be present. Not all coding for the various colors are located in the same place on the chromosome or even located on the same chromosome. For instance, the sex-linked colors are located on the gender chromosome. The only alleles (variations) which are known to exist (meaning the only two bits of coding which replace one another on a chromosome because they code in the same place) are White and Pied (yes, Pied is a pattern). For more about this, please see the white and pied section.
Namely what you will see in birds is blue split to other colors. Blue split to White, Blue split to Purple, Blue split to Bronze, etc. This is because it takes 2 of any color code to make the color display, and having only one (ie, split to the color), will default the bird to the wild type blue coloration. The only color change in a split bird occurs when the bird is split to white (or silver pied). In this case, the bird will show white wing coverlets/primaries
As far as we know, mutation split mutation (ie: Bronze split Opal, Taupe split Charcoal, etc) birds may not all exist. No one so far as proven that any of the colors are alleles of any of the other colors, meaning no one can prove that any of the coding for these colors exist on the same area of the same chromosome and would replace one another. So theoretically this is possible
We do know that the sex-linked colors can carry (be split to) the other colors, as we know they are on the gender chromosome and the others are not.
The current sex-linked colors are Purple, Cameo, Peach, and Sonja's Violeta (the newest). These colors do not transfer between birds like normal colors. Instead they travel on the sex chromosomes. Males must have 2 copies of the allele to display the color but females only need 1 copy. For the sake of simplicity, I will show the transference of the color when bred to a Blue. I will use purple as the sex-linked color. I will add pictures of punnet squares for visual examples when I get the time to use a scanner.
Purple male x Blue female = Blue split Purple males and Purple females
Purple female x Blue male = Blue split Purple males and Blue females
When a sex-linked color is bred to a blue split to its own color (ie purple bred to split purple), males and females of the sex-linked color can be produced. Remember that blues split to sex-linked colors will ALWAYS be male (see below). Additionally, the sex-linked colors will breed true when bred to itself.
Purple female x Blue split Purple male = Blue split Purple males, Purple males, Blue females, and Purple females
Purple male x purple female = Purple males and Purple females
No female will ever be split to a sex-linked color, because they only need 1 copy to display the color. A female with the gene will always be the sex-linked color. I will use Purple again as my sex-linked color for an example.
Purple male x Opal female = Blue split Purple/Opal males and Purple split Opal females
When two sex linked colors are bred together, the male offspring will be blue split the colors of the parents and the females will be the color of the father. Let's use Peach and Purple as our two sex-linked colors.
Peach male x Purple female = Blue split Peach/Purple males and Peach females
If you were to go insane and decide to breed the children of the pairing above together, it would be awesome and look something like this:
Blue split Peach/Purple male x Peach female = Peach males, Blue split Purple/Peach males, peach females, purple females
A note on Peach color: The current theory is that Peach is an interaction of the Purple and Cameo colors. If that is true, a Peach bird will necessarily be "split" Purple and Cameo, and could produce either when bred.
Mechanics of the 'White' Color and Pied Pattern
White and Pied birds are NOT albinos or partial albinos (ok, they are not USUALLY. An albino peafowl would be white, but a white peafowl is not typically an albino). Albinism is the absence of melanin production in the body and applies ONLY to birds who fail to produce melanin. A partial albino is a creature who has other forms of pigmentation (for example, carotenoids) and may still display some color. Albinos will lack color in their skin and eyes, not just their feathers.
Leucism, on the other hand, is a failure to properly deposit pigment (all pigments) on the feathers due to the failure of pigment cells to move to their proper location on the body from the neural crest. Leucism affects only the feathers of the bird, leaving the skin and eyes normal colored. Partial leucism results in the pied coloration (in any bird, not just peafowl. Wild pied or piebald birds can be found, but are very rare and usually are killed quickly by predators or do not get to breed because they don't look right). Total leucism can result in a completely white bird, which is how we have white peafowl. Pale leucism can affect part or all of a bird, resulting in washed out plumage instead of totally white plumage.
Because leucism is a failure of the color to be put into place, not a failure of the color to exist, it is possible for white birds (and pied birds) to exist with other colors and other patterns. A white bird may also be genotypically a purple bird, or a bronze bird, but the 'white' would mask these colors completely because the pigment for them would not be deposited on the feathers. Thus, a bird could genotypically be purple or bronze or any other color, but would phenotypically be white, and would breed true to white. In this way, white birds may be 'split to' other colors or patterns depending on parentage (for instance, a white bird from silver pied parents would breed 100% silver pied offspring if bred to a dark pied from silver pied parents, because both birds would be carrying silver pied... even though neither of them looked silver pied!).
A white bird cannot also be a pied bird, as the pied gene is an allele for the white gene. A bird cannot be both a partial leucistic bird (pied) and a total leucistic bird (white) at the same time. It is also true that a total leucistic bird will never revert to partial leucism, meaning a white bird will never create a pied bird offspring.
In this sense, white and pied are not truly colors or patterns; they are the masking of color and the interruption of patterns. However, we will place them into the color and pattern categories respectively because it's easier.
More information on leucism:
Leucism: Wikipedia Entry
Leucism in Wild Birds
The differences between Albinism and Leucism
An explanation of Patterns
The wild type pattern for the India blue is to have barred wings and full color. The mutations for pattern occur in 4 ways- blackshoulder, pied, silver pied, and white-eye. The 'color' white will mask ALL of these patterns, but the bird will still genotypically have a pattern. In blackshoulders, the barring on the wings becomes a solid, dark color. Barred wing and Blackshoulder are mutually exclusive- no bird can display both. However, barred wing birds can carry (be split to) the blackshoulder pattern.
In white-eye mutations, the eye of the train feathers on the male (not the eyeballs of the bird) can sport white spots or be entirely white (although it's possible for a bird to be white-eye but not display any white in the eyes).
The pied pattern is actually a result of what is called leucism or incorrectly called partial albino. In a leucistic bird, the pigment is not deposited on the feathers properly (unlike an albino, where pigment is absent). In birds, this can be displayed as pale leucism (meaning the color/patterns on the bird is washed out, but still visible) or as pied (meaning there are patches where the pigment is unable to display), resulting in white patches over the bird. As pied is a result of pigment deposition and not of pigment absence, the patches of white will be located in different areas on each bird depending on where pigment deposition is inhibited on an individual bird. The pied pattern has nothing to do with the white color allele and cannot be obtained through breeding a wild type to a white bird.
The silver pied is a result of 3 conditions working together- the pied pattern, the white-eye pattern, and the white color allele. Despite the white color affecting the bird, silver pied IS a pattern and not a color; there can be blue silver pied vs purple silver pied, and others. The silver pied pattern is mutually exclusive to the pied pattern- no bird can display both because of the (probably single or partial) white allele in the silver pied pattern (and I will disclaim this by saying I'm not sure anyone really knows how the silver pied works or came into being *exactly* but there are some good guesses.). The silver pied pattern is inclusive of the white-eye pattern, so all silver pied birds are also white-eye.
For more on the history of the silver pied, see here: Brad Legg's Silver Pied
The Muticus species is also called the Green peafowl. It is an Asiatic peafowl whose wild range is from Burma to Java, and as such they prefer much warmer temperatures than the India Blue. The Greens are the only other relevant species of peafowl. The species has 3 sub-species: Muticus-muticus, Muticus imperator, and Muticus-specifier. There are NO color mutations in this species (yet).
This species can be crossed with the Pavo cristatus or Indian peafowl, but the resulting chicks are considered to be of Indian peafowl descent with green blood mixed in. These chicks are fertile hybrids called Spaldings (named after the lady who did it first).
Spalding and Emerald Birds
A spalding is a hybrid bird, an India Blue with Green blood. The original spalding birds were bred by Mrs. Keith Spalding. Spaldings tend to be taller than normal Blues.
A spalding with 75%+ green blood is referred to as 'Emerald'. Many today refer to their birds as Emerald when this is not actually the case. As many spaldings now are bred for their phenotype and not their genotype, a green looking bird may NOT have as high of green blood as the breeder lets on by saying 'Emerald'. A true Emerald will be 75%+ green by their genotype.
What will happen if I cross....
So you've read all this and still don't quite get it, or you want to see a visual representation of all these crazy words... Well, you're in luck (sort of). I took a few hours over a couple days and created an excel document charting the basic colors and what you would get if you crossed one with another. As color and pattern breed independently, I will create a pattern chart when I feel like being masochistic again. Someday I will find a reliable way of hosting this chart. Today is not that day. Until I do, feel free to PM me with your e-mail address and I will e-mail you a copy.
I'd be a fool not to thank all the patient people who explained, re-explained.... and re-re-explained all of these things to be not less than a gajillion times. Deerman, Kev, and Cherokee Trail Farm were especially were key in explaining the stupid stuff to me very patiently... over and over... and over... and over......... lol! It was much easier once you guys started explaining things 'the hard way' through base genetics... so I've tried my best to replicate that here for anyone who may be missing important information like 'birds have z's and w's instead of x's and y's - and oh yeah they are opposite' and 'the color genes aren't all in the same locus on the same chromosome'.
If you would like to learn more about peafowl genetics, here are some great resources.
Legg's Peafowl Genetics
Hopkin's Livestock Peafowl Genetics
History of Peafowl Color and Pattern Mutations
If you spy incorrect information, please let me know by posting a reply to this thread (do NOT PM me corrections please). Be advised that correction information posted below may be outdated due to me making changes. If you have questions that are NOT answered by the above or have additional helpful links that should be included, please post a reply here or PM me and I will work to get an answer.