"Opals" both Dominant and Recessive

There are two independent opal genes.  One which is dominant in its function and the other recessive in its expression.  For this reason they are called “Dominant opal” and conversely “recessive opal”.  The ones shown below on the left are examples of various forms of  the Dominant opal phenotypes.  Those shown on the right are examples of recessive opals.   Both opal forms are similar in their phenotypes or appearances; and at times are often confused with each another, and another mutation known as "reduced".  However, reduced is a sex-linked gene found on the Z sex chromosome; while both forms of opal are non sex-linked genes, making them autosomal gene mutations.  This simply means they are not sex-related and are to be found on any of the various autosome chromosomes.  

Most of the Opals shown here are in combination with the blue wild type color base.  However, due to the opals effects on color modification, many of them rarely appear to our eyes as being typical blues, browns or ash reds. Dominant opal can be expressed on all three of the basic colors of brown, blue and ash red.  However, recessive opal which is vividly displayed on blues is poorly expressed on brown and ash reds.  The pattern markings (bars, checker etc.) of the blue form of dominant opal is a pinkish white with a dark border line along with a tail end bar being a washed out whitish color. The pattern markings (bars, checker etc.) of the blue forms of recessive opals is a rust red color, and a tail of a metallic baring pattern typical for blue recessive opals. This tail marking is one of the keys to identification and distinguishes recessive opal from its sometime look-alike, reduced and Dominant opal.

Dominant Opal (OD)

Tom Barnharts spread opal

Dominant Opal (Od) is a dominant autosome, thus its name. Recessive Opal (o), as its name indicates, is a recessive autosome. Of the two, only Dominant Opal in the homozygous form (Od//Od) is lethal.  That is, when a bird receives a copy of this gene from both parents it becomes the kiss of death. These squabs often die in the egg or shortly thereafter. Od squabs will have long down at hatching.  Dilute Od squabs will be naked without down fuzz.


Blue dominant opal, heterozygous gempel with white bars on the left,  Blue dominant opal with white bars and checks on the right.

Dominant Opal blue T-pattern left, dominant opal ash red T-pattern right.

Since Od is a dominant gene it may express itself when heterozygous, which simply means it is split for both opal and normal non opal.   Homozygous or pure would mean the bird carried two genes for of the same factor or in this case (Od//Od).   Note that I said it may express itself.  I say may because dominant opal is variable in its expression.  Some opals are poorly expressed while most are very striking in their colors.  It will normally show some washing or whitening in the flights and tail with a washed out pale tail band.   In some cases the wing bars will look pinkish or have a pinkish line on the outer part of the bar.   On some these bars may even be white and this is usually due to the combination of opal and other color modifying genes.  In the checker and T-pattern expressions, Dominant Opal becomes much more vivid.   It shows itself in any number of differing shades of cream, pink and orange hues. In both checker and T-pattern it is one of the most striking of all modifiers.  It losses this effect; however, when combined with Spread where it then takes on a washed out metallic look like the spread opal of Tom Barnharts at the top of this page.  


Two T-pattern heterozygous dominant opals; each on a blue color base.  The first shown o the right is without any other major color modifiers.  However the bird on the right is both Indigo and dominant Opal,  It is the Indigo gene in this bird shown above that gives it the beep blue tail and washed out to nearly white tail bar.   Indigo is also the cause of the bronze colored head, neck, breast and wing shield color.   The marbling metallic wing flights are more typical of the opal effect and between these two color mutations, Indigo and Dominant opal, you have a very striking color combination.   One that is very eye catching as it comes to the landing board with its vivid colors and wide spread open tail on display.

The four Dominant Opals shown below are from Steve Caesar.  They are all blues, one in the bar pattern and the other three of light checker patterns with white flights.


Note how little the dominant opal effect is displayed on the this last blue checker above on the right.   It appears as an almost normal looking blue check with white flights, but if you look closley you will find that opal is there in the center of the checker pattern marks.    Like recessive opal, the overall amounts, of the opal effect, varies greatly from bird to bird.

This Dominant Opal blue checker is submitted by Arnau Constans of Spain.  It is a much softer color than the opal birds above; again demonstrating the variable of the dominant opal gene expression.  Note the washed out tail end bar and wing shield markings along with the metallic color of the wing flights.  This is dominant opal in full display on a blue check pigeon.

Recessive Opal (o)

Red phase recessive opal bar

Our other opal gene is known as “recessive opal” (o).   Note the genetic symbol for this recessive form of opal also uses the letter "o" just as the other, more dominant gene form of Dominant opal (Od) does.  

These two genes are not related in any way.  Take note of the fact that recessive opal is always symbolizes in the lower case while Dominant opal is in the upper case.   Genetic symbols are denoted in that way.   In other words, the dominant genes are listed in the upper case while the recessive ones are given in lower case. This helps to keep their effects in mind while working out all the possibilities of their genotype (genetic make-up) and their phenotype (appearance).

Recessive opal (o) has been a gene in the homing pigeon breed for a very long time. In fact, it may have been included in the genetic package of our earliest form of modern day racing homers.

The late Joseph W. Quinn in his book "The Pigeon Breeders Notebook An Introduction to Pigeon Science" writes that between 1-2% of most strains of racers are homozygous opal o//o and that between 15 and 20 % carry the factor o//+.

This gene first showed itself in my loft after several years of breeding to develop my own family of racers. Some of my original birds were given to me by my good friend Walter Hulden, who passed away at 93 years young and these birds were said to produce some odd colored pigeons from time to time. Well I had them in my loft for over ten years before it first manifested itself. It came from an uncle x niece combination of spread blacks.

Recessive opal spread is a very metallic pastel color on a spread blue or black pigeon.  It varies in form from very light, to medium, to almost black in shades.   The tail is typical for the other recessive opal forms with a washed out color of gray and some baring throughout the tail feathers length; and not just at the feathers end.   The body feathers are often laced with a darker outline.


Reessive opal spread cocks

Now keep in mind that Spread is not a pattern gene but a modifier of patterns.  One that modifies the way pigment granules are placed on the bird.  In the case of spread, it hides both clumped pigment and course spread pigment with additional smooth spread pigment.  Smooth spread pigment is normally found at the birds face area, on the wing tips and the tails end bar.  Therefore, a blue bar with its black wing tips and tail bar becomes a solid black when the spread modifier is present.  However smooth spread of the wing tips and tail end bar on a typical blue color bases pigeon with recessive opal is seen as a metallic color so a spread recessive opal becomes a solid metallic color everywhere pigment is placed.

With some forms of recessive opal, those referred to as red phase opals, the course spread pattern markings, i.e. the bars and checks are changed from black to a  rusty orange or reddish color.  This form of recessive opal, is not the same form we now know as Cherry.  Cherry in the past was lumped in with red phase but it is now known to be an allele of both the red and blue phase forms of recessive opal.  Cherry is symbolized as och .  

In T-pattern, red phase recessive opal is almost a pastel red in pattern on an otherwise metallic gray body.  The Hackle or neck is a metallic maroon to green luster. In the bared form, like the one shown above, it is often mistaken for an Ash Red bar or mealy.   In the blue checker and t-pattern phenotypes it takes on what I believe to be the most beautiful of all pigeon phenotypes.  It produces a lot of pastel reddish pink and metallic coloration which is very striking indeed.

Recessive opal as I have stated above is an autosome recessive gene.  Autosome means it is found on a chromosome other than the sex (Z) chromosome. Therefore, recessive opal is not sex-linked.  Both male and female must have two copies of this recessive opal gene (homozygous for the trait) for it to show its opal effects.   The same is true for their allele Cherry.  Like recessive opal, cherry is also known to have a direct linkage to the birds pattern gene found on this same autosomal chromosome.   Since these two gene loci for opal and pattern are located closely on the same chromosome, they in effect become linked to each other in the replication (reproduction) process.   The closer genes are to one another in the chromosome chain, the more likely they will remain linked together when replicated in the DNA of the egg or sperm.    It appears these two genes are so closely linked that a crossover, to effect a breakage of this link, seldom occurs.  Normally this mechanism of crossing over provide a means to reshuffle genes on the chromosomes but is less likely to occur when the genes are located closely to each other.    So in the case of recessive opal (or its allele cherry) along with the pattern series gene present, the two genes of the same chromosome stay together. Example, if linked to bar it is passed along with bar; when linked with checker it stays with checker.

Keep in mind, it takes two recessive opal genes to make a phenotype, so regardless of which pattern genes the bird carries, it will always be displayed in its dominant pattern form and only show recessive opal if both pattern genes are linked to a corresponding opal gene. In other words when (o//o) is present then it takes on the effect of the dominant pattern in recessive opal regardless of what the lesser dominant pattern is. Also keep in mind that Spread will always mask any and all of the pattern series effects.

Recessive Opal Blue Phase

Recessive opal blue phase, are those that do not show very much red color in the pattern marking areas.  Those that do show a greater amount of red, are known as red phase recessive opals. 

Blue phase recessive opals can look very normal on their wing shields however their tails will show the typical webbing or barring effect of recessive opal.  They come in all patterns from barless to t-pattern.  Spread has an effect on recessive opal and changes the pattern into a metallic coloration with the typical opal tail webbing or barring.

Spread is also an autosome gene. It is not in the pattern series but is dominant to all of them. It only requires one factor to display itself. So regardless of what the pattern underneath the spread is, a recessive opal with one or two factors for spread will show recessive opal spread. The birds shown here are Spread Recessive Opal on blue bar.

Opals in my loft were originally in the bar pattern with most masked by spread. Since crossover takes too long simply wait for to happen and that results in to many extra birds to feed; I had to trade for some in both the check pattern and red phase to get what  was looking for.

Dark phase spread on the left, and very dark phase on right (typically these darker spreads are always hens while the cocks like the two above are lighter in metallic color).


Barless blue phase left, light check blue phase right.

A blue phase rec. opal cock by Larry Davis

Cherry och 

Cherry is an allele of recessive opal and it is only displayed when genetically on a wild type, blue color base; just as both red and blue pahse recessive opals do.  Why the pattern colors is red and not black we do not know for sure.

Both Cherry and recessive opal are to be found in all the typical patterns from barless to t-pattern.  Here the course spread of the pattern marking is turned into the opal red color.  The more pattern displayed the more opal red there is to be seen.  However when the spread factor is added, the red color of the course spread pattern area is masked by the effect of spread changing the course spread into smooth spread.  Since smooth spread is not displayed as red, there are no phenotypes for red phase spreads.  They are simply displayed  in the same color as the blue spread forms.   It is assumed that the same is true for cherry but I have not seen any to know for certin.


Cherry in bar form by Tom Barnhart on the left and one of my red phase dirty bar hens on the right.  

These are not the same mutation but are alleles.


Red phase wing shield and tail pattern of the dirty bared bird above.  Note the ribbing pattern in the tail so common with recessive opal.


These two young birds are from Tom Barnhart's loft, red phase on the left and cherry on the right.

Note how much lighter in ground color the cherry birds are.  Also note how much lighter the cherry tail color is.  This has nothing to do with the gene for dirty but is typical for the cherry mutation itself.

Cherry is a much closer mimic for ash red than a red phase would be.

A cherry hen by Ronda Mariani of Circle Loft

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Copyright 1999 by Ronald Huntley.
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