Mutavi - Research & Advice Group

ANOTHER LOOK AT THE LADY GOULDIAN
(Erythrura Gouldiae)

(Part 2)

By Dirk Van den Abeele
MUTAVI, Research & Advice group

During our initial research of the Lady Gouldian (Erythrura Gouldiae) and its mutations, we have covered the basis of our research. Studies of already existing research reports and new research within MUTAVI brought us more information. We will first focus on the creation of the colors in Lady Gouldians.
We can distinguish several feather areas that are responsible for the different colors and/or mutations of these birds:

Head
Back/ Wing deck
Breast
Abdominal area

Head area:  
Research accomplished within MUTAVI in 1991 by John van Eerd (who regretfully passed away several years later) indicated first and foremost that we are dealing with two different types of feathers. The feathers of the Read Head and Orange Head are different from those of the Black Head.

Also, Van Eerd was able to find differences of feather structure between the male and female Red Head and Orange Head birds. The male birds have barbs that have a long, hookless end. From top to bottom: we have the red zone, then the brown-like zone, followed by a small black zone. The down is gray. These feathers are ornamental-type feathers and contain solely red canthaxanthine (this was already determined and scientifically proven by Brush in 1968).

The hookless end on a head feather of the hen is much shorter, followed by the red zone, then the brown zone (which is minimal and sometimes even absent), and then the deep black zone. Because of this structure and the differences in color proportions, the hen has her typical head color.
When the production of canthaxanthine in the head feathers is disturbed, the result is a less developed red canthaxanthine which expresses itself as a orange color (and thus the Orange Head). This mutation is autosomal recessive to the Red Head. According to me the Red Head can be regarded as the wild form (see part 1). We can therefore use the following genetic symbols: for Red Head: of+ / of+ and for the Orange Head of / of.  

The head feathers of the male and female Black Head are almost identical to each other. The whole barb is covered with little hooks. The feather is almost completely filled with black eumelanin. In other words, in comparison with the feathers of the Red Head this feather is less developed and misses the top where normally the red or orange coloration is deposited. The gene that is responsible for the creation of these type feathers (Black Head) is located at the X-chromosome and is recessive.

It got the genetic formula: Xbf

The fact that this type feather is regarded as being “primitive”, formed for some the motive to reason that the Red Head was a sex-linked dominant mutation. This claim is however incorrect. The most obvious prove to refute this erroneous claim is when we breed an Orange Head male to a Black Head female. The result will be all phenotypic Red Heads. More specifically, the result will be Red Head/ Orange Head/ Black Head males, with Red Head/ Orange Head females.

Let’s write out the genetic formulas:

Formula male: of / of ; Xbf+ / Xbf+ (Orange Head)  
Formula female: of+ / of+ ; Xbf / Y (Black Head)

Number of possible combinations: 16
Number of different genotypes: 2

NO. PERC. NUMBER GENOTYPES

1 50% 8 of+ / of ; Xbf+ / Xbf (RH/ OH/ BH males)
2 50% 8 of+ / of ; Xbf+ / Y (RH/ OH females)

I believe this proves that the Black Head is a mutation that influences the head feather structure. How else is it possible to have dominant offspring from parents who do not possess or display this dominant factor (Red Head in this case)?
Simply said, how can we breed two birds that have no dominant trait, and get offspring with this dominant mutation? The rule of dominant mutations tells us that either the trait is displayed, or it is not present. Furthermore, we should then have SF and DF Red Head males and SF females. If we were then to breed a SF Red Head male with a Black Head female, the result should then be Red Head and Black Head females, and this is not true.

So, the thesis that Red Head is a sex-linked dominant mutation is incorrect. Everything points, genetically spoken, towards Red Head being the basic form. We are not alone in drawing this conclusion.

When MUTAVI started this research, we sought contact with Dr. Terry Martin from Australia, the home of the Lady Gouldian. Terry Martin is a well-known ornithologist/veterinarian and regularly publishes his findings in the Australian Birdkeeper magazine. He is also the author of the recently published book: “A Guide to Colour Mutations & Genetics in Parrots”. We presented him with our findings and this was his answer:
Dirk,
I have come to the same conclusion. Breeders see the Black Head as the wild type because some scientists incorrectly interpreted the workings of the different loci, which have been repeated in books about the Goulds all over the world. They claim that the sexlinked loci are responsible for the production of red and the recessive loci for the change of red into yellow. Their second reason is that the Black Head appears in nature in bigger numbers.

The reasons why I disagree with these claims are as follows:
If the sex-linked locus is responsible for the production of red, then the Black Head cannot have a red tipped beak. The Yellow Head shows us the inactivity of this locus; we all know that yellow pigments are the “early” steps of the production of red pigments.
This is the locus that produces red in the wild type and if that is not activated, the only color it can produce will be yellow.
If the Black Head would be the original wild type, why then have the black “pencil marks” developed around the head? This could only have happened with a Red Head.

The difference in feather structure between a Red Head and a Black Head also indicates that the sex-linked locus checks the head feather structure and allows the deposit of red pigment. Structurally changed feathers cannot contain red, although the bird itself is still able to produce red pigment. This will then be deposited in other regions of the body, like the tip of the beak.
It is clear that the Red Head is the wild type and that evolution is pushing the species in the direction of a color mutation, namely the Black Head.  

(I use the term Yellow Head versus Orange Head, because it is clearly the same locus that these “yellow” colors produces in other Australian finches, including the yellow beak zebra finches and many others. The color may well be yellow/ orange, but I use the term yellow because that always has been the standard with Goulds and zebra finches in Australia, since colors were noticed and recorded.  

Wing deck and abdominal area

The wing deck color of the Red Head, Orange Head, and Black Head is light green. They are structural feathers, meaning that they have a medulla containing the vacuoles and the black eumelanine, a spongy zone, and a cortex containing luteine.

The abdominal feathers are yellow. These feathers lack the eumelanine, so the light is not absorbed in the medulla, but it is reflected by the cortex. Since the cortex contains luteine, we see the light that is reflected as yellow. During research performed by Mr. van Eerd it was determined that phaeomelanine was absent in these feathers, which has been confirmed by recent research by a MUTAVI co-worker Mr. Inte Onsman.

Breast area

Mr. van Eerd described these feathers as follows:  
The purple hookless end of the male is longer than that of the female. The purple breast color is the result of interference in the spongy zone in combination with the brown-phaeomelanine.
The brown-phaeomelanine is situated under the spongy zone in the medulla cells as well as in the barbules. Under the purple zone of the feather one will find the brown zone. The basis of the feather contains a little eumelanine. The purple zone does not play an as big a part regarding the color expression with the female as it does with the male bird. The brown zone has a stronger influence on the color expression with the female than the male, and consequently she expresses a somewhat lighter shade of purple (or even pink-like). The profile of the barb of the male purple breast feather is round to oval shaped, with a slight to strong tendency of expansion of the cortex.

It is important to note that phaeomelanine has been found in the breast feathers.  
To summarize we can pose that the following factors are responsible for the color expression of the Lady Gouldians:
· Eumelanin
· Phaeomelanin
· Feather structure blue
· Lutein
· Canthaxanthin

These last two belong chemically to the group of carotenoids.
With this knowledge, we can take a closer look at some other mutations.

The “blue” mutation  

The first mutation we are going to discuss is the “blue” gold. This mutation affects the color of the abdominal area, wing deck, back, and head. The Red Head will display a “beige” head, the wing deck and back are “blue”, the breast feathers stay original, and the abdominal area gets a “light creamy” coloration.

“Blue” inherits autosomal recessive.
We are going to take a look at the standards of the BNEC. These standards are based on at least 15 different birds.

BLUE MALE “BEIGE” HEAD

Forehead-cheeks-mask: Dark beige, bordered by a black line, which is broader at the throat and creates a black spot at the throat. Behind the black on top of the head is a light blue band.

Neck-back-wing deck: The light blue band transitions into a smooth and evenly dispersed blue wing deck. The shining through of brown by the feather rachis is allowed only with young birds.

Upper tail coverts: The upper tail coverts are pale blue. This blue transitions upwards into bright blue towards the blue on the back, of which the feathers end up in a shade of lighter blue. This then forms a symmetric picture.

Tail: Black. The two middle feathers are longer than the rest of the tail (approx. 1 inch).

Breast: Purple blue.

Abdominal area-flanks: Light beige, which transitions towards the breast area and flanks into beige.

Vent area: White beige.

Undertail coverts: White beige.  

Beak: White gray.

Eyes: Shiny black with gray closed eye ring.

At first sight ordinary “blue”, but it is important to ask ourselves how a blue mutation arises and what a real “blue” bird really is.
“Blue” birds are not able to produce any carotenoid (neither the red canthaxanthin, nor the yellow lutein). We know that there is no blue pigment in feathers of the structural type (these make up the abdominal area and wing deck area). The blue color is produced by light interference in the spongy zone. The feathers of normal (light green backed) birds get their color due to the absorption of daylight by the black eumelanin in the medulla. Then blue light is created by interference in the spongy zone, and due to reflection of this blue light through the cortex (that contains the yellow lutein) the resulting color is green.

Feathers get a yellow color when the black eumelanin is not present. In this case the light is not absorbed anymore by the eumelanin, and is immediately reflected by the cortex (that contains the yellow lutein). Structural feathers of the blue bird lose the yellow coloration (lutein), but the light does get absorbed in the medulla. Blue light is created in the spongy zone because of interference of light and then gets sent out through the colorless cortex. The color we see is therefore blue.  

If we compare this to the “blue” Lady Gouldians we immediately notice something: the abdominal feathers that have lost the yellow pigment in the cortex should all be white, not light-beige. The explanation for this could be two-fold: either there is no lutein left at all but there is some phaeomelanin present, or there is still some lutein left in small quantities. Research has shown that there is absolutely no phaeomelanin present in these feathers, so we must therefore conclude that there is still some lutein left in these feathers. This also implies that the name “blue” is not correct.  

More proof comes from the head color. If all carotenoids are suppressed, then there should be no canthaxanthine present in the feathers of the Red Head and Orange Head mutation. This is however not the case. There is still a minimal quantity left. These birds are described by the standards as “Beige Heads”.

Every fancier knows that the birds should be selected for their blue coloration, because there are various shades of “blue Goulds”. There is still a certain shade left on the wing deck that has an influence on the resulting color. It is more striking when we use the blue band located in the neck with the affected area. This particular area deserves the term blue in my opinion. If we compare the different main areas (excluding the blue band in the neck) we can conclude that the reduction of lutein the biggest is on the wing deck; this is between 90-95% blue. The presence of lutein seems the highest in the abdominal area.

What then could it be?

Keeping in mind the all the existing mutations of birds and the internationally made agreements regarding these, the term “turquoise” seems a better fit. Turquoise represents an allele of the bl-locus which is responsible for a variable reduction of the present cartenoids. We have these examples also with different parakeet-type birds. For example the turquoise roseicollis (which is internationally also described as turquoise) and the turquoise Indian ring neck (which used to be described as pastel blue). This mutation has been given the symbol bltq / bltq.  

In the meantime there is also an “aqua” form known of the Lady Gouldian. If it really is aqua, then that is indeed also an allele of the bl locus. Proof breeding still have to determine what exactly is at hand, and it is therefore too early to talk about this with any certainty.

This all does of course not exclude the possibility of the existence of a real blue Gouldian, but then we have to have a bird with a Black Head (out of the three existing forms), a pure blue wing deck and a pure white abdominal region. In the meantime we have to wonder how these birds should be evaluated at shows. Should one account for different shades in coloration on the wing deck or abdominal region? Or should one stimulate (with which I would disagree) breeders to select their birds based on which is the most blue? If one would allow this to happen, I fear that the term “blue” will always remain an unclear and confusing term. The bluest birds will end up on the shows and will misguide beginning fanciers. We have seen this happen with the Agapornis roseicollis.

Several bird clubs named this mutation “white mask” (or even used the name blue, as this regrettably still happens once and awhile). Because the bird is still able to produce the color red in the facial feathers (psittacine in this case), most birds had a pink coloration on the forehead. The beginning bird fancier got confused by this, because the “white masks” were no white masks at all. This was of course reason for confusion and misunderstanding. We took charge immediately by banning the term “white mask” and to replace it with “pale mask”. Internationally this bird has been called turquoise because this could apply to all other species as well. The next step with lovebirds will be to replace the name “pale face” with “turquoise”, but that will be done at a later time. We perform adaptations step by step, with a clear stream of information towards the fancier and mutual cooperation among the different participating bird clubs. Something I would like to recommend to those involved with the Lady Gouldian!  

This research was started based on the initiative of the BNEC, and together we will take a closer look at every color mutation of the Lady Gouldians. We will determine the genetic symbols, we will determine the locus of the mutation, and if necessary, perform feather research. To do this, we will need the different breeding results of experimental combinations. To be able to do this on a wide scale, we would like to ask all breeders and fanciers of Lady Gouldians to participate in the collection of data. If you would want to cooperate, please contact: Mr. Daniel Wildemeersch Email: erythrura@gmail.com Home page: http://users.skynet.be/fa398872/

We will keep you informed regarding further studies through different articles and the MUTAVI site (http://www.life-research.nl en http://www.euronet.nl/users/dwjgh/) and MUTAVI email newsletter ( subscription for this free newsletter can be done via http://agapornis.be/)

Dirk Van den Abeele
MUTAVI, research & Advice Group


Used literature and sources:
Feather research by Inte Onsman (2003)
Eerd J.v.,(1991)
MUTAVI, Research & Advice Group
Kleur en kleurstoffen in de Gouldamandine

Brush A., Seifried H., (1968)
Pigmentation and Feather structure in Genetic variants of the Gouldian Finch
Auk 85: blz. 416-430

Eerd J.v.,(1989)
De Gouldamandine.
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