Theory: Ml and id+ cause brown eyes in chickens

[Amer]

Over the years I've been obsessed with brown eyes, especially those of my d'Anvers. I stare into the dark depths and ponder. All this pondering led me to wonder: How come no matter what breed you have, brown eyes come with quail coloring?
In my female-line d'Anvers I get brown/dark red eyes in hens and bay eyes in the cocks

But in male breeder lines dark-eyed males are achieved because they have more melanin.

(I really struggled to find a good example of this because d'Anver cock beards tend to obscure the eyes. Also the website this photo came from is completely gone)
And dark eyed quail females are the defaults in all breeds:

(Old English credited to Larson's Miniatures http://larsonsminiatures.com/old-english-game-bantams.html)
And maybe it came obvious to those are familiar with genetics and I am annoying you with my "breakthrough" that was already well known. But when I looked up causes for brown eyes it said extended black and id+. And the sexlinked brown eye gene.
https://www.backyardchickens.com/threads/eye-color-genetics-help-me-help-me.293503/
But quail-colored birds obviously aren't E and it would be weird if somehow the sexlinked brown gene happened to be involved whenever the quail pattern emerged in different breeds.
I think it is caused by the interaction of id+ and Ml. Dark eyes are found in Spangled and pencilled Hamburgs and Silver Sebrights but not in Wyandottes which lack the slate legs. Since both ER based Hamburgs and e^b based Hamburgs have dark eyes, we can extrapolate that it is the id+ gene and not the base color that affects the eye color in Sebrights vs. Wyandottes.
Interestingly, I can't think of an example of a quail chicken with light-colored legs, but if my theory is correct, it would have bay eyes. I feel like that would be the ultimate test.
@KristenG @nicalandia
@MysteryChicken
Writing this post was difficult because quail are an entirely different species of bird and I needed the language to indicate chickens, lol.

 

[KristenG]

Ok, I went and got some pictures. First three are all baby pictures. Slate eyes. Variety doesn’t matter. Self blue and black day old d’Anvers babies. Then a BBR d’Anvers week old chick. Eye color stays like this for about the first month. Then by three months it turns yellow to orange for most of them

Then at 4 months old the true color begins to show. This 4 month old quail d’Anvers has what I call the red eyes. They are more of a golden orangey-bay, I guess. She will always have this color. It is too light.

At about this time, the birds with the brown eyes should be starting to show. Here are some of her male hatch mates. First is a quail d’Anvers cockerel showing medium brown eyes. This is the color I strongly favor in my boys because it is the darkest I have hatched in them yet. As I only recently introduced it into one sublineage, it is still quite rare.

To see the degree of contrast, take note of this next quail d’Anvers male- same hatch group, different subline. You might be interested to know he is from the male color line, so he is a deeper red and is heavy on the black markings. But his eyes don’t really care. They are a bright yellow orange (again, what I probably inaccurately call the red eye - these eyes do seem to gain red pigment with age but not a lot):

And I am getting the same things in my black d’Anvers. Here is a 3-month-old accidental male rumpless d’Anvers showing the brown pigment beginning to deposit in his eyes- plus a full body pic:

And then we have another 3-month old d’Anvers cockerel showing the orange eye. How unfortunate… Note he is still sound in his color in every other way:

And then I may as well show you the other eye color variations. The good news is only one bird (a 3-month black pullet) this year seems to be showing any indication of the “green” eye. The green eye is really a pale yellow that has usually has some brown pigment leaking through. The combination lends the yellow a greenish cast. Sometimes the whole eye will be this color. Most often, it is just part of the eye. I have been working hard to cull against it.

And I was going to show you the marbled eye. I only had one pullet end up with it this year - a white d’Anvers. It is striking. No the pupil is not irregular. Normal pupillary reflex and all that. That is just dark pigment. That is the nature of the marbled eye. I do not know what causes it but I try to get rid of it. I find it seems to be somewhat related to the green eye as the two tend to occur together in families. This particular white is descended from my blacks.

 

[KristenG]

This is the only one since I haven’t bred him so I don’t know if it is simply coincidental or actually linked to the dark eye gene.

Thanks for sharing. These are very green on the inner ring - how neat!

For the record, I was never able to find this post again. I'm fairly confident I know where it was posted, but it's completely gone now so it must have been deleted. Or I'm misremembering and the actual post location is lost to the fog of my brain. At any rate, still following and enjoying the discussion here!

This note inspired me to do some digging. I found an interesting article regarding this topic:
Normal Eye Color in the Chicken

Summary: The above article describes that there are three pigments involved in creating eyecolor and Chickens: hemoglobin from the blood vessels running through the eye - the placement of these vessels and the diameter of them influence how much red you end up seeing (position of the vascular network allowing you to see red is likely genetically controlled as it did not appear to change much over time) ; yellow fat globules, containing xanthophyll pigment from the diet that will fade or intensify according to the amount of pigmented feed they receive and may also have genetic factors; and melanin, which provides a black or brown pigment, and is primarily genetically controlled. It also concludes eye color changes with age and reproduction. This would, indeed suggest that there really are only a few major genetic options: presence or absence of significant melanin (brown vs light); and presence or absence of yellow pigment (this is really only coming to play for pearl eyes and potentially gray/green since those hues are influenced by distribution of fat globules); and how visible the blood vessels are (more red or less red).

If you boil down the options, even more, that means you’re right, they really are only two major options for melanin deposition in the eyes: light or dark. But the amount of variation we see in between suggest that there are a lot of modifying genes.

Then, I went a reread what F.B. Hutt wrote on the topic in his classic “Genetics of the Fowl” Pg 489: “MacArthur (1933) added similar data for a dominant gene Br, which causes a light iris, ranging in color from yellow-orange to bay, in contrast to the brownish-blackish iris.” This quote came from a small subchapter titled “the chromosome map”. It listed the following genes to be linked to this recessive sex-linked light eyed gene Br: K (slow feathering); S (silver); Li (light down); Id ( Inhibitor of dermal melanin- you may be right about this one @Amer !); B (barred); and Ko (head streak). We just have to remember that Br is just as linked to the sex chromosome as br. It just depends on what is occurring together in the parent bird. Crossover can still occur (27% of chicks broke the link between Br and Id) and 44% and 42% between Br and S, then Br and K, respectively. Once crossover occurs, that new combination (it could be light eyes, Br, and dermal melanin id^+ that become linked instead!).

@pipdzipdnreadytogo
Thank you for prompting that dig.

 

[KristenG]

Thank you for the effort of sharing that, very interesting!

I'm hoping to keep the black eyes in my project, so I was curious about this thread.

As an aside: What is head streak?

I was not sure on the head streak. The first thing that came to mind was the stripe on the back of the head in chick down like on this BBR d’Anvers:

So I looked up head streak in Hutt and in page 214 it did talk about the head streak in the wild type down. Some chicks apparently lack this stripe and the trait (lack of a head streak in wild type down). Under the description of Black Breasted Red plumage: Genetics: down color Page 218, Hutt uses the reference from Bateson and Punnett from 1906 and proposed the genotype “st” - recessive lack of headstreak. On page 214 under the description for Spangling,Sp; Genetics: Patterns in Down, the recessive modifier “ma” marbling, that makes the edges of the streak irregular, and “ko” the recessive gene causing a lack of head streak. Hutt doesn’t seem confident that this gene exists on its own unless it only impacts down color and is not linked to adult color, or can be accounted for by differences between gold and silver. Seems like these are real and actual differences in the downs that are genetically controlled, but are difficult to find and replicate, because there are no detectable differences in the adults.

Kinda cool

 

[KristenG]

Ok, it looks like I might have something interesting to add here, so I may as well pipe up. Thanks for the tag @Amer

You all should know that I did start with hatchery stock in my initial flock of d’Anvers in 1998. None of the Quail D’Anvers I started with had dark brown eyes. So I prioritized things other than eye color. When I purchased a pair of show quality Blue Quail, they also had reddish bay eyes instead of brown. I didn’t worry about it and figured eye color would be relatively easy to bring in and fix later. Unfortunately, I was wrong about the process of bringing it in being easy. It is anything but!! Now it seems I am struggling to maintain brown eyes even in my brown-eye sublineage. Eye color, it seems, is more complicated than I imagined.

You should also know that in my black d’Anvers, my initial pair had a female with green eyes. The male had brownish red. Even though most of my black d’Anvers have at least light brown eyes in the females, and reddish brown eyes in the males, I still cannot seem to keep green eyes and red eyes from popping up out of my blacks!

How confusing, right?!

I know from breeding to BBR d’Anvers this year that my all my Quail colored birds definitely carry Melanotic. But clearly, brown eye color is not controlled by the same genes as Melanotic. However, they may be located on the same chromosome and so often inherited together. Unfortunately, Since I my d’Anver eye color is not breeding true, I’m not sure I can tell much about the linkage between brown eyes and melanotic genes even through a purposeful hybridization. I won’t be able to tell on my current hybrids since the quails I used had red eyes. They have red eyes because my goal was to improve type on a BBR and the standard eye color for BBR is red. So, I can only speak to the Melanotic gene not being the same as brown eyes.

I also know that brown eyes are not linked to any of the so called recessive black genes that occur in both quail and black ( both varieties have a number of the same recessive black genes, which is why interbreeding the two varieties causes a lot less disturbance to either variety than it would if you bred to other non-black patterns). I know this because my Brassy Back d’Anvers (products from my interbreeding of black and quail, since not all my blacks carry Columbian) have red eyes. And I selected for so many recessive black melanizers in them that I turned the males nearly 100% solid black -or blue since the blue gene was in there- without the extended black locus. Their eyes? Red. And their legs a paler slate than a true extended black.

But you know what I found IS linked to more brown in the eye? Extended black itself. Indeed, while I still hatch green, gold, marbled, red and brown and dark brown eyes out of my blacks, when I breed them to my quail and get those F2 babies from the outcross, I have hatched a couple hundred of these, the brown eyes are almost always inherited by the blacks, but there are a small percentage of quail that develop them. This suggests that extended black doesn’t cause the darker eyes but that it does have a chromosomal linkage between extended black and a gene that causes more melanin deposition in the eyes.

I really ought to go take some photos for you all!

As to the actual genetics? It seems to be a polygenic trait. The gene for an extra light brown layer of melanin in the eye that is linked to dominant black seems dominant. The rest of the genes seem to be recessive. This makes for a complex set of genes to get to work together since polygenic traits don’t behave as we would like nor How we expect. Not only is it polygenic, but the sex and age of the bird changes its expression. All baby chickens I have seen are born with grayish or greenish or yellowish or dark eyes, or some combination . Mine are usually yellowish green. They start developing the brown tint around 3 months of age and it is the darkest you will see it 5-9 months of age. From there, the melanin fades. This is especially true in the cocks, whose dark brown eye color peaks around 4-5 months before those eyes start turning red. Because of this I always grade my cockerels for eye color at this time and tag the ones with the best eye color. I have had a rare male that has had dark brown eyes that lasted a few years but these boys are so rare in my line ( I bet if you had a line where this was a set trait it wouldnt be an issue though). Females will hold on to the darkness for a their first year- or a few years if that color was dark enough. Right now that is not common for me. Instead, mine start off with a lighter brown eye shade then this will also fade to Amber or a burnt orange later in life. If you get a male that can hold onto his dark eye - that is an asset in my opinion!

My goal is dark brown eyes but I find that there is a medium brown in my quails that is enhanced by the dominant brown from my blacks. I can easily get these medium brown genes into my blacks so I can get really dark eyes from them more often. Now, If only I could get their light brown gene to transfer to the quail d’Anvers without the extended black gene! Someday…

Or maybe I will break down and outcross my birds to make that final step. I want to make sure my brown eyes are breeding true first.

Hopefully this has been interesting and/or helpful!

 

[KristenG]

Oh, forgot to show the effect of age.
Here is a blue Quail d’Anvers cock that had nice medium brown eyes like the first quail cockerel above when he was 4-6 months old. He is now 2-1/2 years and this is what those eyes turn into on an older cock:

And here is a 1-1/2 year old hen that had medium brown eyes as a pullet. As a fairly young adult hen, her pigment has faded out to reddish bay! Disappointing. (And yes, they do groom the beards off each other)

And finally, this is the eye color I would love love love to see in all my black and quail d’Anvers - brown like in this 2-1/2 year old hen who had almost black eyes as a pullet. Her eyes have faded too, but they are still reddish brown. As good as it gets here. You may notice that female eyes are much more likely to be brown and often appear darker. The higher frequency of brown in females suggests this may indeed be sex-linked brown eye. Very dark eyes are possible in the males, but far less probable, complicated by the fact the male eyes tend to go red no matter the color they had as a cockerel ( so you don’t observe it in adult males as easily). I know this is not true in all strains, but this is where I’m at.

I’m just going to add that in the big picture, eye color is a little thing. I’ve gone into a lot of detail about this one nitpicky little trait and it would be easy for someone to hyperfocus on it, since it is easy for a beginner to latch onto. All these years I haven’t been working on eye color I have been working on so many other attributes that I do love in my birds. No, I’m not going to give up my lines for darker eyes. I plan to work through this like I have everything else in my flock. And, eventually, I hope to have the same compact, lovable and friendly, disease resistant, curious, egg-laying and typey chicken packages with darker eyes. It is no different than any other trait that needs bred out. I just thought it would be a single recessive gene but it seems there is more at play than just that. Fun stuff!

 

[KristenG]

@Amer , I think you’re right, there may be some sort of genetic linkage. I do not think that the color genes involved (Melanotic, di^+) are the cause of eyecolor in this case. I’m not even convinced that all d’Anvers are di^+. However, there very may well be a link between certain genes that occur in Quail ( probably e-locus related in my own flock) and genes that cause dark eyes. I say this because of the seeming difficulty in enhancing and / or transferring brown eyes between my sublines. But, if the genes are sex-linked, those particular genes would be connected to silver and gold more than Ml, which is located on chromosome 1 of chickens.

I think it is excellent you are paying such close attention to your bird’s characteristics. I like discussions like this because it makes me take a closer look at my own assumptions.

The only thing I have to say in regards to most quail varieties having dark brown eyes is the fact that wherever the variety occurs, it is required to have brown eyes. Especially overseas where light eye color on a quail patterned bird is considered a serious fault (indicating it may have been an issue at one point). Which Quail d’Uccles are not an American variety, so being European in origin I would expect nothing other than very dark eyes. Eyecolor is typically linked to variety, because the standard calls for a specific eyecolor, and that color typically matches the variety and not necessarily the breed. There are a few exceptions. But there is definitely the possibility of genetic linkages as well.

I don’t have any good pictures of the green eyes here, unfortunately. They are typically not as green as what you were describing in your Arabian Trumpeter males- that sounds pretty…

 

[nicalandia]

Over the years I've been obsessed with brown eyes, especially those of my d'Anvers. I stare into the dark depths and ponder. All this pondering led me to wonder: How come no matter what breed you have, brown eyes come with quail coloring?
In my female-line d'Anvers I get brown/dark red eyes in hens and bay eyes in the cocksView attachment 3578240View attachment 3578241
But in male breeder lines dark-eyed males are achieved because they have more melanin.
View attachment 3578279(I really struggled to find a good example of this because d'Anver cock beards tend to obscure the eyes. Also the website this photo came from is completely gone)
And dark eyed quail females are the defaults in all breeds:
View attachment 3578258(Old English credited to Larson's Miniatures http://larsonsminiatures.com/old-english-game-bantams.html)
And maybe it came obvious to those are familiar with genetics and I am annoying you with my "breakthrough" that was already well known. But when I looked up causes for brown eyes it said extended black and id+. And the sexlinked brown eye gene.
https://www.backyardchickens.com/threads/eye-color-genetics-help-me-help-me.293503/
But quail-colored birds obviously aren't E and it would be weird if somehow the sexlinked brown gene happened to be involved whenever the quail pattern emerged in different breeds.
I think it is caused by the interaction of id+ and Ml. Dark eyes are found in Spangled and pencilled Hamburgs and Silver Sebrights but not in Wyandottes which lack the slate legs. Since both ER based Hamburgs and e^b based Hamburgs have dark eyes, we can extrapolate that it is the id+ gene and not the base color that affects the eye color in Sebrights vs. Wyandottes.
Interestingly, I can't think of an example of a quail chicken with light-colored legs, but if my theory is correct, it would have bay eyes. I feel like that would be the ultimate test.
@KristenG @nicalandia
@MysteryChicken
Writing this post was difficult because quail are an entirely different species of bird and I needed the language to indicate chickens, lol.

Melanotic and other melanin enhancers tend to Darken chicken eggs, Diluters like Barring, Dominant White and Sex Linked Id makes them Lighter.

Birchen is the second most melanized e allele and when not Diluted by known diluter it will have dark eyes

 

[Amer]

Ok, it looks like I might have something interesting to add here, so I may as well pipe up. Thanks for the tag @Amer

You all should know that I did start with hatchery stock in my initial flock of d’Anvers in 1998. None of the Quail D’Anvers I started with had dark brown eyes. So I prioritized things other than eye color. When I purchased a pair of show quality Blue Quail, they also had reddish bay eyes instead of brown. I didn’t worry about it and figured eye color would be relatively easy to bring in and fix later. Unfortunately, I was wrong about the process of bringing it in being easy. It is anything but!! Now it seems I am struggling to maintain brown eyes even in my brown-eye sublineage. Eye color, it seems, is more complicated than I imagined.

You should also know that in my black d’Anvers, my initial pair had a female with green eyes. The male had brownish red. Even though most of my black d’Anvers have at least light brown eyes in the females, and reddish brown eyes in the males, I still cannot seem to keep green eyes and red eyes from popping up out of my blacks!

How confusing, right?!

I know from breeding to BBR d’Anvers this year that my all my Quail colored birds definitely carry Melanotic. But clearly, brown eye color is not controlled by the same genes as Melanotic. However, they may be located on the same chromosome and so often inherited together. Unfortunately, Since I my d’Anver eye color is not breeding true, I’m not sure I can tell much about the linkage between brown eyes and melanotic genes even through a purposeful hybridization. I won’t be able to tell on my current hybrids since the quails I used had red eyes. They have red eyes because my goal was to improve type on a BBR and the standard eye color for BBR is red. So, I can only speak to the Melanotic gene not being the same as brown eyes.

I also know that brown eyes are not linked to any of the so called recessive black genes that occur in both quail and black ( both varieties have a number of the same recessive black genes, which is why interbreeding the two varieties causes a lot less disturbance to either variety than it would if you bred to other non-black patterns). I know this because my Brassy Back d’Anvers (products from my interbreeding of black and quail, since not all my blacks carry Columbian) have red eyes. And I selected for so many recessive black melanizers in them that I turned the males nearly 100% solid black -or blue since the blue gene was in there- without the extended black locus. Their eyes? Red. And their legs a paler slate than a true extended black.

But you know what I found IS linked to more brown in the eye? Extended black itself. Indeed, while I still hatch green, gold, marbled, red and brown and dark brown eyes out of my blacks, when I breed them to my quail and get those F2 babies from the outcross, I have hatched a couple hundred of these, the brown eyes are almost always inherited by the blacks, but there are a small percentage of quail that develop them. This suggests that extended black doesn’t cause the darker eyes but that it does have a chromosomal linkage between extended black and a gene that causes more melanin deposition in the eyes.

I really ought to go take some photos for you all!

As to the actual genetics? It seems to be a polygenic trait. The gene for an extra light brown layer of melanin in the eye that is linked to dominant black seems dominant. The rest of the genes seem to be recessive. This makes for a complex set of genes to get to work together since polygenic traits don’t behave as we would like nor How we expect. Not only is it polygenic, but the sex and age of the bird changes its expression. All baby chickens I have seen are born with grayish or greenish or yellowish or dark eyes, or some combination . Mine are usually yellowish green. They start developing the brown tint around 3 months of age and it is the darkest you will see it 5-9 months of age. From there, the melanin fades. This is especially true in the cocks, whose dark brown eye color peaks around 4-5 months before those eyes start turning red. Because of this I always grade my cockerels for eye color at this time and tag the ones with the best eye color. I have had a rare male that has had dark brown eyes that lasted a few years but these boys are so rare in my line ( I bet if you had a line where this was a set trait it wouldnt be an issue though). Females will hold on to the darkness for a their first year- or a few years if that color was dark enough. Right now that is not common for me. Instead, mine start off with a lighter brown eye shade then this will also fade to Amber or a burnt orange later in life. If you get a male that can hold onto his dark eye - that is an asset in my opinion!

My goal is dark brown eyes but I find that there is a medium brown in my quails that is enhanced by the dominant brown from my blacks. I can easily get these medium brown genes into my blacks so I can get really dark eyes from them more often. Now, If only I could get their light brown gene to transfer to the quail d’Anvers without the extended black gene! Someday…

Or maybe I will break down and outcross my birds to make that final step. I want to make sure my brown eyes are breeding true first.

Hopefully this has been interesting and/or helpful!

Ok, I went and got some pictures. First three are all baby pictures. Slate eyes. Variety doesn’t matter. Self blue and black day old d’Anvers babies. Then a BBR d’Anvers week old chick. Eye color stays like this for about the first month. Then by three months it turns yellow to orange for most of them
View attachment 3584793
View attachment 3584794
View attachment 3584795

Then at 4 months old the true color begins to show. This 4 month old quail d’Anvers has what I call the red eyes. They are more of a golden orangey-bay, I guess. She will always have this color. It is too light.
View attachment 3584796

At about this time, the birds with the brown eyes should be starting to show. Here are some of her male hatch mates. First is a quail d’Anvers cockerel showing medium brown eyes. This is the color I strongly favor in my boys because it is the darkest I have hatched in them yet. As I only recently introduced it into one sublineage, it is still quite rare.

View attachment 3584798
To see the degree of contrast, take note of this next quail d’Anvers male- same hatch group, different subline. You might be interested to know he is from the male color line, so he is a deeper red and is heavy on the black markings. But his eyes don’t really care. They are a bright yellow orange (again, what I probably inaccurately call the red eye - these eyes do seem to gain red pigment with age but not a lot):
View attachment 3584800
View attachment 3584801
And I am getting the same things in my black d’Anvers. Here is a 3-month-old accidental male rumpless d’Anvers showing the brown pigment beginning to deposit in his eyes- plus a full body pic:
View attachment 3584802
View attachment 3584803

And then we have another 3-month old d’Anvers cockerel showing the orange eye. How unfortunate… Note he is still sound in his color in every other way:
View attachment 3584805
View attachment 3584806

And then I may as well show you the other eye color variations. The good news is only one bird (a 3-month black pullet) this year seems to be showing any indication of the “green” eye. The green eye is really a pale yellow that has usually has some brown pigment leaking through. The combination lends the yellow a greenish cast. Sometimes the whole eye will be this color. Most often, it is just part of the eye. I have been working hard to cull against it.
View attachment 3584812

And I was going to show you the marbled eye. I only had one pullet end up with it this year - a white d’Anvers. It is striking. No the pupil is not irregular. Normal pupillary reflex and all that. That is just dark pigment. That is the nature of the marbled eye. I do not know what causes it but I try to get rid of it. I find it seems to be somewhat related to the green eye as the two tend to occur together in families. This particular white is descended from my blacks.
View attachment 3584813

Oh, forgot to show the effect of age.
Here is a blue Quail d’Anvers cock that had nice medium brown eyes like the first quail cockerel above when he was 4-6 months old. He is now 2-1/2 years and this is what those eyes turn into on an older cock:
View attachment 3584815

And here is a 1-1/2 year old hen that had medium brown eyes as a pullet. As a fairly young adult hen, her pigment has faded out to reddish bay! Disappointing. (And yes, they do groom the beards off each other)
View attachment 3584821

And finally, this is the eye color I would love love love to see in all my black and quail d’Anvers - brown like in this 2-1/2 year old hen who had almost black eyes as a pullet. Her eyes have faded too, but they are still reddish brown. As good as it gets here. You may notice that female eyes are much more likely to be brown and often appear darker. The higher frequency of brown in females suggests this may indeed be sex-linked brown eye. Very dark eyes are possible in the males, but far less probable, complicated by the fact the male eyes tend to go red no matter the color they had as a cockerel ( so you don’t observe it in adult males as easily). I know this is not true in all strains, but this is where I’m at.
View attachment 3584827

I’m just going to add that in the big picture, eye color is a little thing. I’ve gone into a lot of detail about this one nitpicky little trait and it would be easy for someone to hyperfocus on it, since it is easy for a beginner to latch onto. All these years I haven’t been working on eye color I have been working on so many other attributes that I do love in my birds. No, I’m not going to give up my lines for darker eyes. I plan to work through this like I have everything else in my flock. And, eventually, I hope to have the same compact, lovable and friendly, disease resistant, curious, egg-laying and typey chicken packages with darker eyes. It is no different than any other trait that needs bred out. I just thought it would be a single recessive gene but it seems there is more at play than just that. Fun stuff!

Okay, cool! I would say that the eyes on my d’Anvers are definitely closer to a dark red than a brown, but brown eyes seem to have been achieved in other quail varieties like d’Uccles which doesn’t seem necessary for the breed so their must be some linkage to the color, imo?

I have a quail d’Anvers hen, Queeny who is a few years old. Her eyes are more of a dark orange, you could say. Maybe I need better pictures.

But you are right, the young pullets have very dark brown eyes, especially this one

My brother has silver quill old English Game Bantams and their eyes are black as coal and they are a few years old. You can barely see the pupils. I wonder what causes this, since the genotype for silver quill is
(e+/e+Db/db+pg/pgS/S)or (e+/e+Db/Dbpg/pgS/S)
That is kinda similar to silver quail, just swap the Co for Db and the Ml for Pg.
Maybe pg is what is responsible for dark eyes of Hamburgs.

Funny about the green eyes.
I got a pair of Arabian Trumpeter pigeons. The breed’s black eyes really look beautiful to me.
Well, the hen died so I got a replacement hen along with another pair, but I got them shipped to me so I never saw a picture. Turns out they were poor quality.
The two hens I got had yellow and pearl eyes, respectively.
But the male had green eyes! Not yellow green, green like human eyes! Very pretty, but not what I was looking for. I wonder if it is linked to the seemingly recessive black eye gene of Arabian Trumpeters.

 

[Amer]

@Amer , I think you’re right, there may be some sort of genetic linkage. I do not think that the color genes involved (Melanotic, di^+) are the cause of eyecolor in this case. I’m not even convinced that all d’Anvers are di^+. However, there very may well be a link between certain genes that occur in Quail ( probably e-locus related in my own flock) and genes that cause dark eyes. I say this because of the seeming difficulty in enhancing and / or transferring brown eyes between my sublines. But, if the genes are sex-linked, those particular genes would be connected to silver and gold more than Ml, which is located on chromosome 1 of chickens.

I think it is excellent you are paying such close attention to your bird’s characteristics. I like discussions like this because it makes me take a closer look at my own assumptions.

The only thing I have to say in regards to most quail varieties having dark brown eyes is the fact that wherever the variety occurs, it is required to have brown eyes. Especially overseas where light eye color on a quail patterned bird is considered a serious fault (indicating it may have been an issue at one point). Which Quail d’Uccles are not an American variety, so being European in origin I would expect nothing other than very dark eyes. Eyecolor is typically linked to variety, because the standard calls for a specific eyecolor, and that color typically matches the variety and not necessarily the breed. There are a few exceptions. But there is definitely the possibility of genetic linkages as well.

I don’t have any good pictures of the green eyes here, unfortunately. They are typically not as green as what you were describing in your Arabian Trumpeter males- that sounds pretty…

This is the only one since I haven’t bred him so I don’t know if it is simply coincidental or actually linked to the dark eye gene.