Ear Color Hypothesis

[SourRoses]

Tell me what you think of this Hypothesis, please...

Backstory: I was chatting with a breeder working on Blue Ear Mosaics, she told me in her most recent generation, her selected males lost the blue ears after they had developed. This was after they were fully mature, they had blued up in the way it happens, then faded back to red. It created a real headache for her as she had to source a replacement male from another breeder to get back on track.

This got me to thinking about how that could possibly work genetically. Timed genes? No, not on fully mature birds. (right?)

Then one day I'm out watching my favorite Genetic Hackle rooster, Custard, who has lemon yellow ears... and I look again.
He has a thicker appearance to the skin on his ears!
I study a nearby red eared bird, and sure enough it looks quite thin in comparison.
So, I go analyze my Blue ear Mosaics.
Even the White Eared Leghorn.
It's the same thing!
Of course, I wondered if it was just the color interacting with light, playing tricks on me... so I watched some more. In real life you can see angles that are hard to photograph. In pictures it's just the color that shows. But I'll throw some up here anyway.
All my red eared birds seem to have a shallower, delicate looking earlobe.

My hypothesis then is this: Mediterranean genetics add an extra layer of skin on their ears, that red eared birds don't have, which makes the colors possible (red being simply vascularization? therefore "uncolored."?)


Custard:

As my Mosaic (then cockerel) ears were "coming in" at sexual maturity...

One of our pullets at 3-4 months old (I really need to get adult pics as they are more vivid now)

Then we look at this White Faced Black Spanish (borrowed pic online). We know it's supposed to be the case that their ears have extended onto the face (Errr, right?) but look at how thick that skin is, the only way it could go so wrinkly, and extends out past his eye.

So... make thoughts at me.
* If someone says this is already well known, well I couldn't find such information anywhere...

 

[Amer]

Hmmm, I do think that a thin layer of skin would be responsible for the white. That would make sense.
I believe fading of the blue is because of the melanin becoming more spread out as the bird ages, and the vascularization of the tissue on mature males. Hens have less developed, smaller combs and earlobes, so of course they have the potential to be darker. (I didn’t hear this anywhere but it would make sense to me.)

 

[Frances L]

I believe fading of the blue is because of the melanin becoming more spread out as the bird ages, and the vascularization of the tissue on mature males. Hens have less developed, smaller combs and earlobes, so of course they have the potential to be darker. (I didn’t hear this anywhere but it would make sense to me.)

I was so excited to be getting Mosaic chickens. Everything looked great and everyone had the beautiful blue ears or at least was starting to have them. As the chickens get close to their one (1) year mark, I have blue earred hens and only 2 out of the 8 roos have blue ears. And so disappointed. Your theory is at least the FIRST one I have ever read. It makes sense. Something happened.

 

[NatJ]

My hypothesis then is this: Mediterranean genetics add an extra layer of skin on their ears, that red eared birds don't have, which makes the colors possible (red being simply vascularization? therefore "uncolored."?)

I am pretty sure you are right about there being an extra layer of something on white earlobes and blue ones.

I don't think it is normal skin, because it does not look like the skin on the rest of the chicken. But yes, there sure seems to be something there.

I can't find much about the mechanism, other than some references to "purines" being involved.

Example:
https://www.backyardchickens.com/threads/purple-and-blue-lobes.1527368/

Blue earlobes are a trait of Silkies due to fibromelanosis! It's due to the overlay of the purines that make white earlobes with the dark skin.

* If someone says this is already well known, well I couldn't find such information anywhere...

I am also having trouble finding it.

 

[Rhodebar Lover]

According to Genetics of Fowl by F. B. Hutt, "The basis for the white earlobes is not known. Louvier found evidence that purine bases in a form not found in other parts of the skin is associated with the white. The effect is apparently produced by some white substance which prevents excessive formation of blood capillaries or obscures them." I am not sure this results in the thickening of the skin but considering that white earlobes do have an added substance, it seems possible. Here is another excellent article explaining earlobe colors. Genetics are very complicated for earlobe inheritance and their appears to be sex linking coming into play. This study explains it in more detail! Hope this helps!

 

[SourRoses]

According to Genetics of Fowl by F. B. Hutt, "The basis for the white earlobes is not known. Louvier found evidence that purine bases in a form not found in other parts of the skin is associated with the white. The effect is apparently produced by some white substance which prevents excessive formation of blood capillaries or obscures them." I am not sure this results in the thickening of the skin but considering that white earlobes do have an added substance, it seems possible. Here is another excellent article explaining earlobe colors. Genetics are very complicated for earlobe inheritance and their appears to be sex linking coming into play. This study explains it in more detail! Hope this helps!

Wow, thank you!
The article was very interesting reading. The study says "your session has timed out"... I would really love to read it!

 

[nicalandia]

Tell me what you think of this Hypothesis, please...

My hypothesis then is this: Mediterranean genetics add an extra layer of skin on their ears, that red eared birds don't have, which makes the colors possible (red being simply vascularization? therefore "uncolored."?)

The Hypothesis has no genetic basis to stand on.

White Earlobes and White face trait in Chickens are a Polygenic Trait with some of those genes beign Sex Linked but most are Autosomal.

The Red Jungle Fowl has White Earlobes, The introgresion of Grey Jungle Fowl not only Brought Yellow Skin/Shanks but also red earlobes, interestingly enough the Green Junglefowl being a Basal Junglefowl has the most colorful of faces and when outcrossed to White Face Spanish The F1 show complete White Face.

I've been thinking of a creating a Blue Faced breed with White Face Spanish and Mosaics.

 

[nicalandia]

White Face Ayam Bekisar..

A Blue Face Bekisar Would look so Amazing with a Huge Blue/Turquoisr Dewlap

 

[SourRoses]

I've been thinking of a creating a Blue Faced breed with White Face Spanish and Mosaics.

I have WFBS eggs in the incubator for making that exact cross with my Mosaics!

 

[nicalandia]

I have WFBS eggs in the incubator for making that exact cross with my Mosaics!

Great, let me know if you need Genetic Advise