Dilutions


NoBuckskin

Okay, maybe not love – but certainly stop worrying about it.

Like a lot of people who find horse color fascinating, I once spent no small amount of time online, spreading the Gospel of Proper Color Terminology. Surely if I just presented the facts in a convincing manner, I could save the world from people who were convinced they had palomino Arabians!

Fortunately for my own sanity, my career as a parent – begun just a few years after large numbers of horse people discovered the internet – got in the way of my missionary zeal. Toddlers do not recognize the need for uninterrupted bathroom breaks, never mind enough time to compose an extended explanation about why you really should not call your double-diluted cream an albino. Children also raised my threshold for the type of thing that required immediate action. I could live with someone on the internet being wrong; it was not like they had just painted on my bathroom walls with chocolate pudding.

Looking back, though, I see that my enforced absence from online discussions had unexpected benefits. For a researcher there is a significant downside to spending a lot of energy “correcting” wrong information. If you spend too much time telling people that some common misperception is wrong, you run the risk of having that response become automatic.  It makes it a lot harder to reassess your position, because it is a rare person that can argue a position for a long time without getting their ego involved in being proven right. From there, it is easy to overstate your case. “Your flaxen chestnut Arabian is not a palomino” becomes “there have never been palomino Arabians”, which then becomes “Arabians do not carry any dilution genes.”  The first is – or at least to date has been – true. The next statement is actually open for debate, and the last one is incorrect. (See also, here. Similarly diluted Morgans can be found here.)

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And intriguing painting of the early Twentieth Century Turkish Arabian, Übeyyan.
How accurate was this portrait? And what color was he?

The other downside to spending a lot of time correcting errors is that if you automatically dismiss something, it is really easy to overlook important information. Even when people are wrong, they may still hold a clue, a piece of the puzzle you are trying to assemble.

I sometimes get asked why I spend so much time with older documents when so much has changed in our understanding of coat color genetics. Why, for instance, spend time translating Valto Klemola’s 1931 paper on “Recessive Pied” when there are papers written just this year and last on what we now call Splashed White? Surely the new information replaces Klemola’s theory about recessive spotting in horses.

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I am sure my husband also wonders why I need books about horse color published in 1912. After twenty years of losing more and more shelf space to them, he has given up asking.

But the fact is that Klemola – and many of the other earlier authors – were not entirely wrong. They were almost always working from a partial picture, but often the piece that they were seeing was not incorrect. It was simply incomplete.  Read with an understanding of the larger picture, what these older researchers have to say can still provide valuable information. The same is true for owners and breeders who may not have the same grounding in the latest scientific theories. They still have the potential to be valuable observers. It is worth being open to what they have to say, without being excessively concerned about the “correctness” of how it is said.

At the moment terminology – particularly the terms we use when talking about white patterns – are in a state of transition. We are struggling with words that do not completely fit our present understanding. I hope to tackle that in more detail in a future post. It is worth remembering, however, that the real reason for adopting a consistent set of terms is so that we may all communicate more clearly with one another. It may take a little more effort, and perhaps a few more words (and patience) than it once did, but that is ultimately the goal.

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ColorShiftTypical

I have been busy with work on the upcoming book, but I wanted to share some good examples of the color shifting found in some horses with the Leopard Complex (Lp) mutation. Appaloosa shows are less common than Paint shows in this area, so I was glad when one was scheduled for the Garrison Arena in nearby Clemson, South Carolina on a weekend that I was free to attend.

The mare above is a shade of warm pewter gray that is very common in appaloosas. I would expect her to test black (E_aa) and negative for dilutions, just as my mare does. What is interesting is that not all black appaloosas end up looking like this. At the same show, there was a jet black leopard. Just why the color shifts on some, but not all, is not yet known, though it does not seem necessary for there to be a true dilution gene present for it to occur.

SnowcapFeet

The change in this guy is more subtle. He might be mistaken for a sun-faded black horse, but look closely at his lower legs. They do not look black, nor do they have the reddish or  yellowish tones that are more typical of sunburnt hair. Instead they have a dark chocolate tone. In my experience, that “off” color is even more noticeable in person – especially in natural light.

That brings me to the last horse. This mare may well be chestnut, but I would not be entirely surprised if she was in fact black-based. Her odd tone is present to an extent in this photo, but it was more obvious in person. She would certainly be an interesting one to test.

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I would also add that all three of these horses are probably homozygous, and the last two images are good shots to show how homozygous horses have shell-colored hooves on their unmarked feet. My own mare is heterozygous, and as her images (linked above) show she is actually more diluted in color than the first two of these. Whatever causes the shifting, it does not seem to be influenced by whether or not the horse is homozygous for Lp.

(Clicking on the last two images will take you to larger versions.)

 

Charli

In the first volume of the Equine Tapestry series, I talked about two cases of unexpected dilute foals. The first was a Dutch Draft filly, Marinka van’t Heereind. The second was the Alt-Oldenburg filly Gaja. There is further information in the upcoming volume that covers the light breeds, where similar horses have been born to purebred Arabians. More recently, an entire family of Morgans has been documented that appears to have this same as-yet-unidentified dilution. Laura Behning has put numerous pictures up with photographic pedigrees on her Morgan Colors site. I highly recommend visiting her page!

Possible New Dilution in Morgans

There are also photos of the Arabian family with the similar dilution on the New Dilutions website.

Mireyenion Tos

The color has been called “light black” for lack of any better term, since it appears to dilute the black hair more strongly than the red hair. Because both the Morgans and the two Arabians are closely linebred, and because none of the parents are unusual in color, it is believed that this might be a recessive dilution. It should be noted that these horses have all tested negative for the known dilutions. In appearance, many have looked like the Laura Behning’s Morgan mare, Positively Charmed (“Charli”), who is pictured at the top of this post. Charli is a tested smoky black with the silver dilution. That particular combination produces a body color like milk chocolate, while the skin tends to have a purplish cast. Many of these horses also have paler eyes, but I have not yet seen a silver smoky that had eyes quite as pale as those seen in this Morgan family.

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I want to thank everyone who provided links and information on horses like the one in the previous post. I encourage those interested in this to read the comments section, where there are more foals with these types of markings. There are also comments on the Equine Tapestry Facebook page. Because some readers have had difficulty with WordPress comments (or links in them), I have gone ahead and put together a Pinterest board with some of the links in the comments. That can be found here.

It does seem likely that this is linked to the smoky cream color, which is a genetically black horse with two copies of the cream dilution. It also appears that most of these foals either lose the markings with age, or at least lose the strong contrast. Someone also shared a classic champagne foal with similar markings, which also faded with age. Classic champagnes are also genetically black.

This ties in with some questions I have had about how cream interacts oddly with the sooty pattern. I have been assembling photos for that post for a while now, and will try to get that up in the next few weeks.

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PerlinoMismark2

I have seen a few double-dilute foals with unusual dark patches recently, so I was happy when Jess Aisthorpe gave me permission to run the images she took of her day-old cream dilute filly. The patches on her body are not from being wet or dirty, but are a deeper color than the rest of her coat.

PerlinoMismark

The largest area of dark hair covers her left shoulder, but she has smaller patches on both sides of her body and her face.

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Her markings are very similar to those found on the smoky cream Morgan, Prairie Hill Apache. To date, the other examples of these darker cream patches that I have seen have all been on black-based double creams. The color on Jess’ filly is not yet known, but she has a buckskin sire and a grey dam with a palomino grandsire, so it is possible that she is a perlino or smoky cream.

It would be interesting to know if markings like these are visible – and a pronounced – when the horse is mature. So far the examples I have seen were all in very young foals. If you have experience with double-dilutes with markings like these, please share them. It would be interesting to see more examples, especially if there are both foal and adult photos.

Although bay horses with the silver dilution look a lot like a bay horse with a flaxen mane and tail, not all bay horses that have lighter manes and tails are necessarily red silvers. There are other reasons a bay horse may have a lighter mane or tail. The next few posts will show some of these red silver mimics.

The first of these is what Arabian breeders often call a Gulastra Plume. The trait takes its name from the Arabian stallion Gulastra. Gulastra himself was a chestnut with a self-colored tail, but flaxen tails were said it was common on his bay descendants. Like a lot of color variations named for specific horses, the “founder” is not necessarily the horse responsible for the original mutation. It is more accurate to say they brought attention to the trait. So not all horses with a Gulastra Plume are descendants of Gulastra. Some have no known Arabian blood at all, like the stout pony at the top of this post.

In other breeds, it is sometimes called silvertail. Compared to an ordinary bay tail, the tail does look silver, but the lighter hairs often have a warm, flaxen tone rather than a cool, silvery one. Some silver-tailed bays – like this guy – have reduced black points on the legs, and flaxen hairs on the lower parts of the leg are not uncommon. This can make them even more likely to be mistaken for a bay silver, but the dark tones on the points are truly black and not a diluted chocolate. It is also possible to find silver tails on bays that have fully black points, though the reduced black seems to be more common.

Most horses with a Gulastra Plume do not have significantly lighter manes. This guy has a few white hairs interspersed in what is an otherwise fully black mane. From a distance, his mane looked black. Were he a silver (even an older silver), I would expect to see some hint of flaxen at least at the forelock.

Here is a comparison shot of this guy’s tail (to the far right) and two of the previously posted red silvers. Notice how the variegation is a bit different with  the two types of tails. Silver dilute tails shift in tone in a way that reminds me of ombré textiles (and the current human hair trend of the same name), whereas the Gulastra Plume is more of a mixture of the two colors.

 

That said, there may well be quite a bit of variation in the tails of horses with a Gulastra Plume. To my knowledge, it has not been formally studied, and as the posts over the next few days will show, the situation with flaxen and silver manes and tails on bays is not entirely clear. It is quite possible that there are multiple factors producing similar results. For that reason, it is often the color of the legs (chocolate rather than black) that is often more reliable when trying to identify bay silvers.

This is probably one of the better-known images of a bay silver horse. It was used to illustrate the color in the paper identifying the silver mutation, and has been widely shared on the internet since that time. His name is Unconventional (“Connor”), and he is a Morgan bred by Laura Behning. Laura was instrumental in identifying and documenting the silver dilution in the Morgan breed. Her website documenting those lines is a wonderful resource for anyone interested in silver, and is particularly notable for the number of images of silver foals.

Here is another image of Connor as an adult. In this image, he still has the strong contrast between his flaxen mane and his body. (This is also another good image for seeing the bay countershading on the face and neck that differentiate bay silvers from chestnuts.)

When silver dilutes are young adults, this contrast is part of what makes the color so striking. It also makes them relatively easy to identify. That is not necessarily true as they age, however. Most horses with lighter manes and tails lose some of that contrast with age, but that seems to be particularly true of silver dilutes. This next image is pretty typical of how the flaxen mane looks on an older silver.

Most bay silvers have dark roots, but as the horse ages the dark parts of the mane tend to spread until it is just the ends of the mane that are pale. The forelock tends to stay palest the longest, as the images of this pony show.

It is likely that, had his mane not been cut, he would have somewhat lighter ends. Still it is the forelock that is unusually pale, and that color changes pretty abruptly at the ears, as the image of his forelock parted and tucked behind his ears shows.

Tails darken as well, usually starting with a dark core like the one visible on this Rocky Mountain Horse.

In some cases, older silver dilutes can appear to have completely dark tails, or at least tails that do not look significantly different from a horse that has sun-faded. This Rocky Mountain horse is a seventeen year-old buckskin silver. Her tail is almost completely dark, while she has retained the paler tips on her mane and the flaxen forelock.

This mare does not show a lot of flaxen contrast on her lower legs. They were visibly chocolate – not black – in person, but the kind of mottling seen on some bay silver legs was not present. It seems that the more uniformly dark silvers are more likely to lose the contrast on their manes and tails, though it seems all lose it to some extent with age.

This does complicate the search for silver in historical records. Horses like the Groninger stallion Iregon do not look silver in the handful of images available, even though they are known sources of the silver dilution. Silver is not visible on chestnut horses, because they have no black pigment to dilute.

And if that was not complicated enough, it appears there are other factors unrelated to silver that can turn the mane and tail of a bay horse silver or flaxen. The next post on silvers will be about some of the silver mimics.

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