Category: Animals

SFR logoThis is a continuation of last month’s excerpt from Both Sides Now. Kevi (Roi, the regent of the confederation) has just pointed out to Mik that his dog, Loco, is in labor.

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Stunned, Mik looked down at Loco. She was panting, turning now and then to look at her sides and digging again at the bottom of the pannier. “She can’t be—I skipped her this season. That’s why I didn’t bring her with me when I—well, you know. Wasn’t sure she was out yet.” He swung down to help Kevi with Jad.

“You may have skipped her. Judging by the date, I’d say she was bred before you knew she was in. Come on, uh, what’s his name, Mikal?”


“All right, Jadel, just sit down right there. Feeling any better? Good. Suppress works fast. Mikal, can you give me a hand? Just keep pressure here and here, while I manipulate his arm.”

Mik swallowed bile, and jumped more than Jad did when the shoulder snapped back into place under his hands. He was more confused than ever in trying to see this man as the hated regent, but Kevi did seem to know what he was doing. “What was that you gave him?” he persisted.

“Mixture of four drugs. First was a painkiller, suppress. It acts very fast. The counterShock is a little slower, but not much. The other two are a muscle relaxant and a mild sedative. Those haven’t quite kicked in yet—don’t worry when you start feeling sleepy, Jad. That’ll keep you from doing further damage by trying to use that shoulder. For right now I want you to lie down in one of the back rooms in that maze of hay so I can use cold packs to keep the swelling from getting worse, and I’ll strap the arm in place when you wake up.”

He made up a couple of ice packs and applied them to Jadel’s shoulder, settling the man in one of the rooms hidden in the hay. Then he went into another room and returned to the front of the cave, carrying an empty box that Mik recognized as one that had held the Confederation supplies he’d traded for. “The dog’s doing fine,” Kevi said as he put an old feed sack in the box, “but I think she could use a little more room. Want to bring her in, Mikal? I’ll have a look at that horse you were leading.”

Whatever else he was, Mik decided, Kevi was an expert at keeping people off balance. Loco was still in the pannier, whimpering, and as Mik lifted her out he felt a very definite kick low on her left side. She licked his chin apologetically, and he sighed. He had thought he had protected her adequately, though now that he thought about it, Blue had seemed awfully interested in her for a couple of days before he had realized she was coming in season. A repeat of the litter Stormy had come from, then. Good bloodlines; he’d just planned to give her a little more time to recover between litters. Must be a small litter, or he’d have noticed something. He just hoped the pups were full term.

Kevi was still going over Star, frowning in concentration, when Mik heard a horse trotting toward the cave. Doc’s bay leopard, he identified the animal when he moved to the door. It didn’t sound like Joker, though—this horse was trotting fluidly, and Doc didn’t look nearly as jarred as he usually did. Mik waved, and got an answering wave from Doc. “How do you like my new assistant?” the vet called as he pulled up by the cave.

“Knows how to reduce a dislocation, anyway,” Mik replied, with a somewhat uneasy glance at Kevi.

The R’il’noid straightened and grinned. “With help,” he said. “How old is this horse, anyway? He’s not too badly hurt—bruises and a couple of pulled muscles—but I can’t do much for old age. Oh, the stuff I’ve got Joker on will help, but it’s pure luck this fellow didn’t break a few bones.”

“Star?” Mik said, trying to think back. He couldn’t remember Jadel on a horse other than Star. “High twenties at least. Maybe thirties.” He felt guilty again. But what else could he have done?

“Does he like the colts?”

Mik looked at this unpredictable R’il’noid in bewilderment. “We can’t turn him out with the mares and foals. He’ll kidnap the foals.”

“If he were mine,” Kevi said, “I’d retire him to baby-sitter and role model for the weanlings. Nothing wrong with his manners, and they’ll learn by watching him.”

And Jadel was far better as a camp organizer and keeper of pedigrees than as a rider, these days. Put Jad in charge of the encampment for those herding the weanlings, come fall. A few people would stay behind this summer to oversee the haying and pick a winter campsite, and Jad was a logical choice. Let him and his beloved Star rest and recover until fall. “You,” he said wryly, still not sure whether Kevi was playing some elaborate game, “are a total surprise.”

“If the stories I heard going around when I was here a few years back are what you’ve heard about me, I imagine I am. I’m being myself, Mikal. More than I’ve had a chance to be for years. Let me strap Jad’s shoulder, and the three of us can talk.”

Letter Y: Yukon Quest

YI don’t think there is such a thing as a greyhound-type sprint race for sled dogs. “Sprints” in dog mushing are races from 3 to 30 miles in length – up to Marathon distance for a human. Even mid-range races are 75 to 300 miles. But there are two really long-distance sled dog races in Alaska: the Iditarod Trail and the Yukon Quest. (The only other truly long-distance race is in Norway.)

The Iditarod, the older of the two Alaskan races, was initiated in 1973 as a memorial to the original Iditarod serum run in 1925. That was a dog team relay from Nenana, the closest place to Nome reachable by Alaska Railroad, to Nome, where a diphtheria epidemic was raging. The original serum run was a pony-express style relay, with the emphasis on speed and keeping the life-saving antitoxin from freezing. No one team or musher traveled the entire distance.

The memorial race was run from Anchorage, far south of Nenana, and was a race between teams and mushers going the entire distance. But the emphasis was on speed, with relatively light sleds and frequent checkpoints with food (for mushers and dogs.)

The Yukon Quest was founded in 1984 to be a different test of dogs and mushers, with mushers carrying much of the gear and food they would need to survive in the Alaskan Wilderness. There are food drops at the widely spaced checkpoints, but these must be prepacked by the musher, and no help with dogs is allowed on the trail. (The middle, mandatory rest, checkpoint is an exception, as is help from other mushers on the trail.) Sleds must be capable of carrying this extra weight, and the original idea was to replicate the dogsled mail that helped build Alaska during the gold-rush days. The race is also international, going from Fairbanks, Alaska, USA to Whitehorse, Yukon, Canada in even years, and in the opposite direction in odd years. The race is over 1000 miles in length, with substantial distances run along the Yukon River.

Although the original intent of the Yukon Quest may have been to emphasize the utility of dogs as transportation before the days of snow machines (which still are behind dogs as far as finding their way in tough weather), today’s competitive mushers not uncommonly run both long-distance races, with the same teams. In fact Lance Mackey was the first musher to win both in the same year, in 2007. Those dogs—and mushers—are tough!

All the photos I could find were copyrighted, but the Flickr site is here.


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It’s Sunday again, time for Weekend Writing Warriors (click on the logo above) and Snippet Sunday (click on the logo below.) You don’t have to comment, but we all like feedback. If I don’t respond, it’s because I had the third (and last) round of chemo on Friday, and I’m coming down fast.

Cone Nebula detail (Hubble)Roi has managed to stop the stampede just before the panicking herd crossed the road into rough country.

The cyclist — the oldest Bateson girl — had caught up with the grazing herd and circled between the animals and the road.  She stopped next to Amber, her eyes curious as she got a good look at Roi.  “Thanks, Miz Leroy,” she said.  “I dunno how you stopped ’em, but I never ‘spected to get the whole herd back safe.”

“Luck,” Amber replied, which was true enough.  “This is Roi Laian, an old friend of ours.  Can you handle them now?”

The girl nodded, sun-bleached blond pigtails bouncing.  “Thank you, too, Mr. Lane,” she said as she turned her cycle toward the grazing animals, pushing them back away from the road.

 Once again Horse Power is free today on Kindle, as it will be September 15 and September 29. By that time I hope to have a print version and will pull it off of Amazon Select. So get your free copy while it’s available! I hope my snippets give an idea of the problem faced by the colonists in this science fiction story that doesn’t read at all like most science fiction. Look at the reviews, all 5-star except one that wanted it longer!

Snippet Sunday logo

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It’s Sunday today, and you know what that means. Lots of snippets from lots of different authors, some of whom can be found by clicking on the logos above and below.

Today’s snippet is from my second published book, Tourist Trap. Here’s the blurb.

A vacation with his three best friends from slavery and a manhood challenge: Roi is given the graduation present he has dreamed of. Dogsledding, hang gliding, a chance to see Pleistocene animals transplanted to a Terraformed vacation world, horseback riding, sailing … all the sports he has returned to with his recovery from paralysis, and a few new ones to learn.

They’re prepared for danger from weather, wild animals and extreme sports. But none of them realize that Roi’s half brother Zhaim, determined to recover his old position as Lai’s heir, intends to kill them if he can—and he’s decided that the dangers of the trip will make a perfect cover for his schemes.

How long will it take them to realize that the “accidents” they keep running into are more than just accidents?

For today I’ve picked a relatively sexy snippet, though it’s not human sex. We’ve already established that Token. one of the saddle horses, is coming is season and becoming difficult to handle as a result.

HubbleThe little meadow was open and gently cupped, with no place in creance range where a horse could be hiding. Roi opened his mind to the horses’ sensory impressions and quickly found Raindrop, Freckles, Dusty, Splash and the three pack horses, but no trace of Token. He called them all in with a suggestion of the grain in the packs, and reached farther for Token. He picked up the massed senses of a wild herd, perhaps an hour’s ride to the west and then, nearer, a flood of rampant equine sexuality.

“Oh, hells,” he groaned. “A wild stud did come in here, and he’s driven her off. I can feel her, but I can’t get through to her to bring her back. Flame, if I ever said you had a one-track mind, I apologize.”

Tourist Trap is available from iUniverse, from Barnes and Noble and from Amazon, but compare prices. Last time I checked, Amazon was still charging way too much for the Kindle version. The publisher e-book price is under $5.

Snippet Sunday logo

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It’s Sunday again, and time for 8 sentence snippets from a number of your favorite authors. Click on the logo above for Weekend Writing Warriors and on the logo below for Snippet Sunday.

Last time I posted about Riya it was from Marna’s point of view, and she was getting re-acquainted with her own home planet. This time the point of view is Lai’s. Marna has told him how to find the trail  and assured him it is safe,  but he is finding that while he is familiar with R’il’nian and Terran ecology, Riyan plants  and animals are quite different.

HubbleThe fact that R’il’nian included a word for feather argued that there had been feathered creatures on R’il’n, but none seemed to be native to Riya.

On the other hand, what was the plant off to his right? Instead of branching upward from the roots, it gave the impression of branching downward into the ground. Another plant looked like the skeleton of a geodesic dome, with a huge, brightly colored structure in clashing shades of pink and orange–flower? fruit?–growing inside the dome and protected by it. He moved closer, and found that the colored filaments were being visited by small, winged creatures covered with rainbow scales. A cautious mental probe of one confirmed that the creature had a backbone and six limbs, the middle two modified for flight.

Plant defenses tended to run more to physical protection such as thorns and sticky trunks than poisons. Lai picked his way around an unfamiliar but very hostile-looking bush that was trying to take over the trail, and was glad he’d elected to wear the tough coverall.

No adventure today, just a little more Riyan ecology. Something has to pollinate the flowers.

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Horse Power cover

(It’s FREE next weekend, June 15-16, at Amazon.)

I put “Horse Power” on Kindle primarily in order to learn how to do it. It turned out to be surprisingly easy, at least for a book which is primarily text.

The first step is to edit your work. Fully. Carefully. This is a sample of your work, and you want it to attract readers.

“Horse Power” had an additional function. It is a bridge, set 20 years after the end of Tourist Trap and relating an important incident in the history of the planet, Horizon, which is central to the trilogy I am now writing. As such, its primary function is to introduce the two books I have published, Homecoming and Tourist Trap, and provide the opening of the trilogy.

Horizon in the trilogy is a planet on which horse and dogs are critical to the stock-rearing economy. The planet has no fossil fuels, and in the wider world of the colonizing company’s owners, horses and dogs were merely luxuries. Stock was to be handled by imported vehicles, powered by fossil fuels imported at high prices. Horse Power was written to explain the transformation.

But it’s only a short story, and one on which I never expected to make any money. I’d give it away happily if it led to interest in Homecoming and Tourist Trap, which explore the earlier relationships among Roi, Amber and Timi. It was a natural to learn how to use Kindle Direct publishing, and the $.99 minimum price and the KDP Select Program, with 5 days free each 3 months, seemed well-suited to my needs. Eventually I want to take it off KDP Select and put it up on Smashwords as well as getting a few hard copies using CreateSpace, but the Kindle Direct program looked like the easiest place to start.

Once I had the edited story, the next step was to write the front matter, the short summaries of Homecoming and Tourist Trap explaining the background of the story, a short teaser for the trilogy, and create a table of contents which would link to each section. This was all done in Microsoft Word 2004 for Mac, using standard Word features such as bookmarks and hyperlinking. When I was sure everything worked, I “printed” the file as a PDF.

I then made the following metadata file, so that I could cut and paste into the Amazon metadata page:

Title: Horse Power

Description: Rumors have reached the Inner Council of the Jarnian Confederation that the Horizon Company is illegally exploiting the colonists. Roi has been sent to find out what’s happening, and he asks his old friends, colonists Timi and Amber, for help. But the Company’s behavior is legal, if immoral. Can the three find a solution to the problem?

Contributors: Sue Ann Bowling

Language: English

Publication date: leave blank

Publisher: Sue Ann Bowling

ISBN none

Categories: science fiction, animals?


Horses, Dogs, Science Fiction, Jarnian Confederation, Fiction, Colonization, Space travel, Debt slavery

DRM no

Cover? I’d seen some work I liked on the Science Fiction and Fantasy Saturday blog hop, and I contacted the artist ( She worked with me to create the cover for Horse Power at a very reasonable price.

With all complete, I filled out the metadata page and uploaded the PDF and the cover. Somewhat to my surprise the book, including the linked table of contents, worked fine on all of the viewers on the testing page, with one exception. I had bookmarked the centered section heads and table of contents title (which must be given the name toc.) As a result, whenever I used the “go to table of contents” or linked to a section from the table of contents, the centering of the title disappeared. I know enough HTML to suspect that the way I bookmarked did not nest the tags correctly. When I next do a revision I will put the bookmarks on the line before the centered titles. It would help I I could figure out how to remove an existing bookmark in Word; I may have to remove and retype part of the text.

I’ll be taking it off KDP Select once I learn other publishing options, but for the moment I still have five free days for this three-month period, and two of them are scheduled for the coming weekend: June 15 and 16. Download a free copy and play with the index and go to index functions, and watch how the centering of the section heads changes as you jump to them as opposed to scrolling to them. Minor, but something I will correct eventually.

Year 6 Day 151

Lioness, MorguefileLittle Gnu is walking again, and even running, though I doubt he will ever have his old speed or agility. Unlike Giraffe, who worked well with Patches, he seems unable to grasp the idea of hunting with a non-human partner. But without hunting partners he cannot hunt mammals effectively, so we were mostly eating fish and small game we could snare.

We did need hides, so I took to stripping the hides off fresh lion kills. At first I mostly relied on a local pride, counting on my warnoff to keep them away long enough for me to separate the hide telekinetically and then leave the carcass to them. Then I realized that they were actually backing off their kills as soon as I appeared, apparently hoping that I would strip the hides and give them easier access to the meat! After some discussion with Gazelle as to the most desirable parts of the carcass, I now teleport some of the better meat as well as the hides back to our home. If the predators are benefiting from my removing the hides, it is only fair that they pay something!

I have also started rotating which species and which individuals or groups of predators I target.

Little Gnu may not be able to hunt, but we are amassing so many tools that I suspect he will do quite well giving them to more able hunters. These people do not seem to have trade as such, but they gain status by giving gifts, and generally are given gifts in return. Meat is a prized gift, but so are exceptionally well-made tools. I’ve seen a couple of individuals who are crippled to some extent so specializing, and there is no reason Little Gnu cannot become one of them.

Dapple grey, trotting

AtoZ 13 logoIf you are looking for the A to Z post for today (F) scroll down or click on the button to the left.

Last week we reviewed the base color and dilution loci. Today we will do a final review of the interspersed white hair and white marking genes, along with the darkening genes. Although the blog series will end today, links will be put in the index to all  posts in this series.

There are two main loci responsible for interspersed white hair. These are Grey (born dark with white hairs becoming more numerous with age) and Roan (born roan with white hairs constant or decreasing with age.)

The Grey locus is the syntaxin-17 (STYX17) locus on equine chromosome 25. It causes an initial increase in melanocytes  followed by their depletion. There are two alleles at this locus: grey and wild-type, with gray being incompletely dominant. (Horses with two copies of the grey allele lighten faster than horses with one grey and one wild-type allele, are less likely to develop a fleabitten appearance, and are more likely to develop melanomas with age.) At this time the progression of graying (dark vs. light mane and tail) and the color of dark hair (usually black, but some individuals become rose grey, with the dark hair remaining red) are not known to be subject to genetic control. In any case the final result is a mostly white horse.

The Roan locus is close enough to the Extension locus that there is significant linkage. It is considered part of the KIT linkage group on equine chromosome 3. There are two alleles: roan (dominant) and wild-type. At one time possession of two roan alleles was thought to be lethal, but this has now been shown not to be true. Classic roan causes interspersed white hairs on the body, but the legs, mane and tail normally remain dark. The frosty pattern, in which the mane and tail are also affected, may be a variant of roan, but the genetic mechanism is at present unknown. Scars commonly lack white hair, causing dark corn marks.

Spotting loci are far more numerous, and some produce roaning as well as white areas.

Blazed face on chestnut

Blazed face on chestnut

Minor spotting genes may be responsible for white facial and leg markings. These genes are present in most breeds, and facial and leg white tend to increase in tandem. Animals with wide blazes and no white on the legs, or with high stockings and plain faces are very often minimally marked animals with one of the other spotting genes.

Tobiano horseThe Tobiano locus is closely associated with the KIT locus, and hence on equine chromosome 3. There are two known alleles, tobiano and wild-type, with tobiano being an incomplete dominant. Generally tobianos are crisply marked, with white crossing the topline. Legs are normally white and the face is plain or has minor markings. Minimal tobianos may have high stockings with plain faces; in the maximal pattern only the head may be colored. Roan or colored spots known as paw prints may occur in white areas on animals with two tobiano alleles. There is a dominant modifier which in the presence of both tobiano and cream produces what is called a calico pattern—the yellow of the buckskin or palomino is broken up, with some areas being red.

Black and white frame horseThe Frame locus is on equine chromosome 17, and is at the locus that controls endothelin receptor b (EDNRB.) The alleles are frame and wild-type. The frame allele is lethal in double dose, producing the so-called lethal white foal syndrome, so all frame horses should have one frame and one wild-type allele. The minimal expression of frame is extensive white on the head with colored legs. The maximal extent may have color confined to the topline and legs. The fact that the frame allele still seems sometimes to come out of nowhere need further clarification—a masking gene may also exist.

The sabino pattern is a combination of spotting and roaning, and extremely variable in expression. It may also have more than one genetic explanation. The Sabino-1 locus is part of the KIT complex (equine chromosome 3) and has two alleles, sabino and wild-type. The sabino allele is incompletely dominant over wild-type, as horses with two sabino alleles generally have more white (even to being almost completely white) than horses with one sabino and one wild-type allele. There are other mutations near the KIT locus that cause white spotting, some of which appear to be lethal in double dose.

The Splashed White locus is yet another that seems to be near the KIT locus, though not at it. The locus probably has two alleles, splashed white and wild-type, with splashed white behaving as an incomplete dominant. The minimal effect of splashed white may not be detectable, or the horse may be more extensively marked with white legs, possibly white underbody and generally white on the head, sometimes to the extent that the whole head is white. Think of a horse trotting through a puddle of white paint with its head lowered. Splashed white is also associated with deafness.

Lone Ranger andSilverManchado is a relatively rare type of spotting found in several breeds in Argentina, though that may be because of the Argentine fascination with coat color. Parts of the body, often including the top of the neck (and mane) are white, often with round colored spots. The genetic basis is unknown.

White with pink skin and dark eyes may be a separate gene, possibly lethal in horses with two white alleles. At the moment, this is somewhat up in the air.

Appaloosa horse

The Leopard locus is the Transient Receptor Potential Cation Channel, Subfamily M, Member 1(TRPM1) locus. It has two alleles, leopard and wild-type, but an enormous array of patterns. Leopard is incompletely dominant over wild-type—horses with two leopard alleles generally have fewer leopard spots than those with one leopard and one wild-type gene, and have a high incidence of night-blindness.

chestnutFinally, darkening due to black hair in the coat may occur in at least three forms. Black hair may be scattered throughout the otherwise red parts of the coat, producing a sooty effect. Black tipping on otherwise red hairs appears to be associated with the agouti locus, and produces shaded effects where the back appears darker than the rest of the horse. Actual black striping of the coat, brindle, is rare but documented. Some types of roan, especially sabino, may produce a type of brindle with white stripes. The genetics are unclear in all of these cases.

Horse Color Summary 1

As a final summary of horse color genetics, let’s go over the loci, what they do, and the alleles at each locus. My primary reference is Sponenberg.

BC bay headThe Agouti locus is widespread in mammals, and is involved with whether and where an animal produces eumelanin (black) or phaeomelanin (red) pigment. The alleles known in horses, listed with the most dominant first, are Wild Bay (Wild-type), Bay, Seal Brown and black. Agouti is hypostatic to Extension, meaning that the effects of the agouti alleles can be seen only if the extension gene allows the animal to produce both eumelanin and phaeomelanin. Note that at this locus, the redder the color, the more dominant.

ChescrThe Extension locus is the same as the melanocortin receptor one locus, or MC1R. Like agouti, it influences whether eumalin or phaeomelanin gets into the coat and occurs in most mammals. The alleles are dominant black (still not confirmed), wild-type, and chestnut. This locus may also have genetic control over the depth of black tipping. Only wild-type and tipping allow the agouti genes to show. In this series, more black is dominant over more red. Extension is epistatic to agouti.

Agouti and extension determine the base color of the horse—bay, brown, black or chestnut.

Dun fjord1crThe various dilution genes generally affect phaeomelanin and eumelanin differently, mane and tail hair and body hair hair differently, and not uncommonly are associated with patterns of dilution.

The Dun locus has two alleles. Wild-type is dun and is dominant over non-dun, but the wild type is rare in many breeds. When present, dun dilutes both black and red pigment on the body, but the degree of dilution varies a great deal. Head, legs, mane and tail are generally much less affected than is the central body, and dorsal stripes almost always occur. “Zebra stripe” markings often occur on legs and the shoulder region. The dorsal stripe may continue down the center of the mane and tail, with the edges diluted.



The Cream locus is also known as the membrane-associated transporter protein (MATP) locus. It probably has three alleles: Wild-type, pearl, and cream. The dominance hierarchy here is complex. A horse with two wild-type alleles is normal color. A horse with one wild-type and one pearl allele looks normal color except for slightly lighter skin. A horse with two pearl alleles will have red lightened to gold and black lightened to beige. A horse with one cream allele and one wild-type allele will have red lightened to gold and black lightened only very slightly. A horse with one cream and one pearl allele will have red lightened to pale cream or ivory and black lightened to beige. Finally, a horse with two cream alleles will be a very pale color, as red lightens to cream and black to a slightly dirty white.

champcrThe Champagne locus is the SLC36A1 locus. It has two alleles: Champagne (dominant) and wild-type. Champagne dilutes red to gold and black to brown or tan. The mane and tail are generally diluted less than is the body.

Silver Dapple8:4:12The Silver Dapple locus is the pre-melanosomal protein 17 (PMEL17) locus. It has two alleles, silver (dominant) and wild-type. The silver allele dilutes black strongly but has little or no effect on red. The allele also produces very strong dilution in mane, tail and lower legs, at times producing horses that appear black with white manes and tails. Far commoner are horses with a blue to chocolate body, often heavily dappled, with distinctly lighter manes and tails. At one time common primarily in ponies.

The Mushroom locus has not yet been located. Two alleles are suspected, wild-type (dominant) and mushroom (recessive.) Mushroom horses resemble silver dapples, but lack dappling and have tested chestnut at the extension locus.

Arab dilution is another possible locus. This is believed to be a recessive allele with a strong lightening effect on black but little or no effect on red. Both Mushroom and Arab dilution are very rare.

I will summarize patterns of white, including grey and roan, next week.

Horse head

Look at the ear tips on this bay.

This article was originally posted April 24, 2011. It is being repeated here with new photos and some revision.

Horse colors are due to the interaction of a large number of genes, many of which we’ve discussed. These may be divided into base color genes, diluting genes, genes that cause interspersed white hairs and marking genes. One type we have not discussed, because the genetics are not really understood, is interspersed black hairs.

I’d like to point out one thing that Sponenberg does not cover: there are two distinct types of darkening due to the presence of black. It takes a magnifying glass and a great deal of patience to tell the difference, but darkening can be due either to interspersed black hairs (called sooty and it can occur on any base color) or to hairs that are red/yellow at the base and black at the tip (producing a shaded appearance and I think occurring only on bay, wild bay and some seal brown horses.)

For the rest of this discussion I will assume the horse is of one of the base colors, but sooty and shading can occur with any dilution or marking genes, or together with roaning or grey. You just have to remember what the other genes do to red and black pigment, or if they have different effects on coarse and fine hair.


Chestnut with sooty gene. The dark mane and tail almost look bay, but the lower legs clearly identify this horse as a chestnut.

Liver chestnuts are often sooty. It takes careful examination to tell if a chestnut has interspersed black hair, but when I was examining them with a magnifying glass, this was true of every liver chestnut I examined. Even red chestnuts often have a few black hairs mixed into the coat and the mane and tail. Bays can also be sooty, but this may be confused by the presence of shading.

In order to understand black shading, it is necessary to go back and look at how the agouti locus affects mammals in general. The locus got its name from a middle and South American rodent, the agouti. This animal has fur in which the individual hairs are banded in black and yellow. As it happens this is very common in mammals, and a number have banded hair. Unless the hair is very coarse this is not obvious—wild gray mice and rabbits, for instance, really have hair banded in black and light yellow.

The banding may vary from multiple bands on a hair to hair with red/yellow/cream bases and black tips. The banding may also vary with type of hair, with some hairs (often the coarsest) being solid black and others (often the finest) being predominantly yellow.


This guy is a mule, but he shows an interesting combination of shading due to the depth of black tipping and the variation of red/yellow pigment.

Remember bay and wild bay are due to genes at the agouti locus. Most bay horses have at least some banded hair on the body, usually with a red base and black tip. This is easiest to see around the edges of the ears, and the banded hairs tend to be most numerous along the spine and spreading down to cover the hips, shoulders and upper barrel. It’s been a long time since I actually looked at individual hairs with a magnifying glass or under a microscope—I was doing this in the late 60’s and early 70’s. But as I recall, just about every bay or buckskin horse I looked at had at least a few black-tipped hairs. In some, the black tipping produced a shaded effect on the body of the horse.

A few horses look black or seal brown in summer coat and quite different in winter. I recall two of these. Duchess was a typical seal brown in the summer—black with tan shading on her flanks, muzzle and under her tail. In winter she looked dark bay. Careful examination of her winter coat showed red near the skin with deep black tips. In her short summer coat, apparently only the tips showed.

The other was even more striking. I first saw him in winter coat, and thought at first he was a blue roan. Careful examination of his coat showed yellow bases with black tips rather than interspersed white hair—a buckskin with deep black tipping. In summer, I knew he was the same horse only because the stable owner identified him—he was a typical seal brown.

Note that this shaded effect due to black tipping is quite different from the counter-shading often seen in red/yellow pigment, which leads to the undersides being lighter than the back. This is very common in mammals, and tends to offset the fact that light comes from above, making the animal less visible to predators. The shading in a bay may be due to the same selection pressure, but the effect on the individual hairs is quite different.

This is an area that needs much more research. Unfortunately with the prominence of DNA in genetic research, researchers seem not to be paying as much attention to the distribution of pigment in the hair.