When I talk about pinto patterns, I often speak about where the white originates. Those are the areas most likely to be white in the most minimally-marked individuals. Patterns progress from their point(s) of origin in relatively predictable ways as the percentage of white increases. This idea of adding white over the colored areas is an easy way to visualize a pattern’s range of expression. The biological process, however, is the other way around. It is the color that spreads during embryonic development. Areas that do not get the cells necessary to develop pigment are white.
What has intrigued me for some years now are factors that appear to add color back again, usually in the form of spots or patches. The most common of these – and the first that I began to notice – were what I call occluding spots. Oddly shaped or placed white face markings often make more sense if you imagine oblong patches of color placed on top of them. This can make a blaze appear broken or, as in the case of the Welsh Pony mare above, narrow and skew off to one side.
The idea that a colored area has been added over the marking – as opposed to the marking being incomplete or irregular in shape – is easier to see when both the marking and the occluding spot are large. This is what Jeanette Gower (Horse Color Explained, 2000) referred to as “badger-faced.” (For those of us familiar with North American badgers, this humorous comparison with European badgers explains why this name was chosen.)
Before I encountered horses with smaller, more abundant spots of color, I assumed these markings were peculiar to the face. However, a badger spot is visible because of the negative space it creates. Presumably, if the spot was just a bit larger, the horse would appear to have a solid face. If a spot completely covered (or completely missed) a leg marking, that might give the impression that occluding spots were specific to the face.
I have come to believe that is not the case. This Paint mare, Flea (BP Rousing Hart), is a striking example of how occluding spots might alter more than just the face markings on a horse.
Photo used with permission from Bremerpark Paint Horses. To see more pictures of Flea and her offspring, please visit their website here.
Patterns like this are appealing to artists trained to see shapes created by positive and negative space. Aside from their aesthetic appeal, however, the idea that there is more white “under” the color is important to breeders as well. Horses like Flea might produce more white than their phenotype might suggest. That is also why the distinction between recoloring and white suppression could be significant.
The horses in this post have large, infrequent spots of overlapping color. In the next post, I am going to talk about what happens with the size and frequency change. This creates some of the most visually striking forms of recoloring, and I have quite a few examples to share.