Overview of Hedgehog Colors: Part 3 of the Color Breeding Series

Hedgehogs are relatively new arrivals to the pet hobbyist scene, and the views on their colors have changed considerably over the years. It has been theorized that initially, there were two main species of African hedgehogs imported to the U.S. as pets, the White-Bellied hedgehog and the Algerian hedgehog (it should be noted that some have noted that the two species that were crossed to create the pet hedgehog may have actually been two regionally separated groups of white-bellied hedgehogs, with no Algerian ever being crossed in). The colors of the two different varieties of hedgehog were similar, but were believed to be distinguishable and show variance in heritability. They both had a black coloration and a brown coloration, although the black colors were not considered to be different by many breeders (creating three colors: Standard, Brown, and Algerian Brown). Crossing the two different brown colors yielded the first known orange colored hedgehogs. Since the initial identification and naming of the colors, a plethora of other shades have been described and named, producing color standards for ninety-two colors currently recognized by the International Hedgehog Association. The interesting quality behind this brief history is that the earlier concepts of hedgehog colors appear to have been closer to the truth than the over-complicated naming system that is currently in common use. The current system names every possible shade along a gamut of colors, without any regard to how they are inherited.

From a study on the inheritance of color in hedgehogs, it has been determined that there are two base colors present in pet hedgehogs, black and brown (or gray and cinnamon, respectively). A second genetic locus (that of the ruby-eyed dilution gene) modifies the appearance of these two colors to produce the other principle colors seen in hedgehogs. If it is assumed that the history behind the colors is correct, then it would have been a Cinnamon x Chocolate/Brown cross (both of which are different shades of brown in appearance) that yielded the first Cinnicots and Apricots (or {bbruru} x {BbRu-} = {bbRuru}, etc.). For a quick tutorial on coat color genetics read: Introduction to Color Genetics.

The semi-expressive qualities of the ruby-eyed dilution trait account for much of the color variations possible in hedgehogs. It dilutes both the black based colors and the brown based colors to an orange-overcast-brown and orange, respectively, but can show either complete, incomplete, or co-dominant expression in the coat. Therefore, under its affect Gray becomes either Chocolate or Brown, and Cinnamon either Cinnicot or Apricot; creating six principle colors in hedgehogs, or twelve when considering the blue-cream diluted variants of these six principle colors.

There are dilute versions of the black-based colors and the brown-based colors. However, there seems to be complications involved in producing diluted black-based colors (Opal, Blue-Fawn, and Fawn), with these three colors being far more difficult to produce than the diluted brown-based colors (Silver-Cinnamon, Silver-Cream, and Cream). Whether or not this is due to problems with incompatibilities between the black and dilute genes or just from gene distribution in the whole pet hedgehog population is still unknown.

Beyond the principle colors there are also a few modifiers present in pet hedgehogs. These traits include snowflake, pinto spotting, and albinism. Both albinism and snowflaking are the result of simple recessive genes (denoted as cc and snsn, respectively), although there could also be another trait that mimics snowflake with a dominant mode of inheritance (Roan: Rn-). Pinto spotting is a dominant trait (S-), but is variably expressive and appears to be capable of skipping generations from time to time (“hidden pintos” might have a pinto freckle here or there).

When considering the six principle colors, along with their blue-cream dilutes and the possible combinations of the common modifiers there is a potential for forty-nine distinct coloration in pet hedgehogs.

Black Based ColorsBrown Based Colors

The Agouti Pattern

The most important thing to remember, when considering the expression of hedgehog colors, is that hedgehogs are agouti (pronounced: uh-goo-tee) patterned animals. There are not any self-colored hedgehogs in the ‘domestic’ bloodlines, at least not yet. Being agouti patterned means that there is an extra pigment in the hair/spine coloration (this extra pigment is the tan/orange melanin known as pheomelanin— the common black/brown pigment is called eumelanin).

Hedgehog Spine

This means that a black hedgehog will never be just black, but, instead, will always have black and tan on its spines. However, the very rare color known as Salt & Pepper is supposedly an exception to this; if they truly are lacking the agouti-induced tan bands, then they could be a different type of color: not necessarily self-colored, but some form of color inhibition– comparable to a silver tabby cat. For the time being, the Salt & Pepper coloration will be set aside. Note in the image above that the base-color appears in between the two agouti-induced bands. The base-color band is indicative of the color genes present in the hedgehog, i.e. whether it is a black or brown based color. However, the shade of the base-color band can also be diluted by overlapping of the agouti bands, which can make black bands look like more of a deep chocolate-brown color.

The main issue that arises with agouti patterns is how much of a color range can exist. A black agouti can have an overall appearance of almost black, uniformly black and brown, or, seemingly, entirely brown. It can be pretty confusing for some people when you hold up a black hedgehog next to a brown one and say “these are the same color”. However, this is not a unique phenomenon; for instance, some brown tabby cats look mostly black next to others that look almost chocolate— brown tabby can be considered an homologous color to black agouti hedgehogs: i.e. the same color within different animals. Breeders of other small animals have reduced this problem by either setting up strict guidelines for what shade an agouti color should be, or by classifying all black agoutis and brown agoutis into one category (the latter, for obvious reasons, would not be a very helpful standard for animals in which agouti is the only pattern).

The overall appearance of the hedgehog depends on the ratio of tan-to-black coloration, not just in the bands, but also in the skin. The agouti-induced pigments accumulate in the skin as they do in the hairs and spines, which can be observed by noticing that the skin color is proportional to the amount of tan on the bands without the presence of modifiers. For instance, if a chestnut colored hedgehog had as much tan on its bands as is shown in the image of the spine above, then its skin would not be truly black, but would instead be very dark brown (still appearing black to some).

The ranges produced by this phenomenon can create an overlap in the outer ranges of various phenotypes, often making it difficult to determine the color of any hedgehogs that are outliers; for instance, a gray hedgehog with considerably more agouti expression than the average amount can be as light as a hedgehog that is genetically chocolate. Likewise, a very dark Chocolate can be darker than some Grays.

Age Related Fading

Age related fading is one of the greatest complications in identifying hedgehog colors. While it is more noticeable in the darker colors it can affect them all. However, it doesn’t affect all hedgehogs, and not all of the hedgehogs that are affected fade out to the same degree, which could indicate a heritable factor.

Ericius 1 yr
Ericius 3 yr

 The trait expresses as an overall reduction of the color intensity as the individual ages, black fading to brown (as is illustrated on the left). Such an occurrence can create issues when it comes to identifying a hedgehog’s color. However, it takes a few years for the color to fade as drastically as is shown here: the Gray hedgehog pictured above is three years old in the photo on the right, which is beyond the age of most hedgehogs’ reproductive age. This reduces the odds of misinterpreting a phenotype due to age related fading when color breeding. The fading usually begins around eight to thirteen months of age, with a slow progression. In some individuals the fading eventually stops, while in others it continues throughout their life.

Juvenile Colors

Slithy Tove 16 Days

The process of pigmentation begins shortly after birth; all baby hedgehogs are born colorless with closed eyes. Pigmentation is typically noticeable in the skin by day two for darker colored hedgehogs, and a few days later for lighter colors, depending on how light; creams might even appear to be albinos until their adult spines grow in. The initial coat colors that appear are often in shades of gray or off-brown. After the first couple weeks of age a second baby coat will begin to grow in: this second coat will usually reveal more of the color that the baby will grow to be, although many of the spines are likely to still be banded by the various shades of the baby grays (the Gray colored baby on the left is sixteen days old, notice how she already has many Gray colored spines along with some that still banded by dark silver).

The eyes tend to open between 15 and 20 days of age, or around two weeks old. The eyes of Grays will be black, while the eyes of Cinnamon babies can appear anywhere from light brown to nearly black when they open. The eyes of a Chocolate or Brown babies are most often black in appearance when they open but occasionally will be dark ruby-red and then darken to black, or near black, with age. The eyes of Cinnicots are most often ruby-red when they open and may or may not darken with age. Apricots eyes are ruby-red when they open and then remain so.

The final quilling process can take place any time between four and twelve weeks of age. After this process is completed a hedgehog has attained its adult coloration. The only changes that are still likely to occur would be snowflaking or roaning, which can happen fairly late in some cases. If the hedgehog is pinto or albino it will be notable from the onset of pigmentation (or, rather, the lack thereof).

Ryan is a guest writer. He has years of experience with coat color genetics, experience with hedgehogs since 1995, and began studying their color genetics in 2001.He earned his degree from Oklahoma State University, College of Arts and Sciences, Department of Microbiology and Molecular Genetics.

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