In some states, spotting a black squirrel is a common occurrence. These black squirrels aren’t a species all their own, though; they may be either a fox squirrel or a gray squirrel.

I say it’s common to see a Black squirrel because Michigan, the state where I reside, has an abundance of them. Many articles online point out that Black squirrels are actually uncommon in North America.

You’re probably wondering how a squirrel that should be red or gray would end up donned in black fur. Well, it’s not a mystery—it’s a genetic mutation. Yep, Black squirrels are mutants—better register them under the Mutant Registration Act.

How This Mutation Happens

Because scientists take time to study and understand things, much speculation has occurred over the years about why there are Black squirrels. If you ask someone, they may think it’s a species all its own. Others believe that black squirrels are adolescent Gray squirrels and change color as they get older. Some online articles say that Black squirrels orginated from Canada.

However, Black squirrels are Gray squirrels. Science has now possibly figured out that when Gray squirrels and Fox squirrels mate, sometimes a strange genetic mutation happens, resulting in black-furred babies.

The book Weird Michigan by Linda Godfrey has a section about the Black squirrels, which is where I first learned about them being “mutants.” Recently, though, some researchers at various universities got together to test the DNA of these genetic anomalies to see what they really are. It turns out that instances of Black squirrel creation are all the fault of the Fox squirrel, a normally reddish-brown colored critter.

The mutation can naturally happen between two Fox squirrels, but when a Black Gray squirrel is found, the reason is that it crossbreeds with a Fox squirrel, and that the mutant gene is passed to their babies.

How Do You Know If the Black Squirrel Is a Fox Squirrel or a Hybrid?

If you spot a Black squirrel, you may wonder if you’re seeing a mutant Gray squirrel or a hybrid Gray and Fox squirrel with the color mutation. It may be difficult to tell, but there are differences between Gray and Fox squirrels. While most Gray squirrels are gray with maybe a tinge of red, and Fox squirrels are red with some black tipping on their tales, they’re also different sizes.

Gray squirrels, which are actually classified as Eastern Gray squirrels, are smaller than the Fox squirrel. An adult Gray squirrel will reach around one pound or a little bit over.  Adult Fox squirrels can be anywhere from one pound to three pounds.  Because of the size differences between these two species of squirrels, one would think that if a bBlack squirrel is larger, it’s a Fox squirrel, and if it’s smaller, it could be a hybrid.

How Common Are Black Squirrels, Really?

Black squirrels are mainly found in the United Kingdom and in the United States. They may be more prevalent than other squirrels of their same species, as well as other species of squirrels because their black fur helps them survive winters better.  Just like a black shirt on a sunny day makes you feel extra warm, the black fur on black squirrels absorbs the sunshine keeping them warmer even on colder days.

In the United Kingdom, it seems that Black squirrels may make up about three-quarters of the entire squirrel population. Black squirrels in the United States seem to be found in the eastern states mostly, and the percentage of these mutants squirrels varies according to what state you’re in. Some articles from states like Ohio report that Black squirrels were once more populous than they are now. Yet, articles from states like Michigan report that there’s an increase in how many Black squirrels can be seen in the wild.

So, the next time you see a Black squirrel, know that you are witnessing something that might be somewhat uncommon, depending on where you live, and that you’re likely looking at a Gray squirrel sporting a black coat.