What Causes White Squirrels and How Rare are They?

Squirrels come in a variety of different colors. The eastern gray squirrel lives up to its name in North America while the fox squirrel can appear reddish-orange, brown, and gray. However, no species of squirrel naturally appears white in the U.S. even though white squirrels do exist. So, what causes white squirrels and just how rare are they in the world today?

Let’s take a look at the situation and find out the source of the squirrels.

What Are White Squirrels?

White squirrels are not a species of their own such as fox squirrels or the Mexican gray squirrel. Instead, white squirrels are most often members of the eastern gray squirrel species, Sciurus carolinensis.

A white squirrel is not merely a squirrel that has white integrated into its fur colors. Instead, these creatures are unusually white for a few different reasons. One option is that squirrels could have greatly reduced pigmentation in their fur due to leucism. As a result, they have all white fur except for the dorsal stripe of gray fur that runs down the length of their bodies.

To be clear, white squirrels are not albino. Albino squirrels are very different because albinism impacts their melanin production. As a result, they have red or pink eyes in most cases. When most people talk about white squirrels, they are referring to the leucistic ones and not the albino ones.

With a basic understanding of white squirrels, it’s possible to consider the causes of white squirrels.

What Caused White Squirrels to Appear?

White squirrels exist due to leucism in existing squirrel species. Leucism is when an animal has a partial loss of pigmentation. Most mammals can be leucistic. In this case, leucism comes as a result of a mutated gene in the animals causing them to have greatly reduced pigmentation in their fur but not changes in other parts of their body like that seen with albinism.

The expression of this recessive allele is very rare. In fact, it’s much rarer to see a white squirrel than it is to see a melanistic black squirrel.

In North America, the eastern gray squirrel is one of the species that most often appears white. White squirrels are not a natural occurrence in the sense that no squirrel species are entirely white, at least in North America. Some tree squirrels in Thailand are white.

White squirrels are not even entirely white. They often have a gray patch on the crown of their heads along with a gray stripe on the top of their bodies. Now that we figured out what causes white squirrels to appear, let’s move on to how it affects their lives.

Do White Squirrels Have Any Advantages?

When black squirrels appear, they get some thermal advantages and the ability to hide from predators. White squirrels are not typically that fortunate concerning the latter. When an eastern gray squirrel sits in a tree, the color of its fur makes it hard to see. They can disguise themselves in other types of vegetation as well.

Unfortunately, white squirrels stand out against natural surrounding environments. They will stand out against all but white trees, in the grass, and just about everywhere else but in the snow.

Yet, they may have a slight advantage in areas where humans live. For example, predators may not easily spot them against the backdrop of a white building or on a light-colored roof.

Also, one of the top reasons that squirrels die is due to being hit by cars. Gray squirrels blend into roads made of asphalt unless it’s freshly laid. Black squirrels and white squirrels would both stand out in such a place, making drivers aware of their presence.  While that may not make all drivers stop, it could cut down on the number of squirrels that are struck by cars.

White squirrels do not get many advantages due to their leucism, but they may get at least one or two.  

Where Do White Squirrels Live?

Leucistic and albino squirrels live in a wide variety of places. In North America, they are often seen in the eastern half of the United States and some in Canada. Oftentimes, they are offspring of the eastern gray squirrel.

Some areas have a higher population of these white squirrels than others. Scientists have received reports from places like Brevard, North Carolina along with Marionville, Ohio where a higher number of white morphs and albinos squirrels live.

Realistically, though, sightings of albino and leucistic squirrels have been reported throughout many of the states in the eastern United States.

Technically, some breeds of naturally occurring white squirrels can be found in parts of Asia as well. Knowing what causes white squirrels and where they’re found, there’s one last piece of the puzzle left to place.

How Many White Squirrels Are Out There?

There is no way to know how many white squirrels are out there. Still, it’s possible to estimate their population. Roughly 2 million eastern gray squirrels live in the wild. Scientists estimate that one in every 100,000 squirrels is born with albinism. Given a population of 2 million squirrels and 0.001% of them being albino, an estimated 20 albino squirrels are in the United States. Still, leucistic squirrels are more common than albino squirrels.

One source observed that roughly 20 to 30% of all the cases reported to them of white squirrels in North America were albino. The rest of them are true white squirrels with leucism. So, if those 20 albino squirrels are 20 to 30% of the white squirrel population, then about 60 to 100 white squirrels have been reported to that organization overall. That probably doesn’t represent the entire population of white squirrels in North America, though.

However, the numbers should provide a baseline to realize just how rare these creatures are compared to the typical morphs.

Knowing what makes white squirrels and why they’re so rare makes every sighting of them special. These creatures represent a small percentage of their species, and many of them are easy targets for predators. It’s fun to notice and appreciate these creatures and realize how rare it is to see one.  

The photo featured at the top of this post is © Christine Bird/Shutterstock.com