Michigan Black Squirrels: One of My Favorite Midwestern Animals

Hey y'all! Midwest Muse is back for another week, and I am very excited to share with you information about my favorite type of squirrel. As spring is quickly progressing, I have seen significantly more animals outside as well as an abundance of blooming plants. I forgot how much I enjoy spring and the feeling of new things growing, both in the world and in my own life. A springtime childhood memory I hold close to my heart is having my mom point out a black squirrel to me while visiting my grandparents' house in Michigan. I remember being told that they can only be seen in Michigan, and I was instantly fascinated. Today, I am going to tell you all about them!

Sourced from Lynn Blackshaw on Pinterest.

Contrary to popular belief, the black squirrels seen in Michigan are not their own species. They are a melanistic variant of the Eastern grey squirrel (Sciurus carolinensis). The Eastern grey squirrel is native to Eastern and Midwestern North America, but today, they can be found all over the United States and parts of Canada. These squirrels play a crucial role in forest regeneration by spreading seeds and serve as a primary food source for multiple predators, helping to maintain biodiversity and a balanced ecosystem. The melanistic variant is commonly seen in the Great Lakes region, with the highest frequencies found in Michigan and Ontario, Canada.

Eastern grey squirrel. Sourced from Randal Phoenix.

Biologists have found that the melanistic variant of the Eastern grey squirrel is a result of genetic mutation, specifically an allele deletion in the melanocortin 1 receptor (MC1R) gene. This receptor plays a large part in pigment production in the squirrel's hair. Because the gene is faulty due to the deletion of the MC1R▲24 allele, there is an overproduction of black pigment, leading the squirrels' fur to be black as opposed to grey.

This genetic mutation is relatively rare; only 1 out of 10,000 squirrels have black fur! However, black fur is an advantageous trait in colder areas, so Northern regions like Michigan and Ontario have an abnormally high frequency of black squirrels. While researchers are still unsure why black squirrels have a higher survival rate and frequency in regions with cold temperatures, there are many hypotheses. A leading hypothesis is that black fur absorbs 20%-30% more heat from the sun than grey fur. This allows squirrels with black fur to retain heat more efficiently, keeping them warm and increasing their chance of survival in cold environments.

Jumping black squirrel in Detroit, Michigan. Taken by Jessica J. Trevino, Detroit Free Press.

As stated above, it is clear that regions with cold temperatures have a higher frequency of black squirrels. However, it is still unclear how and why the frequency of black squirrels varies between populations that live close together. A research team from the College of Wooster in Ohio surveyed local squirrel populations from 2010 to 2018, documenting their fur color. Their data showed that 30% of squirrels in Wooster had grey fur while 70% had black fur. To compare the frequency of black squirrels in Wooster with other cities, they surveyed 60 other cities across Ohio. What they found is surprising: some areas did not have any black squirrels at all. Most notably, in Lodi, Ohio - just 17 miles away from Wooster - there were absolutely ZERO black squirrels despite the close proximity of the two cities. The researchers are unsure why this happens and are working to understand the factors that cause such sharp contrasts in a small geographical area.

A grey squirrel & black squirrel debugging each other. Taken by Jim Edlhuber.

While my mom may have lied about black squirrels only existing in Michigan (I forgive you, Mom), they do account for 56% of squirrels in the state! In Ontario, they are even more common, accounting for 66% of squirrels. I am a huge fan of these little creatures, and I definitely associate them with my grandparents and Michigan, one of my favorite states in the Midwest!

Information from "Black squirrels in Michigan and elsewhere could be evolution in action" by Chioma Lewis & "Interspecies Breeding Is Responsible for Some Squirrels' Black Coloring" by Meilan Solly.