Black squirrels more common than ever in the suburbs

Common mammals like gray squirrels are often overlooked. When a striking black squirrel appears, everyone takes notice. They are actually the same thing; let me explain.

First, we need to look at the big squirrel picture. Squirrels are rodents that fall into two categories: ground squirrels such as the 13-lined ground squirrel, and tree squirrels such as gray and fox squirrels.

The black squirrel is not a separate species, but rather a melanistic form of the gray squirrel. Melanism refers to an inordinate development of dark pigment. It is the opposite of albinism.

In the Southeast, there is a melanistic form of the fox squirrel, but here in Chicagoland, it is usually a dark gray squirrel. So, this article is as much about gray squirrels as it is black squirrels.

Gray squirrels are essentially eating machines. They eat roughly 1.5 pounds of seeds and nuts per week. Squirrels are particularly fond of acorns, hickory nuts, walnuts and, of course, bird seed. They will also eat mushrooms, flowers, buds, and berries.

One-and-a-half pounds doesn't sound like much until you realize that a squirrel only weighs 1 to 1.5 pounds. So, they are eating their body weight every week.

Besides eating fruit that the tree is willing to provide, some squirrels will actually strip the bark off hardwood trees. This unfortunate habit has earned them the nickname "tree rats."

This reminds me of a squirrel description offered by Carrie Bradshaw from HBO's "Sex in the City" - "A squirrel is just a rat in a cuter outfit."

Speaking of stylish outfits, I've seen gray squirrels in all-white and all-black coats.

I had to drive a long way to find albino squirrels, all the way to Olney, Illinois. For a variety of reasons, albino animals don't usually last long in the wild. It is hard for an all-white squirrel to hide from a hungry hawk or owl.

An all-black squirrel stands a better chance - and you stand a better chance of seeing one.

Black squirrels have been in Illinois for quite some time. As early as 1857, Illinois naturalist Robert Kennicott collected 50 black squirrels along the Rock River. Nowadays, gray and black squirrels have adapted to live in our urban and suburban neighborhoods.

The squirrels' acrobatic skills apply to utility lines as well as tree branches. As one observant local commuter told me, she regularly sees an agile squirrel using an overhead utility wire to cross Route 59 near the intersection with Route 14.

The area where you are most likely to see a black squirrel is from Evanston north to Zion. We've had them here in the nature center as well. When you see one, particularly if it is against a snowy backdrop, you can't help but be impressed. There is something about that soft-looking black fur that reminds me of velvet and Cinderella.

In the original Norman-French version of the story, Cinderella is wearing slippers made of vair, the word for squirrel fur. Over time, vair became verre, a homonym meaning glass.

Think about it, hard glass slippers wouldn't be very comfortable. Wouldn't you rather wear slippers made of soft, warm squirrel fur? OK, let's not think about that. Poor squirrels.

• Mark Spreyer is executive director of the Stillman Nature Center in Barrington. He welcomes readers' questions and comments at stillnc@wildblue.net.