Squirrel Appreciation Month: Celebrates Chicago’s Acorn Ambassadors

October is Squirrel Awareness and Appreciation Month, and while some people think these common mammals can be a nuisance, there’s a lot to appreciate and learn about them, according to Joel Brown, who has studied tree squirrels for many years.

“Tree squirrels are incredibly important for tree regeneration,” says Brown, distinguished professor emeritus in biological sciences at the University of Illinois Chicago.

Brown, an Oak Park resident who co-founded Project Squirrel, adds they’re also fun to watch and can teach scientists about ways wild animals adapt to urban and suburban areas. “Watching squirrels is an amazing opportunity to see a nature special going on in real time in your own backyard,” says Brown.

Nathan Proudman, a postdoctoral research associate at the University of Illinois Urbana-Champaign, studies mammals, including squirrels, throughout the state. “The fact that squirrels can thrive within urban spaces is pretty cool,” he says. “I see squirrels as the archetypes of college campuses. They’re a welcome sight as you walk between buildings and observe them scampering between the trees.”

FOUR TREE SQUIRREL SPECIES

Four types of tree squirrels live in Illinois, distinct from ground squirrels such as chipmunks and thirteen-lined ground squirrels, which live in burrows and spend more time on the ground than in trees.

The two most common types are the eastern fox squirrel and eastern gray squirrel. Both scamper through trees; create bundles of leaves, called dreys, in which to raise their young in summer; and are busy, especially in autumn, devouring and caching black walnuts, acorns and other nuts. They also raid bird feeders if they’re not squirrel proof and sometimes choose attics in which to spend winter if they can’t find a good tree cavity.

Other species in the region include the nocturnal flying squirrel, which is difficult to see but likely fairly common, and the very rare red squirrel, probably found only in a small area in Kankakee County. 

Red squirrels were much more common before European settlement, when many more pine trees grew in the state. Proudman explains that red squirrels are specialists that eat pine seeds and need coniferous forests in which to live.

Brown wants people to know that tree squirrels are not carriers of disease. “They do not spread rabies,” he says. “If anything, a squirrel can catch a common cold from a human,” which can be fatal to the squirrel. 

EASTERN GRAY VS. EASTERN FOX SQUIRRELS

Both gray and fox squirrels, which do not hibernate in winter, are found in the Chicago region and can be easily identified.

“The eastern gray squirrel is gray with a white tummy, and the tail has a lovely, white fringe, like a hair accent,” Brown says.

“Fox squirrels have orange tummies and their fur tends to be more orange in color,” he explains. Their tails have a black fringe instead of the white fringe on the gray squirrel.

“The fox squirrels look like they go to a parochial school with a dress code,” Brown continues. “They will almost always look very similar. Gray squirrels look like they go to a public school with no dress code.”

Sometimes gray squirrels are completely black—a form called melanism. Sightings of black squirrels are rising in the Chicago region and across the state, according to Proudman. Recent observations have come from Logan Square, in Chicago, as well as in Highland Park, Zion and Mundelein, among other suburbs.  

“We’ve definitely seen more on cameras this last year than ever before, but we’d have to do more extensive studies to confirm their increase in the region,” says Proudman.

“You’ll even see eastern gray squirrels with odd-looking light-bleached tails or light-orange tails,” Brown adds. “And there are funny-looking squirrels that look like a cross between a fox and a gray squirrel. We’ve done a roadkill survey of these funny-looking squirrels and genetically they all turned out to be the eastern gray squirrels.”

Another difference is size.

“Usually the fox squirrels are much larger and have a stockier build,” Proudman says. “Eastern gray squirrels are built for speed,” he continues, adding, “In urban environments with an abundance of food, gray squirrels can get pretty fat.”

Both gray and fox squirrels live in Brown’s Oak Park neighborhood. Once fox squirrels dominated, now grays tend to be more common there, he says.

His studies at the Morton Arboretum, in Lisle, where both species live, have shown that gray squirrels prefer deep woods, while fox squirrels live on wood margins.

“It’s more difficult for a coyote, fox or hawk to get a squirrel in the deep woods, where the grays dominate,” Brown says. “The fox squirrels are more exposed to predators at wood margins. That could be why the fox squirrels have a more pronounced fur color, which could chase away predators.”

STOCKPILING FOOD FOR WINTER

In October and November, both squirrel species stockpile food for winter. “They’re called scatter-hoarders,” Proudman relays. “Instead of hoarding food all in one place for it to be wiped out completely, they try to spread it across the environment, increasing the chances of supplies being left in winter.”

It’s a common misconception that squirrels don’t have good memories. Actually, they do remember where they planted their stashes, according to Proudman and Brown. But they won’t find all of them, and that’s where their contribution to planting trees comes in.

Squirrels hide their cache in the soil for later retrieval. 

“If they left the acorns and other nuts on the surface, the food will fairly quickly get eaten by something else or it will get covered in mold or fungus or infested with weevils or beetles,” Brown explains. “Every oak tree out there is thankful to a squirrel burying an acorn safely and then forgetting where it is,” he says, adding blue jays also cache acorns and help plant trees.

Proudman says these accidental gardeners also serve as important prey species for red-tailed hawks and other birds and mammals. He once discovered a photo on a hidden camera showing a mink carrying a fox squirrel it had caught for a meal.

Both fox and gray squirrels have almost identical behaviors and diets and are equally adept at raiding bird feeders because of their acrobatic skills. 

Squirrels can hang upside down from a tree while eating a nut, Brown explains. “What’s cool about that is for them to hang upside down on the side of a tree anchored by their hind feet, they have to be able to rotate their ankles. They can rotate their ankles backward,” he says. “They have long sharp claws and long digits, which gives them amazing grasping and clutching abilities. However, they can fall out of trees—and they do.”

Squirrels persevere when raiding bird feeders. “If there’s a bird feeder and they want to get to it, they will study it and try things in steps and test their limits,” Brown says.

BIRD FEEDERS AND ATTICS

To prevent squirrels from stealing bird seed, Brown suggests placing feeders away from rooftops and trees where squirrels could jump from. Certain squirrel baffles can also help. Tossing some food on the ground might work, but it could also attract other unwanted animals, he says. Squirrels will also eat cobs of field corn on feeders designed to attach to trees.

Come winter, squirrels spend lots of time in tree cavities and sometimes attics, if they can get in. If a squirrel gets into an attic in winter, a specialist can remove it, or homeowners can wait until spring when it gets hot and the squirrels leave, Brown suggests.

Tree squirrels mate often in plain view of humans in January. The young are born in May in tree cavities or even attics. Squirrels may mate again in June and raise a second litter in dreys during summer.  

“Squirrels are just one of the most wonderful species around here,” Brown asserts. “They’re not a domestic animal. They’re not feral. They’re not being managed by humans. They’re just nature working all around us.”

Sheryl DeVore has written six books on science, health and nature, as well as nature, health and environment stories for national and regional publications. Read more at SherylDeVore.WordPress.com.

Natural Chicago sponsored in collaboration with Team Green.

 Squirrel Awareness Month Founder Was From Chicago Region

In 1995, Greg Bassett, an Elmhurst resident, founded the Squirrel Lover’s Club after a tree squirrel stood on its legs and looked toward him on a vacation in the Grand Canyon. Bassett created Squirrel Awareness Week for the first seven days of October and later extended it to a full month, now known as Squirrel Awareness and Appreciation Month. Over the years, he spoke of his fondness for squirrels on television shows such as The Today Show and Animal Planet.