I had never seen an Eastern Grey squirrel until I moved to Chicago thirteen years ago. To be honest, I didn’t know what to make of it. Coming from Guangzhou province in China, this grey furry species of squirrels don’t expand into the humid southern weather, where I use lived. It’s been years since I have moved to Illinois and these squirrels are now a common sight. Since the time I began my college career at the University of Illinois, I have noticed squirrels play large part of students’ interaction with nature and wildlife on campus.
The Eastern Grey squirrel (Sciurus carolinensis) is a tree squirrel, a native species from the Midwest to the East Coast states. From far away this species of squirrel might resemble a large rat with a fluffy tail that runs across the trees and shrubs in the quad. Reaching adulthood, a Grey Squirrel will stabilize around one pound in weight and range about 17 to 18 inches in whole body length. Upon getting closer, you can see that the squirrel has a gradation in its fur, going from grey to white, starting from the belly where it’s mostly white to grey on its back. At times you will hear this creature sneak around in the bushes and trees before seeing them, as they scour for food and seek sanctuary from predators.
The average lifespan of the Eastern Grey Squirrel is one to two years.
Interestingly, while the Eastern Grey squirrel is native to the local Urbana-Champaign area, the abundance of Grey squirrels that we see today is actually the result of administration decisions from University of Illinois back in the early 1900’s. In 1847, Philadelphia released three squirrels in Philadelphia’s Franklin Square and with that drew the attention of many visitors. Ever since, squirrels became an attraction in public parks and recreation areas in Philadelphia, Boston, and New Haven. In light of the growing trend in the early 1900’s, the University of Illinois decided introduce the disappeared population of Eastern Grey Squirrel to campus. The main contributor to the reintroduction of squirrel is Dr. Charles W. Rolfe, a Geology Professor, stated in his letter to University President Andrew S. Draper , “I think I shall be able to secure a few… that have been bred in the city and are not afraid of people.” With support from University President Draper, began the reign of Eastern Grey Squirrels on campus. The population of these creatures have certainly flourished over the course of urbanization in the last hundred years.
You might ask, over the course of the past hundred years or so, how has Eastern Grey squirrels become incorporated into our society? And more importantly, what role in biodiversity do they play in our everyday life today? Eastern Grey squirrels have created their place in the urban setting with many interactions interwoven with their food source and habitat. As it turns out, a squirrel’s diet can consist of a wide variety of foods. They can eat acorns, walnuts, tree bark, berries, seeds, and sometimes even fungi. In addition to the natural food sources, children and adults alike, take part in feeding squirrels all around campus. While trees, plants, and humans are food sources for these fluffy creatures, they are also part of the food chain as prey to larger creatures such as cooper hawks, possums, raccoons, coyotes, and foxes. A cycle of life where they play their part as predator and prey.
The deforestation of natural and rural areas destroyed many of the original habitats that squirrels resided in. For most animals, taking away their natural habitat is detrimental to their survival. However, according to Jean Mengelkoch, Mammologist at the Illinois Natural History Survey, “ Eastern Grey squirrels have adapted well to urbanization.” The development in urbanization has benefited squirrels in surprising ways. In fact, some argues that the development of city spaces have eliminated many large predators that prey on squirrels, making it easier for squirrels to thrive in an urban environment. The interaction between people and squirrels is certainly of cultural significance throughout the years and is “one of the mammals you most often seen on campus” during the day. Their food collection provides a method for spreading acorn and walnut tree seeds across the area through the process of burial. Eastern Grey squirrels store food for the winter by burying them in the ground. There are occasions when the seeds are not retrieved by the squirrels, they often sprout into treelings.
If all the squirrels are taken away tomorrow, I would find something missing on the Quad at U of I. Squirrels have become an integrated part of the city’s and the University’s biodiversity that it would strange to not have run into it on my walk to class or my run in the afternoon. So when you see a squirrel next time, maybe think a little more about their history and how they came to be on this very campus. It is after all, humans’ decision in the past that led to their pervasiveness in urban environment all over American cities today.