Squirrel Species & Ecology
Learn about the ecology and behavior of Illinois’ two huntable squirrel species — the Eastern Gray Squirrel and the Eastern Fox Squirrel.
Tree Squirrels vs. Ground Squirrels
Illinois is home to two main categories of squirrels: tree (arboreal) squirrels, which most people think of as “squirrels,” and ground squirrels, which live primarily on the ground.
Illinois Ground Squirrels
- Eastern Chipmunk (Tamias striatus)
- Woodchuck (Marmota monax) — also known as a groundhog or a gopher
- Thirteen-lined Ground Squirrel (Spermophilus tridecemlineatus)
- Franklin’s Ground Squirrel (Poliocitellus franklinii) [Illinois threatened]
Illinois Tree Squirrels
- Eastern Gray Squirrel (Sciurus carolinensis)
- Eastern Fox Squirrel (Sciurus niger)
- Red Squirrel (Tamiasciurus hudsonicus)
- Southern Flying Squirrel (Glaucomys volans)
Woodchucks are classified as state game mammals but are grouped with furbearers because they may be hunted and trapped in Illinois. However, woodchuck hunting is distinct from (tree) squirrel hunting and has its own methods, seasons, and regulations, so it is not covered here.
Eastern Gray Squirrel (Sciurus carolinensis)
Physical Characteristics
- Body length: 8–11 inches (head to tail base)
- Weight: around 1 ¼ lbs
- Tail: roughly the same length as the body, with white fur bordering the bushy gray tail
- Color: Gray (agouti) back, sides, and head, with cream eye circles, white belly, and white tips on ears
Color variations include:
- Melanistic (all black)
- Leucistic (white, pale, or with white or pale splotches, dark eyes)
- Albinistic (albino)
All three of these variations are the same species and can be found in Illinois.
Habitat & Behavior
Common across Illinois, especially in close-canopy forests with nut-bearing or cavity trees and in urban areas.
- Most active at dawn and dusk (crepuscular)
- Eats buds, leaves, fruits, berries, fungi, pecans, acorns, hickory nuts, tree bark, walnuts, and the seeds of various other trees
- Primarily arboreal (lives in trees) but stores nuts in the ground (caches)
- Makes a “kuk-kuk-cut-cut-cut” call; females “bark” when pursued during breeding season
Eastern Fox Squirrel (Sciurus niger)
Physical Characteristics
- Body length: 10–15 inches (head to tail base; largest Illinois tree squirrel)
- Weight: 1 ¾–2 lbs
- Tail: Long and tinted orange
- Belly, ears, and face: rusty orange tint
- Fur: Rusty yellow mixed with black, giving an overall orange hue
Other color variants exist (generally darker-faced), but these are more common in the southern US than in Illinois.
Habitat & Behavior
Common across Illinois, but prefers forest edges and clusters over dense forest. Most often found along agricultural field edges near woods.
- Less common in cities than gray squirrels
- Not commonly found alongside gray squirrels
- Diurnal (active during the day)
- Spends more time on the ground than gray squirrels
- Commonly makes a “bark” call
- Eats fruits, tree buds, hickory nuts, acorns, walnuts, Osage orange fruits, corn, flowers, leaves, fungi, and insects, varying by season and availability
- Caches (stores) extra food
Applying Squirrel Behavior & Ecology to Your Hunt
Both huntable squirrel species are most active at dawn and dusk. For optimal success, hunt squirrels during these times, when they are most active in the trees or on the ground.
Early in the season, cooler, calmer mornings are ideal, as heat and wind send squirrels back to their dreys. Squirrels rely on their vision and hearing to avoid becoming prey. Windy conditions make squirrels less active because moving foliage, trees, and plants obscure predators.
On windy days, pay attention to sheltered areas like valleys or the backs of slopes, where squirrels are generally more active. During these conditions, you can also expect to see squirrels more frequently on the ground rather than in the trees, especially in these wind-protected spots.
Early Season Behavior
- Squirrels nest in dreys and stay mostly in trees.
- Most active on cool, still mornings.
Mid-to-Late Season Behavior
- Squirrels spend more time on the ground collecting and caching nuts.
- Activity decreases in cold weather but increases again in January and February during the breeding season.
- Late winter hunting can be productive as squirrels are more active and visible.
During courtship, males chase females, who may mate with multiple suitors. Females carry young for about 44 days before giving birth to two to six kits in tree dens.
Squirrel activity increases again in January/February during the first of their two annual breeding seasons. The second occurs in late spring and early summer, outside of hunting season. Because squirrels are more active and less likely to stay hidden in tree cavities during breeding season, late winter offers excellent hunting opportunities.
Focusing hunting efforts during the late winter breeding season can be especially beneficial, and it’s a great reason to get outside when winter blues start to set in!
Common Food Resources
Common squirrel foods include acorns, hickory nuts, beech nuts, and black walnuts. Familiarity with these tree nuts helps you identify productive squirrel habitats.
Squirrel Scouting
Look for oak and hickory forests with moderate brush, for easy visibility, and an abundance of food. These spots attract squirrels, making them easier to spot.
Key signs of activity:
- Cavities in dead trees (often with chew marks around the hole)
- Leaf nests high in branches
- Cracked nut shells on stumps or logs
- Disturbed leaves or small holes where squirrels cache nuts
- Tracks in the snow or mud (compare to raccoon, rabbit, and opossum tracks)
A good squirrel hunting area is often a good deer habitat, especially where food sources are plentiful. Squirrel hunting can double as deer scouting.
Recommended Resources
- Tree Squirrels (Wildlife Illinois, IDNR)
- Eastern Gray Squirrel (Sciurus carolinensis) – A Small Game Species Profile by Ryan Lisson