There are over 200 species of squirrels worldwide, but only a handful are commonly found across the United States. Squirrels are rodents belonging to the Sciuridae family, known for their bushy tails, incisors that never stop growing, and their tendency to hoard food. The most abundant and widespread species of tree squirrel in the US is the eastern gray squirrel. However, depending on the region, other common squirrels include the fox squirrel, the American red squirrel, Abert’s squirrel, and the southern flying squirrel. Identifying which types of squirrels live in your area can help prevent damage or nuisance behavior.
Range and Habitats
The eastern gray squirrel (Sciurus carolinensis) is found across most of the eastern half of the United States. Its range extends from Maine to Florida, west to the Dakotas, eastern Colorado and Texas. They prefer living in mature forests with large trees that provide nesting cavities, but are highly adaptable to urban and suburban areas. Eastern gray squirrels build nests high up in tree branches called dreys, consisting of leaves, twigs, bark and other materials. They may have more than one nest per tree for use in different seasons.
Physical Description
Eastern gray squirrels have predominantly gray fur over their bodies, with a white or cream-colored underside. They have a bushy tail with hairs that are gray at the base and grow white toward the tip. Eastern grays weigh between 1-1.5 pounds on average and measure 17-20 inches long including their tail. Their coloration helps provide camouflage while they are up in the trees. Melanistic black and albino white variations exist but are less common.
Behavior and Diet
These squirrels are diurnal, most active early and late in the day. They are omnivorous and quite opportunistic eaters. Eastern gray squirrels dine on tree seeds and nuts, berries, some fruits, fungi, insects, eggs and even small vertebrates. They bury nuts and seeds in caches throughout their territory to retrieve later on. Their excellent sense of smell helps recover these hidden food stores.
Eastern gray squirrels are solitary animals and do not live in colonies. They are territorially, with males having larger home ranges up to 5 acres that overlap other squirrels’ areas. Communication includes complex vocalizations like grunts, squeals, barks and purrs, as well as visual cues with their tail. They breed twice annually, producing litters of 2-6 young after 44 days gestation.
Other Common Tree Squirrels
Fox Squirrel
The fox squirrel (Sciurus niger) is the largest tree squirrel native to North America, nearly twice the size of grays. They are found throughout the central plains, lower Midwest and southwestern United States. Coloration varies widely but generally includes brown, gray and orange. Fox squirrels create leaf nests in tree cavities but some may also den underground. They consume similar foods to eastern grays but take more plant material like fruits and seeds. Fox squirrels are not territorial and often forage in small groups.
American Red Squirrel
As their name suggests, American red squirrels (Tamiasciurus hudsonicus) have reddish fur over much of their bodies with a white underside. They are found across Alaska, Canada, the Rocky Mountains and boreal forests down into New England and the Appalachians. Red squirrels are less than half the size of gray squirrels at 7-9 inches long plus a 4 inch tail. They feed primarily on conifer cones and are highly territorial, defending cone caches against intruders.
Abert’s Squirrel
The Abert’s squirrel (Sciurus aberti) lives in ponderosa pine forests of the southwestern United States and Mexico. It has grayish fur, large tufted ears and a long fluffy tail. Abert’s are dependent on ponderosa pine seeds as their main food source. They build nests high up in pine trees but do not cache food extensively like other species. Their numbers appear to be declining due to habitat loss from logging and fire suppression.
Southern Flying Squirrel
As their name indicates, southern flying squirrels (Glaucomys volans) are capable of gliding long distances by stretching out patagia attached between their wrists and ankles. They live throughout eastern US forests and have a flattened tail that aids their gliding ability. They are nocturnal, feeding on nuts, seeds, fruits and insects at night. Their nests are built in the cavities of snags or logs on the forest floor.
The Most Common overall is the Eastern Gray Squirrel
While a variety of tree squirrels inhabit different regions of the country, the eastern gray squirrel is the most widespread and frequently encountered. They thrive in urban areas as well as large tracts of oak-hickory forest. Eastern grays have adapted readily to human settlements, nesting in buildings and foraging everywhere from parks to backyards. Their intelligent behavior and energetic antics make them fun to observe, even when they are sometimes considered pests. Protecting mature trees and woodland habitats ensures these common North American rodents have space to play, feed and nest.
Conclusion
In summary, the eastern gray squirrel is the most ubiquitous tree squirrel across the continental United States due to its vast range and ability to thrive around humans. Fox squirrels and American red squirrels rank next in terms of abundance and distribution. Identification of squirrels in your neighborhood provides useful clues into the health of local wooded areas. Though they sometimes get into mischief, squirrels bring life and nature to both rural and urban settings for our enjoyment.
| Species | Range | Size | Habitat |
|---|---|---|---|
| Eastern gray squirrel | Eastern US | 17-20 in | Forests & urban areas |
| Fox squirrel | Central & SW US | 18-27 in | Open woodlands |
| American red squirrel | Northern & mountain forests | 7-12 in | Conifer forests |
| Abert’s squirrel | Southwestern US | 19-23 in | Ponderosa pine forests |
| Southern flying squirrel | Eastern US forests | 5-6 in | Hardwood & mixed forests |
