There are over 200 species of squirrels that can be found worldwide, with the vast majority living in tropical regions. In North America, there are 5 main types of tree squirrels and 6 species of ground squirrels that can be found throughout the United States and Canada. The most common species of tree squirrel include the eastern gray squirrel, fox squirrel, red squirrel, Douglas squirrel, and American red squirrel. The major ground squirrel species include the California ground squirrel, rock squirrel, Franklin’s ground squirrel, thirteen-lined ground squirrel, Mexican ground squirrel, and Arctic ground squirrel. Each species occupies a distinct geographical range and fills an important ecological niche.
Tree Squirrels
Tree squirrels get their name from the fact they spend most of their time in trees. They have bodies that are suited to climbing and leaping through the branches with sharp claws, ankle joints that can rotate 180 degrees, and long balancing tails. Tree squirrels build nests, called dreys, in the branches of trees using leaves, twigs, bark, and other materials. Here are the 5 types of tree squirrels found in North America:
Eastern Gray Squirrel
The eastern gray squirrel is the most common and frequently observed tree squirrel in the eastern and midwestern regions of North America. Some key facts about the eastern gray squirrel include:
- Range covers all states east of the Mississippi River up to the Dakotas, Nebraska, and Kansas
- Habitats include mature forests of oak, hickory, walnut, pine and spruce
- Two color variations: gray and black
- Grows up to 20 inches long with a large, bushy tail
- Omnivorous; eats nuts, seeds, acorns, fungi, and insects
- Nests are called dreys and made of leaves in tree branches
- Has doubled its range in the last 100 years, largely due to forest fragmentation
The eastern gray is a prolific breeder and has adapted extremely well to living in close proximity to humans in urban and suburban environments. They are considered a nuisance species in some areas.
Fox Squirrel
The fox squirrel is aptly named for its reddish-brown fur that resembles the color of a red fox. Here are some facts about this tree squirrel:
- Largest species of tree squirrel native to North America
- Weighs up to 2 pounds and measures 18 inches long
- Inhabits open woodlands, especially those with oak, walnut, and hickory
- Most abundant in prairie states and plains of the Midwest
- Omnivorous; eats seeds, nuts, acorns, berries, buds, insects, fungi
- Makes leaf nests and may take over abandoned woodpecker holes
- Has a long breeding season from December to June
Fox squirrels tend to forage on the ground more than other tree squirrels. They have been expanding their range eastward across North America since colonial times. These squirrels are solitary and defend territories.
Red Squirrel
The North American red squirrel goes by several common names including the pine squirrel, chickaree, and American red squirrel. Here are some features of this rodent:
- Small-sized tree squirrel with a body 5 to 9 inches long
- Tail is about 4 to 7 inches long with red-tipped hair
- Ranges across Canada, Alaska, the Pacific Northwest, and New England
- Inhabits coniferous forests, especially pine, spruce, and fir trees
- Builds a nest called a drey high up in evergreen trees
- Hoards pine cones in a central cache called a midden
- Territorial and consumes pine nuts, conifer seeds, nuts, fruit, fungi
- Most active in the early morning and late afternoon
The chickaree call of this squirrel sounds like a repeated vocal trill. The American red squirrel is feisty and defends its territory aggressively.
Douglas Squirrel
Also referred to as the chickaree or pine squirrel, the Douglas squirrel is a small tree squirrel found along the Pacific Coast. Facts about this rodent include:
- Native to the forests of the Pacific Northwest
- Closely related to and resembles the American red squirrel
- Distinctive reddish coat on sides, black on top, white underside
- Grows up to 11 inches long including its 4 to 6 inch tail
- Feeds primarily on conifer seeds like pine nuts and hidden caches
- Territorial, makes nests of twigs high up in fir and pine trees
- Emits a rattling, bird-like call
The Douglas squirrel is an agile climber that depends on old growth forests of fir and pine. Its population declined due to extensive logging but has recovered in some protected habitats.
American Red Squirrel
The American red squirrel is a small North American rodent with red fur, found across Canada, Alaska, and the Rocky Mountains. Key characteristics include:
- Small body from 5 to 9 inches long plus a 3 to 7 inch tail
- Reddish coat top and sides, white below
- Inhabits coniferous forests with spruce, pine, and fir trees
- Builds nests high up in evergreens called dreys
- Hoards pine cones in middens on the forest floor
- Territorial and consumes nuts, fungi, berries, insects
- Makes a rattling “chickaree” vocalization
The American red squirrel is an important part of the boreal ecosystem. Its populations are threatened by deforestation and climate change affecting its food sources.
Ground Squirrels
In contrast to tree squirrels, ground squirrels live primarily on the ground rather than climbing trees. They dig burrows for shelter and hibernation. Ground squirrels are prolific diggers and their burrows provide habitat for other species. Here are the major types of ground squirrels found in North America.
California Ground Squirrel
The California ground squirrel is one of the most common rodents on the west coast. Some facts about it include:
- Grayish coat with flecks of light fur
- Head and body length reaches 11 inches
- Tail is about 7 inches long with white edges
- Inhabits open grasslands, pastures, and disturbed habitats
- Digs burrows up to 30 feet long with multiple entrances
- Omnivorous; eats plants, seeds, fungi, eggs, insects
- Hibernates several months during the winter
California ground squirrels are very social and communicate with a variety of whistles and chatters. They can climb bushes and structure to survey their colony.
Rock Squirrel
The appropriately named rock squirrel inhabits rocky canyons, outcrops, and slopes. Some key facts about it include:
- Large ground squirrel with a body up to 17 inches long
- Long, thick bushy tail adds another 9 to 12 inches
- Coat varies in color but is commonly grayish brown
- Native to the southwestern United States and Mexico
- Spends time sunning on rocks near its burrow
- Eats nuts, fruits, seeds, cacti, eggs, baby birds
- Breeds during spring and summer
Rock squirrels are adept rock climbers and have been observed leaping up to 10 feet between structures. They produce a variety of whistles and barks.
Franklin’s Ground Squirrel
Franklin’s ground squirrel inhabits shortgrass prairies and fields at high elevations. Some key features include:
- Small ground squirrel with body 5 to 7 inches long
- Tail measures about 2 to 3 inches
- Gray fur on top, pale underside with cinnamon hints
- Named after explorer Sir John Franklin
- Digs burrows up to 6 feet deep
- Feeds on roots, shoots, seeds, insects
- Hibernates for 7 or 8 months each year
Franklin’s ground squirrel is active during the day and is preyed upon by hawks, coyotes, snakes, and other predators. It emits a short whistle when alarmed.
Thirteen-Lined Ground Squirrel
The thirteen-lined ground squirrel, also known as the squinnie, is uniquely named for the 13 alternating brown and white stripes along its back. Further facts include:
- Small ground squirrel with body length of 5 to 8 inches
- Tail is about 2.5 inches long
- Inhabits grasslands and prairies of central North America
- Digs burrows up to 15 feet long for shelter and hibernation
- Feeds on seeds, roots, caterpillars, beetles, grasshoppers
- Runs rapidly with its tail straight up
- Chatters and gives shrill whistle warnings
The thirteen-lined ground squirrel’s stripes provide camouflage in tall grasses. It is one of the most common ground squirrels in its range.
Mexican Ground Squirrel
The Mexican ground squirrel occupies arid habitats in the southwestern US and Mexico. Some features include:
- Small ground squirrel with body up to 9 inches long
- Yellowish-gray fur with flecked pattern
- Inhabits desert scrublands, prairies, pasturelands
- Digs burrows in flat, open areas
- Feeds extensively on mesquite beans and fallen seeds
- Breeds during warm rainy season
- Emits a sharp whistle when alarmed
The Mexican ground squirrel’s fur provides camouflage among scattered desert plants and soil. They are active during the day and remain in their burrows in hot or cold weather.
Arctic Ground Squirrel
The arctic ground squirrel, also known as the parka or sik-sik, occupies the tundra of Alaska, Canada, and Siberia. Some interesting facts include:
- Small ground squirrel with a body length under 12 inches
- Fur is brown-gray on top in summer, all white in winter
- Digs extensive burrows that remain below freezing year-round
- Enters hibernation from September to April
- Feeds on roots, leaves, berries, lemmings, bird eggs
- Sociable and entertains with tails straight up
The arctic ground squirrel must put on substantial fat reserves for its winter hibernation under the snow. Groups will stand and monitor for predators before feeding.
Conclusion
In summary, North America is home to 5 major species of tree squirrels and 6 primary types of ground squirrels. Tree squirrels include the eastern gray, fox, red, Douglas, and American red. Ground squirrels include the California, rock, Franklin’s, thirteen-lined, Mexican, and arctic species. Each fills an ecological role and has adapted to thrive in its environment and despite predators. While squirrels play an important part in nature, some species like the eastern gray are seen as pests by humans in urban areas. Proper wildlife management is needed to balance the needs of squirrels and people in shared spaces.
| Squirrel Type | Species | Region |
|---|---|---|
| Tree Squirrel | Eastern gray squirrel | Eastern and midwestern US |
| Tree Squirrel | Fox squirrel | Midwest and plains states |
| Tree Squirrel | Red squirrel | Canada, Alaska, Pacific Northwest, New England |
| Tree Squirrel | Douglas squirrel | Pacific Northwest |
| Tree Squirrel | American red squirrel | Canada, Alaska, Rocky Mountains |
| Ground Squirrel | California ground squirrel | Western US |
| Ground Squirrel | Rock squirrel | Southwestern US and Mexico |
| Ground Squirrel | Franklin’s ground squirrel | Northern prairies and fields |
| Ground Squirrel | Thirteen-lined ground squirrel | Central grasslands and prairies |
| Ground Squirrel | Mexican ground squirrel | Southwestern US and Mexico |
| Ground Squirrel | Arctic ground squirrel | Alaska, Canada, Siberia |