Squirrels are rodents belonging to the family Sciuridae. They can be found across most of the world, with the exception of Australia and Antarctica. There are many different varieties of squirrels, ranging from the familiar tree squirrels to the lesser known ground squirrels, flying squirrels and chipmunks. In this article, we will take a look at the diversity of squirrel species and examine how many varieties exist globally.
Tree Squirrels
The tree squirrels are the most commonly seen type of squirrel in many parts of the world. Tree squirrels live primarily in trees, as their name suggests, and make nests called dreys high up in the branches.
Some of the most widespread tree squirrel species include:
| Common Name | Scientific Name |
|---|---|
| Eastern gray squirrel | Sciurus carolinensis |
| Red squirrel | Sciurus vulgaris |
| Fox squirrel | Sciurus niger |
| Eurasian red squirrel | Sciurus vulgaris |
The eastern gray squirrel is one of the most ubiquitous tree squirrels, found throughout the eastern United States as well as parts of Canada. They have predominantly gray fur with white undersides. The similarly named western gray squirrel is found along the west coast.
The red squirrel is common throughout northern Europe and Asia. They have distinctive reddish fur over much of their body. The American fox squirrel is the largest tree squirrel native to North America and lives in open woodlands.
In all, there are over 200 species of tree squirrels worldwide. They occupy a range of forest habitats from temperate broadleaf forests to tropical rainforests. The diversity of tree squirrels reflects their wide distribution across several continents.
Ground Squirrels
In contrast to tree squirrels, ground squirrels live primarily on the ground rather than climbing trees. They make burrows underground where they sleep, store food and raise young.
Ground squirrels are highly social animals that live in large colonies. Here are some examples of common ground squirrel species:
| Common Name | Scientific Name |
|---|---|
| California ground squirrel | Otospermophilus beecheyi |
| Columbian ground squirrel | Urocitellus columbianus |
| European ground squirrel | Spermophilus citellus |
| Franklin’s ground squirrel | Poliocitellus franklinii |
The California ground squirrel inhabits grasslands and open areas along the west coast of North America, while the Columbian ground squirrel occupies alpine meadows in parts of the northwestern United States and Canada.
Franklin’s ground squirrel lives primarily in the tallgrass prairies of North America. The European ground squirrel is found across eastern Europe and parts of Asia. In all there are around 65 species in the ground squirrel genus Spermophilus.
Flying Squirrels
As their name suggests, flying squirrels are capable of gliding flight. They have an extra fold of skin called the patagium that extends between their front and hind legs, essentially giving them wings to glide between trees.
Some flying squirrel species include:
| Common Name | Scientific Name |
|---|---|
| Southern flying squirrel | Glaucomys volans |
| Northern flying squirrel | Glaucomys sabrinus |
| Japanese giant flying squirrel | Petaurista leucogenys |
| Red giant flying squirrel | Petaurista petaurista |
The southern and northern flying squirrels are the only two flying squirrel species found in North America. The southern species inhabits forests in the eastern half of the United States, while the northern flying squirrel occupies coniferous forests across much of Canada and parts of the northern U.S.
The Japanese giant flying squirrel is one of the largest flying squirrel species, reaching up to 1.5 feet in length. It glides among the treetops of dense broadleaf and coniferous forests on the islands of Japan. There are around 50 species of flying squirrels total.
Chipmunks
Chipmunks are small, striped squirrels native to North America and Asia. They are closely related to ground squirrels but are classified in their own genus, Tamias. Some examples include:
| Common Name | Scientific Name |
|---|---|
| Eastern chipmunk | Tamias striatus |
| Least chipmunk | Tamias minimus |
| Siberian chipmunk | Tamias sibiricus |
The eastern chipmunk is widespread in woodlands and suburban areas of eastern North America. The least chipmunk is the smallest chipmunk species found across western North America.
As its name indicates, the Siberian chipmunk occupies forest habitat across northern Asia. There are over 20 species of chipmunks in total, mostly native to North America and Eurasia.
Conclusion
When all the varieties are totaled, there are an estimated 275 species of squirrels worldwide. This includes:
– 200+ species of tree squirrels
– 65 ground squirrels
– 50 flying squirrels
– 20+ chipmunks
Squirrels occupy a wide range of habitats globally thanks to their diversity. From the familiar urban gray and fox squirrels to the lesser known marmots and prairie dogs, squirrels can be found on every continent except Australia and Antarctica. Their great adaptability has allowed them to thrive in both forests and open country around the world.