There are an estimated 279 species of squirrels in the world. They live on every continent, except Antarctica. North America is home to 68 squirrel species. The exact squirrel population is unknown, but estimates are between 4-10 billion.
The squirrel population is difficult to measure. They live all over the world, so the best we can do is an estimate.
What we do know is that wherever squirrels are found, they face challenges. Some squirrel populations are thriving while others are in decline.
Why are some squirrel populations growing and others declining?
To find out, let’s look at where squirrels live, where they don’t, and what makes some squirrels invasive species while others are close to being endangered.
How Many Species of Squirrels Are There in the World
Different types of tree squirrels, flying squirrels, and ground squirrels make up the estimated 279 species of squirrels in the world. They are native to every continent except Antarctica and Australia.
There are three main types of squirrels:
- Tree squirrels
- Ground squirrels
- Flying squirrels
Here are the current numbers of each type:
- 115 species of ground squirrels.
- 50 species of flying squirrels.
- 28 species of tree squirrels.
The Five Squirrel Subfamilies
Tree squirrels, ground squirrels, and flying squirrels fall into one of the following five subfamilies:
- Ratufinae
- Sciurillinae
- Sciurinae
- Xerinae
- Callosciurinae
Ratufinae

This is the subfamily of giant squirrels, like Indian giant squirrels (Ratufa indica) and black giant squirrels (Ratufa bicolor).
Sciurillinae

This is the subfamily of pygmy squirrels, These are the smallest squirrels in the family and
include the likes of the mouse-sized African pygmy squirrel (Myosciurus pumilio).[1]
Sciurinae
This subfamily encompasses tree squirrels and flying squirrels. There are 28 species of tree squirrels in the world[2] and about 50 species of flying squirrels.
They live across North America, Central America, Southeast, and northern Asia, Siberia, and Scandinavia.[3]
This includes the common eastern gray squirrels (Sciurus carolinensis), American Red squirrels (Tamiasciurus hudsonicus), and Southern Flying Squirrels (Glaucomys volans).
Callosciurinae
This is a subfamily of Asian squirrels native to Southeast Asia.
Where Do Squirrels Live in the World?
Squirrels are native to every continent, except Australia and Antarctica. Today, they are found on every continent, except Antarctica.
Besides Antarctica, squirrels do’nt live in Madagascar, Greenland, southern South America, many oceanic islands (like Hawaii), and deserts.
North America is home to 68 squirrel species. Some of these squirrels have migrated and spread, sometimes naturally and often by way of import.
Today, one of North America’s most prevalent native tree squirrels (the eastern gray squirrel) is considered an invasive species in the following countries:
- England
- Scotland
- Ireland
- Italy
Eastern Gray Squirrels in Great Britain

Imported from the eastern parts of North America in the Victorian era, the gray squirrel has colonized 90% of England and Wales.
They are an invasive species because they threaten the survival of the native Eurasian red squirrel.[7]
According to the European Squirrel Initiative (ESI), gray squirrels damage trees by removing bark. They displace native red squirrels by out-competing them for food and infecting them with the squirrel pox virus.
Eastern gray squirrels are unaffected carriers of squirrel pox, a virus that is fatal to red squirrels.[8]
Invasive Eastern Gray Squirrels in Italy
Eastern gray squirrels are also found in Ticino Valley in Lombardia, Italy.
They found their way to Italy in 1948 when a U.S. ambassador gifted someone four gray squirrels. The pet squirrels escaped and the population of gray squirrels has been growing ever since.
Eurasian red squirrel conservationists estimate that gray squirrels in Italy will extend into Switzerland in 20 years.[9]
Are There Squirrels In Australia?
Squirrels are not native to Australia, but three species of squirrels were introduced in the late 1800s. One of the species is now extinct in Australia.
In many colonized continents, early settlers planted familiar trees and introduced squirrels. This was done to replicate their gardens and parks from home. [10]
Eastern gray squirrels were introduced in Melbourne in 1880. The species is now extinct in the country.
Indian palm squirrels (Funambulus palmarum) and northern palm squirrels (Funambulus pennantii) were introduced to Perth in 1898. Both species have continued to thrive in Australia ever since.[11]
North palm squirrels have become pests in Perth, particularly on local citrus and stone fruit farms. The population of this non-native squirrel is growing as they have few natural predators.

How Many Squirrels Are in the U.S?
There are 68 squirrel species in the U.S. This include several ground squirrels, chipmunks, flying squirrels, tree squirrels, marmots, and prairie dogs living in North America.
Here is a list of squirrels that live in North America:[11]
- Eastern Chipmunk
- Eastern Gray Squirrel
- Northern Flying Squirrel
- Red Squirrel
- Southern Flying Squirrel
- Woodchuck
- Abert’s Squirrel
- Alaska Marmot
- Allen’s Chipmunk
- Alpine Chipmunk
- Arctic Ground Squirrel
- Arizona Gray Squirrel
- Belding’s Ground Squirrel
- Black-Tailed Prairie Dog
- California Chipmunk
- California Ground Squirrel
- Cascade Golden-Mantled Ground Squirrel
- Cliff Chipmunk
- Colorado Chipmunk
- Columbian ground squirrel
- Douglas’ Squirrel
- Fox Squirrel
- Franklin’s Ground Squirrel
- Golden-Mantled Ground Squirrel
- Gray-Collared Chipmunk
- Gray-Footed Chipmunk
- Gunnison’s Prairie Dog
- Harris’s Antelope Squirrel
- Hoary Marmot
- Hopi Chipmunk
- Idaho Ground Squirrel
- Least Chipmunk
- Lodgepole Chipmunk
- Long-Eared Chipmunk
- Merriam’s Chipmunk
- Merriam’s Ground Squirrel
- Mexican Fox Squirrel
- Mexican Ground Squirrel
- Mohave Ground Squirrel
- Nelson’s Antelope Squirrel
- Olympic Marmot
- Palmer’s Chipmunk
- Panamint Chipmunk
- Piute Ground Squirrel
- Red-Tailed Chipmunk
- Richardson’s Ground Squirrel
- Rock Squirrel
- Round-Tailed Ground Squirrel
- Siskiyou Chipmunk
- Sonoma Chipmunk
- Spotted Ground Squirrel
- Texas Antelope Squirrel
- Thirteen-Lined Ground Squirrel
- Townsend’s Chipmunk
- Townsend’s Ground Squirrel
- Uinta Chipmunk
- Uinta Ground Squirrel
- Utah Prairie Dog
- Vancouver Marmot
- Washington Ground Squirrel
- Western Gray Squirrel
- White-Tailed Antelope Squirrel
- White-Tailed Prairie Dog
- Woodchuck
- Wyoming Ground Squirrel
- Yellow-Bellied Marmot
- Yellow-Cheeked Chipmunk
- Yellow-Pine Chipmunk
Migrating Squirrels In North America
Urbanisation, the loss of natural habitats, and climate change have been blamed for some squirrel species migrating to other areas.
This is causing problems for biodiversity.
Southern flying squirrels are migrating from their native home in the eastern half of the United States to the northern parts. They are currently taking over regions once abundant with northern flying squirrels.
It’s believed that climate change could be to blame for their migration.[12]
The presence of southern flying squirrels puts pressure on the endangered northern flying squirrels. This is because southern flying squirrels carry an intestinal parasite (Strongyloides robustus) that is fatal in northern flying squirrels.[13]
What’s more, the decline of the northern flying squirrel has an impact on an entire ecosystem.
Northern flying squirrels eat specific fungi found on conifer trees and disseminate the spores in their scat. The fungus helps conifer trees absorb nutrients and moisture.
Without the northern flying squirrels, old conifer forests (and all the creatures dependent on them) could be in danger too.

New Species of Squirrels Discovered
New species of squirrels are often discovered. This is due to their high reproduction rates, biodiversity, and ever-improving human technology.
New flying squirrel species discovered:
- Humboldt’s flying squirrels
- Tibetan woolly flying squirrel
- Yunnan woolly flying squirrel
The Discovery of Humboldt’s Flying Squirrels
While studying northern flying squirrels’ DNA in 2017, scientists discovered a new flying squirrel living with northern flying squirrels in Oregon.
They named it the Humboldt’s flying squirrels (Glaucomys oregonesis).
This species was thought to be a lineage of the northern flying squirrel but the DNA showed it to be a different species.[14]
As it turns out, Humboldt flying squirrels aren’t a new species at all. They predate northern flying squirrels by 300,000 years.
All this time people have mistaken them for northern flying squirrels because they look alike. Humboldt’s flying squirrels are only slightly smaller and darker.[15]
The Discovery of Tibetan and Yunnan Woolly Flying Squirrels
In 2021, scientists from the Australian Museum Research Institute discovered that the world’s largest squirrel, the woolly flying squirrel, is two different species:
- The Tibetan woolly flying squirrel (Eupetaurus tibetensis)
- The Yunnan woolly flying squirrel (Eupetaurus nivamons)
Years ago, woolly flying squirrels were believed extinct. They were rediscovered in the 1990s.
Now, thanks to the latest research, we know that they are two different species and that they live thousands of miles apart around the Himalayas.[16]