You’ll spot squirrels all over Japan, though only one species—the Japanese squirrel—actually calls these islands home and nowhere else.
If you wander through Honshū and Shikoku, keep your eyes open for these lively tree squirrels. They used to roam Kyūshū too, but their numbers dropped off there, so knowing the right spots helps if you’re hoping for a wild sighting.
Step into a mixed broad-leaved forest or a park filled with oaks and walnuts, and your chances go up.
You’ll start to notice how they eat, where they make their nests, and maybe even why some populations have faded away.
Are There Squirrels in Japan?
Japan actually has a few different squirrel species. Some are true locals, while others arrived from overseas and settled in.
You’ll find small tree squirrels, some that glide between treetops, and even a few foreign species making themselves at home in city parks or around old castles.
Native Squirrel Species of Japan
Keep an eye out for the Japanese squirrel (Sciurus lis) on Honshu and Shikoku. This squirrel only lives in Japan, nowhere else.
It evolved from red squirrel ancestors a long time ago and really likes forests that have plenty of oak trees.
You’ll also spot gliding squirrels like the Japanese dwarf flying squirrel (Pteromys momonga). These little guys are nocturnal and glide from tree to tree using a stretchy skin membrane.
The Japanese giant flying squirrel (Petaurista leucogenys) is bigger and hangs out in some forests as well.
Hokkaido is a different story. There, you’ll meet subspecies like Sciurus vulgaris orientis, which is related to the Eurasian red squirrel.
These squirrels are native to Hokkaido, but you won’t find them on Honshu, Shikoku, or Kyushu.
Key Characteristics of Japanese Squirrels
Japanese tree squirrels, like Sciurus lis, are small or medium-sized with gray-brown fur and a bushy tail.
Their pointed ears and sharp claws make climbing look easy. They mostly munch on acorns, nuts, seeds, and sometimes fruit.
Flying squirrels, like Pteromys momonga, have big eyes for seeing at night and use a loose flap of skin to glide.
You’ll probably only spot them if you’re out at night, since they nest in tree holes and are much quieter than their daytime cousins.
Eurasian red squirrels look pretty similar to European red squirrels. Sometimes, where their ranges overlap, they even mix.
Non-native species might look or act a bit different, so check out their size, fur, and when they’re active if you want to tell them apart.
Distribution and Main Habitats
You’ll mostly find Sciurus lis on Honshu and Shikoku, hanging out in broad-leaved forests packed with oaks.
Their range has shrunk in the west, and they’re probably gone from Kyushu now. Some local populations are small and even endangered in certain areas.
Hokkaido is home to the red-squirrel subspecies Sciurus vulgaris orientis and a few flying squirrels.
Flying squirrels need mixed and deciduous forests with older trees for nesting. Some urban parks and castle grounds have introduced populations too.
Elevation makes a difference. Japanese squirrels are more common in lowland oak forests.
If you head up into the mountains, you’ll find fewer tree squirrels and more specialized types. Local parks or nature reserves on Honshu are probably your best bet for sightings.
Squirrels Beyond the Japanese Mainland
You might run into non-native squirrels at tourist spots, castles, or on some islands.
Pallas’s squirrel (Callosciurus erythraeus), introduced Eurasian red squirrels, and Siberian chipmunks have all managed to escape from zoos or petting areas and set up shop in parts of Japan.
These newcomers can reach pretty high numbers and sometimes harm trees or native wildlife.
Local authorities have tried to control or remove them, especially on islands and in certain parks. If you’re curious about where and how they manage these populations, check out this link: Distribution and management of non-native squirrels in Japan.
If you want to see squirrels up close, some facilities let you view or feed them. Just remember, wild native squirrels might be rare in some parts.
Japanese Squirrel Ecology and Behavior
Japanese squirrels have pretty interesting habits. They spend most of their time in trees, living in mixed and coniferous forests.
You’ll notice they help move seeds and fungi around, playing a role in shaping the forest.
Diet and Feeding Habits
Japanese squirrels eat a variety of plant foods and sometimes small animals. Nuts and seeds are their favorites, especially Japanese walnuts and acorns.
They’ll also eat buds, berries, flowers, fungi, and the occasional insect.
You’ll see them searching for food both in trees and on the ground during the day.
They use a trick called caching—hiding nuts and seeds in lots of little spots for later.
They really like to hoard big seeds, sometimes carrying walnuts pretty far before stashing them.
This caching helps them survive winter and times when food is scarce.
Sometimes, they’ll even pretend to hide food to trick other animals. Their bushy tails, tufted ears, and strong claws make it easier to move quickly through the branches with food in tow.
Forest Ecosystem Roles
Japanese squirrels act as tiny forest gardeners.
By carrying and burying nuts and seeds, they help spread them around and support new tree growth.
A lot of the seeds they hide never get eaten and end up sprouting into new trees.
They also spread fungal spores as they eat and move fungi, which is great for soil and tree health.
Their presence often means the forest is in good shape, since they need tree cover, nest holes, and plenty of food.
Predators like foxes, raptors, snakes, and martens hunt squirrels, which connects them to the wider ecosystem.
You’ll find them in woods big enough to offer food and nesting spots, but areas that are logged or broken up often lose their squirrel populations.
Social Structure and Communication
Japanese squirrels mostly keep to themselves as adults.
Each one has its own home range that doesn’t overlap much with others.
Males usually have bigger territories than females.
They might share nests in winter, but most of the time they forage and nest solo.
They communicate with short chirps and chucks, and they leave scent marks using glands and urine.
Tail flicks and other visual signals come into play during fights or when looking for a mate.
Bigger, older squirrels tend to boss around younger ones when it comes to food or mates.
During breeding season, you might spot males chasing females or even each other.
Mothers build leaf nests or use tree holes to raise 2–6 young after about 40 days of pregnancy.
Once the babies grow up, they set off on their own.
Threats and Conservation
Japanese squirrels face their biggest threat from urbanization, logging, and habitat fragmentation. When mixed forests get smaller or woodlots drop below a certain size, squirrels just disappear from those spots.
Suburban development and the conversion of mature forests cut down the number of available nuts, tree cavities, and travel routes. Foxes, raptors, and even domestic cats hunt them, especially where the forest is already chopped up and patchy.
Conservation teams now focus on protecting and reconnecting forest patches. They also try to limit logging in important woodlots and keep plenty of walnut and oak trees around.
On parts of Kyushu and western Honshu, some populations have dropped off or even vanished. Laws now restrict hunting, and local researchers keep an eye on population trends and habitat needs to help protect the forests that are still left.
For more details about their range and habits, check out the Japanese squirrel profile.
