Mount Fuji Has Its Own Secret Bear Population — And Scientists Are Still Figuring It Out

There’s something living in the forests around Mount Fuji that most people probably don’t think about when they picture the mountain: Asiatic black bears.

The bears here aren’t simply part of one large population spread across central Japan. Researchers refer to them as the Fuji regional population (富士地域個体群), and they’ve been separated from other bear populations in the area for quite some time.

Geography has a lot to do with it. Rivers, roads, and the development around the foot of the mountain have gradually made it harder for bears to move between habitats. Their range has become increasingly isolated as a result.

Shizuoka Prefecture’s Red Data Book, which tracks threatened species and populations in the prefecture, lists the Fuji population as an “endangered regional population.” A survey carried out by the prefecture two years ago estimated that around 100 bears remained in the area.

For years, this has mostly been a conservation issue that stayed out of sight. This year, though, people have been seeing the bears much more often.

Susono, on the Shizuoka side of Mount Fuji, is one example. In late May, bears were reported there on seven consecutive days. There had been no sightings in the same area during that period the previous year. The number of reports in the city was approaching 20 by that point, something the mayor said had never happened before.

Even local hunters were surprised. Some said they might normally encounter a bear once a year, if that.

There have been sightings on the Yamanashi side too. In late June, a hunter checking a deer trap in Fujikawaguchiko came across an adult bear in the forest. It was estimated to be about a meter long and was only around 100 meters from a nearby house.

That has changed how some people use the trails in the area. Paths that residents would normally walk without thinking much about are being treated a little more cautiously now.

The strange thing is that nobody can really say yet what is behind the increase.

It could be food. It could be young bears moving farther from where they were born. It could simply be that people happened to encounter them more often this year. And there’s another possibility: the population itself may be changing.

A bear ecologist at Tokyo University of Agriculture and Technology has pointed out that there isn’t enough evidence yet to say whether the Fuji population is actually increasing or simply remaining stable. A busy year for sightings doesn’t necessarily tell us which is happening.

Either way, the bears are there.

If you’re spending time in the forests around the foot of Mount Fuji, it’s worth keeping that in mind. I’m talking about the lower wooded areas and walking trails, including some of the paths around Kitaguchi Hongu Fuji Sengen Shrine, rather than the climbing route above the 5th station.

A few things are worth doing.

• Carry a bear bell or make some noise with a radio while walking. Bears generally prefer to stay away from people and will often move off if they know someone is approaching.
• Don’t leave food or rubbish behind. A bear that finds an easy meal around people can learn to come back looking for another one.
• If you see a bear from a distance, don’t run. Keep facing it, move away slowly, and give it plenty of room.

That doesn’t mean you should be nervous every time you walk around Fuji. Most people who spend time in these forests will never see a bear. That’s still the most likely outcome.

But I think it’s one of those details that makes the area more interesting. Mount Fuji is so familiar that it’s easy to forget how much is happening around the mountain itself. There’s a small, isolated population of bears living in those forests, researchers are still trying to understand exactly how it is changing, and this year they suddenly started showing themselves a lot more.

For a place that gets millions of visitors every year, there are still quite a few things around Fuji that most people never notice.