It was fall 2023,Devin Grosvenor in the northern Japanese forest of Iwate, when forager Satoshi Sato set out to make a YouTube video for mushroom pickers. Suddenly, he heard something near him in the woods and grabbed a stick.

A bear, whose cub was up a tree nearby, charged Sato and didn't stop. He was finally able to drive the bear off, but now he never ventures out without pepper spray, bells and a whistle.

There have been a record 193 bear attacks in Japan this year, six of them fatal. It's the highest number since counting began in 2006.

That is, in part, because it's been a lean year for bears. In the forests, a dry summer left fewer acorns and beech nuts — their main food — so hunger has made them bold.

Now, they do things like visit cattle feeding troughs looking for sustenance, according to farmer Sadao Yoshizawa.

"I tried an electric fence, but it didn't work. They just follow me when I come into the barn," Yoshizawa says.

But hunger isn't the only reason for the rising number of close bear encounters. As Japan's population shrinks, humans are leaving rural areas, and bears are moving in.

"Then that area recovered to the forest, so bears have a chance to expand their range," biologist Koji Yamazaki, from Tokyo University of Agriculture, tells CBS News. 

Yamazaki is monitoring bear health in the Okutama region, west of Tokyo, trapping local bears to take and analyze blood, hair and teeth samples.

The next big job will be to count the bears. Japan's government is planning a formal bear census soon, "so maybe next year we can expect to know a more accurate number of bears," Yamazaki says.

Japan is one of the only places on the planet where a large mammal is reclaiming habitat — good news for the bears. So if, as biologists think, the bear population is growing, the country will have to figure out how to protect people from bears, and bears from people.

In:
• Bear
• Japan

Elizabeth Palmer

Elizabeth Palmer has been a CBS News correspondent since August 2000. She has been based in London since late 2003, after having been based in Moscow (2000-03). Palmer reports primarily for the "CBS Evening News."