Japan's macaque population is thriving, in large part because conservation efforts started after World War II have been a tad too successful.
The population recovery has paradoxically "provoked and intensified" human-macaque conflicts to the point where people living near the animals now face serious risks of having their own habitats invaded, Hiroto Enari, a primate expert, wrote in a recent study.
The Yamaguchi attacks are unusually dramatic, said Enari, who teaches wildlife management at Yamagata University.
"But if humans give them many opportunities to learn, they might cause more conflict," he said.
Each attack, he added, essentially gives monkeys a chance to study the art of being a nuisance — by removing roof tiles, say, or terrorising garbage dumps. He said the most serious concern is that the animals could spread hepatitis B or other diseases to humans.
Human-monkey conflicts are not new to Asia, a region that has billions of people and a plethora of native macaque species.
In India, rhesus macaque monkeys are viewed as a representation of a Hindu deity. Municipal efforts to eradicate them from the capital, New Delhi, must walk a fine line to avoid triggering a public outcry. Before President Barack Obama visited in 2015, men with slingshots tried to frighten the monkeys off by shrieking and barking.
In Thailand, the city of Lopburi has been under siege for years from crab-eating macaques, a Southeast Asian species. They became more aggressive during the coronavirus pandemic because their main providers of food — tourists — suddenly disappeared.
And in Singapore, where a monkey invasion of an apartment complex was in the news, the National Parks Board said that it would try to stop the chaos by "monkey guarding" the compound: blocking the monkeys' approach and herding them toward forested areas.
The Japanese macaque, or snow monkey, is the world's northernmost nonhuman primate species. Being one in the early 20th century was a tough gig: Humans would have hunted you for food and used your body parts to make traditional medicine.
After World War II, the population was in such critical condition that Japan's government ordered people not to hunt them.
This enabled the Japanese macaque population to rebound, according to Enari's recent study for the journal Mammal Study. The government also restored forests near human settlements, he wrote, producing "rich food resources" for the animals.
Now Japanese macaques generally have enough to eat and lots of nice wetland habitats to hang around in. And some of them pretty much terrorise humans whenever they please.
Although approximately 25,000 monkeys are now killed each year in Japan, mostly by municipalities, hunting them remains illegal, Enari said. But recent surveys suggest that the population is still growing nationwide. He said one reason appears to be that monkeys are moving into abandoned areas near rural communities with shrinking human populations.
Yamaguchi, the western city near Hiroshima where macaques have bitten and scratched dozens of people in recent weeks, may be a perfect staging ground for monkey attacks: Its residential neighbourhoods are sandwiched between hills and mountains.
"I don't know if something is happening in the mountains," Masato Saito, an official with the city's agricultural policy division, said in an interview. "It's hard for us humans to know."
Still, he said, it was clear that a line had been crossed.
"It might be acceptable and understandable if they just ate agricultural crops alone," Saito said. "But if they harm humans, we need to do something."
Sure enough, this week, after some traps that the humans had set for the monkeys failed, the Yamaguchi authorities deputised an agent to shoot to kill.
This article originally appeared in The New York Times.
Written by: Hisako Ueno and Mike Ives
© 2022 THE NEW YORK TIMES
