Experts Sound the Alarm on the Rapid Rise of “Urban Wildlife” in Tokyo’s 23 Wards! The Surprising Reason Why “Vacant Homes Are Becoming New Hotbeds”

When people hear the term “wild animals,” many probably think of bears and other creatures that appear in mountainous areas. However, wild animals such as raccoons and Asian palm civets are now expanding their habitats into residential areas within Tokyo’s 23 wards.

According to the Tokyo Metropolitan Government’s Bureau of Environment, raccoons are expanding their range into the city’s 23 wards, and the presence of Asian palm civets has already been confirmed in nearly all of them. Videos of wild animals filmed in residential areas and near train stations frequently go viral on social media, with many people expressing surprise, asking, “Why here, in the city?”

While bear attacks on people are occurring one after another across the country, a completely different kind of wildlife is quietly gaining a foothold in urban areas. Why are raccoons and Asian palm civets increasing in Tokyo’s 23 wards?

The Reason Behind the Rapid Rise of “Urban Wildlife”

Kaoru Suzuki, an associate professor at Tokyo University of Agriculture and Technology, explains , “It’s not just that they’re being spotted more often; as can be seen from a survey by the Tokyo Metropolitan Government’s Bureau of Environment, it appears that the population itself is growing” (see graph). He analyzed that this is largely due to the animals adapting to the urban environment, rather than significant changes in the human-created environment.

“Crows are a classic example, but raccoons and palm civets can also be considered animals that have adapted to the urban environment. For wildlife to settle and live in an area, they need food, shelter, and places where they can breed and raise their young. The fact that these animals are appearing indicates that there is an environment nearby that meets these conditions.

In large cities like the 23 wards of Tokyo, they feed on food scraps discarded by humans, take up residence in attics and crawl spaces where they can shelter from the rain and wind, and use rivers, irrigation canals, and gutters as travel routes. For nocturnal animals such as raccoons and Asian palm civets, residential areas can be considered a comfortable environment.”

“The ceiling caved in and a raccoon fell through!”

Pest control professionals are on the front lines of these changes. Sho Uchida, General Manager of “Kujo Zaurus,” a company specializing in pest control, says, “We’ve seen a particular increase in raccoon-related inquiries this year.”

“In the past, they were mostly found in the Tama region, Kanagawa, Chiba, and Saitama, but recently, their presence has been confirmed even in the 23 special wards, such as Setagaya and Sumida. Their population has likely grown, and they’ve spread toward the city center while moving along rivers that mark prefectural borders, such as the Tama and Sumida Rivers.”

Most of the damage occurs in the attics of wooden houses. Noise from them running around at night, defecation in the attic, outbreaks of ticks and fleas, and the risk of infectious diseases—

“I once rushed to a scene after receiving a report that repeated defecation in the attic had caused the ceiling boards to rot; the ceiling gave way under the raccoon’s weight, and it fell right into the room. In Setagaya Ward, there was even a case where a female raccoon gave birth to six babies in an attic.

People tend to think of raccoons as eating nuts and the like, but they’re actually omnivores. We even get reports of them preying on koi and goldfish kept in garden ponds,” says Mr. Uchida (mentioned earlier).

Because of their adorable appearance, many people feel the urge to “get closer” when they see a raccoon. However, Mr. Uchida sounds the alarm: “They have sharp claws and teeth. It’s extremely dangerous to feed them or approach them just because they’re cute.”

So, which wild animal should we be most wary of in Tokyo right now? Mr. Uchida continues.

“If I were to rank them, number one would be bats, which are most active during the summer; number two would be raccoons, whose population is on the rise; and number three would be hornets, whose nests tend to grow larger due to the intense heat.

Since wild animals like raccoons and palm civets have their breeding seasons in spring and fall, I get the impression that many homeowners don’t realize they’ve taken up residence until summer. The number of requests for removal is also on the rise, and we expect their population within the 23 wards to definitely continue growing,”

says Associate Professor Suzuki, mentioned earlier.

“Careless contact between humans and animals poses the greatest risk. In addition to adverse effects on the ecosystem, there are public health concerns such as infectious diseases and parasites. Caution is also needed regarding Severe Fever with Thrombocytopenia Syndrome (SFTS), which is transmitted by ticks; it is important not to approach them recklessly to avoid being bitten or contracting the disease.

It is unlikely that their numbers will decrease naturally without any countermeasures. The issue of buildings—so-called vacant homes—that have been left unmanaged for long periods is a cause for concern. Going forward, we must also pay even closer attention to the appearance of large wild animals as they move along riverbanks.”

It’s not just bears in mountainous areas. He notes that urban residents have also entered an era of coexistence with wildlife.