Japan’s famous “cat islands” have enormous feline populations because cats were originally brought there to protect local industries, then stayed and reproduced for generations after those industries faded. On Tashirojima, the most well-known cat island, cats outnumber the roughly 60 remaining human residents by a wide margin. On Aoshima, another popular cat island, around 200 cats share space with just nine people. The story behind these numbers is a mix of economics, geography, and cultural protection that spans centuries.
Silkworms Started It All
The cat population on Tashirojima traces back to Japan’s late Edo period, when silk production was a major industry across the country. Islanders raised silkworms for textiles, and mice were a constant threat to the delicate cocoons. Cats were the simplest, most effective pest control available.
In 1602, a government decree freed all pet cats in Japan specifically to combat the rodent populations threatening silkworm operations nationwide. On Tashirojima, this release of domestic cats into the wild is what created the foundation for today’s thriving feral population. Once the silk industry declined, the cats remained, breeding freely on a small island with few natural predators and a steady food supply from the surrounding sea.
Fishing Villages Brought Cats Too
On Aoshima, the story is slightly different but follows the same logic. The island was a sardine fishing village, and cats arrived on ships during the twentieth century to catch rodents that damaged fishing nets and supplies. When the fishing industry shrank and people began leaving, the cats didn’t leave with them. They reproduced rapidly in an environment with no predators, no traffic, and enough scraps and marine life to survive on.
This pattern repeated across several of Japan’s dozen or so cat islands. Cats arrived for a practical purpose, the human population eventually declined, and the cats kept breeding. The ratio tipped further with each passing decade as young people moved to cities and older residents passed away.
Shrinking Human Populations, Growing Ratios
The dramatic cat-to-human ratios on these islands aren’t just about cats multiplying. They’re equally about humans disappearing. Like many rural and outlying areas in Japan, these islands have experienced severe population decline over the past several decades. Young people leave for education and jobs in cities. The residents who remain are elderly, with the average age on one island reaching 75.
On Aoshima, the human population dropped to single digits. On Tashirojima, only about 60 people remain. As the number of humans falls, the visible density of cats becomes more striking, even if the actual cat population hasn’t grown dramatically in recent years. Forty thousand tourists visit Tashirojima annually, vastly outnumbering both the cats and the people who live there.
Cultural Protection Keeps Cats Safe
What makes Japan’s cat islands unusual isn’t just that cats ended up there. It’s that local culture actively protected them instead of culling them. On Tashirojima, fishermen have long believed cats bring good luck, including large catches of fish. Some fishermen traditionally watched the cats’ behavior for clues about incoming weather before heading out to sea.
The island’s famous Cat Shrine, called Neko Jinja, has its own origin story. According to local legend, a fisherman accidentally injured a cat while working. Feeling remorseful, the islanders built a shrine to honor the cats. Over time, cats became mythologized as guardian spirits of the island. That cultural reverence meant no one was inclined to reduce the population, and the cats were treated as welcome neighbors rather than pests.
How the Cats Are Fed and Managed
The cats on Tashirojima are fed daily by island residents. A scheduled feeding takes place at a community spot called Tashirojima Nyanko Kyowakoku Shimanoeki, where locals set out food around noon. Tourists are specifically asked not to feed the cats, since outside food can cause health problems or change the animals’ behavior. Visitors can watch the feeding but are expected to let the cats approach on their own terms.
This system works during normal times, but the aging human population raises long-term questions. On one island, 13 residents were responsible for roughly 130 cats, a ratio that strained the capacity of elderly caretakers.
Sterilization Is Changing the Future
Not all cat islands are growing. On Aoshima, a spaying and neutering program began in 2018 to curb unchecked population growth. Since then, no new kittens have been born on the half-square-kilometer island. The existing cats are aging, and barring intervention, the population will eventually disappear entirely as the current generation dies off.
This creates a bittersweet trajectory for some of Japan’s most famous cat destinations. The same demographic forces shrinking the human population are now, through managed sterilization, shrinking the cat population too. Islands that became tourist attractions precisely because of their overwhelming number of cats may eventually lose the very thing that draws visitors. For now, though, the cats remain a living artifact of centuries-old island economies, protected by cultural reverence and sustained by the small communities that still call these islands home.