Cat islands and cat towns: why some places fill up with cats

Walk into Kotor's old town after dark and the cats are everywhere, on fortress walls, on café chairs, slipping through doorways that haven't quite shut. Aoshima in Japan has more cats than people by a ratio of six to one. Lanzos in Greece, the Greek island of Syros, the harbour at Essaouira in Morocco. The pattern repeats across continents and centuries, and it has the same engine underneath every time.

Domestic cats reached most of the world as working animals on ships. They were kept to protect grain stores from rats, and wherever ships docked regularly, cats came ashore. Island ports and coastal fishing towns were the first stops, and cats that jumped ship or were left behind found environments that suited them: warm stone, abundant fish scraps, and humans who had strong practical reasons to tolerate them. The cats of Aoshima are direct descendants of animals brought to the island to protect silkworm cultivation from mice. The cats of Kotor arrived with Venetian trade ships and stayed because the walled city's rat population gave them reason to. The founding story varies in detail but rarely in structure.

Once a feral or semi-feral colony establishes itself, it grows quickly unless something actively reduces it. An unspayed female cat can produce two to three litters a year, with four to six kittens per litter. In a location where food is reliable, fish waste at a harbour, tourist scraps at a café, deliberate feeding by residents, survival rates among kittens rise sharply. Island geography compounds this. There is no dispersal to surrounding territory. Cats that would in a mainland city spread across a neighbourhood instead stay concentrated in the same few streets or shoreline. The density that makes these places photogenic is the same density that makes population management genuinely difficult. Trap-neuter-return programmes exist on several famous cat islands, including Aoshima, but the logistics of running a vet programme on an island with no resident vet and irregular ferry access are not simple.

None of these places would have the cat populations they do without active human participation. In Kotor, a non-profit called Cats of Kotor has been managing the colony for years, running neutering drives and maintaining feeding stations. On Aoshima, the island's elderly human population, fewer than fifteen people at the last count, feeds the cats daily. In many Greek fishing villages, the taverna owner who puts out a bowl of scraps every evening is as much a part of the system as the cats themselves. Tourism has added a layer to this. Cat islands attract visitors specifically because of the cats, and that visitor attention brings donations, volunteer programmes, and international press coverage that fund the neutering work. It is a feedback loop: cats bring tourists, tourists bring money, money funds the care that keeps the cats visible and healthy enough to keep attracting tourists.

The photographs show cats sleeping in fishing nets and sitting on ancient walls in golden light. The reality for residents is more complicated. High cat density means disease can move through a colony fast, particularly feline respiratory infections and FIV. Unneutered males fight, and the noise at night is not picturesque. Kittens born to malnourished mothers have high mortality rates. Responsible cat town management, the kind that keeps a colony stable and healthy rather than just large, requires sustained veterinary access, consistent neutering, and someone willing to do it year after year regardless of whether a documentary crew is filming. The places that manage it well are the ones where that infrastructure exists. The places that don't manage it well have the same cat density and significantly more suffering that doesn't make it into the travel features.

The reason cats fill certain places and not others is not mystery or magic. It is a specific combination of historical arrival, reliable food, contained geography, and human tolerance that tipped into human affection. Where those four conditions hold, the cats stay. Where the affection comes without the infrastructure, the colony grows past what the place can support. The famous cat towns worth visiting are the ones where someone worked out that difference a long time ago.