The illustration depicts an unusual event observed on Okunoshima Island, where wild boars have been seen capturing rabbits. Credit: Eri Kondo
Okunoshima Island in Japan is one of the weirdest tourist attractions. Nowadays, it’s known as a “bunny paradise, famous for its huge population of wild, free-range rabbits. But before its bunny days, the island was used as a poison weapons testing ground in World War II.
In fact, the rabbits aren’t endemic to the island. They were brought to the island, some even used to test the effectiveness of the poison weapons. When the island was turned into a park, the rabbit population grew and spread.
But that’s not nearly the only strange thing. There are also boars on the island, and according to a new study, the boars are starting to prey on the rabbits. And, to top it all off, it’s probably the tourists’ fault.
A Dark Paradise
Feeding wild animals is a popular activity at many tourist destinations. This appears harmless, but usually, it’s not. What’s happening on Okunoshima also isn’t harmless.
Visitors are happy to give rabbits bags of pellets and vegetables. The place is often called a “paradise” on social media. But this paradise requires imports.
The study estimates that the island’s natural vegetation could provide about 3.4 metric tons of dry plant food a year — enough for roughly 175 to 287 rabbits. Tourists, by contrast, brought an estimated 8.3 tons of food in 2013 and 27 tons during the 2017 tourism peak. That year, Okunoshima received about 360,000 visitors.
In other words, tourism has pushed the rabbit population beyond the island’s natural carrying capacity (the number of animals the habitat can support without outside help). When tourism fell, the rabbit population also fell. Out of desperation, some rabbits started eating toxic plants.
But the rabbits aren’t the only ones affected by tourists. Researchers spotted boars eating food intended for rabbits, drinking their water, and constantly overruning bunny territory. The tourists may choose the beneficiary, but the island doesn’t always follow that choice.
×
Thank you! One more thing…
Please check your inbox and confirm your subscription.
That’s not the only thing boars are doing. The boars are now hunting rabbits.
How Scavenging May Turn into Hunting
Wild boars eat a remarkably broad diet. They dig for roots, consume crops and take advantage of carrion — the bodies of dead animals. Researchers have detected rabbit DNA in boar diets elsewhere in Europe, but scientists have generally interpreted it as evidence of scavenging or the consumption of young, weak or injured rabbits.
Shingo Kaneko, a professor from the Faculty of Symbiotic Systems Science and Engineering at Fukushima University, Japan, believes something else is happening in Okunoshima.
“When we first heard that a wild boar had preyed on a live rabbit, we were surprised,” Kaneko said. “Wild boars are known to scavenge animal carcasses, but they are not generally regarded as animals that actively hunt live prey.”
A view of Ōkunoshima from Kurotaki-yama. Image via Wiki Commons.
“At the same time, during our fieldwork, we were struck by how closely wild boars, rabbits and humans were interacting on the island. Within this isolated environment, events unlike those we usually observe elsewhere appeared to be occurring throughout the island.”
The study’s authors propose a possible sequence. Boars first encounter vegetables and pellets left by tourists. They learn where and when food appears, including around ferry departure times, when visitors may empty their remaining feed before leaving.
The boars then encounter rabbit carcasses.
A dense population with high juvenile mortality can produce a steady supply of dead animals. Staff and visitors remove some bodies, but others remain inside burrows, thickets and other secluded places. Okunoshima lacks several common Japanese mammalian scavengers, potentially leaving boars with less competition for that food.
Researchers describe two reported episodes: one witnessed by tourists in 2017 and the detailed attack observed in 2024. It’s not clear how often this is happening, but at least occasionally, boars are hunting rabbits.
The Boar Is a Symptom, Not the Root Problem
Removing dangerous boars may protect visitors, but it would not solve Okunoshima’s ecological crisis.
The deeper problem is a dense, introduced rabbit population sustained by weakly regulated feeding. That system has stripped vegetation, created dependence on tourists and supplied food and carcasses to other wildlife. The boar’s attack is one visible result — not the cause.
Management must therefore address the entire system: visitor feeding, rabbit numbers, animal welfare and habitat damage.
The researchers call for regular monitoring of rabbits, vegetation, carcasses and non-target wildlife. Managers also need clear rules on how much food visitors can provide, where they can provide it and who is responsible for sick or injured animals.
Okunoshima faces a basic choice. Authorities can manage the rabbits as dependent animals, with controlled feeding and veterinary care, or treat them as wildlife and restrict feeding. Continuing the current arrangement risks further ecological damage.
Rabbit Island is not a self-sustaining paradise. It is a human-supported ecosystem—and humans must take responsibility for what it has become.
Shingo Kaneko et al, Wild boar predation on feral rabbits in a tourist-fed island population: ecological and management implications from Okunoshima Island, Japan, Journal of Ecotourism (2026). DOI: 10.1080/14724049.2026.2705843
AloJapan.com