Amami Oshima island in Japan is a UNESCO World Heritage site. Its forests are home to many animals that cannot be found anywhere else in the world, including the Amami rabbit, a rare and endangered species. However, in 1979, the island's residents were not worried about the future of these animals. At that time, their cause for concern was a type of venomous pit viper called Habu, according to reports from The Times of India and Cambridge University Press.
The Habu had long been a major problem for humans in the Amami Islands. Between 1967 and 1976, 2,673 cases of Habu bites were recorded across Amami Oshima, Tokunoshima, and neighboring islands. Therefore, authorities were looking for an effective way to reduce the snake population. Amami Oshima authorities turned to the mongoose to drive away the snakes. The history of 'importing' mongooses to Japan is quite old. In 1910, small Indian mongooses (Herpestes auropunctatus, now known as Urva auropunctata) were taken from Bangladesh to Okinawa Island. Later, about 30 mongooses from that very Okinawa were brought to Amami Oshima in 1979. Research has also found evidence of this journey from Bangladesh to Okinawa, and then from Okinawa to Amami.
However, the island authorities' plan to kill snakes using mongooses later backfired. The first reason for the problem was the difference in the lifestyles of the mongoose and the Habu. The Habu is primarily nocturnal, while the mongoose is active during the day. In other words, the predator brought in to kill the snakes had very little chance of even encountering the designated target snakes.
Japan's Ministry of Environment also reported that the mongooses had a predatory impact on many native animals, including the Amami rabbit, instead of the Habu snake. While the mongooses were searching for food during the day, many other animals in the forest became easy prey right in front of them. Moreover, the environment of Amami Oshima was quite favorable for the reproduction of mongooses. There was no shortage of food, and there were no large natural predators. As a result, a large population of mongooses gradually grew from the initial 30. By around the year 2000, the number of mongooses in Amami Oshima reached an estimated 10,000.
Seeing the situation turn critical, local authorities took initiatives to catch the mongooses in the 1990s. A large-scale eradication campaign began in 2000. Traps were set, bait was used, and monitoring began with cameras. Later, specially trained dogs were also deployed to detect the scent of mongooses. In 2005, a team of experts named 'Amami Mongoose Busters' was formed. Japan once had to use over 30,000 traps and more than 300 cameras for monitoring across the island. There was a major problem here: catching 99 percent of the mongooses did not mean the job was done. If even a few mongooses, especially a fertile female, survived anywhere, reproduction could start all over again. Therefore, the hardest part of the eradication campaign was finding the last few.
In April 2018, a mongoose was caught in a trap, and no other mongooses have been found since then. However, Japan did not announce right away that the island was mongoose-free, because saying that an animal has been completely eradicated from a vast area is as easy as it is difficult to prove. Finally, on September 3, 2024, Japan's Ministry of Environment announced that yes, it has been possible to eradicate mongooses from Amami Oshima. According to experts' calculations, the probability of eradication was 98.9 to 99.7 percent. Thus, it took about 45 years to find a final solution to the problem that began in 1979!
The price for this mistake had to be paid not only with time, but also with a huge amount of money. From 2000 to 2024, Japan's expenditure on the mongoose eradication program was about 3.57 billion yen, which is approximately 23.82 million US dollars. Calculated in Bangladeshi currency using a near-current exchange rate, this amount is roughly 2.9 billion taka.
