Photo/Illutration A small Indian mongoose (Provided by the Environment Ministry)

AMAMI, Kagoshima Prefecture--The Environment Ministry said Sept. 3 it has eliminated all invasive mongooses from Amami-Oshima island here, describing the eradication program as a “worldwide unprecedented achievement in protecting biodiversity.”

For years, the government and other organizations have been trying to get rid of the small Indian mongoose, which was introduced to the island around 1979 to reduce the populations of poisonous habu snakes and other dangerous animals.

The mongooses came from Okinawa Prefecture, where they had been introduced earlier also to kill dangerous animals.

But like so many other species-introduction programs, the plan on Amami-Oshima island ran into problems.

The mongooses quickly multiplied and started attacking rare wild animals, such as the Amami rabbit, which is listed on the red list for endangered species.

The government in fiscal 2000 started serious efforts to get rid of the mongooses, which were running rampant on Amami-Oshima island.

In 2005, when the Invasive Alien Species Law was enacted, the government designated the small Indian mongoose as an invasive alien species.

The government also strengthened countermeasures by establishing an experts’ organization named “Amami Mongoose Busters.”

The accumulated number of mongooses caught on the island exceeded 32,000.

In the 2000s, more than 2,000 mongooses were caught annually, but since May 2018, none has been captured.

Traps, motion-detection cameras and sniffer dogs found no indications that mongooses were still present on the island. The numbers of rare native species, such as the Amami rabbit, have increased in recent years.

Environmental experts met on Amami-Oshima island on Sept. 3 and confirmed the “extremely high” probabilities of 98.9 to 99.7 percent that all mongooses were eradicated as of the end of fiscal 2023.

The Environment Ministry made its “eradication declaration” on the same day.

Amami-Oshima island was designated a UNESCO World Natural Heritage site in 2021, along with Tokunoshima and Iriomotejima islands.

The eradication declaration means that a threat to a World Heritage site or “a common asset of human beings” has been removed.

Mongooses were also brought to Hawaii and the Caribbean. Complete eradication of the creatures was successful only on islands of about 1 square kilometer or less in those areas.

By contrast, Amami-Oshima island covers 712 square kilometers, which is larger than the total area of Tokyo’s 23 wards.

“I’d like to praise the achievement of successfully eradicating the highly invasive mongooses from such a large island,” said Toru Ikeda, professor emeritus at Hokkaido University who specializes in invasive species.

“A quarter century may sound a long time, but it was actually impressive that they managed to eradicate the animal in such a short period,” he added.

(This article was written by Tomooki Yasuda and Fumi Yada.)

Related News