Japanese officials say it has been more than three years since any mongooses have been captured on a UNESCO World Heritage island in the country's southwest.
The non-native mammal was introduced and released on Amami-Oshima Island in Kagoshima Prefecture about 40 years ago to reduce the population of habu, a local snake species with lethal venom.
But mongooses started to attack species native to the island, such as the Amami rabbit, and expanded their population to an estimated 10,000 at one time.
The central government launched a project to eradicate mongooses roughly two decades ago. Officials say that since April 2018 none of them have been captured or caught on sensor cameras installed at 451 locations.
The Environment Ministry says this indicates a dramatic decline in the mongoose population on the island, and also a decrease in their numbers per habitat. But it also says nine sightings of the animal were reported in the fiscal year ending in March 2021.
The ministry plans to continue collecting information to completely exterminate mongooses on the island. It hopes to declare their elimination as early as 2023.