Kagoshima: Drastic drop in invasive mongoose population on Amami Oshima island

The Yomiuri Shimbun

18:28 JST, March 5, 2021

KAGOSHIMA — No mongooses have been captured since one was caught in April 2018 on Amami Oshima island, which is seeking to be registered as a UNESCO World Natural Heritage site, the Environment Ministry reported at a study meeting held in Amami City, Kagoshima Prefecture, on Feb. 15.

The ministry, whose aim is to eradicate the animal by the end of fiscal year 2025, evaluated that this is the result of a progressive decline in the density of the invasive alien species’ population.

According to the ministry’s Amami Wildlife Conservation Center, no traps or search dogs have captured a mongoose since April 2018, and they have not been seen on the about 400 sensor cameras installed across the islands. Also, the mongooses’ habitat on the island has not been found for about three years.

Mongooses were brought to the island from Okinawa in 1979 to exterminate venomous habu snakes. However, mongooses are active during the day, so they were unable to do a good job in capturing the nocturnal habu. On the contrary, they became a threat to a rare animal on the island. Their excrements were found to contain the hair of the Amami rabbit, a special natural treasure of Japan.

The number of mongooses is believed to have reached about 10,000 at its peak.

The ministry launched a full-scale pest-control project in fiscal 2000 and formed the team Amami Mongoose Busters, specializing in the capture of mongooses, in fiscal 2005. The number of mongooses captured dropped from about 2,700 in fiscal 2006 to less than 1,000 in fiscal 2007 and less than 100 in fiscal 2014.

“In order to achieve eradication, we need to accumulate enough data,” Shintaro Abe, director of the center, said. “We will move forward with a plan that includes continuous observation and work across the island with search dogs.”

Record rabbit deaths by traffic

KAGOSHIMA — According to the Environment Ministry, a total of 66 Amami rabbits died in traffic accidents in 2020 on Amami Oshima and Tokunoshima islands in Kagoshima Prefecture, the highest number ever.

In addition to the Amami rabbit, the ministry analyzed the number of carcasses and causes of death of the Ryukyu long-furred rat, the Amami spiny rat and the Tokunoshima spiny rat, all of which are special natural treasures and endangered species.

The number of dead Amami rabbits confirmed on both islands was 136, of which 66 died in traffic accidents. These accidents have occurred not only on forest roads but also on national and prefectural roads.

The ministry attributes the high number of accidental deaths of the Amami rabbits to the reduction of the invasive mongoose and other non-native species, which has expanded the roaming area of the rabbits. As a preventive measure, the ministry has been installing signs and distributing flyers to urge people to be careful.

The Amami Wildlife Conservation Center is also working to protect the ecosystem by conducting a study on a road in Amami City to see the effects of restricting traffic.

“Please pay attention to your surroundings, especially at night,” Abe appealed to drivers.