A wild otter was caught on film on Nagasaki Prefecture’s Tsushima Island in February, marking the first sighting of the mammal in Japan in 38 years, a University of the Ryukyus team said Thursday.
It is not known whether the observed otter was a Japanese river otter — which was once found across Japan but is believed to have gone extinct — according to the team of researchers. A river otter was last spotted in 1979 in the city of Susaki, Kochi Prefecture.
Hunting for otter fur and pollution in river habitats had caused a sharp decline in the animal’s population.
The Environment Ministry said an analysis of excrement samples collected on Tsushima Island in July suggested the presence of two Eurasian otters. One is believed to have come from South Korea or Russia’s Sakhalin island, but the origin of the other animal remained unknown.
The team said a camera set up for an ecological survey of the Tsushima leopard cat captured the otter. In the footage, the otter is of adult size and appears to be in good health and nutritional status, the researchers told a news conference at the ministry.
The team said the animal could either be a Japanese river otter that has survived, a Eurasian otter that has crossed the sea from South Korea about 50 km away, or a species that has been brought by humans.
There are more than 10 species of otter in the world. Records show that Japanese river otters lived all over the country until the Meiji Era (1868-1912) and on Tsushima Island during the Edo Period (1603-1868).