The Environment Ministry said Monday that three wild otters are likely inhabiting Tsushima island in Nagasaki Prefecture, following a report last year of the first sighting of the mammal in Japan in 38 years.
The otters — two males and one female — were identified as Eurasian otters, a species also found in South Korea, and not Japanese river otters, which were last spotted in 1979 and are believed to be extinct, according to the ministry.
The ministry analyzed 10 excrement samples collected from the island — which is located roughly halfway between Kyushu and the Korean Peninsula — to identify the sex and DNA characteristics of the otters and found that one of the male otters and the female otter could be related as siblings or as parent and child.
A wild otter was spotted in video footage taken in February last year by a team that was conducting research on the Tsushima leopard cat.
The sighting raised hope that it might be a Japanese river otter, which was designated as extinct by the ministry in 2012 after not being seen for more than 30 years.
The population of Japanese river otters declined sharply because of hunting for their fur and pollution of their habitat.
