Once a resident of rivers throughout Japan, the Japanese river otter hasn’t been seen for more than 30 years. Today, the otter was officially deemed extinct by Japan’s Ministry of the Environment. The unique species of otter was designated as natural monument in Japan as the first Japanese mammal to have survived into the Showa Era (1926-1989) before succumbing to extinction. Two species of Japanese bat and two species of wolves became extinct in the Meija Era (1868-1912).

Over-hunting for its fur combined with habitat destruction from human development drove the river otter to near extinction by the 1930s. By the late ’70s the river otter was added to the “Red List of Threatened Mammals of Japan” as critically endangered. The last official sighting of a Japanese river otter was in 1979 along the banks of the Shinjo River in Susaki, Kochi Prefecture.

An adult river otter grew to about 110 centimeters (43 inches) in length, including a tail of up to 50 centimeters (20 inches), sporting a thick, lush coat of fur and short webbed feet. The typical diet for a Japanese river otter consisted mainly of fish, crab and shrimp, but they also dined on eels, sweet potatoes, watermelons and beetles.

Hope after extinction?

Official survey records from the Ministry of the Environment indicate the river otter disappeared from the northern island of Hokkaido in the 1950s and on the main island of Honshu in the 1960s. In the early 1990s research teams assembled in Kochi Prefecture, located in the southwestern part of the island of Shikoku, to see if they could find evidence of surviving otters. In March 1992 the researchers found hair and excrement that was determined to have come from an otter — perhaps the last official evidence of a surviving Japanese river otter.

But Yoshihiko Machida, professor emeritus at Kochi University, isn’t quite ready to sound the death knell for the Japanese river otter, citing reports of confirmed otter droppings found as late as 1999:

“I think it is possible that they still exist, and I want to continue my investigations,” he said in response to the declaration of the otter’s extinction.

Hope springs eternal.

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