Stable Carbon and Nitrogen Isotopic Composition of a Whisker and Fur from a Stuffed 19th Century Specimen of the Extinct Japanese River Otter Collected from Inland Honshu, Japan

It is generally thought that Japanese river otter (Lutra lutra nippon) became extinct in the 1990s (Ando 2008), and the Japanese Ministry of the Environment officially designated the species as "extinct" in 2012 (Ishii 2014). This represented the first case where a mammal species that had survived into the late 20th century went extinct in Japan. One of the main reasons for the Japanese river otter's extinction was active hunting, with the animal's fur a major target for export and military goods during the first half of the Meiji period (1868-1912) (Ando 2008). The species' internal organs were also traded for use as medicine (Machida 1998). After hunting otters was prohibited by game laws in 1928, only a few records of the species existed in Honshu region until several years after World War II (Ando 2008). Though otters survived throughout the Japanese archipelago (e.g., in Hokkaido, Honshu, and other regions) through the late 1940s and 1950s, few records occurred thereafter except for coastal places in Ehime and Kochi Prefectures in Shikoku, the last home of living Japanese river otters (Ando 2008).