Japanese river otter
||It has been suggested that this article be merged with Japanese otter. (Discuss) Proposed since July 2012.|
|Japanese river otter|
|Subspecies:||L. l. whiteleyi|
|Lutra lutra whiteleyi
The Japanese river otter (Lutra lutra whiteleyi) (日本川獺 Nihon-kawauso?) is an extinct variety of otter formerly widespread in Japan. Dating back to the 1880s, it was even seen in Tokyo. The population suddenly shrank in the 1930s, and the mammal nearly vanished. Since then, it has only been spotted several times, in 1964 in the Seto Inland Sea, and in the Uwa Sea in 1972 and 1973. The last official sighting of one was in the southern part of Kochi Prefecture in 1979, when it was photographed in the mouth of the Shinjo River in Susaki. It was subsequently classified as a "Critically Endangered" species on the Japanese Red List, On 28 August 2012, the Japanese river otter was officially declared extinct by the Ministry of the Environment. On January 10, 2013, dozens of eyewitnesses reported seeing them in Aichi Prefecture.
Fully grown, a Japanese otter was between 65 and 80 cm (25–31 in) long, with a tail measuring 45 to 50 cm (17 to 20 in). It had a thick, lush coat of dark brown fur with short webbed feet.
A nocturnal creature, an otter only left its den after dark to forage for food. Claiming a territory about ten miles in diameter, it marked the area with its droppings about one to three miles apart and sets up three or four nests under rocks or inside bushes. The otters were always on the move, visiting each den only once every three to four days.
Like most otters, the Japanese river otter was not an especially picky eater. While it primarily fed on fish, crab, and shrimp; it also ate eels, beetles, watermelons, and sweet potatoes.
Efforts to prove its existence
Throughout the 1990s, there were several attempts to locate a surviving Japanese river otter.
In December 1991, the Environmental Agency of Japan in partnership with the Kochi prefectural government assembled a research team of experts and began their search. In March 1992, the research group found hair and excrement in Kochi Prefecture and believed to have come from an otter. Also found were three footprints, and ten additional excrement samples. After an analysis of a cross-section of the hair, the researchers determined that it came from an otter. An official from the agency's wildlife protection section stated that the hair was "scientifically solid evidence that confirms the existence of the Japanese Otter."
In 1994, zoological experts visited the area where the excrement was found. They discovered remains of the animal's urine, which the animal is believed to leave during its courtship. The prefectural government of Kochi set up an infrared camera for six months from October 1994 to April 1995 in an effort to capture it on film, but all that was recorded were animals such as raccoon dogs.
Between 4 and 9 March 1996, a group of zoo officials, municipal government officials and animals lovers from across the country searched for the river otter in the areas where finds have been made in the past. Such areas included coastal areas in Susaki, areas along the Niyodo River running through Sakawacho and Inocho, and coastal areas along Shimanto River. No evidence of the animal's existence was found.
- Kenkyusha's New Japanese-English Dictionary, Kenkyusha Limited, Tokyo 1991, ISBN 4-7674-2015-6
- "Red List of Threatened Mammals of Japan". Ministry of the Environment. Retrieved 2010-08-07.
- "Japanese river otter declared extinct". Mainichi jp. Japan: The Mainichi Newspapers. 28 August 2012. Retrieved 28 August 2012.
- Kyodo News, "Japanese river otter declared extinct", Japan Times, 29 August 2012, p. 1