This commemorative issue by Japanese Post is the forth in a series with a wildlife theme. This series features endangered and protected species of rare wildlife. The stamps illustrate the Amami rabbit, the rock ptarmigan, Polemonium kiushianum, the Tokyo bitterling and the Chinese box turtle.
The Amami rabbit (Pentalagus furnessi), also known as the Ryukyu rabbit, is a primitive, dark-furred rabbit which is only found in Amami Oshima and Toku-no-Shima, two small islands in Kagoshima Prefecture in Japan. Often called a living fossil, the Amami rabbit is a living remnant of ancient rabbits that once lived on the Asian mainland, where they died out, remaining only on the two small islands where they survive today.
The rock ptarmigan (Lagopus muta) is a medium-sized gamebird in the grouse family. In Japan it is known as the raichou, which means 'thunder bird.' It is the official bird of Toyama Prefecture and is a protected species nationwide.
Polemonium kiushianum is a critically endangered species of which only eight populations exist in semi-natural grasslands of the Mount Aso area of Kyushu, Japan. Habitat modification and the risk of hybridization with non-indigenous horticultural congeners pose increasing threats to Polemonium kiushianum.
The Tokyo bitterling (Tanakia tanago) is a temperate freshwater fish of the carp family (Cyprinidae). Taxonomically, it belongs to the Acheilognathinae sub-family. In the wild, it is found only on the Kanto Plain of Japan, an area near to the capital city of Tokyo. It was formerly abundant in small streams, but its habitat has been overrun by people and pollution, and it was listed in the 1996 IUCN Red List as "Vulnerable", and there is a real risk that it could become extinct in the wild. It also suffers from competition from the related but more aggressive rosy bitterling. Bitterlings lay their eggs in mussel shells, and the Tokyo bitterling will only lay its eggs in one type of mussel shell, limiting its chances of successful breeding. To help protect it, it has been declared a "national monument" by the Japanese government which gives it special protection.
The Chinese box turtle, also known as the Yellow-margined box turtle, or Golden-headed turtle, is a species of Asian box turtle. Taxonomically, it has been called Cistoclemmys flavomarginata, Cuora flavomarginata, and Cyclemys flavomarginata. In Japan it is found in the Ryukyu Islands, Ishigaki, and Iriomote. The name box turtle refers to C. flavomarginata's ability to bring the plastron to the edges of the carapace. This is enabled by a hinge on the plastron and ligaments connecting the carapace and plastron, which allows for limited movement.