Common snakes found in Japan: Species, habitats, venomous risks, and how to stay safe

Japan's long chain of islands supports a surprisingly rich variety of wildlife, created by isolation, mountains, forests, and the seas surrounding it. Snakes are decidedly included in this landscape, though they are very rarely associated with the country in popular imagination. From quiet forest floors and rice fields, through riverbanks to coastal regions, snakes occupy almost every habitat across Japan. Some are harmless, being a very important constituent in pest control, while a few are venomous and require caution. Knowledge about which snakes exist in Japan, in what locations they can be found, and how dangerous they are helps to replace fear with realism and encourages safer coexistence. With over forty species recorded, Japan provides a fascinating view of snake diversity in East Asia.Japanese rat snakeThe Japanese rat snake is one of the most commonly viewed snakes throughout the main islands. It is a big, nonpoisonous species, reaching from three to seven feet in length. The coloring varies from yellow-green to blue-green, often with brown striping akin to the venomous mamushi. Thus, it's sometimes confused, but Japanese rat snakes pose no risk whatsoever and are good at helping to control rodent populations.Japanese striped snakeAlso known as the four-lined snake, the Japanese striped snake is easily recognised by the four dark lines running from head to tail. It is typically yellow or light brown, though an all-black form known as the crow snake does exist. Found throughout most of Japan except the Ryukyu Islands, this species is non-venomous and poses no threat to people.Jimguri snakeThe jimguri is fittingly named, its name roughly translating to "the burrower". In life beneath the forest floor, it is well-adapted. These snakes are reddish-brown with small dark markings along their body, edged in pale colours. Though much of their time is spent underground, they can often be seen at dawn or dusk. Jimguri snakes are harmless and feed on the small prey of the forest.YamakagashiThe yamakagashi, or tiger keelback, is one of Japan's more unusual venomous snakes. The toxicity does not come merely from venom glands but from toxins acquired by eating poisonous frogs and toads, stored in specialized glands near the back of the mouth, used defensively. While bites are extremely rare, this species is considered dangerous and must not be approached.Japanese keelbackJapanese keelbacks are slender snakes and usually small in size. They are common to rivers, ponds, and mountainous, forested areas. Their light brown colour and yellow markings around the face are their distinctive features. This species feeds on frogs and earthworms and is harmless, though not aggressive.MamushiThe mamushi is Japan's most venomous snake and claims the majority of reported snakebites annually. The pit viper is small, terribly venomous, with an incredibly stout body and definitely patterned markings. Mamushi venom requires immediate treatment at a hospital, which if this treatment is given, fatalities are rare but continue to be an endangering concern in much of the country.Snakes are common throughout Japan, and species of all kinds can be found in practically every ecological zone, from urban parks and agricultural land to forests and wetlands, right into the mountainous regions. Altogether, some estimated 47 snake species are said to inhabit the country, with few of these posing any serious threat to man. Japan itself is divided into eight major regions, each with its own sub-climate and types of habitat that have allowed different snake species to adapt and live. Some populations are even region-specific, such as rare albino rat snakes, which can be found in parts of Yamaguchi Prefecture.