The Japanese rat snake (Elaphe climacophora ) is a medium-sized colubrid snake found throughout the Japanese archipelago (except the far South West) as well as on the Russian-administered Kunashir Island. In Japanese it is known as the aodaishō or "blue general". It is non-venomous. It is hunted by eagles and tanukis.
The snakes hibernate for three to four months, mate in spring and lay 7–20 eggs in early summer.
The Japanese rat snake is a medium-sized non-venomous colubrid snake. In Japanese it is known as the aodaishō or "blue general". It is the largest Japanese snake outside Okinawa. They are variable in color, ranging from pale yellow-green to dark blue-green. Juveniles have a brown-stripe pattern that may be mimesis of the venomous mamushi.
These snakes are found throughout the Japanese archipelago where they inhabit forests, grasslands, fields, farms near villages, and also occur in urban areas.
Japanese rat snakes typically spend their time singly. They are considered arboreal, climbing high into the branches to raid bird nests or just to rest. These snakes have very developed sensory organs which support their daily activities. They have internal ears that enable them to detect sounds at low frequencies and compared to other snakes, they have highly developed vision that allows them to detect the movement of their predators and prey. Because Japanese rat snakes are cold-blooded, their body temperature is susceptible to the temperature of their environments. Thus, they need to maintain their body energy by switching locations and remaining physiologically inactive when winter comes. They hibernate for three to four months before the mating season.
Japanese rat snakes are carnivores and eat small animals such as birds, rodents, frogs, or lizards.
The breeding season of Japanese rat snakes takes place from July to August. Females lay 7-20 eggs in the soft heart of a rotten log or in sandy soil under a rock.
Japanese rat snakes are not considered threatened but in some areas, they suffer from the loss of their native habitat.
According to IUCN Red List, the Japanese rat snake is locally common throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today remain stable.