Environment | ANIMAL TRACKER

Tiger keelback

by Rowan Hooper

* Japanese name: Yamakagashi
* Scientific name: Rhabdophis tigrinus
* Description: The tiger keelback is so named for the beautiful colored pattern of its scales. The snake’s head and body are basically olive green, but its flanks are orange, and there are several rows of black spots running down the body. The underside of the snake is yellow. These snakes can be large, growing between 70-150 cm long.
* Where to find them: They are common in Japan, found from Honshu to Kyushu, in fields, mountainous areas and often near water. They are active from April to November, but hibernate the rest of the year. Reproduction takes place in the summer months and females lay between two and 40 eggs.
* Food: Keelbacks’ favorite food is frogs. Like other snakes, keelbacks dislocate their jaw in order to swallow prey larger than their own heads. Keelbacks can swallow large bull frogs whole.
* Special features: There have only been 29 reported cases of keelback bites since 1917, thanks to the position of the venom-injecting fangs and the venom glands at the rear of the mouth. Bites tend to happen when it’s warm, between April and October, and most occur when people try to catch snakes they’ve found indoors. The venom evolved by tiger keelbacks causes internal bleeding and prevents the blood from coagulating. Symptoms include continuous bleeding from the bite wound, bleeding from the gums, blood in the urine and bleeding from the wound into the surrounding tissues. Nasty though this sounds, fatalities are rare as antivenom is available. This is obtained by injecting tiny amounts of venom into rabbits and goats; these animals then produce antivenom that can be extracted. Keelbacks also have poison glands on their necks. If these glands are pressed hard — for example, when they are picked up and held — they discharge yellow fluid that can damage the eyes if it comes into direct contact.