The Grass Snake may be most easily identified on the basis of the characteristic yellow collar behind its head. This reptile is an excellent swimmer and diver and captures the majority of its prey on and in the water.
Colouring is greyish to brown or olive green with 4 to 6 longitudinal rows along the back which are speckled dark grey to black. On both sides of the neck there is a patch which ranges in colour from white, light yellow to orange-red which is demarcated by a black spot in the direction of the tail. The young Aesculapian Rat Snake also has a similar type of neck collar, but it has no black border towards the tail. Almost completely black Grass Snakes also occur. Male Grass Snakes are normally from 60 to 70 cm, and females from 80 to 100 cm long. Particularly large specimens may reach a total length of up to 2m! Scales are markedly keeled, e.g. have prominent ridges; typical for all native Colubridae, the Grass Snake has nine large clypei, or shield-like plates, on the anterior portion of its head.
With a wide range encompassing all of Austria, the Grass Snake is the most common domestic snake and is almost always found near water.
Endangerment and Conservation Status
Although the Grass Snake is Austria's most common snake, it is still listed as vulnerable.
The Grass Snake is closely associated with water. Natrix natrix is an excellent swimmer and diver and hunts most of its prey on or in the water. Frogs, toads, salamanders, fish and tadpoles are captured then swallowed alive. If disturbed or threatened, the Grass Snake glides noiselessly into the water or other hiding place. Hibernation takes place from October to April, where the snakes often spend the time together in deep cracks in embankments, old logs, etc. From March to April, the Grass Snake emerges from hibernation, sheds its skin, and then mates. Oftentimes, large numbers of Grass Snakes gather at one mating area. From July to August, 10 to 30 long, oval eggs with a length of 25-40mm are laid in tree stumps, piles of leaves or loose mounds of earth. Hatchling snakes depart the nest by using a special egg tooth to chip away at the shells. Fresh hatchlings have a body length of approximately 18cm.
When a Grass Snake is caught by a predator, it doesn't bite but rather defends itself by releasing a foul-smelling, yellowish-white liquid substance from its scent glands. This substance sticks to clothes and skin for some time. Sometimes, however, the animal may "play dead": it turns half of its body on its back, becomes limp, rolls its pupils downward and lets its tongue hang out. After this performance it suddenly revives and attempts to flee.