Grass snake

Many subspecies are recognized, including: Natrix natrix helvetica (Lacépède, 1789) was formerly considered as a subspecies, but following a genetic analysis it was recognised in August 2017 as a separate species, Natrix helvetica, the barred grass snake. Four other subspecies were transferred from N. natrix to N. helvetica, becoming N. helvetica cettii, N. helvetica corsa, N. helvetica lanzai and N. helvetica sicula. The subspecies N. natrix astreptophora, found in the Iberian peninsula, the Pyrenees, and North-Western Africa, has been reclassified as its own species Natrix astreptophora or the Iberian grass snake. ==Description==

The grass snake is typically dark green or brown in colour with a characteristic yellow or white collar behind the head, earning it the alternative name of 'ringed snake'. Its colouration can range from grey to black; darker colours are more prevalent in colder regions, presumably due to the thermal benefits of dark pigmentation. The underside is whitish with irregular black markings that are a useful field identification feature. It can grow to or more in length. == Evolution ==

Fossils of N. natrix are known to date back to the late Early Pleistocene from the site of Somssich Hill 2 in southern Hungary. ==Distribution==

The grass snake is widely distributed in mainland Europe, ranging from mid Scandinavia to southern Italy. It is also found in the Middle East and northwestern Africa. Grass snakes in Britain were previously classified as the subspecies N. n. helvetica but have since been reclassified as the barred grass snake Natrix helvetica. Any records of N. natrix in Britain are now believed to be from imported specimens. ==Ecology==

Feeding Grass snakes mainly prey on amphibians, particularly the common toad and the common frog, although they may also occasionally eat ants and larvae. In captivity, grass snakes have been observed accepting earthworms offered by hand, but they never take dead prey. The snake actively searches for prey, often on the edges of the water, using sight and sense of smell (using Jacobson's organ). They consume prey live without using constriction. The preferred habitat appears to be open woodland and "edge" habitats, such as field margins and woodland borders. These areas may offer adequate refuge while still affording ample opportunity for thermoregulation through basking. Pond edges are also favoured and the relatively high likelihood of observing this elusive species in these areas may explain why it is often associated with ponds and water. Grass snakes, like most reptiles, are at the mercy of the thermal environment and need to overwinter in areas which are not subject to freezing. Thus, they typically spend the winter underground where the temperature is relatively stable. when they may also secrete blood (autohaemorrhage) from the mouth and nose. They may also perform an aggressive display in defence, hissing and striking without opening the mouth. They rarely bite in defence and lack venomous fangs. When caught they often regurgitate the contents of their stomachs. Grass snakes display a rare defensive behaviour involving raising the front of their bodies and flattening their heads and necks so that they resemble cobras. However, the geographic ranges of grass snakes and of cobras overlap very little. However, the fossil record shows that the extinct European cobra Naja romani occurs in Miocene-aged strata of France, Germany, Austria, Romania, and Ukraine, thus overlapping with Natrix species including the extinct Natrix longivertebrata. This suggests that the grass snake's behavioural mimicry of cobras is a fossil behaviour, although it may also serve as protection against predatory birds that migrate to Africa for the winter and encounter cobras there. Protection and threats The species has various predator species, including corvids, storks, owls and perhaps other birds of prey, foxes, and the domestic cat. In Denmark it is protected, as all five species of reptiles were protected in 1981. Two of the subspecies are considered critically endangered: N. n. cetti (Sardinian grass snake) and N. n. schweizeri. == Mythology ==

Baltic ' Historia de Gentibus Septentrionalibus (History of the Northern People), book 3, 1555 In Baltic mythology, the grass snake (Lithuanian: žaltys, Latvian: zalktis) is seen as a sacred animal. It was frequently kept as a pet, living under a married couple's bed or in a special place near the hearth. Supposedly, snakes ate food given to them by hand. Even after the Christianization of Lithuania and Latvia, the grass snake still retained some mythological significance. Despite the serpent's symbolic meaning as a symbol of evil in Christianity, various folk beliefs in Latvia and Lithuania dating even to the late 19th century held that killing grass snakes might bring grave misfortune, or that an injured snake would take revenge on the offender. Ancient Baltic beliefs about grass snakes as household spirits transformed into a belief that a snake (known or not to the inhabitants) lives under every house and that if it leaves, the house will burn down. Common Latvian folk sayings include "who kills a grass snake, kills his happiness" and "when the Saulė sees a dead grass snake, she cries for 9 days". Well-known literary works based on these traditions include Lithuanian folk tale Eglė the Queen of Serpents (Eglė žalčių karalienė) and the Latvian folk fairytale "The grass snake's bride" (Zalkša līgava). These works feature a prevalent theme in Baltic mythology: that grass snakes wear crowns (note grass snake's yellow spots) and that there is a king of snakes who wears a golden crown. According to some traditions, the king of snakes changes every year, dropping his crown in spring, after which the other snakes fight over it (possibly based on the mating of grass snakes). Today, many Latvians and Lithuanians believe that grass snakes bring good luck and protect the home. One tradition is to put a bowl of milk near a snake's place of residence, although there is no evidence of a grass snake ever drinking milk. Driven by late 19th century and 20th century Romantic nationalism, grass snake motifs in Latvia have come to symbolise education and wisdom, and are common ornaments in the military, folk dance groups and education logos and insignia. They are also found on the Lielvārde Belt. Roman Virgil in his 29 BC Georgics (book III, lines 425-439: ) describes the grass snake as a large feared snake living in marshes in Calabria, eating frogs and fish. ==Gallery==

File:Natrix natrix.png|Hunting in early autumn, Sweden File:Ringelnattern3.OGG|Copulation File:Natrix natrix 1.JPG|Grass snake looking out its hideout of water violet in Kirchwerder, Hamburg File:Natrix natrixGrassSnakeRingelnatter 01.jpg|Grass snake in a pond in the nature resort in Zell am See, Salzburg (state), Austria. File:Grass snake eating a frog in forest.jpg|Grass snake eating a frog in the forest in Poland ==References ==