Feeding Barred grass snakes are semi-aquatic and prey mainly on
amphibians, especially
common toads and
common frogs; they also eat fish, some small land mammals and nestling birds, and may occasionally take ants and their larvae. Captive snakes have been observed accepting
earthworms offered by hand, but they never take dead prey items.
Habitat Barred grass snakes are strong swimmers and can be found near freshwater. However, there is evidence that individual snakes do not always require bodies of water throughout the entire season. The preferred habitat appears to be open woodland and "edge" habitats, such as the edges of fields and woodlands. These areas 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 such areas may explain why they are associated with ponds and water. Barred grass snakes also inhabit gardens and parks in their native range, as well as dry grasslands. Like most reptiles, barred grass snakes are at the mercy of the thermal environment and need to overwinter in areas that do not freeze. They typically spend the winter underground, where the temperature is relatively stable.
Reproduction ,
England) As spring approaches, the males emerge first and spend much of the day basking in an effort to raise their body temperature and increase their metabolism. This may be a tactic to maximise sperm production, as the males mate with the females as soon as they emerge up to two weeks later in April, or earlier if environmental temperatures are favourable. The leathery eggs are laid in batches of eight to 40 between June and July, and hatch after around 10 weeks. In order to survive and hatch, the eggs require a temperature of at least , but preferably , with high humidity. Areas of rotting
vegetation, such as
compost heaps, are preferred locations. The young measure about in length when they hatch and are immediately independent.
Migration After breeding in the summer, barred grass snakes tend to hunt and may travel long distances during this time, moving up to several hundred metres in a day. 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 their mouths. They rarely bite in defence. When caught they often regurgitate the contents of their stomachs. Barred grass snakes display a rare defensive behaviour involving raising the front of their bodies and flattening their heads and necks so that they resemble
cobra's hoods. 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 in France, Germany, Austria, Romania, and Ukraine, and thus overlapped 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 protect against predatory birds that migrate to Africa for the winter and encounter cobras there. However, such behaviour is not reported for the species in Britain. Before its reclassification in 2007, the grass snake was included on the updated UK
Biodiversity Action Plan as a species in need of conservation and greater protection. ==References==