Grass Snake Natrix helvetica


Grass Snake Natrix helvetica

Grass Snake attacking a frog in local canal. 6th July 2020. © Peter Hillman

Grass Snake Natrix helvetica

Local canal.
6th July 2020. © Peter Hillman

Family Colubridae

Length up to 100 cm.
Weight up to 20 g.

Also called the Barred Grass Snake, it is a large snake with a distinct collar with two yellow patches. The body colour can vary from olive-green, grey-green, to brownish. There are vertical black bars along the flanks and two lines of alternating black dorsal spots.

The Grass Snake normally hibernates underground, or in deep bracken litter. It emerges in March and normally mates in April. Eggs are laid in June, in damp, warm rotting vegetation, in clutches of 10-40. This is why it is sometimes found in gardens or allotments in compost heaps or manure piles. In August or September the eggs hatch. The snake will release a foul-smelling liquid from its anal gland if handled or if it feels threatened. It will also play dead.

Seen April to October, it can live 10-15 years.

It can bee seen basking in the sun amongst low vegetation, and also seen hunting near water sources for fish and amphibians like frogs and toads. It has numerous back-facing teeth which it uses to seize and grip its prey. Usually it swallows it whole whilst still alive. Frogs and toads are usually seized from behind and swallowed back feet first.

As a superb swimmer, it is commonly found near water like ponds, lakes and canals, and also on commons, in woodland, heathland, hedgerows and gardens. Common throughout England and Wales, rare in northern England and Scotland, and absent from Ireland. Native to Britain.