There are three species of snake that are native to Great
Britain, these being the adder, the grass snake and the smooth snake. The
slow-worm is often mistaken for a snake but is actually a legless lizard.
Adder (Vipera berus)
This is the only venomous snake that is found in Great
Britain (it is absent from the whole of Ireland). The venom is used for
catching its prey, mostly mice and voles, but it is not powerful enough to do
much harm to humans. Adders are in any case very timid and are likely to move
away from people rather than towards them.
Adders (also known as vipers) are usually grey or brown in
colour with a characteristic zigzag pattern on the back and a V-shape on the
back of the head. Males grow to about 60 centimetres (24 inches) long and
females can be longer.
They inhabit heaths, moors and open hillsides and are
sometimes found in sand dunes. Shed skins are a sign that adders are likely to
be around. They often bask in groups in early spring; they prefer gentle warmth
to the full heat of the midday sun.
Male adders emerge from hibernation in February or March,
with females appearing a little later. The young are born fully-formed (i.e not
hatched from eggs) in late summer and take up to three years to reach maturity.
Female adders usually become pregnant only every two years.
Grass snake (Natrix
natrix)
Grass snakes (see picture) are larger than adders, with females growing to
120 centimetres (48 inches) in length (males are smaller). They are light green
in colour with black bars on the flanks and dots on the back.
They inhabit damp grass and ditches and the banks of ponds
and streams. They are found throughout England and Wales apart from the far
north-west of England. They are absent from Scotland and Ireland.
Grass snakes are entirely harmless to humans and most
animals, their prey consisting of frogs and other amphibians.
They emerge from hibernation in April, after which courting
and mating take place. Female grass snakes may travel a long distance (up to a
mile) to find a suitable place to lay their eggs, this being somewhere warm
such as a compost or muck heap or a haystack. Many females may choose the same
site, so hundreds of young grass snakes may hatch at the same time, which will
usually be in August or September.
Young grass snakes provide ready meals for birds, hedgehogs
and badgers.
Smooth snake
(Coronella austriaca)
This is by far the rarest of the three British snake
species, being found only on the heaths of Dorset, Hampshire and Surrey. It is
a protected species, the continued future of which is by no means certain. It
is not easy to spot, especially as it tends to bask underneath warm stones
rather than in the open.
The smooth snake grows to 60 centimetres (24 inches) long
and is slimmer than the adder. It can be any colour from grey to reddish brown
with dark spots down the back.
Smooth snakes prey on lizards and small mammals. As it is
neither venomous nor a constrictor, it holds its prey in its coiled body so
that it can get it into position to be swallowed head first.
Mating takes place in May and up to fifteen young are born
in August or September. The young are delivered in a membrane that is easily
broken. Smooth snakes are self-sufficient from birth.
© John Welford
