Reptiles
Smooth Snake
Coronella austriaca · also called European smooth snake
The smooth snake is the snake almost nobody sees. It is slim, glossy, non-venomous, and so secretive that it can live on a heath for years without being noticed. It also does something unexpected for a small British snake — it constricts its prey, wrapping coils around a lizard nearly its own length and squeezing.
Overview
Coronella austriaca is a slender, non-venomous snake, usually 50 to 70 cm long, grey or grey-brown with rows of small dark spots, a dark stripe through the eye, and a dark mark on the crown. Its scales are flat and unkeeled, which gives it a polished look and its name. It lives across much of Europe in dry, sunny, structurally rich places, and in Britain only on a few lowland heaths.
A lizard hunter that constricts
The smooth snake eats mostly reptiles — common and sand lizards, slow worms, small snakes — and it kills them with constriction, throwing coils around the prey and squeezing before swallowing it head first, often taking animals close to its own length.
Britain’s rarest reptile
In Britain the smooth snake holds on only in Dorset, Hampshire, and Surrey, on the same heaths as the sand lizard that it feeds on, and it is fully protected. It is easily mistaken for an adder, and some are killed on that error, but it has a round pupil, no zigzag, and no venom.
Status
The smooth snake is Least Concern across Europe but declining at the north-western edge. In Britain it is rare, protected, and entirely dependent on the survival of open, well-managed lowland heath.
Smooth Snake: common questions
Is the smooth snake dangerous?
No. The smooth snake has no venom and no fangs able to deliver one, and it poses no threat to people or pets. If cornered or handled it may hiss, jab with a closed mouth, release a foul-smelling musk from glands near the tail, and give a series of small bites, but the tiny teeth do no more than scratch. It kills its prey, which is mostly lizards, by seizing and constricting, not by venom. The main danger runs the other way, in that people who mistake a smooth snake for an adder sometimes kill it, which is one reason British smooth snakes and their sites are strictly protected.
How do you tell a smooth snake from an adder?
Look at the scales, the pupil, and the pattern. The smooth snake has flat, glossy, unkeeled scales, a round pupil, a slim even body, and a pattern of small paired dark spots or bars down the back with a dark stripe through the eye and often a dark heart or crown shape on the head. The adder has keeled, matt scales, a vertical slit pupil, a thicker body with a distinct neck, and a bold continuous dark zigzag down the middle of the back. The adder is venomous; the smooth snake is not. Grass snakes, the third British snake, are larger, greener or greyer, and have a bright yellow-and-black collar.
Where does the smooth snake live in Britain, and can I see one?
In Britain it is confined to a small number of lowland heaths in Dorset, Hampshire, and Surrey, with a few reintroduced populations elsewhere in the south. It is the country's rarest reptile and both the animal and its habitat are legally protected, so there is no casual searching for it. It is also extraordinarily secretive, spending most of its time underground or under cover and rarely basking fully in the open, so even herpetologists carrying out licensed surveys, usually by carefully checking artificial refuges laid out on a heath, may find only a handful in a season. For almost everyone, the smooth snake is a species to read about rather than expect to encounter.
Why is the smooth snake so rare in Britain when it is common in Europe?
Britain sits at the cool, wet, north-western edge of the species' range, where conditions are marginal, and the specific habitat it needs here, dry lowland heath with plenty of lizards, structure, and warm cover, is one of the most reduced habitats in the country. Heath has been lost on a large scale to building, farming, and forestry, and much of the remainder has become overgrown or fragmented. Because the smooth snake breeds slowly, disperses poorly, and depends heavily on the sand lizard and common lizard as prey, small isolated populations struggle to recover from any setback. Its fortunes in Britain are tied directly to the conservation of open, well-managed heathland.