A guide to the British reptiles
There are six native species of reptiles in the UK. Three snakes and three lizards as well as several non-native species.
Adder (Vipera berus)
The adder is the most northerly member of the viper family and is found throughout Britain, from the south coast of England to the far north of Scotland. The adder is Britain’s only venomous snake. It is most often found on heaths, moors and coastal areas, however, it often goes unnoticed. Whilst it has a large range across the UK, recent declines especially in central England, mean it is of major conservation concern.
Grass snake (Natrix helvetica formerly Natrix natrix)
Research showed that Western European grass snakes, including the UK ones, were significantly different from snakes east of the River Rhine, and so merited full species status.
This is the UK’s longest snake, growing to well over a metre in length. Typically grass snakes are grey-green in colour. They have a distinctive yellow and black collar around the neck, with black bars down the sides of the body.
Grass snakes are extremely timid, moving off quickly when disturbed. If cornered they can feign death, and if handled frequently, produce a foul-smelling excretion.
Smooth snake (Coronella austriaca)
The smooth snake is Britain’s rarest reptile, now found naturally only on heathlands in Dorset, Hampshire and only a very few sites in Surrey
They are generally grey or a dull brown colour with black markings arranged in bars or two rows of dots down the back. Smooth snakes nearly always possess a heart-shaped “crown” marking, which covers the top of the head. An eye stripe is usually present, extending from the eyes along the side of the head.
Common lizard (Zootoca vivipara formerly Lacerta vivipara)
The common (or viviparous) lizard is most frequently seen on commons, heaths and moorland. Colouration is commonly a shade of brown with patterns of spots or stripes. Colour variants are not uncommon: everything from yellow through various shades of green to jet black can be encountered.
Sand lizard (Lacerta agilis)
Due to vast habitat loss the species now only occurs naturally on protected heathland sites in Surrey, Dorset, Hampshire and the protected Merseyside dunes systems and they can have quite limited distribution even within these areas.
Thanks to a reintroduction programme, sand lizards have now been re-established at many other sites in these counties and also, its historic range in north and west Wales, Kent, west Sussex, Devon and Cornwall.
Both sexes have brown varied patterns down the back with two strong dorsal stripes. The male has extremely striking green flanks which are particularly bright during the spring. breeding season.
Slow-worm (Anguis fragilis)
Slow-worms are lizards, though they are often mistaken for snakes. Unlike snakes they have eyelids, a flat forked tongue and can drop their tail to escape from a predator. They are widespread throughout the British Isles; it is naturally absent from Ireland.
Slow-worms have a shiny appearance. Males are a greyish brown and females are brown with dark sides. Some females possess a thin line down the back. Juveniles have black bellies and gold or silver dorsal sides, sometimes with a stripe running along the length of the body.
All native reptiles are protected by law in Great Britain. It is illegal to deliberately kill, injure or trade in them.
There is one species of snake, now resident in Britain, probably the result of escape from zoos.
Aesculapian snake (Zamenis longissimus)
Adults uniformly grey, olive or brownish with some light stippling on scales. Two colonies known in the UK: Colwyn Bay, North Wales and Regents Park, London.
There are two further species of European lizard which have gained a firm foothold on the UK Mainland. Both of these species are native to Jersey in the Channel Islands.
The wall lizard (Podarcis muralis)
Some populations occur at a number of sites in Southern England where it is technically a non-native species, having been introduced or escaped into the wild. Pattern and markings are very variable but can be very similar to the viviparous lizard’s. Both male and female can often be coloured quite a bright green – not to be confused with the occasional green tint in the viviparous lizard.
The green lizard (Lacerta bilineata – formerly Lacerta viridis)
This is far and away the largest lizard you are likely to see in this country. It is most unlikely to ever having been native to Britain, although there have been repeated introduction attempts in the past (now, of course, illegal), many of which have survived for a great many years. There is certainly one current breeding colony known in the south of England.
Two terrapin species have become distressingly common in the wild in the UK. They are not however, native. All the individuals in the wild are the result of escapes or deliberate releases.
N.B. The release of exotic species into the wild is a criminal offence under the Wildlife and Countryside Act 1981.