British Reptiles

There are six species of reptiles native to the UK: adders (also known as vipers), grass snakes, smooth snakes, sand lizards, common lizards and slow worms. Dry heathlands are the best natural habitats for British reptiles, but semi-natural areas with heath-like conditions such as railway embankments, sea walls, road verges, churchyards, golf courses and almost any area with a sunny south facing slope and open vegetation may be suitable.

What is a reptile?

Reptiles have characteristic differences which make them quite distinct from other animals.

  1. Their bodies are covered with scales or horny plates.
  2. They are cold blooded which means they control their body temperature by getting their heat directly from the sun or other warm objects, rather than from the food they eat.
  3. Snakes and lizards have teeth which are continually replaced throughout their life.
  4. Reptiles also shed their skins at least once a year depending on species, and you may find a discarded, colourless skin in summer months. Shedding or 'sloughing' allows the reptile to grow, and helps dispose of parasites, dirt and deposits on the skin.
  5. The adder and the common lizard give birth to live young, but other reptiles lay eggs.

    Unless they are warm, reptiles are very sluggish and make an easy meal for cats, foxes, badgers and birds of prey. Lizards are a favourite food for the red-backed shrike. Maintaining the right body temperature is therefore vital to reptiles' survival. In the morning, they find a warm basking site to heat up their bodies, then later they may move back into the shade because they do not sweat and have to be careful not to overheat. During hot summers, adders will try to move to damper, cooler sites. All British reptiles hibernate, spending the winter in burrows or under logs protected from the cold and predators.

    All snakes can eat their prey whole, as their jaws - surrounded by elastic skin - can open very wide, with the upper and lower jaws able to move separately. Reptiles drink from still water, lizards with the help of their tongues while snakes submerge the front of their mouths.


    These are found all over Britain and are our only snakes with a poisonous bite, but this is rarely fatal to humans. Adult adders are usually up to 66 cms long. Background colouration is a light shade of grey or brown with a black zigzag marking along the length of the back. As with all reptiles, colouration varies and becomes duller as sloughing (skin shedding) approaches. Adders have the most varied diet of British snakes, feeding mainly on field voles, but also mice, lizards, nestling birds, eggs and amphibians.

    Grass snake

    Grass snakes, which are usually around 120 cms long, live in a variety of rough habitats with long grass, and lay their eggs into piles of warm, rotting vegetation. They become rarer the further north you travel and are hardly ever found in Scotland. The background colour is dark green and the body is marked with black vertical bars and spots which run along the sides, and there is usually a collar marking.

    Grass snakes are surprisingly good swimmers and they feed mainly on amphibians such as toads, frogs, newts and small fish.

    Smooth snake

    The smooth snake (length up to 70 cms) lives on heathlands in Dorset, Hampshire and Surrey where it can lay its eggs in sandy soils. These snakes have round pupils to their eyes, greyish background colour with usually two rows of darker brown or black markings along the back. Smooth snakes feed on other reptiles, mostly slow worms and lizards, but small mammals such as pygmy shrews and young birds are also taken.

    Sand lizard

    The sand lizard prefers to lay eggs into shallow hollows dug in sandy soil. Like the smooth snake, it is found mainly in southern Britain, but also on the dunes of the Merseyside coast. These lizards, which can grow to 20 cms, have a grey-beige background with dark brown blotches. Sand lizards have the ability to take food in large quantities when it is freely available and will eat most types of insects, worms, slugs, and can eat their own young too, if necessary.

    Common lizard

    Common lizards (also known as viviparous lizard) can live almost anywhere, but they prefer reasonably warm places with good basking sites and are frequently found on the stony ballast around railway lines. Adults can reach 14 cms and colouration can include shades of brown, grey and dark green. They are insect eaters and also eat small snails.

    Slow worm

    Slow worms are really lizards, but have evolved into a legless form to suit their burrowing lifestyle. Slow worms prefer well vegetated places which give good cover from predators. They have an almost cylindrical body which is hard and smooth to the touch, with a polished-looking grey or brown colouration. The young are shades of coppery gold with vivid dark brown sides. They feed mainly upon slugs, but also eat worms, spiders and snails.

    Losing their tails

    Lizards have the ability to 'self amputate' their tails for protection. The process is known as 'autotomy'. Here's what happens. The tail bones have a special weak spot where a contraction of the muscles at that point causes the bone to break and the tail to become loose. The separated tail continues to wriggle for several minutes which holds the attention of the predator while the tail-less lizard makes its escape. The lizard will grow a new tail, (this can take many months) but this is usually more stumpy than the original and less flexible. Slow worms are also capable of autotomy, but are rarely able to grow a new tail afterwards.


    Reptiles are often needlessly killed. Many people are afraid of snakes, but snakes will usually avoid animals larger than they are. Reptile populations have been decimated by the destruction of sandy heathlands as a result of agriculture, housing developments and other pressures. Changes in farming methods have destroyed the habitat of the g grass snake too. Your local wild life trust will be a ble to tell you what British reptiles can be seen in your particular area a nd how you can help conserve them.


    All native reptiles are protected in Britain under the Wildlife and Countryside Act of 1981 . This protection under law helps counteract the decline of all the species. The law makes it an offence to intentionally kill, injure, sell or advertise to sell any of the six native species. There are some exceptions relating only to those bred and kept in captivity or other extraordinary circumstances - in the past collecting reptiles for the pet trade severely depleted local populations. The 1981 Act also protects the rarest reptiles in Britain, the smooth snake and the sand lizard, by making it an offence, to possess, handle, capture or disturb them.

    Further reading

    Langton, T. (1989) Snakes and lizards, Whittet Books.

    If you don't know where to contact your local wildlife trust, then ask The Wildlife Trusts, The Green, Witham Park, Waterside South, Lincoln LN5 7JR Tel: 01522 544400

    Did you know...

    Grass snakes often play dead when caught, by rolling on their backs, becoming limp and letting their tongues hang from their mouths.

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