Reptile biology and general information

Six species of reptile are native to the UK: three species of lizard and three species of snake. Reptiles are ectothermic, relying on external sources of heat to raise their body temperatures to that required for activity. All UK reptile species hibernate from September/October until the spring, emerging in March/April.

Slow-worm Anguis fragilis

The slow worm is not a snake but a legless lizard and, like lizards, can shed its tail to escape predators. Slow worms have a characteristic shiny appearance with females being brown, males blue-grey and juveniles and sub-adults a pale golden colour. Their diet consists of slow moving prey such as slugs and young crickets. Slow worms give birth to live young in September.

Habitat: Slow worms are found in a wide range of habitats, including gardens and allotments, tussocky grassland and beside railway lines.

Common or viviparous lizard Lacerta vivipara

These brown lizards are up to 15cm in length, with patterns of spots and stripes along their bodies. Common lizards feed on insects, earthworms and snails, shaking their prey to stun it before swallowing it whole. Common lizards give birth to live young.

Habitat: Common lizards are found in a wide range of habitats, including heathland, sand dunes and grassland. This species is less likely to be found in urban and suburban areas than the slow worm.

Sand lizard Lacerta agilis

Sand lizards are rare in Britain and can now only be found in areas of heathland in southern England except for one population on the Merseyside coast. Sand lizards are stocky, with blunt snouts and short tails. The females are grey-brown and males brown-black with green flanks, getting brighter during the breeding season. Sand lizards feed predominantly on insects but may also eat fruit and flowers. They lay eggs which hatch in August/September.

Habitat: As its name suggests, this species is restricted to sandy habitats on heathland and sand dunes.

Adder Vipera berus

The adder can be easily recognized by a dark zig-zag stripe along its back, with males being grey green, and females reddish brown. Adders strike their prey, such as lizards and rodents, and inject them with venom. Live young are born in August and all exhibit the reddish female colouring, regardless of gender.

Habitat: Adders tend to inhabit open areas such as heathland and sea cliffs and prefer undisturbed countryside.

Grass snake Natrix natrix

The grass snake is the largest of the UK snakes, occasionally growing to over a metre in length. They are grey-green with a distinct yellow and black collar. Often found close to water, the grass snake feeds on fish and amphibians and is a strong swimmer. Eggs are laid in compost heaps, manure piles and rotting vegetation and hatch in August/September.

Habitat: Found close to water along river banks and ponds but may also be found in hedgerows and farmland.

Smooth snake Coronella austriaca

The smooth snake is a small grey or brown snake with unkeeled scales, giving them a smooth appearance. Smooth snakes are constrictors, coiling tightly around their prey and then swallowing it whole. This species is very rare in England, and is found in heathland areas of southern England. Live young are born in September.

Habitat: Smooth snakes prefer dry habitats, in particular heathland and open woodland.

Threats

While slow worms, common lizards, adders and grass snakes are considered relatively common and widespread in Britain, the sand lizard and smooth snake both have very restricted ranges as a result of loss and fragmentation of their heathland habitat.

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