slow worm

UK Reptile ID

April 1, 2025 by Admin

Written by Paul Arestides, Transforming Lives Trainee

The UK is home to six native species of reptile – three snakes (adder, grass snake and smooth snake) and three lizards (common lizard/ viviparous lizard, sand lizard and slow worm).

In early spring, snakes and lizards will start to emerge from brumation – if you are lucky you may see one or more in your garden or when out walking in the countryside.

All three species of snake in the UK reproduce by laying eggs. The adder and smooth snake incubate eggs internally and then ‘give birth’ to live young. The grass snake lays eggs externally in rotting vegetation, for example, compost heaps.

Take a look below for some more fascinating facts about the UK’s native reptiles.

Grass snake (Natrix helvetica)

Size: 90-150cm in length (females tend to be the longest)

Colour: Usually greenish in colour, with a yellow and black collar, pale belly and dark markings down the sides.

Habitat: Favours wetland habitats but can also be found in grassland and gardens, especially those with a pond!

Interesting fact: The grass snake is the longest snake found in the UK.

Adder (Vipera berus)

Size: 60-80cm in length. Very stocky.

Colour: Grey (males)/ brown (females) with a dark and very distinctive zig-zag pattern down its back. Red eyes.

Habitat: Prefers woodland, heathland and moorland but may also be found in grassland or on the coast.

Interesting fact: The adder is the only venomous snake in the UK. However, bites are exceptionally rare as adders are reclusive and would prefer to retreat than confront a human. The last recorded death from an adder bite in the UK was in 1975.

Smooth snake (Coronella austriaca)

Size: 50-70cm in length.

Colour: Usually dark grey or brown in colour. Similar to an adder but with a more slender body and without the zig-zag pattern along its back.

Habitat: Very rare. Mainly found on a few sandy heaths in Dorset, Hampshire and Surrey, although a couple of reintroduced populations exist in West Sussex and Devon.

Interesting fact: The smooth snake is a constrictor, coiling around its prey to subdue it and crush it to death

Most lizards have four legs and run with a side-to-side motion. However, some, such as the slow worm, are legless. Lizards are mainly carnivorous and often employ a ‘sit-and-wait’ approach to catching prey. In the UK, lizards feed primarily on insects, molluscs and spiders.

Sand lizard (Lacerta agilis)

Size: Up to 20cm.

Colour: Female sand lizards are a sandy-brown colour, with rows of dark blotches along the back. Males have green flanks that are at their brightest during the breeding season, making them easy to spot.

Habitat: The sand lizard is very rare and can only be found on a few sandy heaths in Dorset, Hampshire and Surrey with a few reintroduced populations in the south east, south west and Wales.

Interesting fact: Sand lizards dig burrows for overnight refuge and hibernation.

Slow worm (Anguis fragilis)

Size: 40-50cm.

Colour: Smooth, golden-grey skin. The males are paler in colour and occasionally have blue spots. The females tend to be larger with dark sides and some have a dark line down their back.

Habitat: Slow worms live in most of Great Britain apart from Northern Ireland and are also present on most of the islands in Scotland and the Channel Isles.

Interesting fact: Although similar in appearance to a snake, the slow worm has eyelids (which snakes do not) and can drop its tail when threatened by a predator.

Viviparous/ common lizard (Zootoca vivipara)

Size: 10-15cm in length.

Colour: Variable, but most commonly a brownish-grey, with rows of darker spots or stripes down the back and sides. Males have bright yellow or orange undersides with spots, while females have paler, plain bellies.

Habitat: Heathland, moorland and grassland.

Interesting fact: If threatened by a predator, the common lizard will shed its tail which continues to move – the lizard uses this distraction to make its escape. Although able to regrow its tail, the new one is usually shorter than the original.

Help us by becoming a citizen scientist! Reptiles are widely under-reported and we want your records to see how well reptiles are faring in the UK. Download our free Dragon Finder App to get started.

What our animals are doing this month…

July 1, 2024 by Admin

Written by Emma Byrne, Transforming Lives Trainee

July is a month full of activity for our reptile and amphibian friends! This month, let’s take a closer look at the UK’s only species of legless lizard, the slow worm, and see what they’re up to throughout this warm, summer month…

Slow worms emerge from hibernation in late March, with breeding taking place in April and May. The gestation period is around 11 – 14 weeks, so from July until September, slow worms are giving birth! They are ovoviviparous, which means that females incubate their eggs internally. The eggs hatch inside the slow worm’s body, and the young stay there living off the yolk of their egg. The female will then go on to give birth to between eight and twelve live young. Hatchlings are born still wrapped in their embryonic membranes, which burst open to reveal tiny slow worms, little more than four centimeters long. They can be identified by their gold or silver backs with a black stripe down the middle, a black dot on their head and glossy black sides.

If you hope to spot a slow worm, here are a few helpful tips:

Head out at dusk as this is when slow worms tend to be most active hunting for food.
Make a beeline for open woods, damp heaths, rough grassland and grassland and meadows with hedges and scrub.
If you prefer to stay closer to home – take a look in your garden. Be sure to keep a close eye on your compost heap, as slow worms like to use the warmth to heat up their bodies!
If you’re unsure whether you have a found a slow worm or a small snake, remember unlike snakes, slow worms have eyelids, small ear openings, their tail is detachable and they have notched tongues as opposed to forked tongues.

Always remember to record your amphibian and reptile sightings on our FREE Dragon Finder app.

International Men’s Day: male species

October 19, 2023 by Admin

Written by Chloe Davey, Transforming Lives Trainee.

Ever since I was a young girl, I’ve always had strong bond with nature. Where did this fascination and passion begin? I’ve quite a few people inspire me growing up, I would watch David Attenborough and Steve Backshall every time they were on tv. However, my biggest influence is my dad. He’d take me out on regular walks around nature reserves, identifying every butterfly, bird and animal we came across. As a thank you to these great men and to celebrate International Men’s Day, I would like to discuss some of our native male reptile and amphibian species.

Amphibians

Great crested newt males are easily identifiable with their long, wavy crest stretching across it’s back and tail. However, this magnificent crest can only be seen during mating season to help attract a female. These sweethearts even perform a special courtship ‘dance’ by standing on their front legs and waving their tail from side to side. Male toads, along with the other amazing creatures I will be discussing are smaller than their female counterparts. In breeding season, the males will migrate to the pond they were born, eagerly waiting for the female’s arrival. Froglife has an amazing project called ‘Toads on Roads’ where you can volunteer and get to see this migration for yourself.

A male great crested newt swimming in a pond

Reptiles

Male reptiles visually differ from their female counterparts as they are more colourful. Male slow worms are easily identifiable as they are mostly pale, but can sometimes have small blue scales. Male adders similarly are also pale in colour, but instead have a dark zig-zag pattern stretched across their back. I must admit my favourite male of our native species is the adder. I love its contrasting design of light grey body with a dark and striking pattern.

Male adders are grey or silver along their sides, unlike females which are brown (Photo: Matt Wilson).

I’m always thrilled to see these wonderful creatures and help maintain their habitats. As I said, my dad has always encouraged my love of nature. Now when we go on nature walks, we teach each other about the animals we’ve seen.

Is there someone who has inspired your love of nature?

Reptile Awareness Day

September 28, 2023 by Admin

Written by Jade Walton, Transforming Lives Trainee

The 21^st October marks Reptile Awareness Day, and what better way to celebrate than to learn some interesting facts about our six native reptile species!

In the United Kingdom we have six native reptiles, three snakes and three lizards.

Our snakes are:

Grass snakes

Smooth snakes

and adders

Our lizards are:

Common lizards

Sand lizards

and slow-worm

Each of these reptiles have interesting facts about them that easily set them aside from their other reptile counterparts.

Firstly, lets look to our snakes. Adders are our only venomous species, though not particularly dangerous to most humans, it is best to keep your dog on a lead when walking in areas inhabited by adders. Adders are surprisingly small, usually measuring between 60cm and 80cm when fully grown. Females birth live young that are less than 20cm long.

Next, we come to the smooth snake. Just like their adder relatives, smooth snakes are quite short in length, usually growing to around 60-70cm. These are the rarest of our UK reptile species, only to be found in specific heathland sites. Smooth snakes are also the only snake in the UK to constrict their prey.

Our final snake is the grass snake. Easily the UK’s longest snake growing to around 150cm, they are also the only native snake to lay eggs rather than birth live young. This is a contributing factor as to why they are not found in Scotland as they need warm enough temperatures through the summer months for their eggs to incubate.

Our other three reptile species are types of lizard. Sand lizards are another rare UK reptile as their habitats are greatly limited to certain sandy heathlands. The sand lizard is our only lizard in the UK to lay eggs, which they bury under sand in sunny areas to allow for them to incubate. Like our other lizards, they can drop their tails as a defence mechanism against predators.

Common lizards are widespread throughout the UK, though their numbers are thought to be declining due to habitat loss. They are fairly often mistaken for newts as they are quite similar in appearance, the best way to tell the difference is to see the scaly skin of the lizard versus the smooth skin of the newt, they also move a lot faster.

Our final, and perhaps most confusing reptile is the slow-worm. Many could mistake a slow worm for a snake, given they have no legs, but they are, in fact, a lizard. They are distinguished from snakes by their ability to blink and drop their tails when threatened.

What our animals are doing this month…

October 20, 2022 by Admin

Slow worms in the UK will spend autumn preparing for hibernation, foraging and feeding on slow-moving prey such as slugs. They will hibernate between November and March, but further North, slow worms will have retreated to their hibernation sites in mid-October. Keep an eye out incase you see any before they hibernate!

Slow worms are a type of legless lizard and are often mistaken for snakes. However, unlike snakes they can blink as they have eyelids! They have a flat, forked tongue alongside the ability to drop their tails if attacked by predators. Slow worms are widespread throughout Britain but are absent from Ireland.

They can grow up to 40cm in length with males having larger heads and are usually shades of light to dark brown. Females have dark flanks and they can sometimes have a dorsal line along their body.

Always remember to record your amphibian and reptile sightings on our FREE Dragon Finder app. All of the data collected is sent to the National Biodiversity Network Atlas. You can download the app here.

Reptiles in London

February 28, 2022 by Admin

Although London is a large urban landscape, it is home to a wide range of fauna and flora. One group of London wildlife that is often overlooked are the reptiles. London is home to four native reptile species: Adder, Grass Snake, Common Lizard and Slow-worm.

If you are inspired to go out and look for London’s reptiles, here’s a couple of site suggestions for 3 of the most common species to find around the capital from courtesy of our London team.

Common Lizards:

Little Wormwood Scrubs, Kensington & Chelsea

Slow-worms:

Lesnes Abbey, Bexley

Grass Snakes:

WaterWorks Nature Reserve, Waltham Forest

Remember to report your reptile sightings (including juveniles and eggs) on our free Dragonfinder app.