The NHBS Guide to UK Reptile Identification

Slow worm image by Smudge 9000 via Flickr (CC BY-SA 2.0)

The UK is home to six native species of reptile – three snakes (adder, grass snake and smooth snake) and three lizards (common lizard, sand lizard and slow worm). In early spring, snakes and lizards begin to emerge from hibernation – if you are lucky you may catch a glimpse of one in your garden or when out walking in the countryside. (Interesting note: adders have now been recorded as being active during every month of the year in the UK, a behavioural change which is thought to be linked to overall warmer weather).  

This article aims to provide you with some of the key characteristics of each species which will help you to identify what you’re looking at. You will also find a list of field and identification guides at the bottom of the page which will give you lots more information about each species and help you with your ID.

Snakes

Snakes are part of the suborder Serpentes and, though they vary greatly in size and colour, their limbless, elongated bodies make their overall form very distinct (although some legless lizards, such as the slow worm, may often be mistaken for a snake). The skin of a snake is covered in scales and is a smooth, dry texture – this skin is shed periodically throughout the snake’s life. All snakes are carnivorous and many species have specialised skulls with extra joints enabling them to swallow prey much larger than their heads. Most species are non-venomous and either swallow their prey alive or kill it by constriction. 

All three snake species in the UK reproduce by producing eggs. However, both the adder and smooth snake incubate eggs internally whereas the grass snake lays them in rotting vegetation such as compost heaps. 

Adder (Vipera berus)

Adder image by Jo Garbutt via Flickr (CC BY 2.0)

• Size: 60-80cm in length.
• Colour: Greyish with a dark and very distinctive zig-zag pattern down its back. Red eye.
• 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 very rare as adders are reclusive and would prefer to retreat than confront a human. 

Grass snake (Natrix helvetica)

Grass snake image by Bernard Dupont via Flickr (CC BY 2.0)

• Size: 90-150cm in length.
• 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.

Smooth snake (Coronella austriaca)

Smooth snake image by Odd Wellies via Flickr (CC BY 2.0)

• 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.

Lizards

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.

Although all three species of UK lizard lay eggs, both the common lizard and slow worm incubate these internally, ‘giving birth’ in the late summer. Sand lizards lay shelled eggs that are buried in the sand where they are kept warm by the sun. 

Common lizard (Zootoca vivipara)

Common lizard image by Gail Hampshire via Flickr (CC BY 2.0)

• 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.

Sand lizard (Lacerta agilis)

Sand lizard image by xulescu-g via Flickr (CC BY-SA 2.0)

• 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)

Slow worm image by Oliver Haines

• 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.

In addition to the six native reptiles, several species of non-native reptile can be found in the UK – these include the wall lizard, green lizard, aesculapian snake, European pond terrapin and the red-eared slider.

Recommended reading:

Amphibians and Reptiles
#206083
A comprehensive guide to the native and non-native species of amphibian and reptile found in the British Isles. Professor Trevor Beebee covers the biology, ecology, conservation and identification of the British herpetofauna, and provides keys for the identification of adult and immature specimens as well as eggs, larvae and metamorphs.

Britain’s Reptiles and Amphibians
#174837
This detailed guide to the reptiles and amphibians of Britain, Ireland and the Channel Islands has been produced with the aim of inspiring an increased level of interest in these exciting and fascinating animals. It is designed to help anyone who finds a lizard, snake, turtle, tortoise, terrapin, frog, toad or newt to identify it with confidence.

 

Guide to the Reptiles and Amphibians of Britain and Ireland
#113260
This laminated pamphlet is produced by the Field Studies Council and covers the 13 species of non-marine reptile and amphibian which breed in Britain, as well as the five species which breed in Ireland. These include snakes, lizards, frogs, toads and newts.

 

Field Guide to the Amphibians and Reptiles of Britain and Europe
#246563
This excellent field guide covers a total of 219 species, with a focus on identification and geographical variation. The species text also covers distribution, habitat and behaviour. Superb colour illustrations by talented artist Ilian Velikov depict every species.

 

 

The Amphibians and Reptiles of Scotland
#235838
This book is designed to be an interesting and informative guide to the amphibians and reptiles that are found in the wild in Scotland. The authors have focused on those species native to Scotland, plus those which are non-native but are breeding in the wild.

NHBS Guide to Reptile Survey Equipment

Reptiles play an important role in the function of ecosystems, whether as predators controlling prey populations, or as a source of prey for both birds and mammals. There are eleven species of reptile in the UK, of which six are native and all are protected under UK legislation, with the extremely rare smooth snake and sand lizard protected by additional EU legislation.

Sand lizard Lacerta agilis – Photo: xulescu_g, www.flckr.com

At this time of year reptiles are emerging from hibernation and ecologists are beginning to prepare for the survey season. Reptiles are active between March and October and surveys are carried out in April, May and September when the reptiles are at their most visible. In the main summer months (June – August) reptiles tend to bask less and are unlikely to use any artificial refugia, therefore surveys are not undertaken during this time .

The most common survey methods for reptiles include searching for basking animals on banks, piles of wood and edges of woodland, or laying out artificial refuges like corrugated iron sheets and carpet tiles or roofing felt, which are bedded down well into the vegetation. A wide range of reptile surveying equipment is available to buy on the NHBS website. For any advice please contact our Wildlife Equipment Specialist team who would be happy to help.

Corrugated Reptile Survey Refugia

Corrugated reptile refugia are often used in reptile surveys as they absorb heat and provide shelter from predators, making them an ideal basking spot, especially for slow worms or smooth snakes. The refugia are made from corrugated roofing material (bitumen soaked organic fibres) which is lightweight and waterproof. The material is free from asbestos,non-toxic and is both waterproof and long lasting. The sheets are 2.6mm thick and measure either 500mm x 500mm or 500mm x 1000mm, both with a corrugation depth of 40mm.

Reptile Survey Felt Squares

As with the corrugated refugia above, felt squares also create favourable conditions beneath them for reptiles and are commonly used for surveys, as they are light and will roll up for transport. These tiles are made from bitumen felt and are available in two sizes: 50 x 50cm or 100 x 50cm. 

Snake Hooks 

A snake hook is useful for catching and managing snakes for inspection or translocation. There are two snake hooks available, both made from aluminium which provides a tool which is both strong and lightweight. The standard snake hook comes in two sizes: 100cm or 130cm and has a wooden handle. The telescopic snake hook can be extended from 95cm to a total length of 140cm and the end of the handle has a comfortable rubber grip.

Snake Tongs

Snake tongs are also useful for handling snakes for inspection or translocation. There are two lengths of tongs available: 92cm or 122cm. They are made from an anodized aluminum shaft with a pistol grip handle to provide a lightweight yet strong tool enabling maximum holding pressure with minimal risk to the handler or the snake. 

Snake Handling Gloves

Snake handling gloves are designed to give you protection when handling snakes and to protect you when conducting snake surveys. The gloves are made from leather to minimise the risk of injury from bites and will also help mask your scent. They are available separately for the left or right hand.

N.B. These gloves are not suitable for handling venomous species!

Pesola Light-Line Spring Scale

Native reptile species in the UK range on average from 5 to 100g. Pesola scales are universally acclaimed precision scales which are reliable and durable. The Light-Line range features a transparent tube for panoramic reading and a long, clear double display with coloured marker ring. They are adjusted by hand with a guaranteed accuracy of +/- 0.3% the precision spring is made of corrosion-free, fatigue-resistant alloy, and the scales are impervious to humidity. 

Recommended accessories:

Silva Classic Compass

 

 

 

Rite in the Rain Spiral Bound Notebook

 

 

 

Reptile Holding Bag

 

 

 

dialMax Vernier Dial Caliper

 

 

 

Lifesystems Light & Dry Micro First Aid Kit

 

 

 

WeatherWriter A4 Portrait

 

 

 

A note on licensing

Please note that reptiles in the UK are protected by law. Any reptile survey work must be undertaken by a licensed ecologist. Different levels of license are required for different survey and mitigation methods. For more information, please visit: https://www.gov.uk/guidance/reptiles-protection-surveys-and-licences

If you have any quieries you can contact our Wildlife Equipment Specialist team on 01803 865913 or via email at customer.services@nhbs.com.

 

NHBS Guide: Where to hang and how to maintain your bat box

Natural roosting sites for bats are in decline due to changes in building standards and countryside management practices. Installing a bat box is a simple and affordable way of providing much needed roost space for a variety of species and now is the ideal time to install one, before bats fully emerge from hibernation. However, placing your bat boxes in the correct location and at the correct height is essential to encourage bats to occupy them. With this in mind, we have put together some answers to the most frequently asked questions about bat boxes – covering where and when to put up your boxes, cleaning and maintenance, and the legalities of checking whether they are occupied.

Which bat box should I purchase?

Bat boxes can be placed in trees, on walls and on or in the brickwork of buildings. To help you choose the most suitable bat box based on where you want to locate it, take a look at our three-part series designed to help you make the right choice:  

 

Top 10 Bat Boxes for Trees and Woodland

Top 10 Bat Boxes for Walls and Fences 

Top 10 Bat Boxes for New Builds and Developments

When is the best time to put up a bat box?

Bat boxes can be installed at any time of year, but they are more likely to be used during their first summer if they are put up before the bats emerge from hibernation in the spring. If you are installing bat boxes as part of an exclusion project from a building, it is best to erect the boxes four to six weeks before the exclusion. 

Schwegler 1FF Bat Boxes

Where should I hang my bat box?

All bat boxes should be positioned at a height of 3-6 metres (the higher the better) in an open, sunny position (6-8 hours of direct sunlight, or in a location where it receives the morning sun if this is not possible). Try to install the bat box where it will not be disturbed by bright lights at night such as porch or security lights. 

The most common location to hang a bat box is on a tree using a strong nail that is at least 85 mm in length. It is important to use aluminium nails, as these will not damage a chainsaw (or chainsaw user) should they be left in the tree when it is felled. For more details on how to hang your bat box to a tree, wall or fence, please read our blog on where to hang and how to maintain your nest box, which, although mainly focused on bird boxes, is equally relevant for bat boxes. 

How do I check whether the box is occupied?

Many bat boxes have an opening at the bottom and do not require any maintenance as the droppings will simply fall out of this space. If cleaning is required it is essential that you ensure that the box is not occupied before carrying out any maintenance. Once bats have inhabited a roost site they may only be disturbed by licensed bat workers. If you are unsure whether your bat box is occupied the best way to check for box occupancy is to observe the box at dusk (15 minutes after sunset for around 30 minutes) to watch for any bats leaving. Additionally, you can look under and nearby the box for guano (bat droppings). If there are bats present, wait until later in the season and then check again. It’s also a good opportunity to use a bat detector to identify the bats in your box – take a look at our guide on bat detecting for beginners.

Large Multi Chamber Bat Box

How do I maintain my bat box?

The best time to clean the majority of bat boxes (those suitable for summer roosts) is during the autumn or winter. Once you have ensured the bat box is not occupied you can open the box and clean out any droppings. Whilst you are cleaning the bat box it is a good idea to look for any damage, as this may mean it is unlikely to be used. The most likely damage will be broken seams around the roof, because the constant heating and cooling during the day can warp the wood slightly. To repair this, we would recommend using a roof sealant. 

Head over to the NHBS website to browse our full range of bat boxes. If you have any other questions or would like further advice, please get in touch with our team of Wildlife Equipment Specialists (email: equipment@nhbs.com or phone +44 (0)1803 865913).