The UK is home to three distinct native snake species. These reptiles inhabit various environments across the landscape, playing a part in the country’s ecosystems. Understanding these snakes involves recognizing their characteristics, preferred habitats, and appropriate responses if an encounter occurs.
Native UK Snakes
The UK’s native snake population comprises three species: the adder, the grass snake, and the smooth snake. The adder (Vipera berus) is the sole venomous snake native to the UK. Adders are typically greyish, with males silvery-grey and females reddish-brown. They are recognized by a prominent dark zigzag pattern along their back and a V or X-shaped marking on their head. These snakes generally measure between 50 to 80 centimeters in length.
The grass snake (Natrix helvetica) is the longest of the UK’s native snakes, with females reaching up to 150 centimeters and males typically up to 100 centimeters. This non-venomous species usually exhibits an olive-green to grey-green coloration. A distinguishing feature is the yellow and black collar behind its head, often accompanied by black spots or bars along its sides. Grass snakes can swim and may feign death or release a foul-smelling substance if threatened.
The smooth snake (Coronella austriaca) is the rarest of the three native species. It is more slender than the adder, typically growing to lengths between 45 and 55 centimeters, though some can reach 70 centimeters. Smooth snakes are usually grey or brown with a darker, less distinct pattern on their back compared to the adder’s prominent zigzag. They possess round pupils and sometimes a heart-shaped mark on their head. These snakes are secretive, often remaining hidden.
Habitats and Distribution
Native UK snakes occupy a range of habitats across the country. Adders are widely distributed throughout mainland Britain, though absent from Ireland. They are commonly found in open habitats such as heathlands, moorlands, woodland edges, coastal dunes, and rough grasslands. Adders seek out undisturbed areas and sunny spots for basking, which helps regulate their body temperature.
Grass snakes are widespread across England and Wales but are not found in Scotland or Ireland. They prefer damp environments, including ponds, rivers, and marshes, but also inhabit grasslands, woodlands, and hedgerows. Gardens, particularly those with compost heaps, can attract grass snakes as decaying vegetation provides warmth for their eggs.
The smooth snake has a much more restricted distribution, primarily found on sandy heathlands in specific areas of southern England, including Dorset, Hampshire, Surrey, Devon, and West Sussex. These snakes prefer mature heather and often conceal themselves under stones, logs, or other debris in sunny locations rather than basking openly. Their specific habitat requirements make them vulnerable to habitat loss.
Encountering UK Snakes
Encountering a snake in the UK is a relatively rare event, as these animals are generally timid and prefer to avoid human interaction. If a native snake is sighted, observe it from a distance and avoid disturbing it. All native UK snakes are protected by law, making it illegal to intentionally injure, kill, or sell them. Most snakes will move away on their own if given space.
Should an adder bite occur, immediate medical attention is necessary. While uncommon and rarely fatal, adder bites can cause symptoms such as pain, swelling, bruising, nausea, and dizziness. Remain calm and keep the bitten limb as still as possible, preferably below the level of the heart, to help slow any potential spread of venom. Do not attempt to apply a tourniquet, cut the wound, or suck out the venom. Providing medical professionals with a description of the snake’s color and pattern can be helpful for treatment.
Identifying an adder can be done by looking for its distinctive dark zigzag pattern along its back and a V or X-shaped mark on its head. Grass snakes feature a yellow and black collar, while smooth snakes have a less defined pattern and round pupils. If the snake does not move away or appears injured, contacting organizations like the RSPCA for advice is appropriate.