About Adders - Adder Snakes Facts & Information

UK's Only Venomous Snake

The Adder is the UK's only native venomous snake. The zig zag pattern on its back and its red eye are features that make this snake recognisable.

Male adders and female adders exhibit different physical traits. Males are generally darker, often displaying a dark brown or even grey colouration with a distinct zig zag pattern, while females tend to have a more reddish brown or brown hue background colour, with darker brown markings.

Adders can be distinguished from other reptiles like the grass snake and the smooth snake by their viper family traits and the unique zig-zag pattern on their backs.

They are small to medium-sized snakes, with length typically ranging from 50 to 70 cm. Young adders, or juveniles, often have a more vivid pattern compared to adults.

Adders are protected under the Wildlife and Countryside act, so it's illegal to kill, harm or sell the Adder populations.

Are Adder Bites Harmful?

The Adder (Vipera berus) is the only venomous snake native to the UK. Although an adder bite can be alarming, it is crucial for humans to understand the nature and potential effects of the bite. The venom of an adder is designed to immobilize and digest prey, which primarily includes small mammals, frogs, and lizards.

Adder bites are rarely fatal to healthy adults but can be more serious in young children, the elderly, or individuals with pre-existing health conditions. If bitten, seek medical attention immediately.

Don't worry too much though, it's estimated that there are only around 50 Adder bites per year.

Do Adders Hibernate?

In the UK, Adders typically enter hibernation from late autumn to early spring. The exact timing can vary based on local climate conditions and temperature fluctuations.

The hibernation period usually lasts from November to March, though it can be slightly shorter or longer depending on weather patterns and regional variations.

Adders seek out sheltered sites for hibernation. These can include burrows, rock crevices, leaf litter, or under fallen logs. The key is to find a place that is warm rock offers protection from extreme cold and predators.

Adder Lifespan

In the wild, adders typically have a lifespan of 10 to 15 years. This range can vary based on factors such as habitat quality, food availability, and predation pressure.

In captivity, where threats from predators and harsh environmental conditions are minimised, adders can live longer. They might reach up to 20 years or more, depending on the care provided and the conditions in captivity.

What Do Adders Eat

Adders primarily feed on small mammals such as voles, mice, and shrews. These animals provide a substantial amount of energy and nutrients for the adder. They will also prey on ground nesting birds.

In addition to mammals, Adders also consume Amphibians like frogs and toads. These are often part of their diet, especially in environments where small mammals are less abundant.

Adders occasionally eat other reptiles, including lizards and, less commonly, smaller snakes. This can vary based on the availability of prey in their habitat.

Adder Habitat

Adders are commonly found in woodland habitats, particularly in areas with a mix of open spaces and dense cover. They often prefer deciduous woodlands where they can find ample underbrush and leaf litter to hide and hunt.

Adders also inhabit heath land habitats and moorland areas, where the open, often rocky terrain provides ideal basking spots. These habitats typically feature a mix of heather, gorse, and bracken, which offer both cover and a warm environment for basking.

In addition to woodlands and heath lands, adders can be found in grassland habitats. They favor areas with long grass and patches of low vegetation, which provide both concealment and hunting opportunities.

The Adder is classified as a priority species under the Wildlife and Countryside Act due to habitat loss and declining numbers. Despite this, they are currently listed as of least concern.

To increase your chances of spotting an adder, look in sunny, open areas within their preferred habitats during the spring and summer months

Breeding Season

The breeding season for adders (Vipera berus) typically occurs in the spring, following their emergence from hibernation. In the UK, this period generally spans from April to June. As the temperatures rise and the days become longer, adders become more active and begin to engage in courtship and mating behaviours.

During the breeding season, males often engage in courtship displays to attract females. These displays may involve ritualistic behaviours such as wrestling, where two males will entwine and push against each other to demonstrate strength and stamina. This behaviour helps establish dominance and attract potential mates. In addition to physical displays, males may also use pheromones to communicate their readiness to mate.

Once a male adder successfully courts a female, mating occurs. After mating, females will fertilise their eggs internally. The process of gestation lasts approximately 3 to 4 months, depending on environmental conditions.

As the summer progresses, the female adder will carry the developing embryos until they are ready to be born. The birth typically takes place in late summer, around August to September. Females usually give birth to a litter of 4 to 20 young, depending on their size and condition. The newborn adders are fully formed and able to hunt for small prey almost immediately.

Adder Threats

While adders have few natural predators, they are still at risk from larger animals such as birds of prey and mammals.

Additionally, competition with other species, including non-native predators, invasive species, domestic animals and can affect their ability to find food and shelter.

Invasive species can disrupt the ecological balance and reduce the availability of prey.

Five Facts about Adders

1. Adders are the UK’s only native venomous snakes, using their venom to immobilise and digest small mammals, amphibians, and sometimes other reptiles.

2. They are recognised by their distinctive zig-zag pattern on their backs, which can vary in color from brown and grey to reddish hues, and have a characteristic "V" shape on their heads.

3. Adders inhabit a variety of environments, including woodlands, heath lands, grasslands, and moorlands, where they need both sunny basking spots and areas of cover like leaf litter or undergrowth.

4. They hibernate from late autumn to early spring, seeking shelter in burrows, rock crevices, or leaf litter to survive the winter months.

5. In the wild, adders typically live for 10 to 15 years, although they can live longer in captivity due to fewer threats.