Adder: common viper, Vipera berus berus

A small venomous Eurasian snake which has a dark zigzag pattern on its back and bears live young. 

It is the only poisonous snake in Britain

Adders are one of only three UK snakes. They can be found evenly distributed all over mainland UK and are Scotland's only resident snake. Ireland has no snakes. They are able to stand colder temperatures than the grass snake and smooth snake and are found far north in Scotland as a testament to this ability.

If you are walking in a country park or common you may just get a glimpse of this stunning creature. Our native adder does have a toxic bite so be careful when jumping around in heather so as not to disturb him. As with all our snakes they are very timid and far more fearful of you. They are not aggressive but will defend if disturbed. Adders will always flee from pets and humans. As a child I loved these and would watch them for hours.

Their movement is fast and the markings are both striking and spectacular.

They usually only bite when trodden on or picked up . In many cases the first bite is not toxic and is often a warning. However if you have been bitten please go to the nearest hospital immediately.

While it is estimated that the adder is thought to have claimed the lives of around 10 people within the last 100 years or so, our modern knowledge about snake bites and good access to medical care have greatly reduced the threat that they pose to life. 

Only those that are susceptible to anaphylactic shock (hypersensitivity allergic reaction in humans and other mammals) are at major risk. The venom of the adder is actually quite strong, however, adders do not inject a large amount at any one time or strike repeatedly as with other venomous snakes making them less risk. The elderly, the young and those in ill health are most at risk from the Adders bites.

Adders use venom to immobilize prey. After striking their prey, they will leave the venom to take effect before following the victim’s scent to find the body. This is an economical way of hunting, avoiding any damage that could be caused by struggling with prey. Adders diet consists mainly of small mammals, including voles, shrews, mice, lizards, young birds and frogs.If you find a snake, stay calm, don't touch it, and don’t panic. It’s rare to have one in the garden so treasure it.They do a lot of good and nature has a role for them. There’s no need to be scared because if left alone they will go away.

Adders are found in a variety of habitats, including chalky downs, rocky hillsides, moors, sandy heaths, meadows, rough commons, edges of woods, sunny glades and clearings, bushy slopes and hedgerows, dumps, coastal dunes and stone quarries. Adders will venture into wetlands if dry ground is available nearby. Therefore, they may be found on the banks of streams, lakes and ponds. They usually prefer open ground with grass cover as food is abundant. The easiest time to spot adders is during the spring when they are searching for a mate or when they are sunbathing on sunny rocks or banks.

If you use netting in your garden please ensure it is about 4cm square to reduce the risk of a snake being caught in it. Snakes slither through the netting to get to food like frogs and toads and fish. After they have eaten they are often unable to get back through and get stuck. They are about length: 50-65cm. Females are larger than the males. Adders are relatively short and robust with large heads and a rounded snout. The red-brown eyes have vertical elliptical, rather then round, pupils - a feature of all venomous snakes. Males are usually a grey or buff colour with vivid black markings, although they can also vary from silver to yellow or green in colour. Females are brown with dark red-brown markings that are less prominent than in the males. Both sexes have a zigzag pattern running along the back with a V, H or X-shaped marking at the rear of the head, although this zigzag pattern may be replaced by a straight brown stripe with dark spots on either side. Adders have black undersides. Melanistic or black individuals sometimes occur in more mountainous regions.

Adders are active during the day, spending time basking until their body temperature is high enough to hunt for food. In some of the hotter countries of their range, they may emerge at dawn and dusk to avoid the intense heat. Their only real predator is the buzzard but they are under threat from loss of habitat due to human intervention.

Adders typically hibernate from September to March in log piles or in the abandoned burrows of small mammals in high dry soil. There can be as many as 100 adders in a Hibernacula. Males emerge from hibernation 2-5 weeks before the females and shed their skin before setting off in search of females.

Mating takes place between April and May after hibernation, with males often fighting for females. They rear up at each other and try to push the head of their opponent onto the ground. Eventually, one male will give up and search for another mate this is called “the dance of the adders”

Males follow the females around until she allows them to copulate with her. This takes place in April-May. Adders have a 3 to 4 month gestation period before giving birth and are one of the few snakes that are viviparous (give birth to live young). 

Females give birth in August or September to between 5 and 20 live young although usually the number is between 6 and 10. The young remain close to their mother for a few days,. They are exact replicas of their parents in every way . They are between 14-20 cm long and will live off their yolk sacks before going off in search of food. Females do not breed on consecutive years, as they do not have time to build up sufficient fat reserves to produce another set of young from one breeding season to the next. If the climate is harsh they many not breed for three years.

Adders are protected under the Wildlife and Countryside Act 1981 from being killed, injured or sold.

QUICK FACTS

Diet

Voles, shrews, mice, lizards, young birds and frogs

Physical

Length: 50-65cm. Females larger than males. Males are usually a grey or buff colour with vivid black markings. Females are brown with dark red-brown markings that are less prominent than in the males. Zigzag pattern on back with a V, H or X-shaped marking at the rear of the head.

Age

They can live to 30 years old

Habitat 

Chalky downs, rocky hillsides, moors, sandy heaths, meadows, rough commons, edges of woods, sunny glades and clearings, bushy slopes and hedgerows, dumps, coastal dunes and stone quarries. In wetlands if dry ground is available nearby.

Reproduction

Adders are sexually mature at 3-4 years old.

Mating takes place between April and May after hibernation,

Males follow the females around until she allows them to copulate with her. This takes place in April-May.

Females give birth in late August to between 5 and 20 live young. Females do not breed on consecutive years.

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