Adder

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Adder - Vipera berus.JPG
Scientific Name: 
Vipera berus
Life Span: 
Average 2-3 years but up individuals living up to 10 years have been recorded in the wild.
Length: 
Adults usually up to 65cm in length. Exceptionally 90cm.
Description: 

An often thick-bodied viper with a flat snout, nearly always several large scales on the top of the head. Most adders have a clearly marked dark, zig-zag vertebral stripe. In rare cares the stipe can be sraight edged, broken up or even absent.

Colouring varies accroding to sex: many males are very contrasting especially in the spring, often being very whitish or pale grey with intense black markings; females are frequently brownish or reddish with dark brown markings. Othe colour combinations exist and entirely black specimens may be common -up to 50% in some populations (black animals are thought to absorb heat more effectively). Young animals are often reddish. Belly is grey-brown, or black, sometimes with white spots; tail tip yellow, orange or even red beneath. All adders have a vertical pupil in the eye and a red iris.

Distribution: 

Occurs over much of Europe and is widespread across England, Wales and Scotland but its precise distribution is rather patchy.

Habitat: 
Occurs in a wide variety of habitats including moors, heaths and dunes, and in bogs, open woods, field edges, hedgerows, marshy meadows, and even salt marshes. Adders may travel 0.5-2km, from the areas where they hibernate (and often mate) to their feeding grounds and males may travel up to 200m in a day during the breeding season.
Reproduction: 
Courtship and maing take place in spring. In the presence of a female, rival males sometimes engage in ritual combat where, with bodies entwined and the front halves often raised off the ground as they wrestle. The victor gains access to the female. A female Adder gives birth to around 12 young. At the moment of birth, the young are still constrained by a thin membrane that is soon ruptured. From the moment they are born the young are venomous and armed with hollow, needle-like fangs with which the venom is delivered.
Behaviour: 

Adders seem to spend more time basking and sun-bathing than our other snakes and consequently are encountered on a regular basis. Hibernation takes place from October to March, although in northern parts of the region their appearance in spring may be delayed by up to a month.

In hunting, an adder will usually quickly bite a prey item and then release, the prey animal often wanders off a short way before it dies, and in due course the adder follows it, using its sensitive tongue to 'taste' the route of its prey. Satisfied that the prey is dead, the smake swallows the prey whole - usually head first.

Status: 
Although the adder is by no means rare, it has disappeared from many haunts where it occurred as recently as 50 years ago. Its increasingly fragmented distribution can only have adverse long-term implications for the species' future in the region.
Did You Know?: 

Although these snakes are venomous, they will only bite as a form of defence and only if provoked by being handled or otheriwse physically disturbed. Bites although painful are not fatal except in extremely rare cases.