Adder Bite in the British Army 1979-1988: A Decade of Experience

Viperidae 3 . The adder is a snake which rarely grows larger than 60 cms. It may be distinguished by dark zig-zag markings along its back although they may be obscured if the background colour of the snake is itself dark. Thus, some individuals may be dark red or black. More usually, they are grey or brown. One feature, however, which tends to be constant is the prominent V shaped marking at the back of the head 4 • This may help identify the snake although the only reliable method is to examine the scale type and pattern. The adder's eye is elliptical with a typical viperid vertical slit, as opposed to the round eye shapes ofthe grass and smooth snakes!. Vipera herus is a wide ranging snake which is found throughout the United Kingdom and European continent from Northern Spain and Italy up to the northern regions of Scandinavia. In its more southerly habitats it overlaps with the northerly distribution of some other viperid snakes namely the aspic viper, Vipera aspis, the meadow viper, Vipera corsinii, and the sand viper, Vipera ammodytes 4 • The adder may be distinguished from the others by virtue of the inverted V shape at the back of its head and its preferred habitat. The snake prefers dry, sandy heathland and forest edges. Nevertheless, occasionally it may be found in wetter places. This is especially true when the weather is hot. At such times the reptile may withdraw to areas offering dampness and shelter 5 • The adder exhibits marked seasonal variations in its habits. It goes into hibernation when the autumn temperatures begin to fall. This hibernation will last until spring, usually March, and the snake will resume feeding 5 • Mating takes place in April or May and the young are born in the summer. These timings are approximate but are significant since they are clues to the activity levels of the snake. Thus, when emerging from hibernation the reptile will be sluggish but will possess a full load of venom 5 . During the mating season the snake is likely to be maximally active with a gradual slowing down during late summer. This pattern of activity is of importance in its effect upon human activities. In common with nearly all snakes, the adder will make an attempt to avoid human contace. However, if cornered or surprised the snake will attack. Its defensive posture is one of a loud hissing followed by a strike 8 . Notwithstanding this, many encounters with the adder are inadvertent. Equally, a proportion of adder bites are sustained whilst actually handling the snake 5 •