Asp, European asp, Aspic viper, European viper, Jura viper
The Asp viper (Vipera aspis) is a venomous snake found in southwestern Europe. Bites from this species can be very painful and about 4% of all untreated bites are fatal.
The head of the Asp viper is broad, triangular, and quite distinct from the neck. The tip of the snout is slightly but distinctly upturned. The rostral scale is generally higher than it is wide, touching 2 to 3 scales on the upper side of the snout. Dorsally, the snout is flat with distinct and slightly raised sharp margins. The nasal scale is single (hardly ever divided) and separated from the rostral by a single nasorostral scale. The crown is covered with numerous small and irregular scales of different sizes that are mostly smooth, but sometimes slightly keeled. Frontal and parietal scales are usually not present, but if so, they are small and irregularly shaped, with the frontal separated from the supraoculars by 2 scale rows. The dorsal markings vary strongly, but only rarely take the form of a clear zigzag. Males of this species are a little slimmer than females.
Asp vipers are found in France, Andorra, northeastern Spain, extreme southwestern Germany in the southern Black Forest, Switzerland, Italy, San Marino, and northwestern Slovenia. These snakes have specific habitat requirements. They need warm areas that are exposed to the sun, structured vegetation, and comparatively dry soils. In Italy and France, they are often found in areas with low mountains or hills, notably in limestone regions, but sometimes occur in lower plains. They prefer vegetated areas or environments with at least some coverage. Here they can be found on sunny slopes, in scrublands, in glades, in mountain meadows, in forest clearings, at the borders of woods, in rubbish dumps, and stone quarries. In Italy, Asp vipers occur in mesic chestnut/oak woodlands and often near streams.
Asp vipers are diurnal snakes and lead a solitary life. During the hot weather, they become more active in the evenings. These snakes live in burrows made by small rodents such as voles or mice which they also hibernate during cold winter months. Asp vipers are calm and cautious. They are not aggressive and prefer to flee and hide in cover when disturbed.
A bite from this species can be more severe than from V. berus and is very painful. According to Stemmler (1971), about 4% of all untreated bites are fatal. Lombardi and Bianco (1974) mention that this species is responsible for 90% of all cases of snakebite in Italy and it is the only mortal snake in Italian mountains. Envenomation symptoms include rapidly spreading acute pain, followed by edema and discoloration. Severe haemorrhagic necrosis may occur within a few hours. Vision may be severely impaired, most likely due to the degradation of blood and blood vessels in the eyes. The venom has both coagulant and anticoagulant effects. The venom may also affect the glomerular structure, which can lead to death due to renal failure.
Asp vipers are carnivores and their diet consists of rodents, lizards, and small birds.
The breeding season for Asp vipers occurs between April and May. Females give birth to 5-12 live young after the gestation period that lasts around 3 or 4 months. Baby vipers are born fully developed and can hunt their first prey a few days after birth.
The main threat to Asp vipers is the loss of habitat due to agricultural industry and urbanization. They are also collected for the pet trade and persecuted because of fear. Road mortality poses another threat in some areas.
The IUCN Red List and other sources don’t provide the number of the Asp viper total population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.
