Asp viper, Vipera aspis
(Linnaeus, 1758)

History and origin
The Asp viper was first described by Linnaeus in 1758, the scientific name of this species is Vipera aspis, Vipera meaning viper and aspis meaning 'shield' but also 'cobra', shield because of the form of the head from above.

Characteristics
They are characterised by their triangular head shape and slightly lifted snout.

Description
=Size=
They are born at around 15 cm long, averaging about 60 cm long growing up to sometimes 90 - 100 cm long.
=Morphology=
They are short and stout with a noticeable slim and short tail. Their head is heavily built and described as triangular, indicating at least that the back of the head is noticeably wider, due to the presence of strong jaw muscles. They have keeled scales, an upturned snout, prominent supraocular scales and vertical pupils.
=Patterns & colours=
This species is the morphologically most variable French viper. Depending somewhat on subspecies, the nominal subspecies aspis is gray or brown, sometimes orange, with a seemingly broken-up zigzag pattern consisting of thick cross bands that can be linked by a line that runs down the center of the back. This pattern can be sometimes broken up, sometimes less prominent. Their bellies are generally more constant in colour, often gray or black, with out without lighter dappling. Black specimens occur, especially in the Alps.

Geographical range
Found in the two southernmost thirds of France. In Spain only in the Pyrenees. Switzerland (except extreme east), Italy (except extreme north-east), Sicily and many small islands between Italy and Corsica.

Subspecies
- aspis - Found in France (except the Pyrenees and close regions), Switzerland, and Italian alps.
- hugyi - Found in southern Italy and Sicily, including the former ssp. montecristi from the small island of Montecristo between Italy and Corsica. They have a more vivid pattern, a wavy dorsal zigzag, often rich in brown. This zigzag may be broken up into individual blotches. Pattern may remind of Nose-horned Viper (Vipera ammodytes) or Lataste’s Viper (Vipera latastei) rather than of typical a Asp Viper.
- francisciredi - Found in the Italian peninsula; characterised by light spots on the belly scales.
- zinnikeri - Found in the Pyrenees, and up to around Toulouse northwards. Their pattern is made up of a dark zigzag on a light body and often a paler vertebral band. They are also said to have a more potent venom than the other subspecies (up to x4).
Some authors consider some or several of these subspecies to be separate species.

Sexual differences
Females are larger then the males, especially in late spring when they carry their young.

Seasonal variations
None.

Diet
They eat mainly small mammals but also lizards and other reptiles and birds. Juveniles mainly feed on lizards. They may eat up to three times their body weight every year.

Defensive habits
They prefer to escape but if cornered or caught they will hiss loudly and for long periods, and rapidly attack with their mouth open. Temperament differs between individual specimens. When they bite, they usually do not put their fangs to use and they give what is known as a ‘dry bite’ where no venom is injected.

Reproduction
Breeding occurs when the snakes wake up from hibernation in spring, a week after, they are all looking for each other and mating begins. The female carries around with her about 15 young (extremes of 5 to 25). They are born 2 to 3 months after being conceived.

Sexual maturity, life span
The average life span of Vipera aspis is about 18 years. They reach sexual maturity in their third year for males and in the fifth for females.

Habits
Active by day, but nocturnal in hot weather. They are often observed basking on top of stones. In summer, they are seen more often after rainfall.

Venom
The Asp viper has front fangs that can be retreated. The venom strength depends on the subspecies with ssp. zinnikeri said to have the strongest venom. Bites must receive medical treatment, as they can provoke death in weaker and sensitive people.

Habitat
They are usually found on hillsides or in wet mountainous areas. Sometimes in open wooded areas, stone walls and sometimes in open meadows.

Predators
Natural predators consist of birds of prey but even species of the Coronella genus.

Asp viper - © Daniel Phillips
Asp viper, Vipera aspis aspis - © Daniel Phillips

Asp viper - © Konrad Mebert
Asp viper, Vipera aspis aspis - © Konrad Mebert

Asp viper - © Daniel PhillipsAsp viper, Vipera aspis aspis - © Daniel Phillips

Asp viper - © Daniel Phillips
Asp viper, Vipera aspis aspis - © Daniel Phillips

Asp viper - © Daniel Phillips
Asp viper, Vipera aspis zinnikeri - © Daniel Phillips