Vipera aspis (Linnaeus, 1758)

Species Nomenclature

Vipera aspis (Linnaeus, 1758) reaches an average total length of 60–65 centimetres (24–26 in).

Size Range

Males grow to a maximum total length of 85 cm (33 in), while females rarely exceed 75 cm (30 in). Males are slightly slimmer than females.

Tail Proportion

The species has a very short tail: in females, the tail makes up one-seventh to one-ninth of total body length, and in males it makes up one-sixth to one-eighth.

Head Shape

The head is broad, triangular, and clearly distinct from the neck, with a slightly but definitely upturned snout tip.

Rostral Scale Characteristics

The rostral scale is generally taller than it is wide, and touches 2 to 3 scales on the upper surface of the snout.

Snout Dorsal Surface

The dorsal surface of the snout is flat, with distinct, slightly raised, sharp margins.

Nasal Scale Structure

The nasal scale is almost always single, very rarely divided, and is separated from the rostral by a single nasorostral scale.

Crown Scales

The crown is covered with numerous small, irregular scales of varying sizes; these are mostly smooth, but may be slightly keeled. Frontal and parietal scales are usually absent.

Frontal and Parietal Scale Variation

When present, they are small and irregularly shaped, and the frontal is separated from the supraoculars by 2 scale rows.

Supraocular Scales

The supraocular scales are large and distinct, and separated from each other by 4–7 scale rows.

Circumorbital Scales

Below the supraocular, there are 10–12 small circumorbital scales, rarely 8–18.

Eye and Supralabial Separation

The eye is separated from the supralabials by 2 scale rows, rarely 3.

Eye Diameter

The vertical diameter of the eye is approximately equal to the distance between the eye and the mouth.

Supralabial Count

There are 9–13 supralabials.

Supralabial and Eye Separation

The 4th–5th supralabials, rarely the 4th–6th or 5th–6th, are separated from the eye by 2 rows of small scales, rarely 3, though sometimes a single scale sits between the 4th supralabial and the eye.

Temporal Scales

Temporal scales are generally smooth, but may be slightly keeled.

Midbody Dorsal Scale Rows

At midbody, there are 21–23 rows of dorsal scales, rarely 19 or 25.

Dorsal Scale Keeling

These dorsal scales are strongly keeled, except for the variable outermost rows, which are sometimes smooth.

Ventral Scale Count

There are 134–170 ventral scales: subspecies V. a. aspis averages fewer than 150 ventral scales, while V. a. atra averages more.

Anal Scale

The anal scale is single.

Subcaudal Scale Count

Males have 32–49 paired subcaudal scales, and females have 30–43 paired subcaudal scales.

Dorsal Markings

Dorsal body markings vary widely, and only rarely form the clear zigzag pattern seen in V. berus.

Native Distribution

This species is native to France, Andorra, north-eastern Spain, extreme south-western Germany in the southern Black Forest, Switzerland, Italy, and north-western Slovenia.

Type Locality

Its original type locality was simply recorded as "Gallia", but Schwarz (1936) proposed restricting it to Poitou, France.

Extirpated Range

The species has been extirpated from Bulgaria.

Introduced Population in Netherlands

Between August and October 2006, multiple specimens were discovered in a wooded area near the town of Poortugaal in the Netherlands. The population was surviving well, but the species is not native to the Netherlands; the snakes are thought to have either escaped from captivity or been intentionally released there.

General Habitat Requirements

Vipera aspis has a small set of clear, relatively specific habitat requirements: it needs warm, sun-exposed areas, structured vegetation, and comparatively dry soil.

Regional Habitat in France and Italy

In Italy and France, it is most often found in low mountain or hill areas, particularly in limestone regions, but may also occur in lower plains. It prefers vegetated areas or environments that offer at least some cover.

Specific Habitat Microhabitats

Within these areas, it can be found on sunny slopes, in scrublands, glades, mountain meadows, forest clearings, along woodland borders, in rubbish dumps, and in stone quarries.

Italian Habitat Details

In Italy, it occurs in mesic chestnut and oak woodlands, and is often found near streams.

Elevation Range

While it is not strongly associated with high elevations, it has been recorded at over 2,100 m (6,900 ft) above sea level in the Pyrenees.