About Vipera walser Ghielmi, Menegon, Marsden, Laddaga & Ursenbacher, 2016
Morphological Similarity to Vipera berus
Morphologically, Vipera walser closely resembles the much more widespread Vipera berus.
Cephalic Scale Differences
It differs from Vipera berus by having a higher number of cephalic scales, and more frequently shows fragmentation of the large cephalic shields. Additionally, most individuals of Vipera walser have 1.5 to 2 rows of subocular scales on both sides of the head, while Vipera berus usually only has a single row of these scales.
Colouration Variation
The colouration of Vipera walser is highly variable: some specimens have the typical dorsal zigzag pattern, others have a reduced pattern made of horizontal bars, and melanistic individuals also occur.
Geographic Range
Vipera walser is restricted to a small area in northeastern Piedmont, in the Italian Western Alps.
Disjunct Populations
It has two separate disjunct populations: the southern population, which covers approximately 225 km², is confined to an area of just 500 km² north of Biella, while the northern population covers approximately 45 km² in upper Valsesia.
Habitat Altitude and Precipitation
Vipera walser lives in open habitats at altitudes between 1300 and 2300 m, in valleys that receive high precipitation.
Preferred Slope Characteristics
It is most often found on gentle south-facing slopes with low forest cover.
